Image-Guided Adaptive Radiotherapy for Head And Neck Cancer: Patient Image Acquisition

I. To conduct a clinical imaging study utilizing three novel in-room imaging systems: Oblique Brainlab ExacTrac images, Orthogonal Varian kilovoltage (kV) On-board Imaging (OBI) image, and Varian cone-beam computed tomography (CBCT) imaging to assess their performance in reducing inter- and intrafractional setup errors, relative to weekly megavoltage (MV) electronic portal imaging device (EPID) images, using both bony landmarks and soft tissue changes for head and neck cancer (HNC) patients undergoing external beam radiation therapy (RT). II. To assess the accuracy of CBCT imaging for measuring systematic soft tissue changes in the head and neck (HN) area relative to conventional high resolution contrast enhanced fan-beam computed tomography (CT) (FBCT) as a standard. III. To assess the systematic and random soft tissue motion errors using daily CBCT imaging relative to bony-landmark alignment to evaluate the benefit of soft tissue imaging during radiotherapy. IV. To quantify soft tissue changes during an entire course of radiotherapy (e.g. tumor shrinkage) using daily CBCT imaging. V. To determine the feasibility of using measured set up and soft-tissue motion uncertainties in conjunction with volume changes observed on serial CBCT images, for offline adaptive replanning of HNC patients using available planning tools. VI. To quantify the benefits of adaptive image-guided radiotherapy (IGRT) in HN patients in terms of target coverage and normal tissue avoidance. VII. To determine the feasibility of mounting a phase I/II trial to assess the clinical benefits of image-guided adaptive radiotherapy (IGART) in terms of acute and late toxicities and tumor control. VIII. To build a HNC patient database for future validation of IGART processes using deformable image registration and Virtual Clinical Trials (VCTs). OUTLINE: Patients undergo FBCT once before treatment and once weekly for a total of 6-7 scans, dual CBCT up to 5 times weekly for a total of 33-35 scans, 2-dimensional (2-D) x-ray with Varian kV OBI 5 times weekly for a total of 33-35 scans, 2-D x-ray with Brain Lab ExacTrac 5 times weekly for a total of 33-35 scans, 2-D x-ray with Varian MV OBI once weekly for a total of 6-7 scans, and EPID imaging up to 5 times weekly for a total of 33-35 scans while undergoing IGART.