Parameters to aid clinical decision making and tolerances in quality assurance tests for respiratory gating

Tumor movement during respiration results in significant uncertainties in metrics and tumor dose delivery, particularly in the thorax and abdomen regions. These uncertainties when on the Stereotactic Radiation Therapy (SBRT) modality are related to serious issues such as cell death of important health tissue volumes and the non-treatment of target volume. Large internal margins are needed to ensure the fully cover of the target, but it can't be effective for risk organs that surround the treatment region. Several techniques of respiratory movement management (4D tomography, gating, breath holding, etc.) can be applied as a solution to this problem, all with the objective of reducing the treatment margins and still guaranteeing the coverage of the target. Adequate parameters for performing treatments with respiratory movement management devices need to be defined to ensure image quality and delivery accuracy. The present study aims to review these parameters and contribute to the advancement of treatment techniques that assess tumor movements based on the evaluation of 99 samples used in SBRT treatments. (author)