Cosmetic outcome in patients receiving an interstitial implant as part of breast-conservation therapy.
OBJECTIVE
To study factors related to breast cosmetic outcome in patients treated with an interstitial implant as part of breast-conservation therapy.


METHODS
One hundred fifty-six patients with stage I or II breast carcinoma who received 50 Gy of external-beam irradiation followed by a 20-Gy interstitial boost were examined. The dose homogeneity index (DHI) was calculated for each evaluable implant and was examined in light of other patient-, treatment-, and tumor-related variables previously demonstrated to affect cosmesis.


RESULTS
Of the variables examined, both the DHI (P = .021) and the total excision volume (P = .019) were significantly related to cosmetic outcome (excellent vs less than excellent) in a univariate model. In the multivariate analysis, only the total excision volume remained significant (P = .032). The mean total excision volume +/- SD in patients with excellent cosmetic outcome (81.8 cm3 +/- 84.0) was significantly less than that in patients with less than excellent cosmetic outcome (120 cm3 +/- 84). The probability of excellent cosmetic outcome linearly increased with an increase in DHI. The mean DHI was 0.74 +/- 0.12 for the cases with excellent cosmetic outcome and 0.68 +/- 0.10 for those with less than excellent cosmetic outcome.


CONCLUSIONS
To achieve optimal cosmesis, DHI should be maximized. The volume of tissue removed, however, remains the most significant determinant.
Kramer
B A
BA
Department of Radiation Oncology, New England Medical Center, Tufts University School of Medicine, Boston, Mass., USA.
Arthur
D W
DW
Ulin
K
K
Schmidt-Ullrich
R K
RK
Zwicker
R D
RD
Wazer
D E
DE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D004954:Esthetics; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D011879:Radiotherapy Dosage