Treatment planning for internal radionuclide therapy: three-dimensional dosimetry for nonuniformly distributed radionuclides.
A calculational approach is described that provides the spatially varying radiation absorbed dose, presented as isodose contours superimposed on CT images, from nonuniform and/or irregular cumulated activity distributions. CT images are read from magnetic tape and are displayed on a high-resolution color graphics display monitor. Source tissue geometries are defined on a series of contiguous CT images automatically (by an edge detection algorithm) or manually (using a trackball), thereby obtaining a three-dimensional representation of the various source volumes of activity. Dose calculations are performed using a radionuclide-specific absorbed dose point kernel in the form of a lookup table. The method described yields the spatially varying dose delivered to tumor and normal tissue volumes from a patient-specific cumulated activity distribution in a clinically implementable manner. This level of accuracy in determining normal tissue and tumor doses may prove valuable in the evaluation and implementation of radionuclides and radiolabeled compounds for therapeutic purposes.
Sgouros
G
G
Department of Radiology, New York Hospital-Cornell Medical Center, New York 10021.
Barest
G
G
Thekkumthala
J
J
Chui
C
C
Mohan
R
R
Bigler
R E
RE
Zanzonico
P B
PB
D000465:Algorithms; D001918:Brachytherapy; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011881:Radiotherapy, Computer-Assisted