Long-term clinical and cosmetic outcomes after breast conservation treatment for women with early-stage breast carcinoma according to the type of breast boost.
OBJECTIVE
The present study was performed to compare outcomes after breast conservation treatment with iridium-192 implant boost vs. electron boost.


METHODS
From 1977 to 1983, 141 patients were treated with whole breast radiotherapy followed by iridium-192 boost after breast-conserving surgery. They were matched 1:1 to patients treated with electron boost. Outcome measures included survival, local recurrence, cosmesis, and complications.


RESULTS
Median follow-up was 16.7 and 12.6 years for the implant vs. electron groups (p < 0.001). Rates of local recurrence, freedom from distant metastases, and overall survival at 10/20 years did not differ between the groups, nor did patterns of first failure. Patients in the electron group were more likely to have excellent/good cosmesis than those in the implant group 1 year after radiotherapy (p = 0.014); this trend continued through 10 years but did not reach statistical significance at years 5/10. Complication rates were similar, although patients receiving electron boost seemed less likely to develop breast fibrosis than did those receiving implant boost (23/141 vs. 58/141, respectively, incidence rate ratio 0.7, p = 0.17).


CONCLUSIONS
Twenty-year data demonstrate no difference in rates of local recurrence, freedom from distant metastases, overall survival, or patterns of failure between groups treated with these two well-described radiotherapy boost techniques. Better cosmesis was observed in the electron group 1 year after radiotherapy, with a trend continuing for 10 years. The incidence of complications was similar between the groups, with a trend toward increased fibrosis in patients receiving implant boost.
Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA. hill@xrt.upenn.edu
Christine E
CE
Hill-Kayser
David
D
Chacko
Wei-Ting
WT
Hwang
Neha
N
Vapiwala
Lawrence J
LJ
Solin
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D004583:Electrons / Q000627:therapeutic use; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult
D007496:Iridium Radioisotopes