Meeting Banner
Abstract #2952

Rapid MRI 4D Image Guidance for Motion Management in Lung Cancer Radiotherapy

Amit Sawant1, Sarang Joshi2

1Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States; 2Biomedical Engineering, University of Utah, Salt Lake City, UT, United States

This work investigates real-time MRI for image-guided radiation therapy of moving and deforming lung tumors. We hypothesize that, for the task of lung radiotherapy guidance, MRI acquisition speed can be increased significantly at the cost of loss in image SNR. We present results for scans acquired from two lung cancer patients on a 1.5T scanner under free-breathing conditions and without externally administered contrast using a balanced SSFP sequence. Image acquisition times of ~6.5 frames/s were achieved for 2D time series and ~0.8 volumes/s for a 3D time series. In each case, the tumor and structures of interest were clearly delineated.

Keywords

absence accuracy achieve achieved acquiring acquisition adequate aims amplified anatomy applied approved arrow artifacts artificially augment available balanced beyond biology biomedical body boundary breathing calculations cancer captured cardiac care caused causing centroid city clearly coil complex computed conditions considered contrast correlated cycle deformable deformation degree delineation delivery density desired diameter diaphragm diaphragmatic dome dose doses early electron engineering extrinsic feasibility fidelity flow fluid frame frames free funding geometric grant guidance inclusive indicate individual invasive investigate ionizing lake leading lobe long longer lung management manually mass medical monitoring motion move nevertheless parallel patient patients physics pixel poorly position precision quality radiation radiotherapy rapid real reconstruction registration relatively rendered represent require resolution respectively respiratory rotation salt sampling scanner scope seed series slice slices southwestern space sparse speed steady strategies structures subtracted superior surface surrounding term tomography tool track trajectories trajectory truly tumor tumors uncertainties upper useful variations volume volumetric wall yellow yield yields