Long-term results (10 years) of intensive breast conserving therapy including a high-dose and large-volume interstitial brachytherapy boost (LDR/HDR) for T1/T2 breast cancer.
OBJECTIVE
During the past 15 years many retrospective studies and prospective randomized trials have been published supporting the use of breast conserving treatment (BCT) including surgery and radiotherapy. However, there are still many controversies on the necessary amount of resection, the width of the resection margins and the optimal radiation technique, dose and volume, in particular of the boost. In this retrospective study a large cohort of 410 women with early breast cancer treated with BCT including an interstitial brachytherapy (BT) boost is evaluated after a long follow-up period.


METHODS
In order to clarify the impact of the different treatment-related factors on local control, these were carefully discriminated, based on widely accepted classification and reporting systems for surgery as well as for radiotherapy. The surgical approach was classified according to EORTC criteria and a high rate of quadrantectomies (60%) was found. Dose and volume of interstitial BT is reported according to recommendations of ICRU 58, and reveals a significant radiation dose and volume: minimum target dose, mean central dose (MCD) and '85% of MCD' for low-dose rate (LDR) BT was mean 20, 28 and 24 Gy, for high-dose rate (HDR) BT it was mean '10, 15 and 13 Gy, respectively; the treated volume was 104 cc for LDR BT and 83 cc for HDR BT.


RESULTS
The actuarial rates for overall survival, disease-free survival and disease-specific survival were 97, 90 and 98% at 5 years and 85, 79 and 92% at 10 years. There have been only 16 breast recurrences in 410 treated patients resulting in a 5- and 10-year actuarial local recurrence rate of 2 and 3.9%, respectively; six recurrences (1.5%) were in the original quadrant. Except age and menopausal status, all tumour- and patient-related risk factors had no significant impact on local control.


CONCLUSIONS
Our data confirm that intensive BCT leads to excellent long-term results in terms of local control, masking classical risk factors. This high-dose and large-volume interstitial BT seems to be superior to classical BCT without BT.
Resch
Alexandra
A
Department of Radiotherapy and Radiobiology, Vienna University, Medical School, General Hospital of Vienna, Währinger Gürtel 18-22, Vienna, Austria.
Pötter
Richard
R
Van Limbergen
Erik
E
Biber
Eva
E
Klein
Tanja
T
Fellner
Claudia
C
Handl-Zeller
Leonore
L
Langbauer
Gudrun
G
Schürer-Waldheim
Helmut
H
Staffen
Alfred
A
Jakesz
Raimund
R
Kubista
Ernst
E
Lehr
Stephan
S
Seitz
Wolfgang
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome