Carbon ion radiotherapy in hypofraction regimen for stage I non-small cell lung cancer

From 1994 to 1999, we conducted a phase I/II clinical trial for stage I non-small cell lung cancer (NSCLC) by using carbon ion beams and demonstrated an optimal dose. In the present study, the total dose was fixed at 72GyE in 9 fractions over 3 weeks and at 52.8GyE for stage IA and at 60GyE for stage 1B in 4 fractions over I week. On this schedule, we conducted a phase II clinical trial for 127 patients with stage I NSCLC from 1999 to 2003. The local control rate for 131primary lesions was 91.5%. The local control rate for T1 and T2 tumors was 96.3% and 84.7%, respectively. There was statistical difference for the different tumor size. The five-year cause-specific survival rate of the patients was 67.7% (IA: 84.8, IB: 43.7), and their overall survival was 45.3% (IA: 53.9, IB: 34.2). No toxicities occurred in the skin and no adverse effects worse than grade III. Carbon beam radiotherapy, which is an excellent new modality in terms of high QOL and ADL, was proven to be a valid alternative to surgery for stage I cancer, especially for elderly and inoperable patients.