Results of carbon ion radiotherapy for skin carcinomas in 45 patients

BACKGROUND; Heavy ions represent the best tool for external radiotherapy (RT) of inoperable tumours. Heavy ion RT has been used in the treatment of various tumours, especially for radioresistant tumours mediated by hypoxia, localized near organs at risk. Most of these treatments are concentrated in deep-seated tumours such as those of the brain, head, lung, liver, rectum and urogenital organs, and treatment of skin carcinomas is limited.

To evaluate the outcome and toxicity after carbon ion RT for skin carcinomas at the Heavy Ion Research Facility in Lanzhou, China.

Between November 2006 and March 2009, 45 patients with skin carcinoma [squamous cell carcinoma (SCC) (n = 16), basal cell carcinoma (BCC) (n = 12), malignant melanoma (MM) (n = 7), Bowen disease (n = 8) and Paget disease (n = 2)] were treated with carbon ion RT within a clinical Phase I trial. Patients received total doses of 60-70 GyE for SCC and BCC, 61-75 GyE for MM, 60 GyE for Bowen disease and 42·5 GyE for Paget disease, administered in 6-11 fractions over 6-11 days, with a fraction dose of 7-10 GyE.

The mean follow-up was 24 months, range 12-36 months. The actuarial local control rates at 1 and 3 years were 90·9% and 65·5% for SCC, 91·7% and 80·2% for BCC, 85·7% and 42·9% for MM, 90% and 90% for Bowen and Paget diseases, respectively. The actuarial 1- and 3-year overall survival rates for 45 patients were 88·9% and 86%, respectively. No severe side-effects greater than Common Toxicity Criteria grade 3 have been observed.

The results demonstrated that heavy ion RT offers high local tumour control and progression-free survival rates without significant radiation-induced toxicity for patients with skin carcinomas.