Charged particle radiotherapy of selected tumors in the head and neck

Abstract

For selected tumors in some sites in the head and neck region, charged particles such as protons or helium, carbon, neon and silicon ions provide improved dose distributions, higher tumor doses, and an increased chance of local control and prolonged survival. In tumors with “radioresistant” histologies, slow growth kinetics and/or hypoxic cells, the high-LET component of neon or silicon ions may also offer an added potential for increased effect on tumors. Sixty-seven (67) evaluable patients with tumors in the head and neck region having a histology other than squamous carcinoma received partial or full treatment with charged particles at the University of California Lawrence Berkeley Laboratory. The tumor sites included base of skull or cervical spine, salivary glands, paranasal sinuses, nasopharynx, and miscellaneous sites such as lacrimal gland, soft tissues of the neck, or thyroid. Follow-up ranges from 1–9 years with a mean of 36 months and a median survival (Kaplan-Meier technique) of 50 months. The actuarial local control rate is 60% at 24 months post-treatment. Thirty-one (31) patients with squamous carcinoma of various sites in the head and neck have also been treated using charged particle irradiation; local control was lower (11 of 31 pts) and survival shorter (mean: 9 months) in this group of patients with advanced squamous carcinoma.