Showing papers in "Advances in radiation oncology in 2021"
TL;DR: This is the first reported experience using 50 Gy in 5 fractions for inoperable pancreatic cancer using stereotactic magnetic resonance-guided adaptive radiation therapy (SMART), and allows this ablative dose with promising outcomes while minimizing toxicity.
Abstract: Purpose Patients with inoperable pancreatic adenocarcinoma have limited options, with traditional chemoradiation providing modest clinical benefit and an otherwise poor prognosis Stereotactic body radiation therapy for pancreatic cancer is limited by proximity to organs-at-risk (OAR) However, stereotactic magnetic resonance-guided adaptive radiation therapy (SMART) has shown promise in delivering ablative doses safely We sought to demonstrate the benefits of SMART using a 5-fraction approach with daily on-table adaptation Methods and Materials Patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were treated with 50 Gy in 5 fractions (biologically effective dose10 100 Gy) with a prescribed goal of 95% planning target volume coverage by 95% of prescription, prioritizing hard OAR constraints Daily online adaptation was performed using magnetic resonance-guidance and on-table reoptimization Patient outcomes, treatment factors, and daily adaptation were evaluated Results Forty-four patients were treated with SMART at our institution from 2014 to 2019 Median follow-up from date of diagnosis was 16 months (range, 67-516) Late toxicity was limited to 2 (46%) grade 3 (gastrointestinal ulcers) and 3 (68%) grade 2 toxicities (duodenal perforation, antral ulcer, and gastric bleed) Tumor abutted OARs in 35 patients (795%) and tumor invaded OARs in 5 patients (111%) Reoptimization was performed for 93% of all fractions Median overall survival was 157 months (95% confidence interval, 102-212), while 1-year and 2-year overall survival rates were 682% and 379%, respectively One-year local control was 843% Conclusions This is the first reported experience using 50 Gy in 5 fractions for inoperable pancreatic cancer SMART allows this ablative dose with promising outcomes while minimizing toxicity Additional prospective trials evaluating efficacy and safety are warranted
67 citations
TL;DR: Future collaboration between oncologists, app developers, and patients to optimize PROs assessment and integration with telehealth/telemedicine encounters to increase symptom recognition and enhance patient-provider communication is urgently needed.
Abstract: Purpose In response to the COVID-19 pandemic, there has been a rapid growth in the use of telehealth/telemedicine that will likely be sustained in the postpandemic setting. Mobile health applications (apps) can be used as part of the telehealth encounter to monitor patient-reported outcomes (PROs) and enhance patient-provider communication. Methods and Materials A systematic review was performed of mobile health apps with symptom trackers. We searched the iOS App Store and Android Google Play using the words cancer, oncology, and symptom tracker. Apps were included if they incorporated a symptom tracking function that could allow patients with cancer to record symptoms and PROs. Apps were evaluated using the mobile apps rating scale, which includes engagement, functionality, aesthetics, information, and app subjective quality. Results The initial search yielded 1189 apps, with 101 apps eligible after title and description screening. A total of 41 apps met eligibility criteria and were included in this study. The majority of apps (73%, n = 30) were general health/pain symptom trackers, and 27% (n = 11) were cancer-specific. The app quality mean scores assessed using the mobile apps rating scale ranged from 2.43 to 4.23 (out of 5.00). Only 1 app has been trialed for usability among patients with cancer. Conclusions Although various symptom tracking apps are available, cancer-specific apps remain limited. Future collaboration between oncologists, app developers, and patients to optimize PRO assessment and integration with telehealth/telemedicine encounters to increase symptom recognition and enhance patient-provider communication is urgently needed.
35 citations
TL;DR: Lattice is a modern approach to SFRT delivered with arc-based therapy, which may allow for safe, high-quality SBRT for large and/or deep tumors and is currently being tested in a prospective trial for patients with metastatic cancer who need palliation of large tumors.
Abstract: Purpose Stereotactic body radiation therapy (SBRT) has demonstrated clinical benefits for patients with metastatic and/or unresectable cancer. Technical considerations of treatment delivery and nearby organs at risk can limit the use of SBRT in large tumors or those in unfavorable locations. Spatially fractionated radiation therapy (SFRT) may address this limitation because this technique can deliver high-dose radiation to discrete subvolume vertices inside a tumor target while restricting the remainder of the target to a safer lower dose. Indeed, SFRT, such as GRID, has been used to treat large tumors with reported dramatic tumor response and minimal side effects. Lattice is a modern approach to SFRT delivered with arc-based therapy, which may allow for safe, high-quality SBRT for large and/or deep tumors. Methods and Materials Herein, we report the results of a dosimetry and quality assurance feasibility study of Lattice SBRT in 11 patients with 12 tumor targets, each ≥10 cm in an axial dimension. Prior computed tomography simulation scans were used to generate volumetric modulated arc therapy Lattice SBRT plans that were then delivered on clinically available Linacs. Quality assurance testing included external portal imaging device and ion chamber analyses. Results All generated plans met the standard SBRT dose constraints, such as those from the American Association of Physicists in Medicine Task Group 101. Additionally, we provide a step-by-step approach to generate and deliver Lattice SBRT plans using commercially available treatment technology. Conclusions Lattice SBRT is currently being tested in a prospective trial for patients with metastatic cancer who need palliation of large tumors ( NCT04553471 , NCT04133415 ).
22 citations
TL;DR: This virtual medical student clerkship was created to integrate didactic education with disease specific lectures for medical students, contouring, and hands on learning with telehealth and was successful in integrating radiation oncology virtually formedical students.
Abstract: Corona virus disease 2019 (COVID-19) affected medical student clerkships and education around the country. A virtual medical student clerkship was created to integrate didactic education with disease specific lectures for medical students, contouring, and hands on learning with telehealth. Twelve medical students in their 3rd and 4th year were enrolled in this 2 week elective from April 27, 2020 to June 5, 2020. There was significant improvement of overall knowledge about the field of radiation oncology from pre elective to post elective (P < .001). Feedback included enjoying direct exposure to contouring, telehealth, and time with residents. Overall this 2 week rotation was successful in integrating radiation oncology virtually for medical students. This is now being expanded to multiple institutions as an educational resource and future rotations for medical students.
21 citations
TL;DR: The study's results suggest that spleen unintentional V15 and maximum dose irradiation were associated with lymphopenia during chemoradiation therapy, and all studies found that higher splenic dose increases the risk of lymph Openia.
