Postoperative radiotherapy for malignant tumors of the submandibular gland

Purpose: This retrospective study assessed the outcome and patterns of fail ure for patients with malignant submandibular tumors treated with surgery a nd postoperative radiation. Methods and Materials: Between 1965 and 1995, 83 patients aged 11-83 years old received postoperative radiotherapy after resection of submandibular gl and carcinomas. The most common radiation technique was an appositional fie ld to the submandibular gland bed using electrons either alone or mixed wit h photons. Primary tumor bed doses ranged from 50 to 69 Gy (median, 60 Gy). Regional lymph nodes (ipsilateral Levels I-IV) were irradiated in 66 patie nts to a median dose of 50 Gy. Follow-up time ranged from 5 to 321 months ( median, 82 months). Results: Actuarial locoregional control rates were 90%, 88%, and 88% at 2, 5, and 10 years, respectively. The corresponding disease-free survival rate s were 76%, 60%, and 53%, because 27 of 74 patients (36%) who attained loco regional control developed distant metastases. Adenocarcinoma, high-grade h istology, and treatment during the earlier years of the study were associat ed with worse locoregional control and disease-free survival. The median su rvival times for patients with and without locoregional control were 183 mo nths and 19 months, respectively. Actuarial 2-, 5-, and 10-year survival ra tes were 84%, 71%, and 55%, respectively. Late complications occurred in 8 patients (osteoradionecrosis, 5 patients). Conclusions: High-risk cancers of the submandibular gland have a historic c ontrol rate of approximately 50% when treated with surgery alone. In the cu rrent series, locoregional control rates for high-risk patients with subman dibular gland cancers treated with surgery and postoperative radiotherapy w ere excellent, with an actuarial locoregional control rate of 88% at 10 yea rs. (C) 2001 Elsevier Science Inc.