Results of carbon ion radiotherapy for head and neck cancer.

PURPOSE To evaluate the efficacy of carbon ion radiotherapy for head-and-neck cancer in a phase II clinical trial. MATERIALS AND METHODS Between April 1997 and February 2006, 236 patients with locally advanced, histologically proven, and new or recurrent cancer of the head and neck were treated with carbon ions. The treatment dose was 64.0 GyE/16 fractions/4 weeks (or 57.6 GyE/16 fractions/4 weeks when the wide-range skin was included in the target volume). RESULTS There were grade 3 acute skin reactions in 6% and grade 3 acute mucosal reactions in 10% with no acute reactions worse than grade 3, and grade 2 late skin reactions in 3% and grade 2 late mucosal reactions in 2% with no late reactions worse than grade 2. The 5-year local control rate, by histological type, was 75% for the 85 patients with malignant melanoma, 73% for the 69 with adenoid cystic carcinoma, 73% for the 27 with adenocarcinoma, 61% for the 13 with papillary adenocarcinoma, 61% for the 12 with squamous cell carcinoma and 24% for the 14 with sarcomas. The 5-year over-all survival rate was 68% for adenoid cystic carcinoma, 56% for adenocarcinoma and 35% for malignant melanoma. CONCLUSIONS Carbon ion radiotherapy for head and neck cancer showed the therapeutic effectiveness for malignant melanoma and adenoid cystic carcinoma without severe morbidity of the normal tissues.