Pi meson radiotherapy for advanced head and neck neoplasms: Preliminary results

Under the auspices of the University of New Mexico Cancer Research and Treatment Center, trials are under way at the Los Alamos Meson Physics Facility to evaluate the effects of pi meson irradiation on locally advanced human tumors. This paper summarizes the preliminary results in patients with locally advanced head and neck tumors treated under Phase I and Phase II studies. A total of 26 patients were treated between June 1977 and May 1979 with a minimum follow‐up of 9 months and a maximum follow‐up of 33 months. Sites of disease included the oropharynx in 10 cases (base of tongue in 7, tonsil in 2, and pharyngoepiglottic fold in 1), the supraglottic larynx in 4, the nasopharynx in 5, the oral cavity in 4, the hypopharynx in 2, and the sublingual salivary gland in 1. Twelve of the 26 patients are alive, and 10 survive with no evidence of disease. Doses employed ranged from a minimum of 1,000 peak pion rad in 7 fractions over 9 days to a maximum of 5,400 peak pion rad in 51 fractions over 89 days. The minimum dose employed for any patients treated with peak pions alone was 3,000 rad. These data are analyzed according to dose, site, histology, tumor response, local control, and survival. Results from these cases form the basis of the Phase III randomized trials for advanced squamous‐cell carcinomas of the head and neck, which are currently in progress.