title: Radiotherapy in well-differentiated thyroid cancer: is it underutilized?
abstract: BACKGROUND
  The usual management of thyroid cancer is surgery and radioactive iodine. The role of external beam radiotherapy (EBRT) in well-differentiated thyroid carcinoma remains controversial. Indications for the use of EBRT, contained within both the American and British Thyroid Association published guidelines, include unresectable or non-iodine avid disease, extra-thyroidal extension or distant metastatic disease.
  
  
  METHODS
  A retrospective review of prospectively collected data from a single Australian institution was conducted, analysing patients referred and treated with EBRT for well-differentiated thyroid carcinoma between November 1992 and July 2013.
  
  
  RESULTS
  Of 36 patients referred, 32 were treated with EBRT. Sixteen patients in total received locoregional treatment (six radical, 10 palliative), of whom 81% (13/16) had gross disease and 88% (14/16) had recurrent disease (eight with multiple recurrences). Additionally, 63% (10/16) had multiple surgical resections and 50% (8/16) had previously received multiple courses of radioactive iodine. Overall, 67% (4/6) of patients treated with radical intent had no locoregional recurrence or progression. Thirteen of the 16 patients who received locoregional EBRT remained asymptomatic from their locoregional disease at the time of last follow-up or death. The most commonly treated distant metastatic disease site was bone, with a total of 45 sites irradiated. Of these patients, 93% and 78% were symptom-free at two and four years, respectively.
  
  
  CONCLUSIONS
  Our study suggests that in a select group of patients with well-differentiated thyroid carcinoma, EBRT treatment appears to provide durable tumour and symptom control.
authors.affiliation: William Buckland Radiotherapy Centre, The Alfred, Prahran, Victoria, Australia.
authors.forename: Kevin
authors.initials: K
authors.lastname: So
authors.affiliation: William Buckland Radiotherapy Centre, The Alfred, Prahran, Victoria, Australia.
authors.forename: Robin E
authors.initials: RE
authors.lastname: Smith
authors.affiliation: William Buckland Radiotherapy Centre, The Alfred, Prahran, Victoria, Australia.|Department of Surgery, Monash University, Melbourne, Victoria, Australia.
authors.forename: Sidney R
authors.initials: SR
authors.lastname: Davis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000401:mortality / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000532:radiotherapy*; D016896:Treatment Outcome; D014739:Victoria / Q000453:epidemiology
keywords: radiotherapy; recurrence; thyroid neoplasms