Hyung Jun Yoo

Bio: Hyung Jun Yoo is an academic researcher from University Health System. The author has contributed to research in topics: Radiation therapy & Survival rate. The author has an hindex of 19, co-authored 44 publications receiving 1241 citations.

Stereotactic body radiation therapy for inoperable hepatocellular carcinoma as a local salvage treatment after incomplete transarterial chemoembolization

Abstract: BACKGROUND: The objective of this study was to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) as a local salvage treatment after incomplete transarterial chemoembolization (TACE) for inoperable hepatocellular carcinoma (HCC). METHODS: The main eligibility criteria were a greatest tumor dimension (LD sum) <10 cm, inoperable HCC, and incomplete response after TACE. Prescribed SBRT doses were up to 60 gray (Gy) in 3 fractions, but doses were reduced until normal tissue constraints were allowed. RESULTS: Between May 2008 and February 2011, 50 patients were enrolled in this phase 2 trial, of which 47 patients were evaluable. Forty-one patients had Child-Pugh class A disease (A5/A6 were 32/9), 6 patients had class B7 disease, and 5 patients had portal vein tumor thrombosis. All patients underwent TACE 1 to 5 times before SBRT. SBRT doses ranged from 42 to 60 Gy in 3 fractions (median dose, 57 Gy), and the median LD sum was 29 mm (range, 13-78 mm). Eighteen patients (38.3%) achieved complete remission within 6 months of completing of SBRT, and 18 patients (38.3%) had a partial response. The 2-year local control rate was 94.6%, the overall survival rate was 68.7%, and the progression-free survival rate was 33.8%. Three patients (6.4%) experienced grade 3 gastrointestinal toxicity, and 2 patients (4.3%) experienced grade 4 gastric ulcer perforation. CONCLUSIONS: This trial demonstrated that SBRT after incomplete TACE for inoperable HCC achieves promising rates of response and local control. On the basis of these study results, a modified, multi-institutional, phase 2 trial to reduce gastrointestinal toxicity is recommended. Cancer 2012. © 2012 American Cancer Society.

High-dose stereotactic body radiotherapy correlates increased local control and overall survival in patients with inoperable hepatocellular carcinoma

Abstract: Recent studies using stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) have reported high tumor response and local control. However, the optimal SBRT dose remains unknown, and it is still not clear whether a dose response relationship for local control (LC) and overall survival (OS) exist or not. We performed this study to determine whether a dose response relationship for LC and OS is observed in SBRT for inoperable HCC. Between 2003 and 2011, 108 patients with HCC were treated with SBRT. All patients were unsuitable for surgery or local ablation and had incomplete response to transarterial chemoembolization. Eighty-two patients with a longest tumor diameter (LD) less than or equal to 7.0 cm who were treated with 3-fraction SBRT and were analyzed. This cohort comprised 74 Child-Turcotte-Pugh (CTP) class A patients and 8 CTP class B7 patients. The median LD was 3.0 cm (range, 1.0–7.0 cm), and the median dose was 51 Gy (range, 33–60 Gy). LC and OS rates at 2 years after SBRT were 87% and 63%, respectively, with a median follow-up duration of 30 months for all patients. The 2-year LC/OS rates for patients treated with doses of > 54, 45–54, and < 45 Gy were 100/71, 78/64, and 64%/30%, respectively (p = .009/p < .001). Multivariate analysis revealed that the SBRT dose (p = .005) and Barcelona Clinic Liver Cancer stage (p = .015) were significant prognostic factors for OS. Correlation analysis revealed a positive linear relationship between the SBRT dose and LC (p = .006, R = .899)/OS (p = .002, R = .940) at 2 years. Based on the tumor-control probability model, a dose of 54.8 Gy provides 2-year LC with a 90% probability. Five patients experienced grade 3 or higher gastrointestinal toxicity, and 6 had deteriorating of CTP score by greater than or equal to 2 within 3 months of SBRT. This study demonstrated a dose response relationship for LC and OS with SBRT for HCC. Higher LC rates resulting from an increased dose may translate into survival benefits for patients with HCC.

Image-guided stereotactic body radiation therapy in patients with isolated para-aortic lymph node metastases from uterine cervical and corpus cancer.

Abstract: Purpose The aims of this study were to evaluate the role of stereotactic body radiation therapy (SBRT) as a local treatment for isolated para-aortic lymph node (PALN) metastases originating from uterine cervical and corpus cancer. Methods and Materials We retrospectively enrolled 30 patients with isolated PALN metastases originating from uterine cervical and corpus cancer who had received SBRT using the CyberKnife (CK). All patients were shown to have isolated PALN metastases by computed tomography (CT) and/or positron emission tomography (PET)–CT. The overall survival (OS), local control (LC) rate, and disease progression–free survival (DPFS) rate were calculated according to the Kaplan-Meier method. Comparison between prognosis groups was performed using log-rank analysis. Toxicities were also evaluated. Results The 4-year OS rate was 50.1%, and the median survival time was not reached. The OS rate among symptomatic patients was significantly lower than that among asymptomatic patients (p = 0.002). The 4-year actuarial LC rate was 67.4%. Patients with a planning target volume of ≤17 ml had significantly higher LC rates (p = 0.009). The 4-year DPFS rate was 45.0%, and the median time to disease progression was 32 months. Small planning target volume was a favorable prognostic factor (p = 0.043). Grade 3 or 4 complications requiring hospitalization were reported in 1 patient at 20 months after SBRT. Conclusion The OS and LS rates were promising, and the incidence of toxicities was low. Use of SBRT with the CyberKnife is an effective modality for treating isolated PALN metastases in patients with uterine cervical and corpus cancer.

