Idealized line source configuration for permanent 125I prostate implants.

Background And Purpose: To validate the use of idealized seed orientations in conjunction with the line source formalism for post-implant dosimetry of permanent 125I prostate implants.

Patients And Methods: Post-implant, a CT scan and three fluoroscopic images were obtained for 32 patients having undergone permanent implants. From these images, the seed positions and orientations (phi,theta) were determined (1625 individual seeds).