A feasibility study of accelerated fractionation in radiotherapy of carcinoma of the urinary bladder.
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).
Moonen
L
L
Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam.
van der Voet
H
H
Horenblas
S
S
Bartelink
H
H
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*