title: Second re-irradiation: efficacy, dose and toxicity in patients who received three courses of radiotherapy with overlapping fields.
abstract: OBJECTIVE
  To explore the outcome, cumulative dose and toxicity in 23 patients after a third radiation treatment, with a partial or complete overlap of the previous two irradiated regions.
  
  
  METHODS
  The dose summation of the three radiation plans was made by the planning system. For patients treated with cyberknife or brachytherapy dose summation was done by dose point calculations. Efficacy and toxicity was scored by looking at the reduction of tumor, pain and bleeding.
  
  
  RESULTS
  Symptomatic response was observed in 81% and 73% of the patients after, respectively, the third and second radiation. The median cumulative maximum dose to the tumor and its regions was 133Gy(3) (range: 82-496Gy(3)). The median corrected cumulative dose for the rectum, bowel and bladder resulted in 91Gy(3), 73Gy(3) and 79Gy(3), respectively. Grade 3 acute skin toxicity was only seen in the third radiation course.
  
  
  CONCLUSIONS
  The constraints of 100Gy(3) for rectum, 90Gy(3) for bowel and 110Gy(3) for bladder are safe and can be used as guidelines in the decision for re-irradiation. Symptomatic relieve was seen in 81% of the patients with low grade 3 and no grade 4 acute and late toxicity.
authors.affiliation: Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands. h.abusaris@erasmusmc.nl
authors.forename: Huda
authors.initials: H
authors.lastname: Abusaris
authors.forename: Pascal R M
authors.initials: PR
authors.lastname: Storchi
authors.forename: Rene P
authors.initials: RP
authors.lastname: Brandwijk
authors.forename: Joost J
authors.initials: JJ
authors.lastname: Nuyttens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007422:Intestines / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000532:radiotherapy*; D010166:Palliative Care; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D012007:Rectum / Q000528:radiation effects; D019233:Retreatment; D012189:Retrospective Studies; D012867:Skin / Q000528:radiation effects; D015996:Survival Rate; D001743:Urinary Bladder / Q000528:radiation effects