Abstract: Purpose We conducted a systematic review and a retrospective study to investigate the relationship between spleen irradiation and lymphocyte toxicity. Methods and Materials Forty-six patients diagnosed with locally advanced gastric, esophageal, and pancreatic cancer who underwent radiation therapy were included in this study. The spleen was contoured for each patient. Volumes that received 5 up to 40 Gy (5 Gy increments), minimum, mean, and maximum dose were considered along with lymphocyte count to determine toxicity. Comprehensive and systematic literature searches were performed using PubMed, SCOPUS, Cochrane Central Databases, and Google Scholar. Results Literature review on spleen unintended irradiation and lymphocyte toxicity resulted in 408 patients from 5 studies. In our study, univariate and multivariate linear regressions found an association between V15 (chemotherapy as controlling factor) and nadir lymphocyte count (P = .04) and between DMAX and nadir lymphocyte count (P = .046). An increase of 1 Gy in mean splenic dose was associated with a 1% decrease in absolute lymphocyte count at nadir. Conclusions Although there is no consensus regarding lymphopenia spleen dose volume threshold, all studies found that higher splenic dose increases the risk of lymphopenia. Our study's results suggest that spleen unintentional V15 and maximum dose irradiation were associated with lymphopenia during chemoradiation therapy.
18 citations
TL;DR: SBRT was associated with similar clinical outcomes compared with conventional radiation techniques, despite being delivered over a shorter period of time which would spare patients prolonged treatment burden.
Abstract: Purpose Patients with pancreatic cancer often receive radiation therapy before undergoing surgical resection. We compared the clinical outcomes differences between stereotactic body radiation therapy (SBRT) and 3-dimensional (3D)/intensity-modulated radiation therapy (IMRT). Methods and Materials We retrospectively collected data from the University of Texas MD Anderson Cancer Center. Patients with borderline resectable/potentially resectable or locally advanced pancreatic cancer receiving neoadjuvant SBRT (median, 36.0 Gy/5fx), 3D conformal radiation (median, 50.4 Gy/28 fx) or IMRT (median, 50.4 Gy/28 fx) were included. Overall survival (OS) and progression-free survival were analyzed using Cox regression. Results In total, 104 patients were included in our study. Fifty-seven patients (54.8%) were treated with SBRT, and 47 patients (45.2%) were treated with 3D/IMRT. Patients in the SBRT group were slightly older (median age: 70.3 vs 62.7 in the 3D/IMRT group). Both groups had similar proportions of patients with locally advanced pancreatic cancer (SBRT: 30, 52.6%; 3D/IMRT: 24, 51.1%). All patients were treated with chemotherapy. Patients in the SBRT group underwent more surgical resection compared with the 3D/IMRT group (38.6% vs 23.4%, respectively). At a median follow-up of 22 months, a total of 60 patients (57.7%) died: 25 (25/57, 43.9%) in the SBRT group, and 35 (35/47, 74.5%) in the 3D/IMRT group. Median OS was slightly higher in the SBRT group (29.6 months vs 24.1 months in the 3D/IMRT group). On multivariable Cox regression, the choice of radiation therapy technique was not associated with differences in OS (adjusted hazard ratios [aHR] = 0.5; 95% confidence interval [CI], 0.2%-1.3%, P = .18). Moreover, patients that underwent surgical resection had better OS (aHR = 0.3, 95% CI, 0.1%-0.8%, P = .01). Furthermore, progression-free survival was also similar between patients treated with SBRT and those treated with 3D/IMRT (aHR = 0.9, 95% CI, 0.5%-1.8%, P = .81) Conclusions SBRT was associated with similar clinical outcomes compared with conventional radiation techniques, despite being delivered over a shorter period of time which would spare patients prolonged treatment burden. Future prospective data are still needed to better assess the role of SBRT in patients with pancreatic cancer.
17 citations
TL;DR: SAbR has the potential to extend the the duration of current systemic therapy for selected patients with mRCC, preserving subsequent therapies for later administration possibly enabling longer treatment duration.
Abstract: Purpose Oligoprogression, defined as limited sites of progression on systemic therapy, in patients with metastatic renal cell carcinoma (mRCC) is not uncommon, possibly because of inter- and intratumoral heterogeneity. We evaluated the effect of stereotactic ablative radiation therapy (SAbR) for longitudinal control of oligoprogressive mRCC. Methods and Materials Patients with extracranial mRCC were included in this retrospective analysis if they progressed in ≤3 sites on systemic therapy while demonstrating response/stability at other sites and received SAbR to all progressing sites without switching systemic therapy. Our primary endpoint was modified progression-free survival (mPFS), which we calculated from the start of SAbR to the start of a subsequent systemic therapy, death, or loss to follow-up. Results We identified 36 patients with a median follow-up of 20.4 months (interquartile range, 10.9-29.4). Forty-three sites were treated with SAbR with a median dose of 36 Gy (range, 18-50) in 3 fractions (range, 1-5). Median time to SAbR from the start of systemic therapy was 11.4 months (interquartile range, 6.1-17.1). Median mPFS was 9.2 months (95% confidence interval [CI], 5.9-13.2). Patients receiving SAbR while on immunotherapy exhibited a longer median mPFS (>28.4 months, log-rank P = .0001) than patients not on immunotherapy (9.2 months). Median overall survival from SAbR administration was 43.4 months (95% CI, 21.5-not Reached). The 1-year local control rate was 93% (95% CI, 78.7-97.5). Most SAbR-related toxicities were grade 1 to 2 (33% of patients), with one grade 5 hemoptysis event possibly related to SAbR or disease progression. Conclusions SAbR has the potential to extend the the duration of current systemic therapy for selected patients with mRCC, preserving subsequent therapies for later administration possibly enabling longer treatment duration.
17 citations
TL;DR: The effect of MRI slice thickness on the detection and contoured volume of metastatic lesions in the brain effects detection and segmentation of brain lesions, which can have an important effect on patient management and treatment outcomes.
Abstract: Objectives Stereotactic radiosurgery is a common treatment for brain metastases and is typically planned on magnetic resonance imaging (MRI). However, the MR acquisition parameters used for patient selection and treatment planning for stereotactic radiosurgery can vary within and across institutions. In this work, we investigate the effect of MRI slice thickness on the detection and contoured volume of metastatic lesions in the brain. Methods and Materials A retrospective cohort of 28 images acquired with a slice thickness of 1 mm were resampled to simulate acquisitions at 2- and 3-mm slice thickness. A total of 102 metastases ranging from 0.0030 cc to 5.08 cc (75-percentile 0.36 cc) were contoured on the original images. All 3 sets of images were recontoured by experienced physicians. Results Of all the images detected and contoured on the 1 mm images, 3% of lesions were missed on the 2 mm images, and 13% were missed on the 3 mm images. One lesion that was identified on both the 2 mm and 3 mm images was determined to be a blood vessel on the 1 mm images. Additionally, the lesions were contoured 11% larger on the 2 mm and 43% larger on the 3 mm images. Conclusions Using images with a slice thickness >1 mm effects detection and segmentation of brain lesions, which can have an important effect on patient management and treatment outcomes.
