External Beam Treatment of Tumors by Radiotherapy

Radiotherapy involves placing treatment beams so that a radiation dose strong enough to kill cells is given to every tumor cell, while a nonlethal dose is given to critical and radiosensitive normal tissues. In most hospitals planning is done largely with 2D X-ray images or with 3D computed tomography images, in either case only from cardinal directions. In the methods we have developed and are continuing to develop, multimodality (CT, MRI, and SPECT) 3D images are fused to fully determine the region of tumor tissue, 3D regions corresponding to normal organs are extracted by image analysis, and beams are placed with full flexibility of 3D pose. Beam specification uses a variety of 3D displays, computation of digitally reconstructed radiographs (providing the views that will be available during treatment), and calculation of dose both within tumors and within the selected normal organs. Treatment beam positioning and verification in 3D is made possible by comparing and registering electronic treatment beam-generated radiographs (portal images) during treatment with digitally reconstructed radiographs, which are augmented by graphics images of the situation in 3D and in beam's-eye perspective. Using these methods, we expect to see increased tumor control and decreased morbidity.

With the servers and desktop machines received through the Intel Technology for Education 2000 program, we are moving much of the computational work involved in this project to desktop machines.

For additional information, please see information about PLUNC, the software developed in Department of Radiation Oncology for planning radiotherapy treatment beams.

Last content review: 19 July 2001
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