Local Control and Predictors of Local Recurrence Following MammoSite Radiation Therapy: 5-Year Outcomes

spacing of 1.0 cm and V-150%!30% (p 5 0.0001). Two patients healed after 6 months of conservative treatment. Surgery was required in six patients who developed fat necrosis. Conclusions: With median 72 month followup, Breast Conservation radiation therapy utilizing Interstitial Multi-Catheter HDR Implant has yielded local recurrence rates and cosmetic results which compare favorably to EBRT in selected patients. There was no difference in LR between patients with IDC and DCIS. Treatment with anthracycline based Chemotherapy, large (O200 cm) implant volumes, and V-150% O30%, appear to be relative contraindications to Interstitial HDR Implant. Finally, catheter spacing of 1 cm yielded optimal dosimetry and minimized complications. Compared to Mammosite technique, the Interstitial Multi-Catheter method offers greater flexibility of radiation delivery. Advantages include, no concern regarding surgical cavity shape irregularities, balloon conformality to surgical cavity, balloon rupture, balloon movement, air gaps, skin balloon proximity to skin, balloon shape distortion, and catheter movement within the balloon.