Showing papers in "Clinical Nuclear Medicine in 2012"
TL;DR: 18F-NaF PET/CT positivity tends to associate with increasing PSA level in prostatectomized men and may occur in lower PSA ranges than conventionally recognized, whereas the yield of 18F-FDG PET/ CT is relatively limited.
Abstract: Prostate cancer is the most common cancer and the second leading cause of cancer death affecting men in the United States.1 Despite successful treatments for localized prostate cancer, up to 40% of men will eventually (most within 10 y from primary treatment) experience a detectable rise in the serum prostate-specific antigen (PSA) level (biochemical failure), suggesting that prostate cancer can metastasize early in the course of the disease.2 However, biochemical failure may occur years before metastases become clinically evident, and the clinical course can be markedly different. The stratification of men with biochemical recurrence is an important unmet clinical need.
Conventional imaging evaluation with CT and 99mTc-based bone scintigraphy (BS) may be negative or indeterminate in a substantial number of men with biochemical failure. 111In-capromab pendetide (ProstaScint; EUSA Pharma, Inc, Langhorne, Pa), which is a radiolabeled antibody targeted at the prostate-specific membrane antigen, has low sensitivity for detecting osseous metastases and poor specificity, making it of limited clinical value.3 More sensitive and specific imaging procedures may provide valuable information because treatment options are primarily based on detection and location of disease, for instance, observation in the absence of frank metastases, and the use of bone-targeted therapy for bone metastases.
There is an increasing interest in the potential role of PET in prostate cancer. Several promising radiotracers are currently being investigated in the imaging evaluation of prostate cancer including 18F- or 11C-choline, 18F- or 11C-acetate, 16β-18F-fluoro-5α -dihydrotestosterone, targeted to the androgen receptor, anti–1-amino-3-18F-fluorocyclobutane-1-carboxylic acid, a synthetic l-leucine analog, and prostate-specific membrane antigen–based PET radiotracers.4 However, the contribution of these radiotracers to decision-making in prostate cancer remains undefined, and this will require continued investigation.
18F-FDG is the most common PET radiotracer used for oncologic applications. The ability of 18F-FDG PET to detect cancer is based on elevated glucose metabolism in malignant tissue in comparison to that in normal tissue.5 Current literature suggests that 18F-FDG PET/CT may be useful in the imaging evaluation of men with metastatic prostate cancer.6 Similarly, 18F-NaF PET/CT offers significantly higher sensitivity and specificity for identifying bone metastases in comparison to 99mTc-based BS.7,8 Recent decision by the Center for Medicare and Medicaid Services to reimburse sites participating in the National Oncologic PET Registry for 18F-NaF PET/CT scans has facilitated use of this sensitive imaging method in patients with cancer.9
There is lack of data regarding the potential utility of 18F-NaF and 18F-FDG PET/CT in men with biochemical recurrence of prostate cancer, who have negative conventional imaging studies. In view of the current critical need for early and accurate localization of occult metastatic disease in biochemical failure of prostate cancer, we set out to perform a prospective evaluation of 18F-NaF and 18F-FDG PET/CT imaging in this population.
124 citations
TL;DR: Dedifferentiation in TC is accompanied by GLUT1 upregulation and increased proliferation, and the results suggest that F-18 FDG PET/CT is an important imaging modality for ATC and PDTC.
Abstract: PURPOSE Glucose transporters 1 (GLUT1) facilitates glucose uptake in cancer. An inverse relationship between I-131 and F-18 fluorodeoxyglucose (FDG) uptake in PET/CT ("flip-flop phenomenon") was described for thyroid cancers (TCs) during dedifferentiation. We investigated the relationship among GLUT1 expression, proliferation, iodine concentration, and glucose uptake in different TC types, with emphasis on "poorly differentiated thyroid carcinoma" (PDTC). METHODS For immunohistochemistry, 95 thyroid tumors (follicular adenoma, papillary TC, follicular TC, PDTC, and anaplastic TC [ATC]) were investigated for GLUT1 expression and proliferation (Ki-67 index). For PET/CT study, 47 F-18 FDG PET/CT of patients with TC (22 PDTC), 39 corresponding I-124 PET/CT, and glucose and iodine uptake were evaluated. PTC and FTC were summarized under differentiated TC (DTC). RESULTS Immunohistochemistry: 65% of TC expressed GLUT1. The number of GLUT1-positive TC and GLUT1 expression increased with escalating dedifferentiation/aggressiveness of TC types (P < 0.001). A correlation between proliferation and GLUT1 expression was noted (P < 0.001). PET/CT study: F-18 FDG uptake was measured in 81% of cases. Occurrence of F-18 FDG-avid cases as well as median F-18 FDG maximum standardized uptake values were lowest in DTC, intermediate in PDTC, and highest in ATC. Accordingly, numbers of iodine-avid cases and median I-124 maximum standardized uptake value featured an inverse pattern. CONCLUSIONS Dedifferentiation in TC is accompanied by GLUT1 upregulation and increased proliferation. PDTC was found to be intermediate between DTC and ATC in terms of GLUT1 expression and F-18 FDG or I-124 uptake, suggesting that the flip-flop phenomenon occurs at a dedifferentiation stage in between. Furthermore, the results suggest that F-18 FDG PET/CT is an important imaging modality for ATC and PDTC.
