Radiology, Vol 184, 275-279, Copyright © 1992 by Radiological Society of North America
Three-dimensional viewing of and dosimetric calculations in Au-198 implants of the prostate
VN Avizonis, DH Hussey, KM Anderson, SK Jani and KS Berbaum
Division of Radiation Oncology, University of Iowa College of Medicine, Iowa City.
A three-dimensional system for dosimetric calculation of radiation from
interstitial brachytherapeutic implants was developed and was compared with
conventional dosimetry performed with a commercial two-dimensional system.
Software programs written for this study enabled the authors to place
radioactive sources in the correct reconstructed anatomic locations,
compute the isodose distribution around these sources, and display the
isodose curves in their correct relationship to anatomic structures. Eight
radiation oncologists evaluated the usefulness of both systems.
Verification studies in phantoms and in 20 patients with gold-198 implants
in the prostate gland showed that the experimental system was very accurate
in volume reconstruction, seed localization, isodose distribution,
point-dose calculation, and computation of dose- volume histograms.
Although the dose depictions in the two systems matched almost exactly,
statistically significant differences existed in interpretation of the
dosimetric data generated by both systems. For example, the oncologists
consistently believed that the dose to the prostate was lower when the
three-dimensional system was used (P less than or equal to .0001).
