PRIMARY OBJECTIVES:
I. Establish the technical feasibility of MRI for performing functional soft-tissue targeting of radiotherapy in the pelvis and thorax. (Group I) II. Acquire clinical MR imaging data to evaluate image quality tradeoffs and operational parameter settings. (Group I) III. Validate the selection of MRI technique factors by comparing visibility of soft tissue structures in MRIs, cone beam (CB)CTs and fan beam (FB)CTs of the same patient. (Group II) IV. Assess the feasibility of using deformable image registration to map contours from FBCT to MRI, CBCT to MRI, MRI to MRI and vice versa. (Group II) V. Compare morphologic and functional changes in target and normal structures, visualized on MRI, CBCT and FBCT images, in response to radiation therapy and identify opportunities for treatment adaptation. (Group II)
OUTLINE:
Patients undergo MRI and FBCT at baseline, within the first 3 weeks of radiotherapy and between week 4 and 6 of radiotherapy. Patients with lung cancer may undergo 4 dimensional (4D) CBCT on the same day as the second and third MRI and FBCT.
