Influence of the initial rectal distension on posterior margins in primary and postoperative radiotherapy for prostate cancer

Analysis of Interfraction Prostate Motion Using Megavoltage Cone Beam Computed Tomography

“…When analyzed individually, a slight posterior trend was seen in 2 patients (8%). Trends toward posterior motion of the prostate and decreasing rectal volume have been seen in previous studies (23)(24)(25)(26) and have been attributed to an increase in rectal emptying caused by acute proctitis as treatment progresses. However, in these previous studies, three-or four-field techniques were used for all or the large majority of patients.…”

Conformal Arc Radiotherapy for Prostate Cancer: Increased Biochemical Failure in Patients With Distended Rectum on the Planning Computed Tomogram Despite Image Guidance by Implanted Markers

“…The gain in FFBF in the high dose arm remained in the low-risk subgroup in the Massachusetts General Hospital trial (227 of 393 patients) but disappeared in the Dutch trial (120 of 664 patients). Several investigative groups have recently pointed at the importance of rectal filling at the time of the planning CT as a possible cause of subsequent geographical miss resulting in increased biochemical failure (5,6,19). However the impact of rectal distention on biochemical control is limited to those patients positioned without a daily online verification protocol (5,6).…”

Seed Displacements after Permanent Brachytherapy for Prostate Cancer in Dependence on the Prostate Level

“…The distance of the prostate to the rectal wall is larger at the base compared to the intraoperative TRUS. Rectal mobility increases with increasing distance from the apex [27,28], so that the rectal wall at the level of the prostate apex should be in a special focus to keep the rectal dose as low as possible. Longer strands seem to shift more easily along the prior needle track inferiorly and posteriorly, while single seeds are more likely to tilt in the prostate tissue.…”