Edema and Seed Displacements Affect Intraoperative Permanent Prostate Brachytherapy Dosimetry

Intraoperative CBCT D90 showed a greater correlation with the day 30 dosimetry than intraoperative TRUS. Edema seemed to cause most of the systematic difference between the intraoperative and day 30 dosimetry. Seeds near the rectal wall showed the most displacement, comparing TRUS and CBCT, probably because of TRUS probe-induced prostate deformation.