Modeling positioning uncertainties of prostate cancer external beam radiation therapy using pre-treatment data.

ABSTRACT:

Purpose

To investigate the influence of treatment plan data and image guidance (IG) on positioning uncertainty during prostate cancer (PCa) radiotherapy (RT).

Methods

Body mass index (BMI), planning target volume (PTV), bladder volume (BV), and rectal cross section area (RCS) were collected for 267 consecutive PCa patients undergoing daily IGRT. Radiographic isocenter corrections to intra-prostatic fiducials for 12,490 treatment fractions were used to derive random (RE) and systematic (SE) inter-fraction uncertainties for the cardinal axes. These data were used to simulate RE and SE for weekly IG and Action Level (AL)-IG treatment protocols.

Results

SE and RE were 2-5 and 3-4mm in the cardinal axes, respectively, during simulation of no IG. Without IG, positive correl

SUBMITTER: Munck af Rosenschold P 

PROVIDER: S-EPMC4822486 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature