Rikiya Onimaru1, Hiroshi Onishi2, Taro Shibata3, Masahiro Hiraoka4, Satoshi Ishikura5, Katsuyuki Karasawa6, Yukinori Matsuo4, Masaki Kokubo7, Yoshiyuki Shioyama8, Haruo Matsushita9, Yoshinori Ito10, Hiroki Shirato11. 1. Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan. Electronic address: ronimaru@pop.med.hokudai.ac.jp. 2. Department of Radiology, University of Yamanashi Graduate School of Medical Science, Chuo, Japan. 3. JCOG Data Center, Center for Research Administration and Support, National Cancer Center, Tokyo, Japan. 4. Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan. 5. Department of Radiology, Koshigaya Municipal Hospital, Koshigaya, Japan. 6. Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan. 7. Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe, Japan. 8. Department of Clinical Radiology, Kyushu University Graduate School of Medicine, Fukuoka, Japan. 9. Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. 10. Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan. 11. Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Abstract
PURPOSE: A dose escalation study to determine the recommended dose (RD) with stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinomas (NSCLC) was conducted. The results of the group with PTV⩾100cc are reported in this paper. MATERIALS AND METHODS: The continual reassessment method (CRM) was used to determine the dose level that patients should be assigned to and to estimate the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was Grade 3 or higher radiation pneumonitis (RP), and Grade 2 or higher RP was used as a surrogate DLT. The RD was equal to the MTD. The dose was prescribed at D95 of the PTV. RESULTS: Thirteen patients were accrued. More patients should have been enrolled but we decided not to prolong the study period. No patients experienced Grade 3 RP. Two patients experienced Grade 2 RP at 50Gy in 4 fractions. The predicted MTD was 50.2Gy. The posterior probability of the Grade 2 RP frequency over 40% was 5.3% for the dose level of 50Gy. The RD was determined to be 50Gy. CONCLUSIONS: The RD was determined to be 50Gy in 4 fractions in this population.
PURPOSE: A dose escalation study to determine the recommended dose (RD) with stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinomas (NSCLC) was conducted. The results of the group with PTV⩾100cc are reported in this paper. MATERIALS AND METHODS: The continual reassessment method (CRM) was used to determine the dose level that patients should be assigned to and to estimate the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was Grade 3 or higher radiation pneumonitis (RP), and Grade 2 or higher RP was used as a surrogate DLT. The RD was equal to the MTD. The dose was prescribed at D95 of the PTV. RESULTS: Thirteen patients were accrued. More patients should have been enrolled but we decided not to prolong the study period. No patients experienced Grade 3 RP. Two patients experienced Grade 2 RP at 50Gy in 4 fractions. The predicted MTD was 50.2Gy. The posterior probability of the Grade 2 RP frequency over 40% was 5.3% for the dose level of 50Gy. The RD was determined to be 50Gy. CONCLUSIONS: The RD was determined to be 50Gy in 4 fractions in this population.