17 citations
TL;DR: In this article, the clinical potential of spot-scanning hadron arc (SHArc) therapy with a heavy-ion gantry was evaluated using a series of in silico studies.
Abstract: Purpose To evaluate the clinical potential of spot-scanning hadron arc (SHArc) therapy with a heavy-ion gantry. Methods and Materials A series of in silico studies was conducted via treatment plan optimization in FRoG and the RayStation TPS to compare SHArc therapy against reference plans using conventional techniques with single, parallel-opposed, and 3-field configurations for 3 clinical particle beams (protons [p], helium [4He], and carbon [12C] ions). Tests were performed on water-equivalent cylindrical phantoms for simple targets and clinical-like scenarios with an organ-at-risk in proximity of the target. Effective dose and dose-averaged linear energy transfer (LETD) distributions for SHArc were evaluated against conventional planning techniques applying the modified microdosimetric kinetic model for considering bio-effect with (α/β)x = 2 Gy. A model for hypoxia-induced tumor radio-resistance was developed for particle therapy with dependence on oxygen concentration and particle species/energy (Zeff/β)2 to investigate the impact on effective dose. Results SHArc plans exhibited similar target coverage with unique treatment attributes and distributions compared with conventional planning, with carbon ions demonstrating the greatest potential for tumor control and normal tissue sparing among the arc techniques. All SHArc plans exhibited a low-dose bath outside the target volume with a reduced maximum dose in normal tissues compared with single, parallel-opposed, and 3-field configuration plans. Moreover, favorable LETD distributions were made possible using the SHArc approach, with maximum LETD in the r = 5 mm tumor core (~8 keVμm-1, ~30 keVμm-1, and ~150 keVμm-1 for p, 4He, and 12C ions, respectively) and reductions of high-LET regions in normal tissues and organs-at-risk compared with static treatment beam delivery. Conclusion SHArc therapy offers potential treatment benefits such as increased normal tissue sparing. Without explicit consideration of oxygen concentration during treatment planning and optimization, SHArc-C may mitigate tumor hypoxia-induced loss of efficacy. Findings justify further development of robust SHArc treatment planning toward potential clinical translation.
16 citations
TL;DR: The ability to rapidly segment the liver with high accuracy achieved in this investigation has the potential to enable the efficient integration of biomechanical model-based registration into a clinical workflow.
Abstract: Purpose The deformable nature of the liver can make focal treatment challenging and is not adequately addressed with simple rigid registration techniques. More advanced registration techniques can take deformations into account (eg, biomechanical modeling) but require segmentations of the whole liver for each scan, which is a time-intensive process. We hypothesize that fully convolutional networks can be used to rapidly and accurately autosegment the liver, removing the temporal bottleneck for biomechanical modeling. Methods and Materials Manual liver segmentations on computed tomography scans from 183 patients treated at our institution and 30 scans from the Medical Image Computing & Computer Assisted Intervention challenges were collected for this study. Three architectures were investigated for rapid automated segmentation of the liver (VGG-16, DeepLabv3 +, and a 3-dimensional UNet). Fifty-six cases were set aside as a final test set for quantitative model evaluation. Accuracy of the autosegmentations was assessed using Dice similarity coefficient and mean surface distance. Qualitative evaluation was also performed by 3 radiation oncologists on 50 independent cases with previously clinically treated liver contours. Results The mean (minimum-maximum) mean surface distance for the test groups with the final model, DeepLabv3 +, were as follows: μContrast(N = 17): 0.99 mm (0.47-2.2), μNon_Contrast(N = 19)l: 1.12 mm (0.41-2.87), and μMiccai(N = 30)t: 1.48 mm (0.82-3.96). The qualitative evaluation showed that 30 of 50 autosegmentations (60%) were preferred to manual contours (majority voting) in a blinded comparison, and 48 of 50 autosegmentations (96%) were deemed clinically acceptable by at least 1 reviewing physician. Conclusions The autosegmentations were preferred compared with manually defined contours in the majority of cases. The ability to rapidly segment the liver with high accuracy achieved in this investigation has the potential to enable the efficient integration of biomechanical model-based registration into a clinical workflow.
16 citations
TL;DR: Since the onset of COVID-19 pandemic, the majority of patient visits were able to move to telehealth but observed inconsistent utilization of the audio-video telehealth platform.
Abstract: Purpose The widespread coronavirus disease 2019 (COVID-19) pandemic has resulted in significant changes in care delivery among radiation oncology practices and has demanded the rapid incorporation of telehealth. However, the impact of a large-scale transition to telehealth in radiation oncology on patient access to care and the viability of care delivery are largely unknown. In this manuscript, we review our implementation and report data on patient access to care and billing implications. Because telehealth is likely to continue after COVID-19, we propose a radiation oncology-specific algorithm for telehealth. Methods and Materials In March 2020, our department began to use telehealth for all new consults, posttreatment encounters, and follow-up appointments. Billable encounters from January to April 2020 were reviewed and categorized into 1 of the following visit types: in-person, telephonic, or 2-way audio-video. Logistic regression models tested whether visit type differed by patient age, income, or provider. Results There was a 35% decrease in billable activity from January to April. In-person visits decreased from 100% to 21%. Sixty percent of telehealth appointments in April were performed with 2-way audio-video and 40% by telephone only. In-person consultation visits were associated with higher billing codes compared with 2-way audio-video telehealth visits (P < .01). No difference was seen for follow-up visits. Univariate and multivariable analysis identified that older patient age was associated with reduced likelihood of 2-way audio-video encounters (P < .01). The physician conducting the telehealth appointment was also associated with the type of visit (P < .01). Patient income was not associated with the type of telehealth visit. Conclusions Since the onset of the COVID-19 pandemic, we have been able to move the majority of patient visits to telehealth but have observed inconsistent utilization of the audio-video telehealth platform. We present guidelines and quality metrics for incorporating telehealth into radiation oncology practice, based on type of encounter and disease subsite.
TL;DR: With the COVID-19 crisis limiting visiting medical student rotations and programs transitioning to hosting remote interviews, programs focus resources towards portraying the culture of their program and city, accurately depicting program information, and offering virtual electives or virtual interaction to increase applicant exposure to residency program culture.
