Mixed-Beam Photon-Neutron Therapy in Recurrences and Nodal Metastases of Head and Neck Cancer

The therapeutic advantage of fast neutrons in the treatment of advanced low-grade tumors of the salivary glands and nasal cavity, such as adenoidcystic carcinomas, mucoepidermoid tumors, and adenocarcinomas, is well known and confirmed by the literature. Most reports describe local tumor control rates of 67%–85% after therapy with fast neutrons versus 24%–34% after photon therapy [2, 4, 9, 10, 15–17]. In contrast, the effect of fast-neutron therapy in squamous cell carcinoma is discussed controversely, and the results of random­ized studies reach from significant advantages to no benefit at all, in comparison to conventional radiotherapy. From the biological point of view the high repair rate and the high share of hypoxic cells in advanced squamous cell carcinomas indicate the use of fast neutrons.