|The hard palate is the most common site of minor salivary gland tumors in the oral cavity. Squamous cell carcinomas arising from the hard palate are rare, are usually ulcerative, and invade the underlying bone in the early stage of disease. Most carcinomas are well differentiated with a 15% to 20% incidence of lymph node metastases; the submandibular, upper jugular, and subdigastric nodes are commonly involved. Exceptional early lesions without bony involvement can be treated satisfactorily with radiation therapy alone; surgery is reserved for salvage of irradiation failures. Advanced, deeply ulcerative, infiltrative lesions with bone destruction are better treated by combined radiation therapy and surgery; the resulting bone defect can be corrected by an obturator. Malignant salivary gland tumors are always treated by combined surgery and postoperative radiation therapy. Some inoperable malignant minor salivary gland tumors have been successfully controlled with high-dose irradiation. (see NCI oral cavity cancer, see NCCN guidelines and NCCN dose, read review article here|
Radiation Therapy Management (from Perez Textbook)
Radiation therapy for very early carcinoma of the hard palate is generally directed to treating the primary site. Parallel opposing lateral portals cover the entire palate to deliver doses of approximately 60 Gy in 6 weeks. The primary lesion should be boosted to bring the total dose to 70 Gy in 7 weeks.
|For advanced disease with bony destruction and positive nodes, primary resection is
performed, followed by postoperative radiation therapy of approximately 60 Gy in 6 weeks.
Radiation Therapy Results
Results of radiation therapy for carcinoma of the hard palate are sparse. Scattered case reports suggest that local control can be achieved in approximately one third to one half of the patients treated.Patients with nodal metastases and bony destruction are unlikely to be cured by surgery or radiation therapy alone, and combined radiation therapy and surgery has improved results
see selected abstracts below
Oral Oncol 2001 Sep;37(6):493-7
Carcinoma of the hard palate treated with radiotherapy: a retrospective review of 31 cases.
Yorozu A, Sykes AJ, Slevin NJ
Christie Hospital, Wilmslow Road, M20 4BX, Manchester, UK.
There are few studies reporting the results of radical radiotherapy for carcinoma of the hard palate. We have examined our results of patients treated within a single institution, and assessed survival, local control and morbidity. A retrospective analysis was made on 31 patients with hard palate carcinoma treated with external beam radiotherapy at the Christie Hospital between 1990 and 1997. Twenty-six patients received radiotherapy alone and five were treated for post-operative positive surgical margins. The 5-year actuarial survival rate was 55%. The actuarial 5-year local control rate was 53%, rising up to 69% after salvage surgery. Survival was 48% for squamous cell carcinomas and 63% for salivary gland carcinomas, the difference was not significant. The only significant predictor of local control was T-stage, with 80% 5-year local control of T1-2 lesions and 24% control of T3-4 lesions. N-stage was the only significant factor predicting for survival. Radiation necrosis occurred in one patient. Radical radiotherapy for carcinoma of the hard palate is safe and well tolerated. It is an effective treatment for both squamous cell carcinoma and salivary gland carcinoma.
J Otolaryngol 1993 Apr;22(2):118-20
Carcinoma of the hard palate.
Kovalic JJ, Simpson JR
Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, Missouri.
Thirteen patients with primary carcinoma of the hard palate were seen over an 18-year period at the Mallinckrodt Institute of Radiology. Nine patients had adenoid cystic carcinoma, three had squamous cell carcinoma, and one patient had mucoepidermoid carcinoma. The median tumor size was 3 cm3. The patients were clinically staged: T = 1, T2 = 5, T3 = 3, T4 = 4. All were N0M0. Ten patients underwent excision and postoperative irradiation. The remaining three patients were treated definitively with radiotherapy. The 10-year disease-free survival is 77% with an actuarial local control rate of 92%. Patients with negative surgical margins had an improved local control and disease-free survival. Duration of radiation therapy, total tumor dose or histology had no impact on outcome. We conclude that combined surgery and irradiation gives good 10-year local control and disease-free survival rates in patients with this disease.