Abstract: Background Recently, the Coalition for Physician Accountability Work Group on Medical Students in the Class of 2021 recommended limiting visiting medical student rotations, conducting virtual residency interviews, and delaying the standard application timeline due to the ongoing COVID-19 pandemic. These changes create both challenges and opportunities for medical students and radiation oncology residency programs. We conducted a comprehensive needs assessment to prepare for a virtual recruitment season, including a focus group of senior medical students seeking careers in oncology. Methods A single 1.5-hour focus group was conducted with 10 third- and fourth-year medical students using Zoom videoconferencing software. Participants shared opinions relating to visibility of residency programs, virtual clerkship experiences, expectations for program websites, and remote interviews. The focus group recording was transcribed and analyzed independently by 2 authors. Participants' statements were abstracted into themes via inductive content analysis. Results Inductive content analysis of the focus group transcript identified several potential challenges surrounding virtual recruitment, including learning the culture of a program and/or city, obtaining accurate information about training programs, and uncertainty surrounding the best way to present themselves during a virtual interview season. In the present environment, the focus group participants anticipate relying more on departmental websites and telecommunications since in-person interactions will be limited. In addition, students perceived that the educational yield of a virtual clerkship would be low, particularly if an in-person rotation had already been completed at another institution. Conclusion With the COVID-19 crisis limiting visiting student rotations and programs transitioning to hosting remote interviews, we recommend programs focus resources towards portraying the culture of their program and city, accurately depicting program information, and offering virtual electives or virtual interaction to increase applicant exposure to residency program culture.
TL;DR: A unique virtual RO shadowing experience for UIM students is created to address a critical gap in exposure to radiation oncology, heightened by the COVID pandemic, with the goal of improving diversity, equity and inclusion in the authors' field.
Abstract: Purpose In response to the COVID-19 pandemic, current AAMC guidelines discourage away rotations, posing significant challenges for attracting students to radiation oncology (RO). This is particularly concerning for medical students underrepresented in medicine (UIM) due to the potential of widening existing disparities in applicant and workforce composition. To proactively address this, we created a Radiation Oncology Intensive Shadowing Experience (RISE) to expose UIM students to the field of radiation oncology. Methods and materials Key stakeholders within the residency program, including both UIM faculty and residents with experience in health disparities and medical education designed a one-week virtual Radiation Oncology Intensive Shadowing Experience (RISE) intended for fourth year UIM students recruited through established national organizations serving UIM medical students. A one-week disease specific curriculum was developed using four components: 1) foundational exposure to radiation oncology, 2) didactic teaching, 3) mentorship opportunities, and 4) a capstone experience. Mentorship was continuously weaved through the experience by attendings, peer resident mentors and a UIM resident panel to optimize exposure. Results RISE was successfully initiated at two academic medical centers with twelve UIM students enrolled through August. Anonymized pre- and post- clerkship surveys were developed for students, residents and faculty involved in RISE to evaluate participants' satisfaction, resident and attending time burden, and perceptions of program effectiveness. Conclusions We created a unique virtual RO shadowing experience for UIM students to address a critical gap in exposure to radiation oncology, heightened by the COVID pandemic, with the goal of improving diversity, equity and inclusion in our field.
TL;DR: Find a place for RO in medical school curricula remains to be a challenge with most surveyed students reporting no exposure to RO during their education, and concern over the job market was the primary deterrent.
Abstract: Purpose The purpose of our study was to better understand and identify concerns that may be responsible for the declining radiation oncology (RO) residency applicant pool. Methods and Materials All RO residency programs affiliated with a US medical school were asked to participate in the study survey. An optional and anonymous survey consisting of 12 questions was emailed to all graduating medical students in 2020 at the 12 allopathic medical schools that agreed to survey administration. Survey responses were collected from March to May 2020. Results The study consisted of 265 survey responses out of 1766 distributed to eligible medical students, resulting in a response rate of 15.0%. The majority of students reported no exposure to RO (60.8%) and never considered it as a career option (63.8%). Neutral perceptions of the field were more common (54.3%) than positive (39.6%) and negative (6.0%). The top factors attracting medical students to RO were perceptions of high salary, favorable lifestyle and workload, and technological focus. The top negative factors were the field’s interplay with physics, competitive United States Medical Licensing Examination board scores for matched applicants, and the focus placed on research during medical school. In the subgroup of students who were interested in RO but ultimately applied to another specialty, the job market was the most salient concern. Conclusions Finding a place for RO in medical school curricula remains a challenge, with most surveyed students reporting no exposure during their education. Concern over the job market was the primary deterrent for medical students interested in pursuing RO. For disinterested students who had not considered RO as a career option, the required physics knowledge was the main deterrent.
TL;DR: In this article, the authors report their experience with re-radiation for locoregional recurrent or second primary breast cancer and assess adverse events using the Common Terminology Criteria for Adverse Events v5.0.
Abstract: Purpose Reirradiation poses a distinct therapeutic challenge owing to risks associated with exceeding normal tissue tolerances and possibly more therapeutically resistant disease biology. We report our experience with reirradiation for locoregional recurrent or second primary breast cancer. Methods and Materials Between 1999 and 2019, all patients with breast cancer treated with repeat breast/chest wall radiation therapy (RT) at our institution were identified. Adverse events were assessed using the Common Terminology Criteria for Adverse Events v5.0. Fisher exact, Mann-Whitney rank-sum, and unpaired t tests were used for statistical analysis. Freedom from locoregional recurrence and distant metastasis as well as overall survival were calculated using the Kaplan-Meier method. Results Seventy-two patients underwent reirradiation. Median prior RT dose, reirradiation dose, and cumulative dose were 60 Gy (interquartile range [IQR], 50-60.4 Gy), 45 Gy (IQR, 40-50 Gy), and 103.54 Gy2 (IQR, 95.04-109.62 Gy2), respectively. Median time between RT courses was 73 months (IQR, 29-129 months). Thirty-four patients (47%) had gross residual disease at time of reirradiation. Course intent was described as curative in 44 patients (61%) and palliative in 28 (39%). Fifty-two patients (72%) were treated with photons ± electrons and 20 (28%) with protons. With a median follow-up of 22 months (IQR, 10-43 months), grade 3 adverse events were experienced by 13% of patients (10% acute skin toxicity and 3% late skin necrosis). Time between RT courses and reirradiation fields was significantly associated with the development of grade 3 toxicity at any point. Proton therapy conferred a dosimetric advantage without difference in toxicity. At 2 years, locoregional recurrence-free survival was 74.6% and overall survival was 65.5% among all patients, and 93.1% and 76.8%, respectively, among curative intent patients treated without gross disease. Distant metastasis-free survival was 59.0% among all curative intent patients. Conclusions Reirradiation for locoregional recurrent breast cancer is feasible with acceptable rates of toxicity. Disease control and survival are promising among curative intent reirradiation patients without gross disease.
TL;DR: IMPT is safe and feasible for treatment of HCC, according to a retrospective review of patients treated with IMPT with curative intent from June 2015 to December 2018.
