title: A feasibility study of accelerated fractionation in radiotherapy of carcinoma of the urinary bladder.
abstract: OBJECTIVE
  To establish the shortest possible overall treatment time, with respect to acute and late toxicity, in which a radiation dose of 66 Gy in 2 Gy/fraction can be administered to the urinary bladder.
  
  
  METHODS
  In a stepwise fashion the overall treatment time of our routinely used conventional treatment schedule (66 Gy in 2 Gy/fraction in 6.5 weeks) was reduced to 5 weeks (Step 1) and then 4 weeks (Step 2). Shortening of the overall treatment time was obtained by giving two daily fractions during the last part of the treatment. The interfraction interval was a minimum of 6 h. Toxicity was scored according to a modified scheme of the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer. Fifteen patients received the 5-week schedule and 25 patients received the 4-week schedule.
  
  
  RESULTS
  Note that feasibility was very good for the 5-week schedule. No Grade > or = 3 acute bowel or bladder toxicity was seen in these patients. Severe late complications did not occur. In the 4-week schedule, acute bladder toxicity was unaffected but acute bowel toxicity was considerably increased. Of the 25 patients, 16 suffered from Grade 3 toxicity, 3 from Grade 4, and 1 from Grade 5 toxicity. Actuarial analysis at 3 years showed a 31% incidence of Grade 4 late bladder complications.
  
  
  CONCLUSIONS
  It is concluded that the 5-week schedule is well tolerated. In contrast, the 4-week schedule shows unacceptable acute bowel toxicity and an increased incidence of late bladder complications (p = 0.043).
authors.affiliation: Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam.
authors.forename: L
authors.initials: L
authors.lastname: Moonen
authors.forename: H
authors.initials: H
authors.lastname: van der Voet
authors.forename: S
authors.initials: S
authors.lastname: Horenblas
authors.forename: H
authors.initials: H
authors.lastname: Bartelink
mesh_terms: D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000532:radiotherapy*; D005240:Feasibility Studies; D006801:Humans; D007422:Intestines / Q000528:radiation effects*; D008875:Middle Aged; D011832:Radiation Injuries / Q000473:pathology*; D011879:Radiotherapy Dosage; D013997:Time Factors; D016896:Treatment Outcome; D001743:Urinary Bladder / Q000528:radiation effects*; D001749:Urinary Bladder Neoplasms / Q000532:radiotherapy*