112 citations
TL;DR: Whole-body FDG PET or PET/CT is a valuable imaging tool for the assessment of patients with multiple myeloma, especially for the appraisal of extramedullary involvement.
Abstract: AimThe purpose of the current study was to conduct a systematic review and meta-analysis of the published literature to evaluate the diagnostic accuracy of FDG PET or PET/CT for intramedullary and extramedullary lesions in multiple myeloma.MethodsThe authors conducted a systematic MEDLINE search of
101 citations
TL;DR: 18F-FDG PET/CT imaging has relatively low sensitivity (especially in cN0 patients) for detection of inguinal lymph node involvement in penile cancer patients, which does not justify its routine use, however, patients with clinically palpable lymph nodes may benefit from 18F- FDGPET/CT because the sensitivity in this subgroup of patients is high.
Abstract: Purpose:Metastatic involvement of the inguinal lymph nodes is associated with decreased survival and is a strong prognostic factor in penile squamous cell carcinoma. The aim of the current systematic review was to evaluate the accuracy of 18F-FDG PET/CT for inguinal lymph node staging in penile squa
84 citations
TL;DR: More than one-third of PET/CT-positive sarcoidosis patients had osseous abnormalities on PET/ CT, and the majority of these lesions could not be detected on low-dose CT.
Abstract: Background:The prevalence of bone involvement in sarcoidosis has been estimated to be 3% to 5%, mostly affecting the phalanges. The aim of this study was to assess the prevalence and distribution pattern of bone and bone marrow involvement as detected by positron emission tomography/computed tomogra
84 citations
TL;DR: Dual-phase 99mTc sestamibi scintigraphy with SPECT/CT enables to identify a parathyroid adenoma in about two-thirds of patients with primary hyperparathyroidism and allows the surgeon to plan appropriate surgery.
Abstract: Purpose:To assess the diagnostic value of dual-phase 99mTc sestamibi scintigraphy with neck and thorax single-photon emission computed tomography/computed tomography (SPECT/CT) in patients with primary hyperparathyroidism, and to analyze the relationships between SPECT/CT data and serum calcium or p
79 citations
TL;DR: It is suggested that pretreatment primary tumor SUVmax and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.
Abstract: PURPOSE To compare primary tumor (18)F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUV(max)) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) obtained in the same patients with head and neck squamous cell carcinoma (HNSCC) to clarify the prognostic significance of both indexes. MATERIALS AND METHODS The study population comprised 26 patients with HNSCC visible on both pretreatment FDG PET/CT and DWI. Correlation between SUV(max) and ADC (b values; 0 and 800 seconds/mm(2)) was analyzed by the Spearman's rank test. Disease-free survival (DFS) was calculated by the Kaplan-Meier method. Prognostic significance was assessed by the long-rank test and Cox proportional hazards analysis. RESULTS SUV(max) and ADC correlated significantly and negatively (ρ = -0.566, P = 0.005). High (>12.1) SUV(max) (P 12.1) and 73% (19/26) for ADC(≤ 0.88) without significant difference between them (P = 0.52). Disease event hazards ratios for significant unadjusted SUV(max) (P = 0.015) and ADC (P = 0.039) remained significant when adjusted for other dichotomized clinical covariates (SUV(max); P = 0.009-0.039, ADC; P = 0.017-0.037) except SUV(max) for ADC and ADC for SUV(max) and T stage. CONCLUSION These results suggest that pretreatment primary tumor SUV(max) and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.
70 citations
TL;DR: MET should be the radiotracer of choice in the evaluation of recurrence of primary brain tumors because the sensitivity for detection and delineation of the possible recurrent tumor, as well as secondary deposits, is higher with MET.
