Onimaru Rikiya, Onishi Hiroshi, Shibata Taro, Hiraoka Masahiro, Ishikura Satoshi, Karasawa Katsuyuki, Matsuo Yukinori, Kokubo Masaki, Shioyama Yoshiyuki, Matsushita Haruo, Ito Yoshinori, Shirato Hiroki
Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Department of Radiology, University of Yamanashi Graduate School of Medical Science, Chuo, Japan.
Radiother Oncol. 2017 Feb;122(2):281-285. doi: 10.1016/j.radonc.2016.11.022. Epub 2016 Dec 16.
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.
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 D of the PTV.
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.
The RD was determined to be 50Gy in 4 fractions in this population.
开展一项剂量递增研究，以确定立体定向体部放射治疗（SBRT）用于外周T2N0M0非小细胞肺癌（NSCLC）的推荐剂量（RD）。本文报告了计划靶体积（PTV）≥100cc组的研究结果。
采用连续重新评估法（CRM）来确定患者应被分配到的剂量水平，并估计最大耐受剂量（MTD）。剂量限制毒性（DLT）为3级或更高等级的放射性肺炎（RP），2级或更高等级的RP用作替代DLT。RD等于MTD。剂量规定为PTV的D。
共纳入13例患者。本应纳入更多患者，但我们决定不延长研究周期。没有患者出现3级RP。2例患者在分4次给予50Gy剂量时出现2级RP。预测的MTD为50.2Gy。对于50Gy的剂量水平，2级RP频率超过40%的后验概率为5.3%。确定RD为50Gy。
该人群的RD确定为分4次给予50Gy。
