Abstract

Purpose
When the Calypso reports a large prostate rotation and one does not have the means to make corrections, it is helpful to quantify its dosimetric effects. We have devised a simple scheme to achieve this in Pinnacle TPS. If it is determined that the PTV margin is inadequate, an alternate larger‐margin plan may be adapted for the day.
Methods
A three‐step process using the Pinnacle Image fusion module was formulated to analyze the clinical effect of prostate rotation. The process includes (1) translating the image set such that the rotational axis is about the isocenter, (2) performing 3D rotations of the structures of interest, and (3) restoring the coordinates associated with the plan. The rotated structures are imported and overlayed on the original plan for evaluation. The tool was applied to three prostate cancer patients with relatively large rotations (95 fractions total). Prostate rotations are primarily due to …

Date

2015

Authors

S Narayanan, R Velasco‐Schmitz, K Claeys, P Cho

Journal

Medical Physics

Volume

42

Issue

6Part4

Pages

3228-3229

Publisher

American Association of Physicists in Medicine