Abstract: Purpose Our purpose was to assess the safety and efficacy of intensity modulated proton therapy (IMPT) for the treatment of hepatocellular carcinoma (HCC). Methods and Materials A retrospective review was conducted on all patients who were treated with IMPT for HCC with curative intent from June 2015 to December 2018. All patients had fiducials placed before treatment. Inverse treatment planning used robust optimization with 2 to 3 beams. The majority of patients were treated in 15 fractions (n = 30, 81%, 52.5-67.5 Gy, relative biological effectiveness), whereas the remainder were treated in 5 fractions (n = 7, 19%, 37.5-50 Gy, relative biological effectiveness). Daily image guidance consisted of orthogonal kilovoltage x-rays and use of a 6° of freedom robotic couch. Outcomes (local control, progression free survival, and overall survival) were determined using Kaplan-Meier methods. Results Thirty-seven patients were included. The median follow-up for living patients was 21 months (Q1-Q3, 17-30 months). Pretreatment Child-Pugh score was A5-6 in 70% of patients and B7-9 in 30% of patients. Nineteen patients had prior liver directed therapy for HCC before IMPT. Eight patients (22%) required a replan during treatment, most commonly due to inadequate clinical target volume coverage. One patient (3%) experienced a grade 3 acute toxicity (pain) with no recorded grade 4 or 5 toxicities. An increase in Child-Pugh score by ≥ 2 within 3 months of treatment was observed in 6 patients (16%). At 1 year, local control was 94%, intrahepatic control was 54%, progression free survival was 35%, and overall survival was 78%. Conclusions IMPT is safe and feasible for treatment of HCC.
TL;DR: MRI-guided reirradiation for isolated recurrence within the prostate or in the prostate bed appears to be safe with excellent dosimetric results.
Abstract: Purpose This prospective registry study evaluated the feasibility of stereotactic magnetic resonance imaging (MRI)–guided radiation therapy for the local treatment of isolated prostate cancer recurrence within the gland or prostate bed after primary radiation therapy. Methods and Materials Patients with isolated recurrence without any regional or distant extension after treatment by external radiation therapy of the prostate gland/bed or by prostate brachytherapy were included. A 173-second Fast Imaging with Steady state Precession (TrueFISP) sequence was used for MRI simulation, and the gross tumor volume was delineated using multimodal images. The initial treatment plan varied from 27.5 Gy in 5 fractions to 38.7 Gy in 9 fractions and was adapted at each session, if necessary. The primary endpoint was acute toxicities (according to the Common Terminology Criteria for Adverse Events v5.0 criteria). Secondary endpoints were the effects of the adaptive treatment on target volume coverage, late toxicities, and oncologic events. Results Twenty patients were included. After a minimum follow-up of 6 months, grade 2 dysuria (from grade 1 at baseline; n = 1), grade 2 polyuria (n = 1), grade 1 urinary incontinence (n = 1), grade 1 urinary pain (n = 2), and grade 1 diarrhea (n = 1) were reported. All initial treatment plans met the tumor coverage objectives, with a mean 95% planning target volume value of 95.7%. No plan exceeded the bladder and rectum dose constraints, but 8 exceeded the urethra dose constraints because of urethra proximity to the planning target volume. The initial plan was adapted in 7 patients (35%). The tumor coverage improved by 3.7% compared with the predicted plan (P = .0001) without increase in the dose to organs at risk. The biochemical control rate for the whole cohort was 75% (15/20 patients) including the 4 patients who received androgen-deprivation therapy. Conclusions MRI-guided reirradiation for isolated recurrence within the prostate or in the prostate bed appears to be safe with excellent dosimetric results.
TL;DR: A deep learning framework to accurately predict fluence maps from patient anatomy and directly generate intensity modulated radiation therapy plans that can effectively plan pancreas SBRT cases within 2 minutes is proposed.
Abstract: Purpose Treatment planning for pancreas stereotactic body radiation therapy (SBRT) is a challenging task, especially with simultaneous integrated boost treatment approaches. We propose a deep learning (DL) framework to accurately predict fluence maps from patient anatomy and directly generate intensity modulated radiation therapy plans. Methods and Materials The framework employs 2 convolutional neural networks (CNNs) to sequentially generate beam dose prediction and fluence map prediction, creating a deliverable 9-beam intensity modulated radiation therapy plan. Within the beam dose prediction CNN, axial slices of combined structure contour masks are used to predict 3-dimensional (3D) beam doses for each beam. Each 3D beam dose is projected along its beam’s-eye-view to form a 2D beam dose map, which is subsequently used by the fluence map prediction CNN to predict its fluence map. Finally, the 9 predicted fluence maps are imported into the treatment planning system to finalize the plan by leaf sequencing and dose calculation. One hundred patients receiving pancreas SBRT were retrospectively collected for this study. Benchmark plans with unified simultaneous integrated boost prescription (25/33 Gy) were manually optimized for each case. The data set was split into 80/20 cases for training and testing. We evaluated the proposed DL framework by assessing both the fluence maps and the final predicted plans. Further, clinical acceptability of the plans was evaluated by a physician specializing in gastrointestinal cancer. Results The DL-based planning was, on average, completed in under 2 minutes. In testing, the predicted plans achieved similar dose distribution compared with the benchmark plans (-1.5% deviation for planning target volume 33 V33Gy), with slightly higher planning target volume maximum (+1.03 Gy) and organ at risk maximum (+0.95 Gy) doses. After renormalization, the physician rated 19 cases clinically acceptable and 1 case requiring minor improvement. Conclusions The DL framework can effectively plan pancreas SBRT cases within 2 minutes. The predicted plans are clinically deliverable, with plan quality approaching that of manual planning.
TL;DR: By study completion, 50% of patients receiving palliative extracranial radiation therapy avoided simulation, streamlining the treatment process and maximizing patient convenience.
Abstract: Purpose Our purpose was to report outcomes of a novel palliative radiation therapy protocol that omits computed tomography simulation and prospectively collects electronic patient-reported outcomes (ePROs). Methods and Materials Patients receiving extracranial, nonstereotactic, linear accelerator-based palliative radiation therapy who met inclusion criteria (no mask-based immobilization and a diagnostic computed tomography within 4 weeks) were eligible. Global pain was scored with the 11-point numerical pain rating scale (NPRS). Patients were coded as having osseous or soft tissue metastases and no/mild versus severe baseline pain (NPRS ≥ 5). Pain response at 4 weeks was measured according to the international consensus (no analgesia adjustment). Transition to ePRO questionnaires was completed in 3 phases. Initially, pain assessments were collected on paper for 11 months, then pilot ePROs for 1 month and then, after adjustments, revised ePROs from 1 year onwards. ePRO feasibility criteria were established with reference to the paper-based process and published evidence. Results Between May 2018 and November 2019, 542 consecutive patients were screened, of whom 163 were eligible (30%), and 160 patients were successfully treated. The proportion of patients eligible for the study improved from approximately 20% to 50% by study end. Routine care pain monitoring via ePROs was feasible. One hundred twenty-seven patients had a baseline NPRS recording. Ninety-five patients had osseous (61% severe pain) and 32 had soft tissue (25% severe pain) metastases. Eighty-four patients (66%) were assessable for pain response at 4 weeks. In the 41 patients with severe osseous pain, overall and complete pain response was 78% and 22%, respectively. Conclusions By study completion, 50% of patients receiving palliative extracranial radiation therapy avoided simulation, streamlining the treatment process and maximizing patient convenience. Pain response for patients with severe pain from osseous lesions was equivalent to published evidence.
