Background and objectives: The commonest site of local breast recurrence after breast conservation surgery is the primary tumor bed. We have tested the feasibility of outpatient high dose rate brachytherapy to the primary tumor bed as the only radiation. Our technique relies on the placement of surgical clips to mark the tumor bed.
Methods: Between March 1992 and January 1996, 39 patients with clinical T1 T2 breast cancer were enrolled in this pilot study. The first 13 patients had intraoperative implantation of the breast. The remaining 26 patients had outpatient postoperative implantation under general anesthesia (2 patients) or local anaesthesia (24 patients). High dose rate brachytherapy was given twice daily at least 6 hours apart for a total dose of 37.2 Gy in 10 fractions over 5-7 days.
Results: Three patients had mild clinical cellulitis responding to oral antibiotics. One patient had a small sinus in the lumpectomy scar requiring local excision to heal. Four patients developed fat necrosis at the lumpectomy site at 4 (1 patient), 13 (1 patient), and 18 months (2 patients) post radiotherapy. Patient rated satisfaction with treatment was high. At a median followup of 20 months, one infield local recurrence has been salvaged by wider resection and postoperative conventional external beam radiation.
Conclusions: Except for fat necrosis, which may be associated with this technique, complications have been minimal. Outpatient implantation under local anesthesia is feasible. Longer followup is required to establish the local control rates.