Prefraction displacement and intrafraction drift of the prostate due to perineal ultrasound probe pressure.
Minglun LiNina-Sophie HegemannFarkhad ManapovAnne KolbergPatrick Dominik ThumUte GanswindtClaus BelkaHendrik BallhausenPublished in: Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al] (2017)
The pressure applied by a perineal US probe has a quantitatively similar impact on prostate displacement as transabdominal pressure. Shifts are predominantly in the cranial direction (typically 2-4 mm) with some component in the anterior direction (typically <1 mm). Slight probe pressure can improve image quality, but excessive probe pressure can distort the surrounding anatomy and potentially move risk organs closer to the high-dose area.