Abstract: PURPOSE OF STUDY With the availability of multiple positron emission tomography (PET) tracers for neurooncology, there is a need to define the appropriate tracer in a given clinical setting, and it is in this regard that we undertook this study to directly compare F-18 flurodeoxyglucose (FDG) PET and C-11 methionine (MET) PET for the evaluation of recurrence in primary brain tumors. PATIENTS AND METHODS Thirty-seven patients with a history of treated primary brain tumors referred for evaluation of recurrent disease were initially included in the study. Two patients had to be excluded because of insufficient follow-up. There were 23 males and 12 females, mean age: 33.7 ± 16.4 years; range: 5 to 65 years. All patients underwent the MET and FDG study on the same day. Visual image interpretation was performed independently by 2 PET physicians for each tracer using the plain PET and fused PET/CT images; the FDG images were evaluated first. Images were analyzed semiquantitatively using tumor to normal contralateral cortex ratios (T/N). Each patient was followed up for a minimum of 18 months. Imaging results were compared with histopathology on tumor excision or biopsy in 14 patients and with clinical follow-up and MRI/MRS at the end of 18 months in 21 patients. RESULTS The final diagnosis was tumor recurrence in 24 patients and no recurrence/stable disease in 11 patients. On FDG, findings in 15/35 (42%) were suggestive of recurrent tumors. On MET, findings in 24/34 (70.5%) cases were suggestive of recurrent tumors. Spatially separated secondary lesions including intraventricular deposits were clearly delineated in 5 cases, 3 were glioblastoma multiforme (GBM) and 2 were anaplastic astrocytomas. One of the secondary lesions was missed on FDG PET. Using a cutoff for T/N ratio on FDG of >0.75 to differentiate recurrence from no recurrence, sensitivity of FDG was 81.2% (confidence interval [CI] = 54.4%-96%), whereas specificity was 88.9% (CI = 51.8%-99.7%). Area under the curve was 0.819 (CI = 0.615-0.943), P = 0.0003. Using a cutoff for T/N ratio of >1.9 to differentiate recurrence from no recurrence, sensitivity of MET was 94.7% (CI = 74.0%-99.9%), whereas specificity was 88.89% (CI = 51.8%-99.7%). Area under the curve was 0.942 (CI = 0.785-0.995), P < 0.0001. Interobserver agreement, κ coefficient, for MET was 0.93, suggesting good interobserver agreement, whereas for FDG, it was fair (0.23). CONCLUSIONS MET should be the radiotracer of choice in the evaluation of recurrence of primary brain tumors because the sensitivity for detection and delineation of the possible recurrent tumor, as well as secondary deposits, is higher with MET. MET-PET is an easier technique to interpret, irrespective of the glioma grade, with less interobserver variability and straightforward localization of tumorous accumulation.
70 citations
TL;DR: Both quantitative and visual determinations allow accurate differentiation between recurrent glioma and radiation necrosis by both FDG and FLT PET.
Abstract: Purpose The objective was to compare F-fluorodeoxyglucose (FDG) and F-fluorothymidine (FLT) PET in differentiating radiation necrosis from recurrent glioma. Materials and methods Visual and quantitative analyses were derived from static FDG PET and static and dynamic FLT PET in 15 patients with suspected recurrence of treated grade 2 glioma or worse with a new focus of Gd contrast enhancement on MRI. For FDG PET, SUVmax and the ratio of lesion SUVmax to the SUVmean of contralateral white matter were measured. For FLT PET, SUVmax and Patlak-derived metabolic flux parameter Kimax were measured for the same locus. A 5-point visual confidence scale was applied to FDG PET and FLT PET. Receiver operating curve analysis was applied to visual and quantitative results. Differences between recurrent tumor and radiation necrosis were tested by Kruskal-Wallis analysis. On the basis of follow-up Gd-enhanced MRI, lesion-specific recurrent tumor was defined as a definitive increase in size of the lesion, and radiation necrosis was defined as stability or regression. Results For FDG SUVmax, the FDG ratio of lesion-white matter, and FLT Kimax, there was a significant difference between mean values for recurrent tumor and radiation necrosis. Recurrent tumor was best identified by the FDG ratio of lesion-contralateral normal white matter (area under the curve of 0.98, confidence interval of 0.91 to 1.00, sensitivity of 100%, and specificity of 75% for an optimized cutoff value of 1.82). Conclusions Both quantitative and visual determinations allow accurate differentiation between recurrent glioma and radiation necrosis by both FDG and FLT PET. In this small series, FLT PET offers no advantage over FDG PET.
63 citations
TL;DR: The ability to indicate insufficient target irradiation by a low SUV could aid in selection of appropriate candidates for PRRT, and larger series are needed to confirm and validate these initial findings.
Abstract: PURPOSE Selection of candidates for peptide receptor radionuclide therapy (PRRT) is increasingly based on receptor positron emission tomography (PET) imaging, including the common tracer 68Ga DOTATOC. However, no studies have yet compared standardized uptake values (SUVs) and absorbed doses in this field. MATERIALS AND METHODS We retrospectively analyzed a consecutive cohort of 21 patients with 61 evaluable tumor lesions undergoing both pretherapeutic 68Ga DOTATOC-PET/CT (Biograph Duo [Siemens Medical Solutions, Erlangen, Germany]; PET acquisition, 75.3 ± 15.4 minutes postinjection; 117.3 ± 33.9 MBq 68Ga DOTATOC) and PRRT with Lu octreotate (7.47 ± 1.39 GBq; intratherapeutic tumor dosimetry with serial whole-body scans; 1, 2, and 4 days postinjection) at our institution. SUVs were compared with the tumor-absorbed doses per injected activity (D/A0) of the subsequent first treatment cycle. RESULTS The correlation of SUV and D/A0 was r = 0.72 (SUVmean) and r = 0.71 (SUVmax), both P 15; SUVmax >25) resulted in high D/A0 (>10 Gy/GBq) in 66.7% to 70.8% and low D/A0 (<5 Gy/GBq) in only 8.3% to 12.5% on subsequent PRRT. The mentioned low D/A0 range, on the other hand, was achieved by all lesions with SUVmean <7 or SUVmax <9. CONCLUSIONS Somatostatin receptor PET imaging may predict tumor-absorbed doses. The ability to indicate insufficient target irradiation by a low SUV could aid in selection of appropriate candidates for PRRT. However, larger series are needed to confirm and validate these initial findings.
