Avoiding Mastectomy: Accelerated Partial Breast Irradiation for Breast Cancer Patients with Pacemakers or Defibrillators

The objective of this study was to evaluate the safety, toxicity, and planning concerns involved in accelerated partial breast irradiation (APBI) for patients with breast cancer who have a pacemaker or an automatic implantable cardioverter-defibrillator (AICD) and who desire breast conservation. We performed a review of prospectively obtained data for patients with early-stage breast cancer with a pacemaker or AICD treated between April 2007 and July 2010. Patients were treated with either 3D conformal external beam irradiation (3D-CRT) or high-dose rate balloon brachytherapy (HDRBB) as performed in the National Surgical Adjuvant Breast and Nowel Project (NSABP) B-39/Radiation Therapy Oncology Group (RTOG) 0413 protocol. Device interrogation was performed after the first and last radiation treatment, with comparative cardiac monitoring performed before and after the first three treatments. Eight patients were treated and have a mean follow-up of 6 months. Three patients received HDRBB delivering 34 Gy in 10 fractions. Mean planning target volume for evaluation (PTV_EVAL) coverage was 93.6%. The maximum radiation dose delivered to any device was 1.03 Gy, with a mean pacemaker distance to lumpectomy cavity (DLC) of 9.1 cm. Five patients received 3D-CRT consisting of 38.5 Gy in 10 fractions. The mean 90% PTV_EVAL coverage was 97.3%. Maximum dose delivered to any device was 1.68 Gy at a DLC of 9 cm. Local toxicity did not exceed grade 1, and no adverse device events were noted. APBI in patients with pacemakers or AICDs who desire breast preservation seems to be a technically safe and reasonable application of targeted radiation therapy.