BACKGROUND: To define rectal dose volume constraints (DVC) to prevent    grade2 late @entity137 (LRT) after intensity modulated radiotherapy (IMRT) for @entity263 ( @entity263 ). MATERIAL AND METHODS: Six hundred thirty-seven @entity263 @entity1 were treated with primary (prostate median dose: 78Gy) or postoperative (prostatic bed median dose: 74Gy (adjuvant)-76Gy (salvage)) IMRTwhile restricting the rectal dose to 76Gy, 72Gy and 74Gy respectively. The impact of @entity1 characteristics and rectal volume parameters on    grade2 LRT was determined. DVC were defined to estimate the 5% and 10% risk of developing    grade2 LRT. RESULTS: The 5-year probability of being free from    grade2 LRT, @entity190 and persisting symptoms is 88.8% (95% CI: 85.8-91.1%), 93.4% (95% CI: 91.0-95.1%) and 94.3% (95% CI: 92.0-95.9%) respectively. There was no correlation with @entity1 characteristics. All volume parameters, except rectal volume receiving    70Gy (R70), were significantly correlated with    grade2 LRT. To avoid 10% and 5% risk of    grade2 LRT following DVC were derived: R40, R50, R60 and R65 <64-35%, 52-22%, 38-14% and 5% respectively. CONCLUSION: Applying existing rectal volume constraints resulted in a 5-year estimated risk of developing late    grade2 LRT of 11.2%. New rectal DVC for primary and postoperative IMRT planning of @entity263 @entity1 are proposed. A prospective evaluation is needed.

Rectal @entity137 after intensity modulated radiotherapy for XXXX : Which rectal dose volume constraints should we use?

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity137 :: ('MESH:D064420', 'Disease') :: ['rectal toxicity'] @entity263 :: ('MESH:D011471', 'Disease') :: ['prostate cancer', 'PC'] @entity190 :: ('MESH:D006473', 'Disease') :: ['non-rectal blood loss']
@entity263 :: (MESH:D011471,Disease) :: ['prostate cancer']
