title: Results of surgery plus postoperative radiotherapy for patients with malignant parotid tumor.
abstract: OBJECTIVE
  The latest version of the World Health Organization (WHO) histologic classification of salivary gland malignancies was published in 2005. To contribute to data accumulation on the basis of this latest version, a retrospective study was performed.
  
  
  METHODS
  Participants comprised 27 patients who underwent postoperative radiotherapy between 2000 and 2013. Two, eight, and 17 patients were allocated to low, intermediate, and high-grade groups, respectively, in accordance with the latest WHO classification. The radiation field included the tumor bed and ipsilateral regional lymph nodes for 25 patients. The radiation dose was 46-60 Gy (median 56 Gy).
  
  
  RESULTS
  Median duration of follow-up was 41 months. Five-year locoregional control was 89 %. Two patients experienced local recurrence and 7 patients developed distant metastases. No patients in the low or intermediate-grade groups developed distant metastases. Overall 3 and 5-year survival for all patients were 81 and 75 %, respectively. Five-year overall survival for patients in the low and intermediate-grade groups was 100 %, compared with 59 % for patients in the high-grade group (p = 0.03).
  
  
  CONCLUSIONS
  Favorable locoregional control was achieved for patients with malignant parotid tumors who underwent surgery plus postoperative radiotherapy. Patients with high-grade tumors frequently experienced distant metastases and prognosis was poor.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan. shogo313@gmail.com.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan. shogo313@gmail.com.
authors.forename: Shogo
authors.initials: S
authors.lastname: Matsuda
authors.affiliation: Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Iguchi
authors.affiliation: Department of Radiology, Izumi Municipal Hospital, 4-10-10, Fuchucho, Izumi, 5940071, Japan.
authors.forename: Takuhito
authors.initials: T
authors.lastname: Tada
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Hosono
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Osawa
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Yuuko
authors.initials: Y
authors.lastname: Kuwae
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Morimoto
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Okazaki
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Amano
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Miki
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tsutsumi
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Shimatani
authors.affiliation: Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.|Department of Radiation Oncology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, 5458585, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
keywords: Malignant parotid tumor; Postoperative radiotherapy; Surgery; WHO classification