62 citations
TL;DR: By improving activity recovery, especially for nonenlarged nodes, PSF significantly improves the sensitivity, NPV, and negative LR of FDG-PET for nodal staging in non–small cell lung cancer.
Abstract: AimThe aim of the present study was to evaluate the impact of point spread function (PSF) reconstruction on quantitative values and diagnostic accuracy of FDG PET/CT for nodal staging in non–small cell lung cancer.Patients and MethodsFifty-eight consecutive PET/CT examinations were reconstructed wit
TL;DR: In this article, the clinical and histopathologic factors that are related to FDG avidity in the recurrence/metastases of patients with differentiated thyroid carcinoma (DTC) who present with elevated thyroglobulin (Tg) levels and negative 131I whole-body scans (WBSs) were determined.
Abstract: Aims This study aimed (a) to determine the clinical and histopathologic factors that are related to FDG avidity in the recurrence/metastases of patients with differentiated thyroid carcinoma (DTC) who present with elevated thyroglobulin (Tg) levels and negative 131I whole-body scans (WBSs), (b) to clarify Tg cutoff levels in this setting, and (c) to evaluate the impact of PET/CT on patient management strategies and hence to critically look into the importance of PET/CT in combination with Tg in clinical decision making. Methods A total of 105 patients with DTC with negative 131I WBS and neck ultrasound but elevated Tg, who underwent FDG PET/CT for the suspicion of recurrent/metastatic disease, were included in this analysis. All patients had previously undergone total thyroidectomy and radioiodine ablation/therapy. PET/CT results were correlated with Tg levels and clinical and histopathologic characteristics of the primary tumor compared with the follow-up data. Results PET/CT was true-positive in 69 patients (of which 23 had surgically amenable disease), true-negative in 20, false-positive in 6 patients and false-negative in 10 patients. Extrathyroidal spread was an independent risk factor related to FDG-avid recurrence. Tumor size was significantly higher in PET-positive patients than others, 2.25 (1.8) versus 1.5 (1.1) cm, P = 0.02. Significant correlation was observed between PET positivity and high Tg levels (P = 0.0001). Receiver operating characteristic curve analysis demonstrated a Tg cutoff of 1.9 ng/mL under thyroid-stimulating hormone suppression, 38.2 ng/mL with thyroid-stimulating hormone stimulation. Among PET-negative patients, no recurrence was detected in patients with undetectable/suppressible Tg in on-therapy state. Conclusions PET positivity correlated with extrathyroidal spread, and elevated Tg in recurrent/metastatic DTC. FDG PET/CT in combination with Tg levels was crucial in defining management strategies in patients with DTC with negative 131I WBS. A negative FDG PET/CT scan predicts a favorable prognosis and lack of recurrence on follow-up in patients with "suppressible Tg" levels in the on-therapy state despite significant elevation of Tg in the off-therapy state.
TL;DR: 18F-FDG PET/CT is accurate for detecting acute symptomatic, proximal DVT and metabolic activity in thrombosed veins decreases with time, suggesting that 18F- FDG PET may be helpful in assessing the age of the clot.
Abstract: Since the initial reports 35 years ago, duplex ultrasonography (US) has virtually replaced contrast venography for the diagnosis of acute deep vein thrombosis (DVT).1,2 In addition to excellent overall performance, the examination does not involve radiation exposure or nephrotoxic contrast agents, can be performed portably, and is widely available. Despite the many advantages of duplex US for the identification of DVT, it is technically dependent on the experience of the individual performing and interpreting the procedure and can also be technically compromised by obesity, edema, or the presence of wounds or overlying bandages. For DVT within the body cavity, compression maneuvers cannot be performed and nonocclusive thrombus may limit the utility of color Doppler US.
18F-FDG is a glucose analog taken up avidly by cells that are metabolically active, including macrophages, endothelial cells, and lymphocytes. In addition to its important role in oncology, 18F-FDG combined with PET can also be used to image the vasculature (reviewed in Joshi et al3). 18F-FDG accumulates in macrophage-rich areas in atherosclerotic lesions and is also very sensitive for the diagnosis of large-vessel vasculitis, reflecting the acute inflammatory responses of the vessel wall.4
Inflammation also contributes to the development of DVT when endothelial cell injury or activation leads to increased expression of cell adhesion molecules promoting leukocyte adhesion and thrombus initiation. Subsequently, other cells, such as neutrophils and macrophages, accumulate within the developing venous thrombus (reviewed in Saha et al5). Because of this robust inflammatory response, increased uptake of 18F-FDG on PET scans may also occur in septic6,7 and aseptic venous thrombosis.8–11
In the current study, the role of 18F-FDG PET was examined in the evaluation of acute, proximal, symptomatic DVT. The primary hypothesis was that the metabolic activity of thrombosed vein segments would be significantly higher than nonthrombosed vein segments. The secondary hypothesis was that the metabolic activity of thrombosed vein segments would decrease with the time from DVT symptom onset.
