2G05-Treatment Planning System from 2D to 3D

TD14-Treatment Planning System from 2D to 3D

Cheng B. Saw, PhD

UPMC Cancer Centers, Pittsburgh, PA 15232

This presentation will examine the underlying principles behind 2-dimensional (2D) and 3-dimensional (3D) treatment planning systems.  In 2D treatment planning systems, the dose distributions are computed in the central plane, the plane that passes through the beam axes.  The dose algorithms assume a cylindrical geometry and do not account for irregularities off the central plane.  An axial CT scan through the plane is often used for treatment planning purposes.  With the advancement of computer technology, fast speed computers with large storage capacity become available, making 3D treatment planning systems possible.  In 3D treatment planning system, a series of CT scans through the target volume is required.  The dose algorithms take into account the scattered components from off axes tissues.  Virtual simulation is feasible with 3D treatment planning system.  Surface and isodose rendering present newer technique of visualization.  The patient data acquisition, beam data collection, dose algorithms, display functions, and documentation will be discussed.