Multicatheter, Single-Entry Breast Brachytherapy Applicator

The SAVI applicator from BioLucent Inc, Aliso Viejo, Calif, offers a multicatheter, single-entry approach to breast brachytherapy as part of breast-conserving cancer treatment. It received 510(k) clearance from the FDA in July 2006.

The applicator was developed to combine the advantages of two forms of accelerated partial breast irradiation (APBI), a follow-up procedure to lumpectomy that helps prevent a local recurrence of cancer. The applicator combines the tissue-sparing dosimetry of interstitial brachytherapy with the single-entry ease of intracavitary ("balloon") brachytherapy.

As a hybrid of the interstitial and intracavitary approaches, the SAVI device is designed to give more flexibility in treatment planning to the radiation oncologist and physicist. One of the primary benefits of the technology is that it allows better shaping of the radiation dose.

The SAVI applicator is an expandable bundle of catheters. Prior to expansion, the physician places the applicator into the lumpectomy cavity through a small incision. By turning a mechanism from outside the breast, the physician expands the catheter bundle inside the cavity. Delivery of radiation through the applicator's individual catheters allows physicians to control the radiation dose delivered by each catheter. After delivery of the prescribed radiation dose, the physician collapses the catheter bundle and retracts the SAVI applicator through the initial incision.

In APBI, radiation can be delivered from either an internal or external source. Internal APBI, also called breast brachytherapy, places radiation sources inside the breast, focusing radiation on only the tissue where cancer is most likely to reoccur. This approach can spare healthy breast tissue, the chest wall, and inner organs from radiation exposure, as well as eliminate many of the cosmetic side effects associated with whole-breast irradiation.

The Spec Sheet

1. Three models: The applicator comes in three models, with three different diameters. Each model has a central lumen, or catheter. The six-catheter model is expandable to 3 cm; the eight-catheter model is expandable to 4 cm; and the 10-catheter model is expandable to 5 cm.
2. Delivery devices: The applicator and its six catheters are compatible with most commercially available high dose rate afterloaders and transfer tubes.
3. Multiple delivery options: Clinicians can elect to deliver radiation through any or all of the catheters. Each catheter allows for multiple dwell positions of the radiation source, which is iridium 192.

The Visible DIfference

SAVI allows more precise delivery of radiation, potentially eliminating radiation damage to the skin or chest wall. The device is designed to better shape the radiation dose and improve flexibility in treatment planning for physicians and medical physicists.