Laryngoscope 1980 Apr;90(4):576-84
Radiotherapy in the management of primary malignancies of the hard palate.
Chung CK, Johns ME, Cantrell RW, Constable WC
Primary malignancies of the hard palate are rare. Only 66 cases have been seen at the University of Virginia Hospital in the 43 years from 1932 through March 1975. There was 32 squamous cell carcinomas, 25 salivary gland tumors and 9 nonepithelial malignancies. The nonepithelial malignancies were a diverse group and are not considered further. The results of treatment for the squamous cell carcinoma group and salivary gland tumors have been analyzed by stage and mode of therapy. Although no great improvement in the results of surgery or combined therapy have been observed over the years in the squamous cell carcinoma group, there has been a dramatic improvement in the results of treatment with radiation therapy from the orthovoltage era to the super-voltage era. Primary control with radiation therapy for the squamous cell carcinoma group was 2/5 (40%) in the orthovoltage era and 7/7 (100%) in the supervoltage era. Surgery would appear to be the appropriate treatment for salivary gland tumors with possibly a place for combined therapy. Radiation therapy proved useful in salvaging certain surgical failures. The time of appearance of local recurrence following initial therapy, the incidence of distant metastases and second primary tumors were analyzed and are presented.
Head Neck 1993 May-Jun;15(3):241-4
Radiotherapy for adenoid cystic carcinoma of the palate.
Regine WF, Mendenhall WM, Parsons JT, Stringer SP, Cassisi NJ, Million RR
Department of Radiation Oncology, University of Florida College of Medicine, Gainesville.
This is an analysis of 16 patients with adenoid cystic carcinoma of the palate who were treated with curative intent by radiotherapy alone (9) or surgery and radiotherapy (7). No patient received adjuvant chemotherapy. Follow-up ranged from 3 years to 19 years with 69% of the patients having follow-up of more than 5 years. Two patients in the radiotherapy alone group developed local recurrences, and both have had long-term surgical salvage. No local failures were seen in the combined therapy group. Twelve patients (75%) are alive and disease-free. Two patients died with distant disease, one within each treatment group. One patient in the combined therapy group is alive at 8 years with distant metastases, while one in the radiotherapy alone group died of intercurrent disease at 12 years. No significant complications were seen in either treatment group.
Zhonghua Zhong Liu Za Zhi 1986 Mar;8(2):130-2
[Treatment of cancer of the hard palate--analysis of 93 patients].
From Jun. 1958 to Jun. 1977, 128 patients with cancer of the hard palate were treated in our hospital. Of them, 93 (58 male and 35 female), proved by pathology and followed up more than five years, were analysed. The peak age was between 40 approximately 59 years (comprised 48% of all patients). Sixty-six patients were treated by radiation only and 27, by the non-randomized combination of surgery and radiation. The dose for radiation alone was 7,000-10,000 rad (for the neck 4,000-5,000 rad) and for the combined therapy was 5,000 rad. The five year survival rates of radiation alone and the combined therapy were 24% and 59% (P less than 0.05). The factors influencing prognosis were: 1. Age--patients with ages in the fourth and fifth decades gave the best result (51%). 2. Clinical stage--the five year survival rates in stage I, II, III and IV were 92%, 43%, 37% and 17%, respectively. The results of the combined therapy were better than those of the radiation alone, whatever the stage was. 3. Dose--when the dose for radiation alone exceeded 7,000 rad, the results were better. The combined therapy gave more satisfactory results with the dose 5,000-8,000 rad. The final outcome was not influenced by sex and pathological classification. Of 72 patients who died, 55 were treated by radiation alone (64% of patients died of local uncontrol), and 17 by the combined therapy, (died of hematogenous spread 47% and local recurrence 41%).