Intra-fraction displacement of the prostate bed during post-prostatectomy radiotherapy.

ABSTRACT:

Background

To measure intra-fraction displacement (IFD) in post-prostatectomy patients treated with anisotropic margins and daily soft tissue matching.

Methods

Pre-treatment cone beam computed tomography (CBCT) scans were acquired daily and post-treatment CBCTs for the first week then weekly on 46 patients. The displacement between the scans was calculated retrospectively to measure IFD of the prostate bed (PB). The marginal miss (MM) rate, and the effect of time between imaging was assessed.

Results

A total of 392 post-treatment CBCT's were reviewed from 46 patients. The absolute mean (95% CI) IFD was 1.5 mm (1.3-1.7 mm) in the AP direction, 1.0 mm (0.9-1.2 mm) SI, 0.8 mm (0.7-0.9 mm) LR, and 2.4 mm (2.2-2.5 mm) 3D displacement. IFD ≥  ± 3 mm and ≥  ± 5 mm was 24.7%

SUBMITTER: Bell LJ 

PROVIDER: S-EPMC7821719 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature