The role of fast neutron radiation therapy in the management of advanced salivary gland malignant Neoplasms

Fifty‐three patients with locally advanced salivary gland malignant neoplasm were treated with fast neutron radiation therapy. All patients received treatment for gross inoperable, residual unresectable, or recurrent disease—clinical situations in which results using photon irradiation were suboptimal. With a median follow‐up of 42 months and a minimum follow‐up of 1 year, locoregional tumor control in the treatment field was achieved in 92% (48 of 52) of patients. An additional eight patients had regional failures outside the treatment field, resulting in an overall locoregional tumor control rate of 77% (40 of 52). The 5‐year actuarial locoregional control rates were 65% overall and 75% in patients with node‐positive disease. Grouping patients according to prior treatment status, actuarial 5‐year locoregional control rates were 92% for patients treated definitively (without a prior surgical procedure), 63% for those treated postoperatively for gross residual disease, and 51% for those treated for recurrent disease after a surgical procedure. The P values associated with these differences were 0.12 and 0.01, respectively. There were no instances of radiation‐induced facial nerve damage. This study suggests that neutron irradiation alone should be the therapy of choice in the treatment of advanced‐stage salivary gland tumors and that surgery should be limited to those patients in whom disease‐free margins can be obtained. The potential morbidity of a debulking surgical procedure before neutron irradiation is not warranted by an improvement in locoregional control over that achievable with neutron therapy alone.