Radiotherapy for parotid cancer

Parotid malignancies represent a heterogeneous group of tumors primarily managed by surgical extirpation. Moderately high recurrence rates are seen after surgery alone, and postoperative radiotherapy has been used for patients with higher risks for local failure.

To assess the role of radiotherapy in the management of patients with malignant tumors of the parotid gland, the records of 68 patients receiving megavoltage therapy at our institution from 1966 to 1989 were reviewed. Patients were placed into three groups for analyses. Group I was composed of 41 patients receiving radiotherapy following total gross removal of parotid cancer by surgical procedures, varying from excisional biopsy through total parotidectomy. Radiation dose for this group ranged from 4,995 to 6,500 cGy. Group II was composed of 10 patients treated with radiotherapy after incisional biopsy or excision with positive margins. These patients received radiation doses of 4,000-9,470 cGy. Group III was composed of 17 patients receiving radiotherapy for a postsurgical local recurrence. Their radiation dose ranged from 4,300 to 8,400 cGy.

Two of the 41 patients from group I developed a local recurrence. Two of these patients also developed distant metastases, one concurrent. Two of 10 group II patients failed locally, whereas three developed distant metastases. Only nine of the 17 patients in group III were controlled locally, and four patients developed distant dissemination.

Total gross excision of parotid cancer, sparing facial nerve if possible and followed by regional radiotherapy, provides excellent rates of local control and survival with modest toxicity. Patients presenting postoperatively with gross residual tumor or recurrence after surgery should be considered for trials of more aggressive treatment with combined chemotherapy or altered fractionation schemes of irradiation.