Accelerated Partial Breast Irradiation (APBI) refers to the use of limited, focused RT as a more convenient alternative to conventional whole breast radiation radiation therapy (WBRT) for women following breast-conserving surgery. Compared with WBRT, APBI delivers a higher dose of RT per day to a limited volume of tissue, encompassing the lumpectomy bed with margin over a shorter period of time and leading to potentially fewer late skin and surrounding organ side effects . The results from the randomized study comparing APBI to whole breast radiation therapy have not yet been reported, however, many single institutional studies demonstrate equivalent outcomes in highly selected patients with favorable breast cancer features. Treatment options with accelerated partial breast irradiation available through our departments include:
1. Intracavitary Brachytherapy: A radiation delivery device is placed into the lumpectomy cavity. Single lumen and multi-lumen balloon catheter and non-balloon devices have all been used successfully. A radioactive source imbedded in a wire is guided into the catheter to temporarily expose the 1-2 cm radial margin beyond the cavity to the prescribed dose of radiation, taking approximately 5-10 minutes. This is repeated twice daily for 5 days, for a total of 10 fractions.
2. Intraoperative Radiation Therapy (IORT) : Intraoperative RT condenses the entire therapeutic dose into a single fraction, permitting surgery and radiation to be completed in one day. Potential advantages include accurate delivery of radiotherapy directly to the surgical margins and a decreased dose of radiation to skin and subcutaneous tissue since these can be retracted during treatment. This treatment is offered at Advocate Good Shepard Hospital and Advocate Illinois Masonic Medical Center.
3. External beam radiation therapy (EBRT) with 3D conformal or IMRT treatment techniques: This treatment utilizes a linear accelerator-based treatment algorithm to design radiation utilizes multiple angled beams to create a dose-distribution that conforms to the 1-2 cm margin beyond the lumpectomy cavity. Similar to brachytherapy approaches, this treatment is performed twice daily for a total of 10 fractions over 5 days.
4. CyberKnife APBI: CyberKnife is a robotic radiation therapy delivery system which is non-invasive, employing an unlimited number of angled beams in the design of dose distributions that are highly precise to the target, with minimal exposure to surrounding tissues, and capable of live-tracking and correcting for movement associated with respiration in a seamless manner. Such treatment is offered at our Illinois CyberKnife treatment center at Advocate Lutheran General Hospital on a registry study.
