Evaluation of late morbidity in patients with carcinoma of the uterine cervix following a dose rate change.
BACKGROUND
A retrospective analysis of late complications for patients with cervical cancer treated with two different brachytherapy schedules in one institute, using the French-Italian glossary.


METHODS
From 1979 until 1986, a total of 77 patients were treated with external radiation followed by two intracavitary applications with the Gynatron Cs-137 afterloading (dose rate 0.54 Gy/h). After 1986, 66 patients received intracavitary applications with Selectron-LDR (dose rate 1.07 Gy/h). Because of the expected increase in complications with increasing dose rate, the dose per application was reduced from 25 Gy to 20 Gy.


RESULTS
49/77 late gastrointestinal and urinary complications were scored in the Gynatron group and 46/68 in the Selectron group. Actuarial estimates at 5 years showed 42% and 54.1% late gastrointestinal complications and 16.9% and 24.1% for late urinary complications in the patients treated with, respectively, the Gynatron and Selectron.


CONCLUSIONS
Despite the dose reduction, there remains a clear dose rate influence on the late morbidity. Correction for this influence is essential.
Rodrigus
P
P
Department of Radiotherapy, Dr. Bernard Verbeeten Instituut, Tilburg, The Netherlands.
De Winter
K
K
Venselaar
J L
JL
Leers
W H
WH
D001918:Brachytherapy / Q000009:adverse effects; D002277:Carcinoma / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D007410:Intestinal Diseases / Q000209:etiology; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology*; D012189:Retrospective Studies; D001745:Urinary Bladder Diseases / Q000209:etiology; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*