Virtual planning of multicatheter brachytherapy implants for accelerated partial breast irradiation.

Over the last decade, increasing numbers of breast cancer patients are being treated using interstitial radioactive implants (brachytherapy). Multiple catheters are placed in the breast using a free-hand or template-guided approach. The configuration of the catheters and their relation to the tumor target volume are crucial to effective treatment. Catheter insertion requires a high level of experience to produce an implant of excellent quality. Construction of optimal catheter configuration prior to the procedure (virtual planning) would reduce the dependence of implant quality on the skill of the physician. Currently available commercial planning systems do not allow for virtual planning. We have developed software which inputs the target anatomy for a prospective patient and matches it to a previously-delivered catheter configuration from an institutional implant library. The archived catheter arrangement is then customized to fit the new target volume. The user can actually explore the implications of variations in catheter number and spatial arrangement. This may significantly improve the quality of implants that would otherwise be designed strictly based on a physician's prior experience. In an academic environment, this new resource could lead to better, faster results in the treatment of breast cancer.