A Volume, Motion, and Anatomically Adaptive Approach to Photon and Proton Beam Radiotherapy

Overview

This pilot study will determine changes over time in tumor volume/motion \& patient anatomy, as well as dose distributions to normal organs. The study will inform medical decision-making about need for (and timing of) re-calibration of radiation dosimetry plans. Weekly CT and/or serial MR scans will be employed for those patients receiving 7-8 wks of radiation therapy. The study will enroll 30 patients in each stratum: Non small cell lung cancer (NSCLC), Head \& Neck, gastrointestinal (GI) and Gynecologic tumor.

This is a pilot study to estimate the degree of tumor volume, tumor motion and patient anatomy change during treatment with photon or proton beam radiotherapy. Patients will undergo simulation with an MR scan and/or CT scan per best clinical practices, and 4D imaging will be employed as indicated, at the discretion of the treating radiation oncologist. Photon beam treatment plans and Proton beam treatment plans will be generated from these images. Based on the location of the primary tumor, patients will undergo either up to weekly 3D or 4D CT and/or serial MR scans during treatment. These images will be compared to the initial CT/MR scans used for treatment planning and analyzed for changes in tumor volume and tumor anatomic location. At the end of treatment, the frequent 3D or 4D CT and/or serial MR images will be compared to the initial treatment planning images to quantify the changes in tumor volume and tumor motion during the course of radiation treatment. Each CT and/or MR Scan will also be used to evaluate the changes in dose distribution to the target volumes and normal tissues that occur with the initial photon treatment plan and initial proton treatment. The changes in tumor volume, tumor motion and dose distribution during the course of radiation treatment will be analyzed to determine the effect of tumor changes on radiation treatment efficacy.