TL;DR: The interbreath-hold variation is not insignificant, especially in the SI direction, and Acquiring multiple breath-hold CT scans at simulation can help quantify the reproducibility of the interb breath hold and design a PSBH margin for treatment.
Abstract: Purpose In patients undergoing stereotactic body radiation therapy (SBRT) for pancreatic adenocarcinoma, the reproducibility of tumor positioning between deep-inspiration breath holds is unclear. We characterized this variation with fiducials at simulation and treatment and investigated whether a patient-specific breath-hold (PSBH) margin would help account for intrafraction variation at treatment. Methods and Materials We analyzed 20 consecutive patients with pancreatic cancer who underwent SBRT with deep-inspiration breath holds. At simulation, 3 additional breath-hold scans were acquired immediately after the contrast-enhanced planning computed tomography (CT) scan and used to quantify the mean and maximum variations in the simulation fiducial position (Sim_Varavg and Sim_Varmax), as well as to design the internal target volume (ITV) incorporating a PSBH margin. Results At treatment, a mean of 5 breath-hold cone beam CT (CBCT) scans were acquired per fraction for each patient to quantify the mean and maximum variations in the treatment fiducial position (Tx_Varavg and Tx_Varmax). Various planning target volume (PTV) margins on the gross tumor volume (GTV) versus ITV were evaluated using CBCT scans, with the goal of >95% of fiducials being covered at treatment. The Sim_Varavg and Sim_Varmax were 0.9 ± 0.5 mm and 1.5 ± 0.8 mm in the left-right (LR) direction, 0.9 ± 0.4 mm and 1.4 ± 0.4 mm in the anteroposterior (AP) direction, and 1.5 ± 0.9 mm and 2.1 ± 1.0 mm in the superoinferior (SI) direction, respectively. The Tx_Varavg and Tx_Varmax were 1.2 ± 0.4 mm and 2.0 ± 0.7 mm in the LR direction, 1.1 ± 0.4 mm and 1.8 ± 0.6 mm in the AP direction, and 1.9 ± 1.0 mm and 3.1 ± 1.4 mm in the SI direction, respectively. The ITV was increased by 21.0% ± 8.6% compared with the GTV alone. The PTV margin necessary to encompass >95% of the fiducial locations was 2 mm versus 4 mm in both LR and AP and 4 mm versus 6 mm in SI for the ITV and the GTV, respectively. Conclusions The interbreath-hold variation is not insignificant, especially in the SI direction. Acquiring multiple breath-hold CT scans at simulation can help quantify the reproducibility of the interbreath hold and design a PSBH margin for treatment.
TL;DR: With shifting reimbursement, brachytherapy represents the pinnacle in hypofractionated, conformal radiation therapy, and with extensive long-term data in support of the treatment modality brachyTherapy is primed for a renaissance.
Abstract: The recent global events related to the coronavirus disease of 2019 pandemic have significantly changed the medical landscape and led to a shift in oncologic treatment perspectives. There is a renewed focus on preserving treatment outcomes while maintaining medical accessibility and decreasing medical resource utilization. Brachytherapy, which is a vital part of the treatment course of many cancers (particularly prostate and gynecologic cancers), has the ability to deliver hypofractionated radiation and thus shorten treatment time. Studies in the early 2000s demonstrated a decline in brachytherapy usage despite data showing equivalent or even superior treatment outcomes for brachytherapy in disease sites, such as the prostate and cervix. However, newer data suggest that this trend may be reversing. The renewed call for shorter radiation courses based on data showing equivalent outcomes will likely establish hypofractionated radiation as the standard of care across multiple disease sites. With shifting reimbursement, brachytherapy represents the pinnacle in hypofractionated, conformal radiation therapy, and with extensive long-term data in support of the treatment modality brachytherapy is primed for a renaissance.
TL;DR: In this article, the authors investigated the relationship between post-operative stereotactic radiosurgery (SRS) and leptomeningeal disease (LMD) in 7 tertiary care centers.
Abstract: Purpose Postoperative stereotactic radiosurgery (SRS) is associated with up to 30% risk of subsequent leptomeningeal disease (LMD). Radiographic patterns of LMD (classical sugarcoating [cLMD] vs. nodular [nLMD]) in this setting has been shown to be prognostic. However, the association of these findings with neurologic death (ND) is not well described. Methods and Materials The records for patients with brain metastases who underwent surgical resection and adjunctive SRS to 1 lesion (SRS to other intact lesions was allowed) and subsequently developed LMD were combined from 7 tertiary care centers. Salvage radiation therapy (RT) for LMD was categorized according to use of whole-brain versus focal cranial RT. Results The study cohort included 125 patients with known cause of death. The ND rate in these patients was 79%, and the rate in patients who underwent LMD salvage treatment (n = 107) was 76%. Univariate logistic regression demonstrated radiographic pattern of LMD (cLMD vs. nLMD, odds ratio: 2.9; P = .04) and second LMD failure after salvage treatment (odds ratio: 3.9; P = .02) as significantly associated with ND. The ND rate was 86% for cLMD versus 68% for nLMD. Whole-brain RT was used in 95% of patients with cLMD and 52% with nLMD. In the nLMD cohort (n = 58), there was no difference in ND rate based on type of salvage RT (whole-brain RT: 67% vs. focal cranial RT: 68%, P = .92). Conclusions LMD after surgery and SRS for brain metastases is a clinically significant event with high rates of ND. Classical LMD pattern (vs. nodular) and second LMD failure after salvage treatment were significantly associated with a higher risk of ND. Patients with nLMD treated with salvage focal cranial RT did not have higher ND rates compared with WBRT. Methods to decrease LMD and the subsequent high risk of ND in this setting warrant further investigation.
TL;DR: The data suggest that the use of fiducial markers does not negatively affect clinical outcomes in patients with localized pancreatic cancer.
