5-year results of pulsed dose rate brachytherapy applied as a boost after breast-conserving therapy in patients at high risk for local recurrence from breast cancer.
OBJECTIVE
The aim of this study was to evaluate effect, toxicity, and cosmesis of a prospectively applied pulsed dose rate (PDR) brachytherapy boost schedule in patients with stage I/II/IIIa invasive breast cancer.


METHODS
A total of 113 patients were treated after breast-conserving surgery (BCS) and external beam radiotherapy (median 50 Gy, range 46-52). The boost dose was graded in accordance to the pathologic tumor characteristics: 20-25 Gy: incomplete resection (n = 34), vascular invasion (n = 27), close margin resection (n = 41); 15 Gy: T2G3 stage (n = 11). PDR brachytherapy (37 GBq, (192)Ir source) was carried out after geometric volume optimization with 1 Gy/pulse/h. The implantation and dose specification were performed similar to the rules of the Paris system.


RESULTS
The overall local failure rate after a median follow-up of 61 months was 4.4% (5/113). The actuarial 5- and 8-year local recurrence-free survival rates were 95% and 93%, respectively. Cosmesis was rated by 90% of the patients as excellent or good. 14/113 patients experienced grade III (all caused by planar telangiectasia) and none of the patients grade IV late toxicity of the skin (RTOG/EORTC). A boost dose of 25 Gy resulted in a significantly higher rate of late toxicity (Fisher's exact test, p < 0.01).


CONCLUSIONS
PDR brachytherapy is safe, effective, and provides good cosmesis. A CLDR breast boost can be replaced by PDR brachytherapy without significant loss of therapeutic ratio.
Harms
Wolfgang
W
Department of Clinical Radiology, Radiation Therapy, University of Heidelberg, Germany.
Krempien
Robert
R
Hensley
Frank W
FW
Berns
Christiane
C
Fritz
Peter
P
Wannenmacher
Michael
M
D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018275:Carcinoma, Lobular / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology* / Q000401:mortality; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D012306:Risk