Timing of Chemotherapy after MammoSite radiation therapy system breast brachytherapy: analysis of the American Society of Breast Surgeons MammoSite breast brachytherapy registry trial.
OBJECTIVE
To evaluate cosmetic outcome and radiation recall in the American Society of Breast Surgeons registry trial, as a function of the interval between accelerated partial breast irradiation (APBI) and initiation of chemotherapy (CTX).


METHODS
A total of 1440 patients at 97 institutions participated in this trial. After lumpectomy for early-stage breast cancer, patients received APBI (34 Gy in 10 fractions) with MammoSite RTS brachytherapy. A total of 148 patients received CTX within 90 days of APBI. Cosmetic outcome was evaluated at each follow-up visit and dichotomized as excellent/good or fair/poor.


RESULTS
Chemotherapy was initiated at a mean of 3.9 weeks after the final MammoSite procedure and was administered </=3 weeks after APBI in 54 patients (36%) and >3 weeks after APBI in 94 patients (64%). The early and delayed groups were well balanced with respect to multiple factors that may impact on cosmetic outcome. There was a superior cosmetic outcome in those receiving chemotherapy >3 weeks after APBI (excellent/good in 72.2% at </=3 weeks vs. excellent/good in 93.8% at >3 weeks; p = 0.01). Radiation recall in those receiving CTX at </=3 weeks was 9 of 50 (18%), compared with 6 of 81(7.4%) in those receiving chemotherapy at >3 weeks (p = 0.09).


CONCLUSIONS
The majority of patients receiving CTX after APBI have excellent/good cosmetic outcomes, with a low rate of radiation recall. Chemotherapy initiated >3 weeks after the final MammoSite procedure seems to be associated with a better cosmetic outcome and lower rate of radiation recall. An excellent/good cosmetic outcome in patients receiving CTX after 3 weeks was similar to the cosmetic outcome of the overall patient population who did not receive CTX.
Haffty
Bruce G
BG
Department of Radiation Oncology, The Cancer Institute of New Jersey, UMDNJ-Robert Wood Johnson Medical School, New Brunswick, NJ, USA.
Vicini
Frank A
FA
Beitsch
Peter
P
Quiet
Coral
C
Keleher
Angela
A
Garcia
Delia
D
Snider
Howard
H
Gittleman
Mark
M
Zannis
Victor
V
Kuerer
Henry
H
Whitacre
Eric
E
Whitworth
Pat
P
Fine
Richard
R
Keisch
Martin
M
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods / Q000706:statistics & numerical data*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D019651:Plastic Surgery Procedures; D012042:Registries; D012955:Societies, Medical; D013518:Surgery, Plastic; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
D000970:Antineoplastic Agents