Using Electromagnetic Guidance to Guide Catheter Insertion in Breast Brachytherapy

Full Name: Harry C. Brastianos

Academic Affiliation: Queen’s University

Position: Resident

Abstract: Introduction:The most common cancer in women in Canada is breast cancer. Breast-conserving therapy remains the mainstay of treatment for early stage breast stage cancer. The conventional way to treat breast cancer is to use whole breast radiation treatment. Another treatment modality is to use accelerated partial breast irradiation, where the treatment time is one week or less. One can deliver radiation using multi-catheter interstitial breast brachytherapy. In this technique, catheters are placed within the tumor bed. Current imaging techniques including fluoroscopy and ultrasound have difficulties delineating the positions in three dimensions. To ensure an adequate position, we will apply electromagnetic guidance. Electromagnetic guidance is the equivalent of using a “GPS” system to place catheters. We will use electromagnetic tracking to place catheters in breast phantoms.

Materials and Methods:We made anthropomorphic plastic phantoms with a tumor bed that can be visualized using imaging. The control arm used ultrasound. The experimental arm used electromagnetic tracking and ultrasound. Ten to fifteen catheters were inserted in six phantoms. The goal was to place the catheters within the tumor bed. Three phantoms were inserted with ultrasound, while the other three were inserted with electromagnetic tracking and ultrasound.

Results:Using only ultrasound, 17 out of 25 catheters passed through the tumor bed. With combined electromagnetic tracking and ultrasound guidance, 35 out of 40 catheters passed through the tumor bed.

Conclusions: Electromagnetic tracking is a technique that can be in delivering radiation to women. More work will be done to translate this technique in patients.