TL;DR: In this study, 18F-DOPA PET/CT results more accurate than CT/MR in advanced stage NB therefore should be taken into consideration for the diagnostic workup of these patients.
Abstract: AIM: Role of 18F-DOPA PET/CT in neuroblastoma (NB) compared with CT/MR. MATERIALS AND METHODS: In all, 21 patients (M:F = 14:7; mean age, 7.4 years) affected by advanced stage NB (III-IV) were prospectively enrolled. Overall, 37 paired 18F-DOPA PET and CT/MR scans were performed, and for each, we identified site and number of lesions. Standard of reference was based on a multidisciplinary assessment, including 123I-MIBG, selective biopsy, and clinical-instrumental monitoring. Both scan-based and a lesion-based analysis was performed, and for each modality, we calculated sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy. RESULTS: On the scan-based analysis, 18F-DOPA PET and CT/MR showed the following rates: sensitivity, specificity, NPV, PPV, and accuracy were 100%, 92.3%, 100%, 96%, and 97.3% versus 91.7%, 61.5%, 80%, 81.5%, and 81.1%, respectively (P = 0.014). Overall 179 findings were reported at imaging, of which 139 (77.7%) resulted true sites of disease at final outcome. On the lesion-based analysis, the 2 imaging modalities showed the following sensitivity, specificity, NPV, PPV, and accuracy rates: 90.6%, 90%, 73.5%, 96.9%, and 90.5% versus 47.5%, 27.5%, 13.1%, 69.5%, and 43% (P < 0.00001). CONCLUSIONS: In our study, 18F-DOPA PET/CT results more accurate than CT/MR in advanced stage NB therefore should be taken into consideration for the diagnostic workup of these patients.
TL;DR: The nuclear imaging methods (dual phase, subtraction), the role of SPECT and SPECT/CT, and the clinical results of parathyroid scintigraphy in different clinical situations are provided.
Abstract: In recent years, preoperative imaging has become essential in the evaluation of sporadic primary hyperparathyroidism (HPT) for selecting good candidates for minimally invasive HPT. Its role in patients with secondary/tertiary HPT is under investigation. Imaging is mandatory before reoperative parathyroid surgery for persistent or recurrent HPT, whatever the setting. This review provides detailed information regarding the nuclear imaging methods (dual phase, subtraction), the role of SPECT and SPECT/CT, and the clinical results of parathyroid scintigraphy in different clinical situations.
TL;DR: Interestingly, in the patient population, lung cancer was found to be the most frequent malignancy metastasizing to the skeletal muscles, and FDG PET/CT can potentially detect unsuspected SMM.
Abstract: AIM: To define the radiological imaging features and clinical findings of the pa- tients with skeletal muscle metastasis. MATERIALS AND METHODS: 4454 computed tomography (CT), 1802 magnetic resonance imaging (MRI) and 2569 positron emission to- mography/computed tomography (PET/CT) imaging studies of the oncology patients per- formed between March 2009 and July 2012 in the Radiology and Nuclear Medicine Departments of our hospital were retrospectively reviewed. RESULTS: Fifty-two patients had 91 different metastatic skeletal muscle masses. Twenty-one patients (40%) were diagnosed with lung carci- noma as being the most common primary source. Forty-seven patients (90%) had metasta- tic disease somewhere else at the time of detec- tion of skeletal muscle metastasis. Thirty-three patients (63%) had lymph node metastasis which was the most common site. Muscles mostly af- fected by metastatic disease were gluteals (15%), psoas (8.7%), erector spinae (8.7%), rec- tus abdominis (7.6%), latissimus dorsi (6.5%). The mean size of the lesions was 30 mm (range, 10-120 mm). The most common appearance on contrast-enhanced CT was a rim-enhancing in- tramuscular mass with central hypoattenuation. On MRI, skeletal muscle metastases mostly re- vealed isointense signal on T1-weighted images, heterogeneous high signal with peritumoral ede- ma on T2-weighted images and extensive en- hancement with central necrosis on gadolinium- DTPA (diethylene triamine pentaacetic acid) en- hanced images. CONCLUSIONS: Skeletal muscle metastasis may be an incidental finding on CT. The most common CT appearance is a rim-enhancing in- tramuscular mass with central hypoattenuation. On MRI, extensive tumoral enhancement, central necrosis and peritumoral edema are highly ac- ceptable features of skeletal muscle metastasis.
