Accelerated partial breast irradiation: 5-year results of the German-Austrian multicenter phase II trial using interstitial multicatheter brachytherapy alone after breast-conserving surgery.
OBJECTIVE
To evaluate the impact of accelerated partial breast irradiation on local control, side effects, and cosmesis using multicatheter interstitial brachytherapy as the sole method for the adjuvant local treatment of patients with low-risk breast cancer.


METHODS
274 patients with low-risk breast cancer were treated on protocol. Patients were eligible for the study if the tumor size was < 3 cm, resection margins were clear by at least 2 mm, no lymph node metastases existed, age was >35 years, hormone receptors were positive, and histologic grades were 1 or 2. Of the 274 patients, 175 (64%) received pulse-dose-rate brachytherapy (D(ref) = 50 Gy). and 99 (36%) received high-dose-rate brachytherapy (D(ref) = 32.0 Gy).


RESULTS
Median follow-up was 63 months (range, 9-103). Only 8 of 274 (2.9%) patients developed an ipsilateral in-breast tumor recurrence at the time of analysis. The 5-year actuarial local recurrence-free survival probability was 98%. The 5- year overall and disease-free survival probabilities of all patients were 97% and 96%, respectively. Contralateral in-breast malignancies were detected in 2 of 274 (0.7%) patients, and distant metastases occurred in 6 of 274 (2.2%). Late side effects ≥ Grade 3 (i.e., breast tissue fibrosis and telangiectasia) occurred in 1 patient (0.4%, 95%CI:0.0-2.0%) and 6 patients (2.2%, 95%CI:0.8-4.7%), respectively. Cosmetic results were good to excellent in 245 of 274 patients (90%).


CONCLUSIONS
The long-term results of this prospective Phase II trial confirm that the efficacy of accelerated partial breast irradiation using multicatheter brachytherapy is comparable with that of whole breast irradiation and that late side effects are negligible.
Strnad
Vratislav
V
Department of Radiation Oncology, University Hospital Erlangen, Erlangen, Germany. vratislav.strnad@uk-erlangen.de
Hildebrandt
Guido
G
Pötter
Richard
R
Hammer
Josef
J
Hindemith
Marion
M
Resch
Alexandra
A
Spiegl
Kurt
K
Lotter
Michael
M
Uter
Wolfgang
W
Bani
Mayada
M
Kortmann
Rolf-Dieter
RD
Beckmann
Matthias W
MW
Fietkau
Rainer
R
Ott
Oliver J
OJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001317:Austria; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D001943:Breast Neoplasms / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018572:Disease-Free Survival; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D005858:Germany; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000379:methods; D047368:Tumor Burden