title: Would larger radiation fields lead to a faster onset of pain relief in the palliation of bone metastases?
abstract: OBJECTIVE
  Hemibody irradiation has been shown to relieve bony metastatic pain within 24-48 hours of treatment, whereas for local external beam radiation, onset of pain relief is 1-4 weeks after radiation. The primary objective of this study is to examine whether there is a relationship between the areas of radiation treatment and onset of pain relief.
  
  
  METHODS
  From Jan 1999 to Jan 2002, a total of 653 patients with symptomatic bone metastases were treated with external beam radiation. Pain scores and analgesic consumption were recorded at baseline and Weeks 1, 2, 4, 8, and 12. The areas of radiation treatment for all patients were calculated, then correlated with the response and analyzed in various ways. We first compared pain score alone with mean radiation field size. Second, we combined pain score and analgesic consumption. Last, we implemented the International Consensus end points for pain score and analgesic intake.
  
  
  RESULTS
  Assessment of 653 patients showed no significant correlation comparing pain scores alone with radiation field area, with the exception of Week 4 for partial responders. Again, no significant correlation was found when combining both analgesic intake and pain score against radiation field size. Even when implementing the International Consensus end point definitions for radiation response, the only significant correlation between radiation field size and response was observed in Week 2 for partial response.
  
  
  CONCLUSIONS
  There was no statistical significance between mean areas of radiation treatment with the onset of pain relief.
authors.affiliation: Rapid Response Radiotherapy Program, Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada. edward.chow@sunnybrook.ca
authors.forename: Edward
authors.initials: E
authors.lastname: Chow
authors.forename: Leila
authors.initials: L
authors.lastname: Makhani
authors.forename: Shaelyn
authors.initials: S
authors.lastname: Culleton
authors.forename: Nadiya
authors.initials: N
authors.lastname: Makhani
authors.forename: Lori
authors.initials: L
authors.lastname: Davis
authors.forename: Sarah
authors.initials: S
authors.lastname: Campos
authors.forename: Emily
authors.initials: E
authors.lastname: Sinclair
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000700:Analgesics / Q000008:administration & dosage; D000704:Analysis of Variance; D001859:Bone Neoplasms / Q000150:complications / Q000532:radiotherapy* / Q000556:secondary*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy / Q000209:etiology / Q000532:radiotherapy*; D010147:Pain Measurement / Q000379:methods; D010166:Palliative Care / Q000379:methods; D011879:Radiotherapy Dosage; D055815:Young Adult
chemical_list: D000700:Analgesics