Effect of a urinary catheter on seed position and rectal and bladder doses in CT-based post-implant dosimetry for XXXX brachytherapy.

@entity1 @entity263 @entity737
PURPOSE: To assess the variability in rectal and bladder dosimetric parameters determined according to post-implant computed tomography (CT) images in @entity1 with or without a urethral catheter. MATERIAL AND METHODS: @entity1 with @entity263 who were scheduled to undergo CT after brachytherapy between October 2012 and January 2014 were included. We obtained CT series with and without a urinary catheter in each @entity1 . We compared the rectal and bladder doses in 18 @entity1 on each CT series. RESULTS: The shifts in the seed positions between with and without a catheter in place were 1.3    0.3 mm (mean    standard deviation). The radiation doses to the rectum, as determined on the CT series, with a urethral catheter were higher than those on CT without a catheter (p < 0.001). Radiation doses to the bladder with a catheter were significantly lower than those without a catheter (p = 0.027). CONCLUSIONS: @entity737 ( @entity737 ) with no catheter showed significantly lower rectal doses and higher bladder doses than those of @entity737 with a catheter. We recommend the @entity737 procedure for CT images in @entity1 without a catheter. Use of CT with a catheter is limited to identifying urethral position.
