Current status and perspective of heavy ion beam therapy for patients with pelvic recurrence after primarily resected rectal cancer

Purpose: To evaluate the tolerance for and effectiveness of carbon ion radiotherapy in patients with locally recurrent rectal cancer. Patients and Methods: We conducted a phase I / II dose escalation study of carbon ion radiotherapy. One hundred twelve patients with 117 sites of locally recurrent cancer receiving carbon ion radiotherapy were analyzed. Results: None of 112 patients experienced National Cancer Institute-Common Toxicity Criteria grade 3 to 5 acute reactions. The local control rate in patients treated with 67.2 GyE, 70.4 GyE and 73.6 GyE in the present study was 70%, 89% and 97% at 5 years, respectively. The overall survival rates in patients treated with 73.6 GyE were 72% at 3 years and 40% at 5 years. Conclusion: Carbon ion radiotherapy seems to be a safe and effective modality in the management of locally recurrent rectal cancer, providing good local control and offering a survival advantage without unacceptable morbidity.