Permanent brachytherapy with radioactive seeds is a widely available and effective treatment for low-risk prostate cancer patients. An important factor affecting tumour control and complication rates is implant quality. Therefore, dosimetric post-implant evaluation (postplanning) is recommended as a standard-of-care practice to ensure the quality of the implant technique and to obtain dosimetric data for establishing dose-response relationships. Currently, the relationship between delivered dose and tumour response is not clear, which to a large extent may be attributed to the uncertainties related to post-implant dosimetry. Seed reconstruction, prostate delineation and image fusion inaccuracies play an important role in this, though it is not known how large their impact is on the post-planning evaluation parameters. In this research, we quantified and compared these uncertainties for different imaging techniques. The overall aim was to improve the quality of post-implant evaluation in order to obtain more consistent and reliable dosimetric post-plan information.

(BELG J MED ONCOL 2014;8(1):18–20)