TL;DR: 2 different PET scan patterns in patients with ALE are found, an easily recognizable mixture of hyper- and hypometabolism that has also been described in a few recent case reports and is potentially specific for ALE and the other is indistinguishable from neurodegenerative disease.
Abstract: PurposeAutoimmune limbic encephalitis (ALE) is a severe, but treatable, neuropsychiatric disorder that is difficult to diagnose clinically. With the goal of improving diagnosis of this disorder, we retrospectively evaluated the cerebral FDG PET pattern in a group of patients with ALE.Materials and M
TL;DR: Positron emission tomography/computed tomography with 11C-choline was performed in a prostate cancer patient with skeletal metastases, treated with hormonal therapy, and the finding was suggestive for a parathyroid adenoma on subsequent ultrasound, then confirmed byParathyroid scintigraphy and histopathological analysis performed after hemithyroidectomy.
Abstract: Positron emission tomography/computed tomography (PET/CT) with 11C-choline is an established diagnostic tool for restaging prostate cancer patients with biochemical failure after primary treatment. In the present case, 11C-choline PET/CT was performed in a prostate cancer patient with skeletal metastases, treated with hormonal therapy. In addition to the detection of pathologic uptake at prostate and vertebra, 11C-choline uptake occurred in the neck. The finding was suggestive for a parathyroid adenoma on subsequent ultrasound, then finally confirmed by parathyroid scintigraphy and histopathological analysis performed after hemithyroidectomy.
TL;DR: PET/CT is useful in the diagnosis of spondylodiskitis, with more accurate results than combined bone scan and 67Ga, and SPECT/CT with 67Ga is recommended, especially when planar bone scan
Abstract: PurposeThis study aimed to prospectively evaluate the usefulness of PET/CT using 18F-FDG in comparison to bone scan and 67Ga in the diagnosis of spondylodiskitis.Material and MethodsThis prospective study included 34 patients (15 women and 19 men) aged 59 (18) years with clinical symptoms of spondyl
TL;DR: FDG PET/CT was proven to be more efficient than serum CA-125 assay and CI in detecting recurrences of ovarian cancer after treatment and should be considered a useful diagnostic tool in the surveillance of patients that received treatment for epithelial ovarian carcinoma.
Abstract: ObjectiveThis study aimed to evaluate the efficiency of 18F-FDG PET/CT in suspected recurrence of epithelial ovarian cancer, after treatment, comparing outcomes of PET/CT with histological tumor subtype, CA-125 serum levels, and findings of conventional diagnostic imaging modalities (CI).MethodsData
TL;DR: Patients with a metabolic response measured by early changes of TLP and late changes of TLG and TLP showed a significantly better PFS than metabolically nonresponding patients, and a cutoff value of 20% or 30% for definition of metabolic response showed better differentiation between metabolically responding and non responding patients.
Abstract: PurposeThe aim was to assess the value of tumor lesion glycolysis (TLG) and tumor lesion proliferation (TLP) determined by FDG and 3’-deoxy-3’-18F-fluorothymidine (FLT) PET for response prediction and prognostic differentiation in patients with advanced non–small cell lung cancer (NSCLC) treated wit
TL;DR: 68Ga-DOTANOC PET/CT seems to be a promising modality for detecting primary tumor in patients with carcinoma of unknown primary of neuroendocrine origin.
Abstract: Objective:To evaluate the role of 68Ga-DOTANOC (68Gallium-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI3-octreotide) PET/CT for localization of the primary tumor in patients with carcinoma of unknown primary of neuroendocrine origin.Material and Methods:Twenty patients (me
TL;DR: In the presence of unilateral lymphedema, the contralateral limb is often also abnormal, therefore, care should be taken before diagnosing unilateral lymphatic dysfunction, as reduced ilioinguinal nodal accumulation may be the only apparent abnormality.
Abstract: PURPOSE
To determine how often lymphatic dysfunction is bilateral when, clinically, lymphedema appears unilateral.
METHODS
Lymphoscintigraphy was performed after subcutaneous Tc-99m-nanocolloid injection in the first webspaces of both feet. The percentage of injected radioactivity accumulating in the ilioinguinal regions was recorded in dedicated images separately acquired at 60 and 180 minutes after injection.
RESULTS
Within a consecutive series of 204 patients, 74 had unilateral clinical lymphedema of whom 68 had abnormal scintigraphy. Of these 68 patients, 46 had unilateral abnormal scintigraphy affecting the clinically abnormal limb, but 20 patients had bilateral abnormal scintigraphy and 2 had unilateral abnormal scintigraphy in the clinically unaffected limb. Thus, 32% (22/68) of patients in whom clinical lymphedema appeared to be unilateral, nevertheless, had abnormal scintigraphy in the clinically normal limb. Twenty-nine patients had no clinical evidence of lymphedema in either limb and were scintigraphically normal bilaterally. Mean ilioinguinal nodal accumulation at 180 minutes in the 44 limbs of 22 of these clinically and scintigraphically normal patients (dedicated ilioinguinal imaging was not performed in all patients) was 13.1% (standard deviation, 8.8%), higher (P = 0.02) than the mean value of 9.3% (standard deviation, 5.0%) in the clinically and scintigraphically normal contralateral limbs of 39 patients with unilateral clinical lymphedema.
