title: Single fraction radiotherapy is efficacious: a further analysis of the Dutch Bone Metastasis Study controlling for the influence of retreatment.
abstract: OBJECTIVE
  The Dutch Bone Metastasis Study on the effect on painful bone metastases of 8 Gy single fraction (SF) vs. 24 Gy in multiple fractions (MF) showed 24% retreatment after SF vs. 6% after MF (p < 0.001). The purpose of the present study was to evaluate factors influencing retreatment and its effect on response.
  
  
  METHODS
  The database on all randomized patients was reanalyzed with separately calculated responses to initial treatment and retreatment.
  
  
  RESULTS
  Response to initial treatment was 71% after SF vs. 73% after MF (p = 0.84). Retreatment raised response to 75% for SF; MF remained unaltered (p = 0.54). The response status after initial treatment did not predict occurrence of retreatment: 35% SF vs. 8% MF nonresponders and 22% SF vs. 10% MF patients with progressive pain were retreated. Logistic regression analyses showed the randomization arm and the pain score before retreatment to significantly predict retreatment (p < 0.001). Retreatment for nonresponders was successful in 66% SF vs. 33% MF patients (p = 0.13). Retreatment for progression was successful in 70% SF vs. 57% MF patients (p = 0.24).
  
  
  CONCLUSIONS
  With or without the effect of retreatment, SF and MF radiotherapy provided equal palliation for painful bone metastases. Irrespective of response to initial treatment, physicians were more willing to retreat after a single fraction. Overall, retreatment was effective in 63% of retreated patients.
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Center, Leiden, The Netherlands. y.m.linden@skf-rif.nl
authors.forename: Yvette M
authors.initials: YM
authors.lastname: van der Linden
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Lok
authors.forename: Elsbeth
authors.initials: E
authors.lastname: Steenland
authors.forename: Hendrik
authors.initials: H
authors.lastname: Martijn
authors.forename: Hans
authors.initials: H
authors.lastname: van Houwelingen
authors.forename: Corrie A M
authors.initials: CA
authors.lastname: Marijnen
authors.forename: Jan Willem H
authors.initials: JW
authors.lastname: Leer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000700:Analgesics / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010146:Pain / Q000188:drug therapy / Q000209:etiology / Q000532:radiotherapy*; D010147:Pain Measurement; D016016:Proportional Hazards Models; D011879:Radiotherapy Dosage; D019233:Retreatment; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000700:Analgesics