Abstract: Purpose Localized pancreatic cancer is commonly treated with stereotactic body radiation therapy (SBRT), which often requires the placement of fiducial markers. We compared the clinical outcomes of patients with and without fiducial markers. Methods and Materials We retrospectively collected data on patients with pancreatic cancer treated with neoadjuvant SBRT at a single institution. Patients were divided into 2 groups based on the placement of a fiducial marker. Local recurrence was the primary outcome. Time to event endpoints were analyzed using COX regression. Results We included 96 patients with unresectable pancreatic cancer: 46 patients (47.9%) did not have a fiducial marker, and 50 patients (52.1%) had a fiducial placed. Patients in the fiducial group were older and had more locally advanced pancreatic cancer compared with those who did not have a fiducial placed. Most patients in both groups (92.7%) received chemotherapy before SBRT treatment. SBRT was delivered to a median of 36 Gy over 5 fractions in the no-fiducial group, and 38 Gy over 5 fractions in the fiducial group. At a median follow-up of 20 months, local recurrence was similar irrespective of fiducial placement (adjusted hazard ratio [aHR] 0.6, 95% CI 0.3-1.3, P = .59). Furthermore, no difference in overall survival was noted between the 2 groups (aHR 0.8, 95% CI 0.3-1.9, P = .65). In patients who eventually underwent surgery post-SBRT, no difference in surgical margins (P = .40) or lymphovascular invasion (P = .76) was noted between the 2 groups. No patient developed acute pancreatitis after fiducial placement. Conclusions Our data suggest that the use of fiducial markers does not negatively affect clinical outcomes in patients with localized pancreatic cancer. Prospective confirmation of our results is still needed.
TL;DR: A significant proportion of patients who undergo RT for HNC suffer from chronic opioid use (COU), and high-risk factors for COU include an oropharyngeal primary, history of psychiatric disorder, former/current alcohol abuse, and pre-treatment opioid use.
Abstract: Purpose Opioid addiction is a major public health concern. Chronic opioid use (COU) patterns after radiation for head and neck cancer (HNC) remain poorly understood. The aim of this study was to estimate the prevalence of COU and to identify its risk factors in patients with HNC undergoing curative-intent radiation therapy (RT) or chemoradiotherapy (CRT). Methods and Materials We performed a systematic review and meta-analysis using the PubMed (Medline), EMBASE, and Cochrane Library databases, queried from dates of inception until January 2020. COU was defined as persistent use of opioids ≥ 3 months after treatment completion. Meta-analyses were performed using random effects models. Heterogeneity was assessed using the I2 value. Results Seven retrospective studies, reporting on 1841 patients, met the inclusion criteria. Median age was 59.4 (range: 56.0-62.0) years with 1343 (72.9%) men and 498 (27.1%) women. Primary tumor locations included oropharynx (n = 891, 48.4%), oral cavity (n = 533, 29.0%), larynx (n = 93, 5.1%), hypopharynx (n = 32, 1.7%), and nasopharynx (n = 29, 1.6%). Eight hundred fifty-four (46.0%) patients had stage I/II and 952 (50.3%) had stage III-IV disease. Three hundred one (16.3%) patients had RT alone, 738 (40.1%) received CRT, and 594 (32.3%) underwent surgery followed by adjuvant RT/CRT. The proportion of patients with HNC who developed COU post-RT/CRT was 40.7% at 3 months (95% confidence interval [CI]: 22.6%-61.7%; I2 = 97.1%) and 15.5% at 6 months (95% CI: 7.3%-29.7%; I2 = 94.3%). Oropharyngeal malignancies had the highest rate of COU based on primary tumor location (46.6%; 95% CI: 30.8%-63.1%; P < .0001). High proportions of COU were found in patients with a history of psychiatric disorder(s) (61.7%), former/current alcohol abuse (53.9%), and opioid requirements before radiation treatment (51.6%; P = .035). Conclusions A significant proportion of patients who undergo RT for HNC suffer from COU. High-risk factors for COU include an oropharyngeal primary, history of psychiatric disorder, former/current alcohol abuse, and pre-treatment opioid use. New strategies to mitigate COU are needed.
TL;DR: A review of emerging cybersecurity threats and a literature review of cyberattacks that affected radiation oncology practices are conducted and an assume breach mentality (threat-informed defense posture) and adopting a cloud-first and zero-trust security strategy are recommended.
Abstract: Purpose Modern image guided radiation therapy is dependent on information technology and data storage applications that, like any other digital technology, are at risk from cyberattacks. Owing to a recent escalation in cyberattacks affecting radiation therapy treatments, the American Society for Radiation Oncology's Advances in Radiation Oncology is inaugurating a new special manuscript category devoted to cybersecurity issues. Methods and Materials We conducted a review of emerging cybersecurity threats and a literature review of cyberattacks that affected radiation oncology practices. Results In the last 10 years, numerous attacks have led to an interruption of radiation therapy for thousands of patients, and some of these catastrophic incidents have been described as being worse than the coronavirus disease of 2019 impact on centers in New Zealand. Conclusions Cybersecurity threats continue to evolve, making combatting these attacks more difficult for health care organizations and requiring a change in strategies, tactics, and culture around cyber security in health and radiation oncology. We recommend an assume breach mentality (threat-informed defense posture) and adopting a cloud-first and zero-trust security strategy. A reliance on computer-driven technology makes radiation oncology practices more vulnerable to cyberattacks. Health care providers should increase their resilience and cyber security maturity. The increase in the diversity of these attacks demands improved preparedness and collaboration between oncologic treatment centers both nationwide and internationally to protect patients.
TL;DR: Low compliance to planned treatment was observed for radiation and concurrent chemotherapy due to lockdown and fear of contracting COVID, will likely lead to increased risk of cancer related mortality.