CONCLUSIONS
In the presence of unilateral lymphedema, the contralateral limb is often also abnormal. On lymphoscintigraphy, therefore, care should be taken before diagnosing unilateral lymphatic dysfunction. Quantification should be included in routine lymphoscintigraphy, as reduced ilioinguinal nodal accumulation may be the only apparent abnormality.
TL;DR: There is a frequent physiological uptake of 68Ga-DOTA-TOC by the pancreas uncinate process, which may be caused by an accumulation of pancreatic polypeptide-containing cells expressing somatostatin receptors.
Abstract: Purpose To characterize a commonly occurring increased uptake by the uncinate process of the pancreas at PET/CT using 68Ga-DOTA-d-Phe1-Tyr3-octreotide (68Ga-DOTA-TOC). This tracer has replaced In pentetreotide (OctreoScan®) for somatostatin receptor scintigraphy at our laboratory. Methods Fifty of our first 74 PET/CT examinations with 68Ga-DOTA-TOC could be evaluated in retrospect. None of these patients had surgery or showed any pathology in the pancreas head at the concomitant CT. Results Thirty-five of the 50 examinations (70%) showed an uptake by the uncinate process sufficiently intense to be interpreted as pathologic and simulating a tumor. Mean SUVmax was 9.2. Mean SUVmean using an isoactivity cut-off of >75% and >50% was 7.8 and 6.0, respectively. Volume calculations of the uncinate process activity using these definitions gave 0.9 mL and 4.2 mL, respectively. Conclusion There is a frequent physiological uptake of 68Ga-DOTA-TOC by the pancreas uncinate process. This may be caused by an accumulation of pancreatic polypeptide-containing cells expressing somatostatin receptors. If there is a normal finding at concomitant diagnostic CT, this uptake should be regarded as physiological.
TL;DR: The CT-based AC improved the specificity but decreased the sensitivity leading to nonsignificant improvement in overall diagnostic accuracy of Tc-99m sestamibi/tetrofosmin MPI.
Abstract: Objective: The aim of the present study was to evaluate whether computed tomography based-attenuation correction (CT-AC) provides any advantage over non–attenuation-corrected (NAC) images for qualitative and quantitative analysis of single photon emission tomography (SPECT) myocardial perfusion imaging (MPI). Methods: We retrospectively evaluated data of 171 patients who underwent stress rest MPI SPECT/CT as per standard protocol. Angiography done within ±3 months of MPI was taken as reference standard. Two readers independently evaluated CT-AC and NAC images. Receiver operating characteristic curve analysis was done using ≥50% and ≥70% stenosis as cutoff. The size and severity of perfusion defects were also compared on CT-AC and NAC images. Results: For both readers, the area under the receiver operating characteristic curve was larger for CT-AC images than for NAC images at both ≥50% and ≥70% cutoff, but the difference was not significant. CT-AC images had significantly lower sensitivity for detecting right coronary artery disease compared with NAC (29% vs. 50% for reader 1 and 25.8% vs. 43.2% for reader 2). However, the specificity improved with CT-AC. Inferior defects were significantly smaller in CT-AC than NAC (P = 0.0002), with no significant difference for anterior defects (P = 0.544). There was significant variation in severity between CT-AC and NAC images for both overall (P = 0.001) as well as for inferior defects (P = 0.0007), but not for anterior defects (P = 0.279). Conclusion: In our study, the CT-based AC improved the specificity but decreased the sensitivity leading to nonsignificant improvement in overall diagnostic accuracy of Tc-99m sestamibi/tetrofosmin MPI.
TL;DR: The use of commercially available 3D-SSP quantitation improved diagnostic accuracy for evaluation of MCI and AD with 18F FDG PET with the help of a receiver operating characteristic curve analysis.
Abstract: IntroductionWe examined the clinical impact of commercially available quantitation software using 3-dimensional stereotactic surface projection (3D-SSP) on the diagnostic accuracy of 18F fluorodeoxyglucose positron emission tomography (18F FDG PET) in mild cognitive impairment (MCI) and Alzheimer di
TL;DR: PSAV can be used to stratify the risk of positive 11C choline PET/CT in PCa patients with biochemical failure and patients with PSAV >1 ng/mL/y should be selected to increase the positive detection rate of 11CcholinePET/CT.
Abstract: Purpose:We previously showed that prostate-specific antigen (PSA) doubling time (PSADT) is a significant predictor of 11C choline positron emission tomography/computed tomography (PET/CT) findings in prostate cancer (PCa) patients. This study compared PSA velocity (PSAV) and PSADT to predict 11C cho
TL;DR: In this paper, the authors evaluate the distribution of F-18-labeled fluoromethylcholine (FCho) in normal structures and tumors of the head region using positron emission tomography (PET) and magnetic resonance imaging.
