Carbon Ion Radiotherapy for Locally Recurrent 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. Fifty-five patients with 59 sites of locally recurrent cancer received carbon ion radiotherapy. Twenty-three relapses originated in the presacral region, 16 in the pelvic side walls, 14 in the perineal region and 6 in the colorectal anastomosis. The total dose ranged from 67.2 to 73.6 gray equivalent (GyE) and was administered in 16 fixed fractions over 4 weeks (4.2 to 4.6 GyE/fraction). Results: None of 32 patients treated with the highest total dose of 73.6 GyE experienced National Cancer Institute - Common Toxicity Criteria grade 3 to 5 acute reactions. The overall local control rates were 92% at 1 year and 79% at 3 years of follow-up. Dose escalation was then halted at this level. The median survival time was 38 months (range, 7 to 52 months), and the 1- and 3-year overall survival rates were 91% and 65%, respectively.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.NIRS-MD Anderson Symposium on Clinical Issues for Particle Therap