Abstract: Purpose To report real world compliance to radiation in gynecological cancers during the complete lockdown phase of COVID 19 pandemic. Methods From 23rd March, 2020 until 30th June, 2020 complete lockdown was imposed in India. During this period there was restructuring of cancer care and radiation oncology department due to operational policies prevalent in the institution, and the care for gynaecological cancer was based on the evolving international recommendations. Institutional review board approval was obtained to audit patterns of care during complete lockdown phase. Descriptive variables were used to report on patient characteristics, compliance, delays, toxicity and observed deviations in recommended care. Result During the lockdown period spanning 100 days, treatment of 270 and telephonic follow-up of 1103 gyneconcological cancer patients was undertaken. Of 270 new patients, due to travel restrictions, 90 patients were referred to the facilities in vicinity of their residence. Of the remaining 180 patients, 138 were planned for complete treatment at our institution and 42 were referred to our centre for brachytherapy. Of 138 patients, only 106 (76%) completed the planned external radiation. Twenty four (26%), patients completed full course of concurrent chemotherapy, 11 (12%) received chemotherapy dose reduction and 57 (62%) received no concurrent chemotherapy. Treatment delay of upto 3 weeks noted in 8.6% patients due to COVID infection. No grade IV-V acute sequelae were observed. No excess adverse effects were observed in high risk population. Low rate of symptom burden was observed amongst 1103 patients on telephonic follow-up. with 100 (9.6%) patients reporting symptoms Amongst these, (54/100) 54% had complete resolution of symptoms within 4 weeks of teleconsultation, while 10% had disease progression. Conclusion Low compliance to planned treatment was observed for radiation and concurrent chemotherapy due to lockdown and fear of contracting COVID, will likely lead to increased risk of cancer related mortality. Rapid restructuring of care is needed to prevent the same as COVID pandemic further evolves. Summary The current article provides a real world audit of treatment for gynecological cancers during the complete lockdown phase of COVID Pandemic within tertiary cancer centre in India. Unacceptable treatment delays were noted within the health care system primarily due to societal restrictions posed due to lockdown. No untoward adverse effects were noted as a direct result of COVID infection. Treatment was overall well tolerated by patients.
TL;DR: In this article, a 3-dimensional fully convolutional network was trained with 315/264 parotid/submandibular glands, and SPMs were created using Monte Carlo dropout (MCD) and boosted by placing a Gaussian distribution (GD) over the model's parameters during sampling.
Abstract: Purpose Contouring organs at risk remains a largely manual task, which is time consuming and prone to variation Deep learning-based delineation (DLD) shows promise both in terms of quality and speed, but it does not yet perform perfectly Because of that, manual checking of DLD is still recommended There are currently no commercial tools to focus attention on the areas of greatest uncertainty within a DLD contour Therefore, we explore the use of spatial probability maps (SPMs) to help efficiency and reproducibility of DLD checking and correction, using the salivary glands as the paradigm Methods and Materials A 3-dimensional fully convolutional network was trained with 315/264 parotid/submandibular glands Subsequently, SPMs were created using Monte Carlo dropout (MCD) The method was boosted by placing a Gaussian distribution (GD) over the model's parameters during sampling (MCD + GD) MCD and MCD + GD were quantitatively compared and the SPMs were visually inspected Results The addition of the GD appears to increase the method's ability to detect uncertainty In general, this technique demonstrated uncertainty in areas that (1) have lower contrast, (2) are less consistently contoured by clinicians, and (3) deviate from the anatomic norm Conclusions We believe the integration of uncertainty information into contours made using DLD is an important step in highlighting where a contour may be less reliable We have shown how SPMs are one way to achieve this and how they may be integrated into the online adaptive radiation therapy workflow
TL;DR: An automatic image-processing framework to create patient-specific eye models and to determine the full 3D tumor shape and size automatically is developed and may have a direct effect on clinical workflow, as it enables an accurate 3D assessment of tumor dimensions, which directly influences therapy selection.
Abstract: Purpose The optimal treatment strategy for uveal melanoma (UM) relies on many factors, the most important being tumor size and location Building on recent developments in high-resolution 3D ocular magnetic resonance imaging (MRI), we developed an automatic image-processing framework to create patient-specific eye models and to subsequently determine the full 3D tumor shape and size automatically Methods and Materials From 15 patients with UM, 3D inversion-recovery gradient-echo (T1-weighted) and 3D fat-suppressed spin-echo (T2-weighted) images were acquired with a 7T MRI scanner First, the sclera and cornea were segmented from the T2-weighted image by mesh-fitting The T1- and T2-weighted images were then coregistered From the registered T1-weighted image, the lens, vitreous body, retinal detachment, and tumor were segmented Fuzzy C-means clustering was used to differentiate the tumor from retinal detachments The tumor model was verified and (if needed) edited by an ophthalmic MRI specialist Subsequently, the prominence and largest basal diameter of the tumor were measured automatically based on the verified contours These results were compared with manual assessments on the original images and with ultrasound measurements to show the errors in manual analysis Results The framework successfully created an eye model fully automatically in 12 cases In these cases, a Dice similarity coefficient (mean surface distance) of 977%±084% (017±011 mm) was achieved for the sclera, 968%±105% (020±006 mm) for the vitreous body, 916%±483% (015±006 mm) for the lens, and 860%±74% (035±027 mm) for the tumor The manual assessments deviated, on average, 039±031 mm in prominence and 17±122 mm in basal diameter from the automatic measurements Conclusions The described framework combined information from T1- and T2-weighted images to accurately determine tumor boundaries in 3D The proposed process may have a direct effect on clinical workflow, as it enables an accurate 3D assessment of tumor dimensions, which directly influences therapy selection
TL;DR: A dose–response relationship between osteoarthritis and the volume of the femoral head receiving an EQD2 dose of ≥40 Gy was found and was found to indicate an increased risk of clinically relevant osteOarthritis at long-term follow up.
Abstract: Purpose The aim of the present study was to analyze the long-term incidence of hip complications after external beam radiation therapy compared with age-matched controls from the general population. We also investigated whether there were any dose−response associations. Methods and materials A total of 349 patients with prostate cancer treated to curative dose with external beam radiation therapy between 1997 and 2002 were included in the study. Physical and fractionation-corrected dose-volume descriptors were derived for the femoral heads, pubic bone, and sacrum. Information on skeletal events was collected for the patients and 1661 matched controls through the Prostate Cancer database Sweden. Uni- and multivariable Cox proportional hazard regressions were used to analyze the time to event. Results Data from 346 patients were available for analysis. The median mean physical dose and corresponding equivalent 2-Gy/fraction dose (EQD2) to the femoral heads were 35.5 Gy and 28.7 Gy, respectively. The median follow-up time was 16.0 years. During the follow up, 12 hip fractures occurred. Hip osteoarthritis was diagnosed in 36 cases, with 29 cases leading to replacement surgery. No increased risk of hip fractures was found. Hip osteoarthritis was the only event for which a statistically significant difference was found between the irradiated cohort and the controls (cause-specific hazard ratio: 1.56; 95% confidence interval, 1.07-2.26; P = .02). The cumulative incidence of osteoarthritis at 10 years was 8.1% and 4.9% in the irradiated cohort and the controls, respectively. A significant relationship between osteoarthritis and the volume of the femoral head receiving ≥40 Gy (ie, EQD2) was found. Conclusions In this study of 346 patients treated with conventional radiation therapy, we found no increased risk of hip fracture but an increased risk of clinically relevant osteoarthritis at long-term follow up. Our results indicate a dose–response relationship between osteoarthritis and the volume of the femoral head receiving an EQD2 dose of ≥40 Gy.