Abstract: Purpose: To evaluate the distribution of F-18-labelled fluoromethylcholine (FCho) in normal structures and tumors of the head region using positron emission tomography (PET) and magnetic resonance imaging.
Materials and Methods: We retrospectively reviewed the positron emission tomography, magnetic resonance imaging, and the coregistered images obtained in 17 patients with suspected high-grade gliomas. The accumulation of F-18-FCho in the normal structures and in brain lesions was visually and semiquantitatively assessed. A 4-point grading system was used for the visual analysis. A standardized uptake value (SUV) was used to quantify uptake.
Results: In the normal brain parenchyma, F-18-FCho uptake was faint (SUVmean, 0.15 +/- 0.03 (SD)). Uptake was generally moderate in the choroid plexus (SUVmean, 0.82 +/- 0.16), cavernous sinus (SUVmean, 0.87 +/- 0.19), extraocular eye muscles (SUVmean, 1.10 +/- 0.27), masticatory muscles (SUVmean, 0.99 +/- 0.22), and bone marrow (SUVmean, 1.06 +/- 0.26), whereas uptake was usually moderately intense in the pituitary gland (SUVmean, 1.90 +/- 0.21). Uptake was variable in the lacrimal glands and the mucosa of the nasal cavity (for SUVmean of subgroups see text). Intense uptake was observed in the parotid glands (SUVmean, 3.27 +/- 0.73). (Moderately) intense F-18-FCho uptake was observed in glioblastomas (range SUVmax, 2.26-6.37) and typical meningiomas (range SUVmax, 3.75-5.81). Uptake was globally faint in grade II and III gliomas (range SUVmax, 0.33-0.78). F-18-FCho uptake was also demonstrated in benign lesions, such as a tumefactive demyelinating brain lesion.
Conclusions: F-18-FCho uptake was faint in the normal brain parenchyma and usually moderate in the choroid plexus, cavernous sinus, extraocular eye muscles, masticatory muscles, and bone marrow. Uptake in the pituitary gland was generally moderately intense, whereas uptake in the lacrimal glands and the mucosa of the nasal cavity was variable. Parotid glands had intense uptake. Also, uptake in glioblastomas and meningiomas was usually (moderately) intense, whereas uptake in grade II and III gliomas was globally faint. However, F-18-FCho uptake was not tumor specific.
TL;DR: Knowledge of the normal 68Ga-DOTA-TATE distribution is highly important for accurate interpretation of this novel imaging modality, which is increasingly being used in the imaging of neuroendocrine tumor.
Abstract: UNLABELLED The aim of this study was to describe the normal physiological distribution of (68)Ga-DOTA-TATE using the SUV to reflect the density of somatostatin receptors in various organ systems. METHODS A total of 250 patients (90 men and 160 women) were imaged on a Biograph 64 PET/CT TruePoint (Siemens Medical Solutions) 60 to 80 minutes after injection of 120 to 200 MBq (3.2-5.4 mCi) of (68)Ga-DOTA-TATE. Visual assessment was performed on all studies on the multimodality workstation, and sites of increased uptake were recorded. The SUVmax was also calculated for each organ demonstrating increased (68)Ga-DOTA-TATE uptake. RESULTS Visual assessment of the (68)Ga-DOTA-TATE PET/CT studies revealed increased uptake in the pituitary, salivary, thyroid glands, liver, spleen, adrenals, kidneys and bone reflecting normal increased somatostatin receptor expression. These sites were confirmed to be disease free on clinical follow-up and on correlation with other imaging (CT/MRI/ultrasound). Using semiquantitative analysis, SUVmax values were the highest in the pituitary gland [11 (4.5)], spleen [18.9 (6.6)], adrenal [14.0 (5.6)], and kidneys [14.2 (3.6)]. In addition, increasing uptake in the uncinate process of pancreas was noted in 12% of patients with SUVmax of 9.2 (3.3). Moderate (68)Ga-DOTA-TATE uptake was also present in salivary gland [3.4 (1.8)], thyroid [2.9 (1.2)], and normal liver [6.5 (2.2)]. The bones generally showed low (68)Ga-DOTA-TATE uptake with an SUVmax of 1.0 (0.3). CONCLUSIONS Knowledge of the normal (68)Ga-DOTA-TATE distribution is highly important for accurate interpretation of this novel imaging modality, which is increasingly being used in the imaging of neuroendocrine tumor.
TL;DR: In the lumbar spine, SPECT/CT seems to increase specificity for detection of nonunion of interbody devices compared with CT alone, and it can detect screw loosening as well as CT.
Abstract: Purpose:SPECT fused with computed tomography (CT) provides a new approach for more accurate diagnosis of pseudathrosis after spinal fusion procedures. The aim of this study was to compare the findings of SPECT fused with CT (SPECT/CT) with those of CT alone for the diagnosis of pseudarthrosis.Materi