Hippocampus avoidance whole brain radiation therapy: A practical IMRT planning and delivery approach to RTOG 0933

International Conference on Medical Physics

August 03-05, 2015 Birmingham, UK

Joe Andreas

Posters-Accepted Abstracts: J Nucl Med Radiat Ther

Abstract :

The goal of this work was to develop a more practical technique to meet the requirements of the RTOG 0933 protocol for sparing the hippocampus while irradiating the whole brain. Whole brain radiation therapy (WBRT) has been linked to decrease in neurocognitive function (NCF) and increase in memory loss leading to lower quality of life for patients. Hippocampus avoidance WBRT (HA-WBRT) may help to mitigate these issues by delaying the decline in NCF. RTOG 0933 is a phase II clinical trial aimed at HA-WBRT for patients with metastatic brain lesions. Published results from this study showed significant benefit in preserving short term memory function for these patients. While the trial allows several methods of treatment, including tomotherapy, volumetric arc therapy and linac-based IMRT, treatment at many cancer centers is limited to linac-based step-and-shoot IMRT. The linac-based method suggested by RTOG involves nine gantry angles on a number of different planes. Our goal was to find a more practical solution for the planning and delivery of HA-WBRT according to the RTOG 0933 protocol. We were able to achieve our goal by developing a technique that requires only seven gantry angles and no couch movements. All of our plans met the protocol requirements and were accepted into the study. The method developed in our center is a practical technique for HA-WBRT. Our process gave reproducible results in the patients we accrued to RTOG 0933 and should allow many more centers to be able to deliver HA-WBRT.