Interim cosmetic results and toxicity using 3D conformal external beam radiotherapy to deliver accelerated partial breast irradiation in patients with early-stage breast cancer treated with breast-conserving therapy.

PURPOSE: We present our ongoing clinical experience utilizing three-dimensional (3D)-conformal radiation therapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer treated with breast-conserving therapy. METHODS AND MATERIALS: Ninety-one consecutive patients were treated with APBI using our previously reported 3D-CRT technique. The clinical target volume consisted of the lumpectomy cavity plus a 10- to 15 -mm margin. The prescribed dose was 34 or 38.5 Gy in 10 fractions given over 5 consecutive days. The median follow-up was 24 months. Twelve patients have been followed for > or =4 years, 20 for > or =3.5 years, 29 for >3.0 years, 33 for > or =2.5 years, and 46 for > or =2.0 years. RESULTS: No local recurrences developed. Cosmetic results were rated as good/excellent in 100% of evaluable patients at > or = 6 months (n = 47), 93% at 1 year (n = 43), 91% at 2 years (n = 21), and in 90% at > or =3 years (n = 10). Erythema, hyperpigmentation, breast edema, breast pain, telangiectasias, fibrosis, and fat necrosis were evaluated at 6, 24, and 36 months after treatment. All factors stabilized by 3 years posttreatment with grade I or II rates of 0%, 0%, 0%, 0%, 9%, 18%, and 9%, respectively. Only 2 patients (3%) developed grade III toxicity (breast pain), which resolved with time. CONCLUSIONS: Delivery of APBI with 3D-CRT resulted in minimal chronic (> or =6 months) toxicity to date with good/excellent cosmetic results. Additional follow-up is needed to assess the long-term efficacy of this form of APBI.

Analysis of treatment efficacy, cosmesis, and toxicity using the MammoSite breast brachytherapy catheter to deliver accelerated partial-breast irradiation: the william beaumont hospital experience.

PURPOSE: To review our institution's experience of treating patients with the MammoSite (Cytyc Corp., Marlborough, MA) breast brachytherapy catheter to deliver accelerated partial-breast irradiation (APBI), for determining short-term treatment efficacy, cosmesis, and toxicity. METHODS AND MATERIALS: From January 2000 to April 2006, 80 patients treated with breast-conserving therapy (BCT) received adjuvant radiation using the MammoSite (34 Gy in 3.4-Gy fractions prescribed to 1.0 cm from the balloon surface). Twenty-three patients (29%) had Stage 0 breast cancer, 46 (57%) had Stage I breast cancer, and 11 (14%) had Stage II breast cancer. The median follow-up was 22.1 months. RESULTS: Two ipsilateral breast-tumor recurrences (IBTRs) (2.5%) developed for a 3-year actuarial rate of 2.9% (no regional failures were observed). On molecular-based clonality assay evaluation, both recurrences were clonally related. Younger age at diagnosis was the only variable associated with IBTR (continuous variable, p = 0.044; categorical variable [<55 years vs. >/=55 years], p = 0.012). The percentages of patients with good/excellent cosmetic results at 12 and 36 months were 96.9% and 88.2%, respectively (p = NS). Patients with applicator-to-skin spacing <7 mm and those who received adjuvant systemic chemotherapy exhibited lower rates of good/excellent cosmetic results, though the association was not statistically significant. The overall incidence of symptomatic seromas and any seromas was 10% and 45%, respectively. The overall incidence of fat necrosis and infections was 8.8% and 11.3%, respectively. CONCLUSIONS: Early-stage breast-cancer patients treated with adjuvant APBI using the MammoSite catheter exhibited a 3-year treatment efficacy, cosmesis, and toxicity similar to those observed with other forms of interstitial APBI at this length of follow-up.

Long-term efficacy and patterns of failure after accelerated partial breast irradiation: a molecular assay-based clonality evaluation.

PURPOSE: To determine the long-term efficacy and cosmetic results of accelerated partial breast irradiation (APBI) by reviewing our institution's experience. METHODS AND MATERIALS: A total of 199 patients with early-stage breast cancer were treated prospectively with adjuvant APBI after lumpectomy using interstitial brachytherapy. All patients had negative margins, 82% had Stage I disease, median tumor size was 1.1 cm, and 12% had positive lymph nodes. The median follow-up for surviving patients was 8.6 years. Fifty-three patients (27%) have been followed for >or=10 years. RESULTS: Six ipsilateral breast tumor recurrences (IBTRs) were observed, for a 5-year and 10-year actuarial rate of 1.6% and 3.8%, respectively. A total of three regional nodal failures were observed, for a 10-year actuarial rate of 1.6%. Five contralateral breast cancers developed, for a 5- and 10-year actuarial rate of 2.2% and 5.2%, respectively. The type of IBTR (clonally related vs. clonally distinct) was analyzed using a polymerase chain reaction-based loss of heterozygosity assay. Eighty-three percent of IBTRs (n = 5) were classified as clonally related. Multiple clinical, pathologic, and treatment-related factors were analyzed for an association with the development of an IBTR, regional nodal failure, or contralateral breast cancer. On multivariate analysis, no variable was associated with any of these events. Cosmetic results were rated as excellent/good in 99% of patients. CONCLUSIONS: Long-term results with APBI using interstitial brachytherapy continue to demonstrate excellent long-term local and regional control rates and cosmetic results. According to a polymerase chain reaction-based loss of heterozygosity assay, 83% of recurrences were classified as clonally related.