Phase I study of stereotactic body radiation therapy for peripheral T2N0M0 non-small cell lung cancer with PTV < 100 cc using a continual reassessment method (JCOG0702)

Abstract

Key Words: phase I study, continual reassessment method, non-small cell lung cancer (NSCLC), stereotactic body radiotherapy, SBRT. Short running title: Previous presentationThis work was presented at the 55th Annual Meeting of the American Society for Radiation Oncology, September 22 -25, 2013 in Atlanta, GA. / 28Abstract Purpose: To estimate the maximum tolerated dose (MTD) and to determine the recommended dose (RD) of stereotactic body radiation therapy (SBRT) for peripheral T2N0M0 non-small cell carcinoma (NSCLC) with target volume (PTV) < 100 cc. 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 MTD. Dose limiting toxicity (DLT) was grade 3 radiation pneumonitis (RP) within 180 days after the start of SBRT, grade 2 RP was used as a surrogate DLT. The RD was equal to the MTD. The dose was prescribed at D 95 of the PTV.Results: Fifteen patients were accrued. Only 1 experienced grade 2 RP at 60 Gy in 4fractions. It was difficult to fulfill the dose constraints at 60 Gy in 4 fractions, and the maximum dose level assigned by CRM was changed to 55 Gy in 4 fractions. The lower limit of 95% of the credible interval exceeded the adjacent level, and the RD was determined as 55 Gy in 4 fractions. Conclusions:The RD of SBRT for peripheral T2N0M0 NSCLC with PTV < 100 cc was determined to be 55 Gy in 4 fractions. / 28

Phase I study of stereotactic body radiation therapy for peripheral T2N0M0 non-small cell lung cancer (JCOG0702): Results for the group with PTV ⩾ 100 cc

“…We previously reported the results for patients with PTV < 100cc, and the RD was 55 Gy (D 95 ) for these patients with PTV < 100 cc [9]. One of the reasons for the lower RD in this report may be the differences in the irradiated lung volume.…”

“…The eligibility and exclusion criteria, the radiotherapy methods and the study design for the group with PTV ≥ 100 cc are the same as those previously reported for the group with PTV < 100cc [9].…”

“…The fraction number was fixed at 4. The dose constraints of the OARs are as same as in the previous report [9].…”

A randomized Phase III trial of comparing two dose-fractionations stereotactic body radiotherapy (SBRT) for medically inoperable Stage IA non-small cell lung cancer or small lung lesions clinically diagnosed as primary lung cancer: Japan Clinical Oncology Group Study JCOG1408 (J-SBRT trial)

“…In order to achieve better local control, we chose to administer 55 Gy in four fractions prescribed at the dose covering 95% of the volume (D 95% ) of the planning target volume (PTV) as the dose and fraction schedule. This was determined to be the recommended dose for peripheral c-Stage IB NSCLC with PTV < 100 cc in a Phase I study of SBRT known as JCOG0702 (19). We also confirmed through simulation that further dose escalation would be difficult for c-Stage IA disease when considering the dose constraints of organs at risks.…”

A phase I/II study on stereotactic body radiotherapy with real-time tumor tracking using CyberKnife based on the Monte Carlo algorithm for lung tumors

“…On the other hand, stereotactic body radiotherapy (SBRT) is spreading worldwide as a new treatment modality for stage I NSCLC and oligometastasis [1][2][3]. Previous studies on SBRT for lung tumors have shown that dose escalations are desirable for improving local tumor control, considering overestimation of radiation doses by previously used dose calculation algorithms [4][5][6]. More precise dose calculation algorithms such as the Monte Carlo…”