A Phase I/II Clinical Trial of Preoperative Short-Course Carbon-Ion Radiotherapy for Patients With Squamous Cell Carcinoma of the Esophagus

Background: Carbon-ion radiotherapy (CIR) has been under development. We report the results of a phase I/II clinical trial of preoperative CIR for esophageal squamous cell carcinoma (ESCC). Methods: Thirty-one thoracic ESCC patients were enrolled. They were first treated with CIR. The radiation dose was escalated from the initial dose of 28.8 GyE up to 36.8. Four to 8 weeks after CIR followed by clinical evaluation of the therapy, surgery was performed. Thereafter, a pathological evaluation was made. Results: Acute toxicity was not seen except in one case (3.2%), and there were no late toxicities. Throughout the study period, there were no cases of withdrawal due to the effects of preoperative CIR. Twelve out of 31 (38.7%) patients achieved a clinical complete response (CR) and 13 patients (41.9%) achieved a partial response. Twelve out of 31 patients (38.7%) achieved a pathological CR. The overall 1-, 3-, and 5-year survival rates in the stage I cases were 91%, 81%, and 61%, and was 100%, 85%, and 77% for the stage II, and 71%, 43%, and 29% for the stage III cases, respectively. Conclusions: CIR showed strong local tumor control and is highly effective as a neoadjuvant therapy without severe adverse events. J. Surg. Oncol. 2012; 105:750-755. (C) 2011 Wiley Periodicals, Inc.