title: Pain flare is a common adverse event in steroid-naïve patients after spine stereotactic body radiation therapy: a prospective clinical trial.
abstract: OBJECTIVE
  To determine the incidence of pain flare after spine stereotactic body radiation therapy (SBRT) in steroid-naïve patients and identify predictive factors.
  
  
  METHODS
  Forty-one patients were treated with spine SBRT between February 2010 and April 2012. All patients had their pain assessed at baseline, during, and for 10 days after SBRT using the Brief Pain Inventory. All pain medications were recorded daily and narcotics converted to an oral morphine equivalent dose. Pain flare was defined as a 2-point increase in worst pain score as compared with baseline with no decrease in analgesic intake, a 25% increase in analgesic intake as compared with baseline with no decrease in worst pain score, or if corticosteroids were initiated at any point during or after SBRT because of pain.
  
  
  RESULTS
  The median age and Karnofsky performance status were 57.5 years (range, 27-80 years) and 80 (range, 50-100), respectively. Eighteen patients were treated with 20-24 Gy in a single fraction, whereas 23 patients were treated with 24-35 Gy in 2-5 fractions. Pain flare was observed in 68.3% of patients (28 of 41), most commonly on day 1 after SBRT (29%, 8 of 28). Multivariate analysis identified a higher Karnofsky performance status (P=.02) and cervical (P=.049) or lumbar (P=.02) locations as significant predictors of pain flare. In those rescued with dexamethasone, a significant decrease in pain scores over time was subsequently observed (P<.0001).
  
  
  CONCLUSIONS
  Pain flare is a common adverse event after spine SBRT and occurs most commonly the day after treatment completion. Patients should be appropriately consented for this adverse event.
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Chiang
authors.forename: Liang
authors.initials: L
authors.lastname: Zeng
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.forename: Fiona
authors.initials: F
authors.lastname: Lochray
authors.forename: Renee
authors.initials: R
authors.lastname: Korol
authors.forename: Andrew
authors.initials: A
authors.lastname: Loblaw
authors.forename: Edward
authors.initials: E
authors.lastname: Chow
authors.forename: Arjun
authors.initials: A
authors.lastname: Sahgal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000700:Analgesics / Q000008:administration & dosage / Q000627:therapeutic use*; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D017567:Karnofsky Performance Status; D017116:Low Back Pain / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D013125:Spinal Neoplasms / Q000556:secondary / Q000601:surgery*; D013904:Thoracic Vertebrae
chemical_list: D000700:Analgesics; D005938:Glucocorticoids; D003907:Dexamethasone