Adenoid cystic carcinoma of the salivary glands. Management of recurrent, advanced, or persistent disease with hyperthermia and radiation therapy.

Adenoid cystic carcinomas (ACC) of the salivary glands are aggressive tumors characterized by multiple late local recurrences and distant metastases. Current therapy includes wide local excision and high-dose postoperative radiation therapy (XRT) (5400 to 7000 cGy). Despite early aggressive treatment, local recurrence remains a major problem with limited safe and effective therapeutic options available. The excellent local responses obtained in four patients (six sites) with ACC of the head and neck treated either with additional low-dose irradiation (2160 to 3420 cGy) in conjunction with two to five hyperthermia (HT) treatments or with full dose XRT and HT as part of the overall treatment plan are reported. All HT treatments were for 45 minutes once steady state conditions were obtained. Monitored intratumoral temperatures for all treatments achieved average maximum (Tmax), average mean (Tave), and average minimum (Tmin) temperatures of 44.2 degrees C, 41.2 degrees C, and 38.9 degrees C, respectively. A complete response was obtained for all six fields with no significant long-term complications. Two patients remain alive and free of local disease at 42 and 63 months of follow-up. Two patients died--one with metastases (with persistent local control) and one with a local recurrence at 9 and 30 months, respectively, after XRT and HT. This is the first report of HT and low-dose XRT in the management of previously irradiated ACC and suggests a potential role for the use of this modality in the treatment of ACC.