title: Radiotherapy for nonadenoid cystic carcinomas of major salivary glands.
abstract: OBJECTIVE
  To report outcomes in patients treated with postoperative radiotherapy for nonadenoid cystic carcinomas of the major salivary glands.
  
  
  METHODS
  From 1998-2011, 37 patients with nonadenoid cystic carcinomas of the major salivary gland underwent postoperative radiotherapy. The median radiation dose was 60 Gy (range, 45-70 Gy). TNM distribution included T1-2 (n=16, 44%), T3-T4 (n=21, 56%), N0 (n=19, 51%), and N+ (n=18, 49%). Histologies included adenocarcinoma (n=13, 35%), squamous cell carcinoma (n=8, 22%), mucoepidermoid carcinoma (n=8, 22%), and other (n=8, 21%). Median follow-up was 4.7 years for all patients (range, 0.3-14.1 years) and 5.0 years for living patients (range, 1.2-12.2 years).
  
  
  RESULTS
  Five-year local-regional control, overall survival (OS), and cancer-specific survival (CSS) were 97%, 76%, and 84%. On univariate analysis, OS was significantly worse for patients ≥65 years old (p=0.04). CSS was significantly worse for positive perineural invasion (p=0.02), extraparenchymal extension (p=0.04), and in patients who received no chemotherapy (p=0.02). Doses >60 Gy was significantly worse for OS (p=0.003) and CSS (p=0.003), although these patients had higher TNM (>T2, p=0.01) and trended towards a higher rate of extraparenchymal extension (p=0.08). Four patients (11%) developed ≥grade 2 toxicities; 3 patients developed early toxicities and one patient developed late toxicities.
  
  
  CONCLUSIONS
  Radiotherapy for salivary gland tumors provides excellent local-regional control when combined with surgery. Distant metastasis is the predominant pattern of failure, although chemotherapy seemed to improve cancer-specific survival.
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Melody P
authors.initials: MP
authors.lastname: Chung
authors.forename: Chad
authors.initials: C
authors.lastname: Tang
authors.forename: Cato
authors.initials: C
authors.lastname: Chan
authors.forename: Wendy Y
authors.initials: WY
authors.lastname: Hara
authors.forename: Billy W
authors.initials: BW
authors.lastname: Loo
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kaplan
authors.forename: Nancy
authors.initials: N
authors.lastname: Fischbein
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003528:Carcinoma, Adenoid Cystic / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011182:Postoperative Care / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012468:Salivary Gland Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D016896:Treatment Outcome