Clinical implementation of a knowledge based planning tool for prostate VMAT.

Background: A knowledge based planning tool has been developed and implemented for prostate VMAT radiotherapy plans providing a target average rectum dose value based on previously achievable values for similar rectum/PTV overlap. The purpose of this planning tool is to highlight sub-optimal clinical plans and to improve plan quality and consistency.

Methods: A historical cohort of 97 VMAT prostate plans was interrogated using a RayStation script and used to develop a local model for predicting optimum average rectum dose based on individual anatomy.

IGRT/ART phantom with programmable independent rib cage and tumor motion.

Purpose: This paper describes the design and experimental evaluation of the Methods and Advanced Equipment for Simulation and Treatment in Radiation Oncology (MAESTRO) thorax phantom, a new anthropomorphic moving ribcage combined with a 3D tumor positioning system to move target inserts within static lungs.

Methods: The new rib cage design is described and its motion is evaluated using Vicon Nexus, a commercial 3D motion tracking system. CT studies at inhale and exhale position are used to study the effect of rib motion and tissue equivalence.

A pre-clinical assessment of an atlas-based automatic segmentation tool for the head and neck.

Background And Purpose: Accurate conformal radiotherapy treatment requires manual delineation of target volumes and organs at risk (OAR) that is both time-consuming and subject to large inter-user variability. One solution is atlas-based automatic segmentation (ABAS) where a priori information is used to delineate various organs of interest. The aim of the present study is to establish the accuracy of one such tool for the head and neck (H&N) using two different evaluation methods.

Evaluation of margining algorithms in commercial treatment planning systems.

Introduction: During commissioning of the Pinnacle (Philips) treatment planning system (TPS) the margining algorithm was investigated and was found to produce larger PTVs than Plato (Nucletron) for identical GTVs. Subsequent comparison of PTV volumes resulting from the QA outlining exercise for the CHHIP (Conventional or Hypofractionated High Dose IMRT for Prostate Ca.) trial confirmed that there were differences in TPS's margining algorithms.

Bridges to life: evaluation of an in-prison restorative justice intervention.

Restorative justice initiatives have been identified as primarily, if not exclusively, useful as a "front-end" diversionary option reserved for non violent property crimes and minor assaults. In-prison restorative justice programs are rare and have not been examined for their impact on recidivism. Bridges to Life (BTL) is a voluntary, manualized, ecumenical faith-based restorative justice program offered to incarcerated offenders who are within nine months of their release.

Tolerance levels for quality assurance of electron density values generated from CT in radiotherapy treatment planning.

Methods are described which relate the uncertainty in relative electron density derived from CT numbers to the uncertainty in treatment plan calculation for both photon and electron beams. These relationships are used to generate tolerance levels for electron density quality assurance measurements. These tolerance levels are dependent on treatment beam energy and tissue thickness, and are generally broader than current recommendations.