1. Prospective Phase I/II Trial of Carbon Ion Radiotherapy for Locally Advanced Non-small-cell Lung Cancer (NSCLC) Abstract title: CIRT for Locally Advanced NSCLC W. Takahashi* 1,2, N. Yamamoto 2, M. Nakajima 2, A. Sakumi 1, H. Yamashita 1, K. Nakagawa 1, H. Tsuji 2, T. Kamada 2 1.Research Center of Charged Particle Therapy, National Institute of Radiological Sciences 2.Department of Radiology, The University of Tokyo Hospital Session title: Lung 2 - Locally Advanced Disease and Imaging Date/Time: 2014-09-17 10:45 Location: Room D-2 Monitor number: 8

2. CIRT for locally advanced NSCLC Background/Purpose Although concurrent chemoradiotherapy (CCRT) has become the standard approach for unresectable LA-NSCLC, most patients are not candidates for this treatment due to comorbidities. To assess outcomes and the toxicity of CIRT for medically inoperable/unresectable LA-NSCLC, a single-institution Phase I/II trial was conducted. M&M Clinical stage IIA to IIIB (UICC 6 th ed) LA-NSCLC patients were enrolled. Phase I (dose escalation): 68, 72, 76 GyE (16 fractions/4 weeks) ⇨ Phase II: the recommended dose based on the Phase I study Respiratory-gated CIRT was delivered using 3 or 4 coplanar beam angles.

3. CIRT for locally advanced NSCLC Results Of the 36 patients treated in Phase I, two grade 3 adverse events (radiation pneumonitis and tracheoesophageal fistula) were observed in the 76 GyE group. Accordingly, for Phase II, the next consecutive 26 patients were treated with 72 GyE, with no grade 3 to 5 toxicities resulting. For the entire cohort, the 3-year overall survival (OS), local control rate (LCR), disease-free survival (DFS), and cause-specific survival (CSS) were 43.0%, 93.1%, 28.9%, and 66.6%, respectively. The most frequent pattern of initial disease progression was distant metastases alone (18 patients), followed by regional lymph node and distant metastases (5 patients). We observed 3 local recurrences. As expected, N2 metastases were found to be significantly associated with poor prognosis (23% 3-year overall survival, P =.03).

4. Take home points The management of inoperable LA-NSCLC patients who are not candidates for CCRT remains one of the most challenging issues in oncology. As a new management option for such LA-NSCLC patients, our standard CIRT regimen (72GyE/16fr) has the potential to improve survival. We were able to achieve, with manageable toxicity, a 3y-LCR and 3y- OS of 93.1% and 43.0%, respectively.