Survey of the Patterns of Using Stereotactic Ablative Radiotherapy for Early-Stage Non-small Cell Lung Cancer in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Stereotactic ablative radiotherapy (SABR) is an effective emerging technique for early-stage non-small cell lung cancer (NSCLC). We investigated the current practice of SABR for early-stage NSCLC in Korea. MATERIALS AND METHODS: We conducted a nationwide survey of SABR for NSCLC by sending e-mails to all board-certified members of the Korean Society for Radiation Oncology. The survey included 23 questions focusing on the technical aspects of SABR and 18 questions seeking the participants' opinions on specific clinical scenarios in the use of SABR for early-stage NSCLC. Overall, 79 radiation oncologists at 61/85 specialist hospitals in Korea (71.8%) responded to the survey. RESULTS: SABR was used at 33 institutions (54%) to treat NSCLC. Regarding technical aspects, the most common planning methods were the rotational intensity-modulated technique (59%) and the static intensity-modulated technique (49%). Respiratory motion was managed by gating (54%) or abdominal compression (51%), and 86% of the planning scans were obtained using 4-dimensional computed tomography. In the clinical scenarios, the most commonly chosen fractionation schedule for peripherally located T1 NSCLC was 60 Gy in four fractions. For centrally located tumors and T2 NSCLC, the oncologists tended to avoid SABR for radiotherapy, and extended the fractionation schedule. CONCLUSION: The results of our survey indicated that SABR is increasingly being used to treat NSCLC in Korea. However, there were wide variations in the technical protocols and fractionation schedules of SABR for early-stage NSCLC among institutions. Standardization of SABR is necessary before implementing nationwide, multicenter, randomized studies.

The first private-hospital based proton therapy center in Korea; status of the Proton Therapy Center at Samsung Medical Center

PURPOSE: The purpose of this report is to describe the proton therapy system at Samsung Medical Center (SMC-PTS) including the proton beam generator, irradiation system, patient positioning system, patient position verification system, respiratory gating system, and operating and safety control system, and review the current status of the SMC-PTS. MATERIALS AND METHODS: The SMC-PTS has a cyclotron (230 MeV) and two treatment rooms: one treatment room is equipped with a multi-purpose nozzle and the other treatment room is equipped with a dedicated pencil beam scanning nozzle. The proton beam generator including the cyclotron and the energy selection system can lower the energy of protons down to 70 MeV from the maximum 230 MeV. RESULTS: The multi-purpose nozzle can deliver both wobbling proton beam and active scanning proton beam, and a multi-leaf collimator has been installed in the downstream of the nozzle. The dedicated scanning nozzle can deliver active scanning proton beam with a helium gas filled pipe minimizing unnecessary interactions with the air in the beam path. The equipment was provided by Sumitomo Heavy Industries Ltd., RayStation from RaySearch Laboratories AB is the selected treatment planning system, and data management will be handled by the MOSAIQ system from Elekta AB. CONCLUSION: The SMC-PTS located in Seoul, Korea, is scheduled to begin treating cancer patients in 2015.

Role of Postoperative Radiotherapy for Microscopic Margin Involvement in the Squamous Cell Carcinoma of Esophagus / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The objective of this study was to assess the effect of postoperative radiotherapy on the outcome of esophageal cancer with microscopically positive resection margin by comparing the results with those of patients with negative resection margin. MATERIALS AND METHODS: Medical records of 88 patients treated with macroscopic resection followed by postoperative radiotherapy for stage II or III squamous cell carcinoma of the esophagus from June 1984 to March 2008 were reviewed. Twelve patients had received chemotherapy. Patients were classified into two groups based on resection margin status: negative resection margin (group A, n=66) and microscopically positive resection margin (group B, n=22). Median follow-up duration of living patients was 68 months (range, 18 to 115 months). Median total radiation dose of group A and group B was 51.5 Gy (range, 45 to 69 Gy) and 52.1 Gy (range, 45 to 64 Gy), respectively. RESULTS: Median overall survival and disease-free survival were 15 and 10 months, respectively. The five-year overall survival, disease-free survival, and local control rates for group A and group B were 15.9% and 16.4%, 13.5% and 9.1%, and 76.3% and 69.6%, respectively. No statistically significant difference in terms of overall survival, disease-free survival, and local control (p=0.295, p=0.209, and p=0.731, respectively) was observed between group A and group B. Seven patients experienced toxicity of grade 3 or higher. CONCLUSION: A significant portion of patients with margin involvement reached long term survival after addition of postoperative radiotherapy. These results suggest a potential role of postoperative radiotherapy, especially for patients with margin involvement.

Postoperative chemoradiotherapy in high risk locally advanced gastric cancer

PURPOSE: To evaluate treatment outcome of patients with high risk locally advanced gastric cancer after postoperative chemoradiotherapy. MATERIALS AND METHODS: Between May 2003 and May 2012, thirteen patients who underwent postoperative chemoradiotherapy for gastric cancer with resection margin involvement or adjacent structure invasion were retrospectively analyzed. Concurrent chemotherapy was administered in 10 patients. Median dose of radiation was 50.4 Gy (range, 45 to 55.8 Gy). RESULTS: The median follow-up duration for surviving patients was 48 months (range, 5 to 108 months). The 5-year overall survival rate was 42% and the 5-year disease-free survival rate was 28%. Major pattern of failure was peritoneal seeding with 46%. Locoregional recurrence was reported in only one patient. Grade 2 or higher gastrointestinal toxicity occurred in 54% of the patients. However, there was only one patient with higher than grade 3 toxicity. CONCLUSION: Despite reported suggested role of adjuvant radiotherapy with combination chemotherapy in gastric cancer, only very small portion of the patients underwent the treatment. Results from this study show that postoperative chemoradiotherapy provided excellent locoregional control with acceptable and manageable treatment related toxicity in patients with high risk locally advanced gastric cancer. Thus, postoperative chemoradiotherapy may improve treatment result in terms of locoregional control in these high risk patients. However, as these findings are based on small series, validation with larger cohort is suggested.