Five-year followup for MammoSite APBI –From a Single Community Practice

Purpose:  To review the treatment results in 123 patients using accelerated partial breast irradiation (APBI) with the MammoSite device in early breast cancer. Special reference is made to patient's acceptance, cosmetic results, recurrence, and early complications.

Methods and Materials:  Between June 2002 and August 2007, 123 women with early breast cancer underwent placement of the MammoSite catheter for treatment of early breast cancer. In total, 117 patients underwent HDR treatment: 70 patients were treated with a spherical device and 47 with ellipsoidal balloon. Six devices had to be removed, 4 due to bad dosimetry, including bad conformance and unacceptable balloon-skin distance and 2 due to finding of positive margins. Dose deliver ranged from 30.6 to 34 Gy in 10 fractions twice a day. All patients had met the following inclusion criteria: negative margins, tumor dimension less than 3 cm, and no evidence of metastatic disease. Followup ranged from 3 to 66 months with a median of 22 months

Results:  The overall satisfaction of the patients after treatment was 100%. Good to excellent cosmetic outcomes were achieved in 90%. Five of 117 (4%) women developed infection. Seroma formation occurred in 66 (54%) of the patients documented by followup ultrasound. Seven of these underwent percutaneous aspiration. Two required surgical intervention for excision of fat necrosis. There were 4 recurrences in the entire group: one patient developed a new primary tumor elsewhere in the treated breast and 3 patients developed distant metastases with local control of the primary tumor. Better cosmesis was seen in patients treated with ellipsoidal devices and greater than 6 mm balloon to skin distance.

Conclusions:  This study supports the use of accelerated partial breast irradiation as an effective modality for treatment of early breast cancer. We report more than 5 years of experience and more than one hundred treated patients with HDR with a very low complication rate and 90 % of good/excellent cosmetic results without recurrence in the treated breast region. The procedure is well accepted by patients as well as by the referring physicians.