Analysis of treatment efficacy, cosmesis, and toxicity using the MammoSite breast brachytherapy catheter to deliver accelerated partial-breast irradiation: the william beaumont hospital experience.
OBJECTIVE
To review our institution's experience of treating patients with the MammoSite (Cytyc Corp., Marlborough, MA) breast brachytherapy catheter to deliver accelerated partial-breast irradiation (APBI), for determining short-term treatment efficacy, cosmesis, and toxicity.


METHODS
From January 2000 to April 2006, 80 patients treated with breast-conserving therapy (BCT) received adjuvant radiation using the MammoSite (34 Gy in 3.4-Gy fractions prescribed to 1.0 cm from the balloon surface). Twenty-three patients (29%) had Stage 0 breast cancer, 46 (57%) had Stage I breast cancer, and 11 (14%) had Stage II breast cancer. The median follow-up was 22.1 months.


RESULTS
Two ipsilateral breast-tumor recurrences (IBTRs) (2.5%) developed for a 3-year actuarial rate of 2.9% (no regional failures were observed). On molecular-based clonality assay evaluation, both recurrences were clonally related. Younger age at diagnosis was the only variable associated with IBTR (continuous variable, p = 0.044; categorical variable [<55 years vs. >/=55 years], p = 0.012). The percentages of patients with good/excellent cosmetic results at 12 and 36 months were 96.9% and 88.2%, respectively (p = NS). Patients with applicator-to-skin spacing <7 mm and those who received adjuvant systemic chemotherapy exhibited lower rates of good/excellent cosmetic results, though the association was not statistically significant. The overall incidence of symptomatic seromas and any seromas was 10% and 45%, respectively. The overall incidence of fat necrosis and infections was 8.8% and 11.3%, respectively.


CONCLUSIONS
Early-stage breast-cancer patients treated with adjuvant APBI using the MammoSite catheter exhibited a 3-year treatment efficacy, cosmesis, and toxicity similar to those observed with other forms of interstitial APBI at this length of follow-up.
Chao
K Kenneth
KK
Department of Radiation Oncology, Beaumont Cancer Institute, William Beaumont Hospital, Royal Oak, MI 48072, USA.
Vicini
Frank A
FA
Wallace
Michelle
M
Mitchell
Christina
C
Chen
Peter
P
Ghilezan
Michel
M
Gilbert
Samuel
S
Kunzman
Jonathan
J
Benitez
Pamela
P
Martinez
Alvaro
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D001940:Breast / Q000473:pathology / Q000528:radiation effects* / Q000601:surgery; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D002278:Carcinoma in Situ / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D019583:Dose Fractionation, Radiation; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology; D016016:Proportional Hazards Models; D011832:Radiation Injuries / Q000473:pathology; D016896:Treatment Outcome