title: Determining the incidence of pain flare following palliative radiotherapy for symptomatic bone metastases: results from three canadian cancer centers.
abstract: OBJECTIVE
  To determine the incidence of pain flare following radiotherapy (RT) for painful bone metastases.
  
  
  METHODS
  Patients with bone metastases treated with RT were eligible. Worst pain scores and analgesic consumption were collected before, daily during, and for 10 days after treatment. Pain flare was defined as a 2-point increase in the worst pain score (0-10) compared to baseline with no decrease in analgesic intake, or a 25% increase in analgesic intake with no decrease in worst pain score. Pain flare was distinguished from progression of pain by requiring the worst pain score and analgesic intake return to baseline levels after the increase/flare (within the 10-day follow-up period).
  
  
  RESULTS
  A total of 111 patients from three cancer centers were evaluable. There were 50 male and 61 female patients with a median age of 62 years (range, 40-89 years). The primary cancers were mainly breast, lung, and prostate. Most patients received a single 8 Gy (64%) or 20 Gy in five fractions (25%). The overall pain flare incidence was 44/111 (40%) during RT and within 10 days following the completion of RT. Patients treated with a single 8 Gy reported a pain flare incidence of 39% (27/70) and, with multiple fractions, 41% (17/41).
  
  
  CONCLUSIONS
  More than one third of the enrolled patients experienced a pain flare. Identifying at-risk individuals and managing potential pain flares is crucial to achieve an optimal level of care.
authors.affiliation: Department of Radiation Oncology, Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Amanda
authors.initials: A
authors.lastname: Hird
authors.forename: Edward
authors.initials: E
authors.lastname: Chow
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.forename: Rebecca
authors.initials: R
authors.lastname: Wong
authors.forename: Jackson
authors.initials: J
authors.lastname: Wu
authors.forename: Emily
authors.initials: E
authors.lastname: Sinclair
authors.forename: Cyril
authors.initials: C
authors.lastname: Danjoux
authors.forename: May
authors.initials: M
authors.lastname: Tsao
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barnes
authors.forename: Andrew
authors.initials: A
authors.lastname: Loblaw
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta; D000700:Analgesics / Q000627:therapeutic use*; D001847:Bone Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D001859:Bone Neoplasms / Q000532:radiotherapy* / Q000556:secondary; D001943:Breast Neoplasms / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009864:Ontario; D010146:Pain / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D010147:Pain Measurement; D011471:Prostatic Neoplasms / Q000473:pathology; D011879:Radiotherapy Dosage
chemical_list: D000700:Analgesics