Treatment of salivary gland neoplasms with fast neutron radiotherapy.
OBJECTIVE
To evaluate the efficacy of fast neutron radiotherapy for the treatment of salivary gland neoplasms.


METHODS
Retrospective analysis.


METHODS
University of Washington Cancer Center, Neutron Facility, Seattle.


METHODS
The medical records of 279 patients treated with curative intent using fast neutron radiotherapy at the University of Washington Cancer Center were reviewed. Of the 279 patients, 263 had evidence of gross residual disease at the time of treatment (16 had no evidence of gross residual disease), 141 had tumors of a major salivary gland, and 138 had tumors of minor salivary glands. The median follow-up period was 36 months (range, 1-142 months).


METHODS
Local-regional control, cause-specific survival, and freedom from metastasis.


RESULTS
The 6-year actuarial cause-specific survival rate was 67%. Multivariate analysis revealed that low group stage (I-II) disease, minor salivary sites, lack of skull base invasion, and primary disease were associated with a statistically significant improvement in cause-specific survival. The 6-year actuarial local-regional control rate was 59%. Multivariate analysis revealed size 4 cm or smaller, lack of base of skull invasion, prior surgical resection, and no previous radiotherapy to have a statistically significant improved local-regional control. Sixteen patients without evidence of gross residual disease had a 100% 6-year actuarial local-regional control. The 6-year actuarial freedom from metastasis rate was 64%. Factors associated with decreased development of systemic metastases included negative lymph nodes at the time of treatment and lack of base of skull involvement. The 6-year actuarial rate of development of grade 3 or 4 long-term toxicity (using the Radiation Therapy Oncology Group and European Organization for Research on the Treatment of Cancer criteria) was 10%. No patient experienced grade 5 toxic effects.


CONCLUSIONS
Neuron radiotherapy is an effective treatment for patients with salivary gland neoplasms who have gross residual disease and achieves excellent local-regional control in patients without evidence of gross disease.
Douglas
James G
JG
Department of Radiation Oncology, University of Washington Cancer Center, Seattle, USA. drjay@u.washington.edu
Koh
Wui-jin
WJ
Austin-Seymour
Mary
M
Laramore
George E
GE
D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy*; D005214:Fast Neutrons / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D017247:Neutron Capture Therapy / Q000379:methods*; D011829:Radiation Dosage; D012468:Salivary Gland Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D015996:Survival Rate