PURPOSE: To study the effects on gastrointestinal and urological acute morbidity, a randomized @entity137 study, comparing conventional and three-dimensional conformal radiotherapy (3DCRT) for @entity263 was performed. To reveal possible volume effects, related to the observed @entity137 , dose-volume histograms (DVHs) were used. METHODS AND MATERIALS: From June 1994 to March 1996, 266 @entity1 with @entity263 , stage T1-4N0M0 were enrolled in the study. All @entity1 were treated to a dose of 66 Gy (ICRU), using the same planning procedure, treatment technique, linear accelerator, and portal imaging procedure. However, @entity1 in the conventional treatment arm were treated with rectangular, open fields, whereas conformal radiotherapy was performed with conformally shaped fields using a multileaf collimator. All treatment plans were made with a 3D planning system. The planning target volume ( @entity343 ) was defined to be the gross target volume (GTV) + 15 mm. Acute @entity137 was evaluated using the EORTC/RTOG morbidity scoring system. RESULTS: @entity1 and @entity5 characteristics were equally distributed between both study groups. The maximum @entity137 was 57% grade 1 and 26% grade 2 gastrointestinal @entity137 ; 47% grade 1, 17% grade 2, and 2% grade > 2 urological @entity137 . Comparing both study arms, a @entity344 was observed (32% and 19% grade 2 @entity137 for conformal and conventional radiotherapy, respectively; p = 0.02). Further analysis revealed a marked reduction in medication for anal symptoms: this accounts for a large part of the statistical difference in gastrointestinal @entity137 (18% vs. 14% [p = ns] grade 2 rectum/sigmoid @entity137 and 16% vs. 8% [p < 0.0001] grade 2 anal @entity137 for conventional and conformal radiotherapy, respectively). A strong correlation between exposure of the anus and anal @entity137 was found, which explained the difference in anal @entity137 between both study arms. No difference in urological @entity137 between both treatment arms was found, despite a relatively large difference in bladder DVHs. CONCLUSIONS: The reduction in gastrointestinal morbidity was mainly accounted for by reduced @entity137 for anal symptoms using 3DCRT. The study did not show a statistically significant reduction in acute rectum/sigmoid and bladder @entity137 .

Acute morbidity reduction using 3DCRT for XXXX : a randomized study.

@entity1 :: ('9606', 'Species') :: ['patients', 'Patient'] @entity137 :: ('MESH:D064420', 'Disease') :: ['toxicity'] @entity263 :: ('MESH:D011471', 'Disease') :: ['prostate carcinoma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity343 :: ('187978', 'Species') :: ['PTV'] @entity344 :: ('MESH:D005767', 'Disease') :: ['reduction in gastrointestinal toxicity']
@entity263 :: (MESH:D011471,Disease) :: ['prostate carcinoma']