Oligometastases confined one organ from colorectal cancer treated by SBRT

Abstract: To determine the feasibility and efficacy of stereotactic body radiotherapy (SBRT) for oligometastases from colorectal cancer (CRC). Total of 59 patients with 78 lesions confined to one organ and treated from 2001 to 2006 were involved in this retrospective review. These patients presented with 1-4 metastatic lesions of largest diameter of <7 cm, progressed after chemotherapy, and were amenable to local treatment. The median radiation dose administered was 42 Gy, which was delivered in 3 fractions. Lymph node lesions were most frequent, followed in order by the lung and liver. Five-year overall survival and local control rates were 29 and 19%, respectively. Cumulative gross tumor volume, site of metastasis, and SBRT dose were found to be significantly associated with overall survival. In terms of local control, a cumulative GTV below 23 ml was found to be a significantly favorable prognostic factor. Acute grade 1-2 toxicities occurred in 24 of the 59 patients, and a late grade 4 complication occurred in 2 (3%), and these were relieved by bypass surgery. CRC patients with oligometastases generally fare well after SBRT. In particular, the survival rates of patients with a pelvic LN or a small tumor are promising.

Clinical practice guidelines in oncology

Abstract: Ductal carcinoma in situ (DCIS) of the breast represents a heterogeneous group of neoplastic lesions in the breast ducts. The goal for management of DCIS is to prevent the development of invasive breast cancer. This manuscript focuses on the NCCN Guidelines Panel recommendations for the workup, primary treatment, risk reduction strategies, and surveillance specific to DCIS.

Radiobiology for the Radiologist

Abstract: The text consists of two sections, one for those studying or practicing diagnostic radiology, nuclear medicine and radiation oncology; the other for those engaged in the study or clinical practice of radiation oncology--a new chapter, on radiologic terrorism, is specifically for those in the radiation sciences who would manage exposed individuals in the event of a terrorist event. The 17 chapters in Section I represent a general introduction to radiation biology and a complete, self-contained course especially for residents in diagnostic radiology and nuclear medicine that follows the Syllabus in Radiation Biology of the RSNA. The 11 chapters in Section II address more in-depth topics in radiation oncology, such as cancer biology, retreatment after radiotherapy, chemotherapeutic agents and hyperthermia.

Survival of squamous cell carcinoma of the head and neck in relation to human papillomavirus infection: review and meta-analysis.

Abstract: Human papillomavirus (HPV) has been associated with head and neck squamous cell carcinomas (HNSCC), especially of the oropharynx, with highest distribution in the tonsils. HPV infection has been associated with improved outcome, although not all the studies show consistent results. The reason for this is not clear. We reviewed all published articles and conducted a meta-analysis on the overall relationship between HPV infection and overall survival (OS) and disease-free survival (DFS) in HNSCC. Patients with HPV-positive HNSCC had a lower risk of dying (meta HR: 0.85, 95% CI: 0.7-1.0), and a lower risk of recurrence (meta HR: 0.62, 95%CI: 0.5-0.8) than HPV-negative HNSCC patients. Site-specific analyses show that patients with HPV-positive oropharyngeal tumours had a 28% reduced risk of death (meta HR: 0.72, 95%CI: 0.5-1.0) in comparison to patients with HPV-negative oropharyngeal tumours. Similar observations were made for DFS (meta HR: 0.51, 95% CI: 0.4-0.7). There was no difference in OS between HPV-positive and negative non-oropharyngeal patients. The observed improved OS and DFS for HPV-positive HNSCC patients is specific to the oropharynx; these tumours may have a distinct etiology from those tumours in non-oropharyngeal sites.

Sequential Phase I and II Trials of Stereotactic Body Radiotherapy for Locally Advanced Hepatocellular Carcinoma

Abstract: Purpose To describe outcomes of prospective trials of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC). Patients and Methods Two trials of SBRT for patients with active HCC unsuitable for standard locoregional therapies were conducted from 2004 to 2010. All patients had Child-Turcotte-Pugh class A disease, with at least 700 mL of non-HCC liver. The SBRT dose range was 24 to 54 Gy in six fractions. Primary end points were toxicity and local control at 1 year (LC1y), defined as no progressive disease (PD) of irradiated HCC by RECIST (Response Evaluation Criteria in Solid Tumors). Results A total of 102 patients were evaluable (Trial 1, 2004 to 2007: n = 50; Trial 2, 2007 to 2010: n = 52). Underlying liver disease was hepatitis B in 38% of patients, hepatitis C in 38%, alcohol related in 25%, other in 14%, and none in 7%. Fifty-two percent received prior therapies (no prior sorafenib). TNM stage was III in 66%, and 61% had multiple lesions. Median gross tumor volume was 117.0 mL (rang...