title: Outcomes and prognostic factors for major salivary gland carcinoma following postoperative radiotherapy.
abstract: OBJECTIVE
  To report outcomes of postoperative radiotherapy (PORT) for major salivary gland carcinoma (SGC) and identify patients at high risk of distant metastases (DM).
  
  
  METHODS
  Patients with major SGC treated between 2000-2012 were identified. All patients underwent initial primary resection, with neck dissection (ND) therapeutically (if N+) or electively in high risk N0 patients. PORT was delivered using 3D-CRT or IMRT. Multivariable analysis (MVA) assessed predictors for DM, cause-specific (CSS) and overall survival.
  
  
  RESULTS
  Overall 304 patients were identified: 48% stage III-IVB, 22% lymphovascular invasion (LVI), 50% involved margins and 64% high risk pathology. ND was performed in 154 patients (51%). Adjuvant chemotherapy was used in 10 patients (3%). IMRT was delivered in 171 patients (56%) and 3D-CRT in 133 (44%). With a median follow-up of 82 months, the 5-(10-) year local, regional, distant control, CSS and OS were 96% (96%), 95% (94%), 80% (77%), 83% (82%) and 78% (75%), respectively. DM was the most frequent treatment failure (n=62). On MVA, stage III-IVB and LVI significantly correlated with DM, CSS and OS, while positive margins predicted DM and CSS, and high risk pathology predicted DM. No grade ⩾ 4 RTOG late toxicity was reported; 9 patients had grade 3, including osteoradionecrosis (n=4), neck fibrosis (n=3), trismus (n=1) and dysphagia (n=1).
  
  
  CONCLUSIONS
  Surgery and PORT with 3D-CRT/IMRT produced excellent long-term outcomes. Further research is required for patients with stage III-IVB, LVI, positive margins and high risk pathology to determine the incremental benefit of systemic therapy in management of SGC.
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ali
authors.initials: A
authors.lastname: Hosni
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shao Hui
authors.initials: SH
authors.lastname: Huang
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery/Surgical Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Goldstein
authors.affiliation: Department of Biostatistics, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
authors.forename: Biu
authors.initials: B
authors.lastname: Chan
authors.affiliation: Department of Medical Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Hansen
authors.affiliation: Department of Pathology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ilan
authors.initials: I
authors.lastname: Weinreb
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Scott V
authors.initials: SV
authors.lastname: Bratman
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Meredith
authors.initials: M
authors.lastname: Giuliani
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Hope
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: O'Sullivan
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Waldron
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada. Electronic address: Jolie.Ringash@rmp.uhn.on.ca.
authors.forename: Jolie
authors.initials: J
authors.lastname: Ringash
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011379:Prognosis; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012189:Retrospective Studies; D012468:Salivary Gland Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012469:Salivary Glands / Q000473:pathology; D055815:Young Adult
keywords: Intensity modulated radiotherapy; Metastasis; Prognosis; Salivary gland cancer; Survival