THE ROLE OF RADIOTHERAPY IN THE MANAGEMENT OF SALIVARY-GLAND CARCINOMAS

A retrospective study was performed on 44 patients with carcinoma originating in the major and minor salivary glands to examine the effects of postoperative radiotherapy on locoregional and distant control and survival. 22 patients were treated by surgery alone and the 22 other patients were treated by a combination of surgery and postoperative irradiation. In the surgery group, local recurrence developed in all 8 patients with evidence of residual disease at the surgical margins, whereas local control was achieved in 7 of 15 patients with positive surgical margins in the combination group and the control rate was related to the amount of residual disease. Neck metastasis, which developed in 13 patients (30 %), was not affected by the status of surgical margins or by the treatment modality. On the other hand, the incidence of distant metastasis seen in 19 patients (43 %) was much higher in patients with positive surgical margins and the development of distant metastasis in these patients was not prevented by postoperative irradiation. The survival rates at 5, 10 and 15 years were 54, 48 and 41 %, respectively, for the irradiated patients, whereas the values for the patients treated by surgery alone were 75, 70 and 70 %, respectively. The results indicate that postoperative irradiation is effective in controlling local recurrence but not neck and distant metastases. Wide excision with sufficient surgical margins followed by postoperative radiotherapy and systemic chemotherapy are essential to obtain a better prognosis.