Increasing treatment accuracy for cervical cancer patients using correlations between bladder-filling change and cervix-uterus displacements: proof of principle.

Purpose: To investigate application of pre-treatment established correlations between bladder-filling changes and cervix-uterus displacements in adaptive therapy.

Materials And Methods: Thirteen cervical cancer patients participated in this prospective study. Pre-treatment, and after delivery of 40 Gy, a full bladder CT-scan was acquired, followed by voiding the bladder and acquisition of 4 other 3D scans in a 1h period with a naturally filling bladder (variable bladder filling CT-scans, VBF-scans).