Five-year analysis of treatment efficacy and cosmesis by the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation.
OBJECTIVE
To present 5-year data on treatment efficacy, cosmetic results, and toxicities for patients enrolled on the American Society of Breast Surgeons MammoSite breast brachytherapy registry trial.


METHODS
A total of 1440 patients (1449 cases) with early-stage breast cancer receiving breast-conserving therapy were treated with the MammoSite device to deliver accelerated partial-breast irradiation (APBI) (34 Gy in 3.4-Gy fractions). Of 1449 cases, 1255 (87%) had invasive breast cancer (IBC) (median size, 10 mm) and 194 (13%) had ductal carcinoma in situ (DCIS) (median size, 8 mm). Median follow-up was 54 months.


RESULTS
Thirty-seven cases (2.6%) developed an ipsilateral breast tumor recurrence (IBTR), for a 5-year actuarial rate of 3.80% (3.86% for IBC and 3.39% for DCIS). Negative estrogen receptor status (p=0.0011) was the only clinical, pathologic, or treatment-related variable associated with IBTR for patients with IBC and young age (<50 years; p=0.0096) and positive margin status (p=0.0126) in those with DCIS. The percentage of breasts with good/excellent cosmetic results at 60 months (n=371) was 90.6%. Symptomatic breast seromas were reported in 13.0% of cases, and 2.3% developed fat necrosis. A subset analysis of the first 400 consecutive cases enrolled was performed (352 with IBC, 48 DCIS). With a median follow-up of 60.5 months, the 5-year actuarial rate of IBTR was 3.04%.


CONCLUSIONS
Treatment efficacy, cosmesis, and toxicity 5 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI with similar follow-up.
Vicini
Frank
F
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48072, USA. fvicini@beaumont.edu
Beitsch
Peter
P
Quiet
Coral
C
Gittleman
Mark
M
Zannis
Vic
V
Fine
Ricky
R
Whitworth
Pat
P
Kuerer
Henry
H
Haffty
Bruce
B
Keisch
Martin
M
Lyden
Maureen
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D002278:Carcinoma in Situ / Q000737:chemistry / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000737:chemistry / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000473:pathology; D011879:Radiotherapy Dosage; D011960:Receptors, Estrogen / Q000032:analysis; D012042:Registries; D016896:Treatment Outcome; D047368:Tumor Burden
D011960:Receptors, Estrogen