The role of post-operative radiation therapy in the treatment of malignant tumors of the parotid gland. Imperato JP, Weichselbaum RR, Ervin TJ.  J Surg Oncol 1984 Nov;27(3):163-7 Twenty-nine patients treated with postoperative radiotherapy for malignant tumors of the parotid gland were reviewed at the Joint Center for Radiation Therapy. Most patients were treated between 5,000 and 6,500 rad. All were treated because of microscopic residual disease, extra capsular extension, or tumor close to the facial nerve. The overall results showed one in-field failure, two marginal recurrences, and eight patients failed distantly. Poor prognostic factors included high-grade, extracapsular extension, and nodal involvement. We conclude that patients with malignant tumors of the parotid should be treated with postoperative radiation therapy if any of the bad prognostic signs are present. This may enable the surgeon to spare the facial nerve and obtain local control results equal to or better than more radical surgical procedures.

Laryngoscope 1985 Sep;95(9 Pt 1):1059-63

High-grade malignancies of the parotid gland: effective use of planned combined surgery and irradiation.

Matsuba HM, Thawley SE, Devineni VR, Levine LA, Smith PG

The trend toward treatment of parotid gland malignancies with planned combined surgery and postoperative radiation therapy is currently being followed by many centers, although prospective studies confirming the efficacy of this treatment regimen have only recently begun. We have reviewed only our "high-grade" histologic types: adenocarcinomas, malignant mixed tumors, high-grade mucoepidermoid carcinomas, squamous cell carcinomas, and undifferentiated carcinomas. Acinic cell carcinomas, adenoid cystic carcinomas, and low-grade mucoepidermoid carcinomas were excluded from study because of their different biologic behavior. Since 1974, we have employed the approach of surgical extirpation with preservation of the facial nerve when possible for all parotid tumors, combined with planned postoperative radiation therapy (50-70 Gy). We reviewed the 37 cases of "high-grade" parotid gland malignancies and compared the patients treated with the combined modality approach with our historical patients treated initially with surgery alone. Despite an apparent higher stage at presentation, our combined treatment group ultimately had significantly better local control (70% vs. 20%), and an equivalent survival rate at five years. Tumor was present at the margin of resection in 14 (74%) cases treated with combined surgery and irradiation. The facial nerve was preserved in six of these patients with positive margins, and only one of these patients developed a local or regional treatment failure. In conclusion, our data confirms the efficacy of surgical exploration to determine the extent of disease and surgical resection, preserving facial nerve function if possible, followed by postoperative radiation therapy at adequate doses. Control of local-regional disease was much improved by combined modality therapy as opposed to surgical resection alone, despite the prevalence of residual microscopic disease in the resection margins. Facial nerve function is optimally preserved by this approach of conservative surgery combined with postoperative radiation therapy.

Cancer 1993 May 1;71(9):2699-705

Carcinoma of the parotid gland. Analysis of treatment results and patterns of failure after combined surgery and radiation therapy.

Spiro IJ, Wang CC, Montgomery WW

Department of Radiation Oncology, Massachusetts General Hospital Cancer Center, Boston.

BACKGROUND. The authors retrospectively studied 62 patients with malignant parotid tumors, treated by combined surgery and radiation therapy between 1975 and 1989. No patients were lost to follow-up, and all living patients were interviewed. The median follow-up time was 66 months. RESULTS. Among the 62 patients, there were five isolated local failures. Distant failure was observed in 11 patients. Neck failure was uncommon except in patients with advanced neck disease on presentation. The actuarial 5-year and 10-year local control rates were 95% and 84%, respectively. The corresponding actuarial disease-free survival (DFS) rates were 77% and 65%, respectively. Patients with larger tumors, recurrent disease, or involvement of the facial nerve tended to have lower DFS rates. No statistically significant differences were observed for patients treated with once-daily versus twice-daily radiation therapy fractionation schemes. CONCLUSIONS. Treatment was well tolerated, and severe treatment sequelae were uncommon. In summary, surgery in combination with radiation therapy is highly efficacious in controlling malignant tumors of the parotid gland.

Clin Oncol (R Coll Radiol) 1995;7(1):16-20

An analysis of radiotherapy in the management of 104 patients with parotid carcinoma.

Sykes AJ, Logue JP, Slevin NJ, Gupta NK

Christie Hospital, Manchester, UK.

A retrospective analysis was made of 104 patients with parotid carcinoma treated with radical radiotherapy between 1977 and 1986. Eighty-seven patients received postoperative radiotherapy and 17 had radiotherapy alone. The 5- and 10-year survival figures, corrected for intercurrent deaths, were 60% and 49% respectively, with primary control rates of 68% and 58%. Local control was significantly better for patients initially presenting with T1/T2 disease, but local relapse still occurred in 23% of these patients. Of 13 patients with acinic cell tumours, four developed local recurrence and a further two had metastatic disease. These patterns of relapse suggest that patients with parotid carcinoma should receive postoperative radiotherapy irrespective of disease stage or histological type.

Ann Surg Oncol 1994 Nov;1(6):468-72

Radiotherapy for parotid cancer.

Toonkel LM, Guha S, Foster P, Dembrow V

Department of Radiation Oncology, Mount Sinai Comprehensive Cancer Center, Miami Beach, Florida 33140.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.