Dosimetric performance of Strut-Adjusted Volume Implant: a new single-entry multicatheter breast brachytherapy applicator.

PURPOSE: To evaluate the dosimetric performance and clinical utility of the Strut-Adjusted Volume Implant (SAVI) (Cianna Medical, Aliso Viejo, CA) applicator when used as the sole method of radiation therapy for patients with early breast carcinoma. METHODS AND MATERIALS: The dosimetric performance of a Phase II clinical trial has been reported using the SAVI applicator for patients with early breast carcinoma. Cavity volume, planning target volume, dose homogeneity, and dose for organs at risk had been calculated. As a result, the D(90) and D(100) averages had been presented especially on the distances to the skin and the chest wall because these are critical parameters using the MammoSite (Cytyc Corp., Marlborough, MA) technique. RESULTS: D(90) and D(100) averages were 95.8% and 91.2%, respectively. The average dose homogeneity index was 55.9%. Average minimum distances to the skin and chest wall were 15.1 and 23.4mm, respectively. The average D(max) values to the skin and ribs were 249 and 199 cGy/fraction, respectively. The mean V(20) for the lungs was 17.9 cc. The average V(150) and V(200) were 30.80 and 14.91 cc, respectively. CONCLUSIONS: With this study, we have been able to optimize dose distribution to obtain clinically acceptable dose plans, while minimizing doses to healthy tissues. The dose sculpting versatility of SAVI in the clinical setting makes the SAVI applicator a useful addition to the tools available for accelerated partial breast irradiation.

Four-year clinical update from the American Society of Breast Surgeons MammoSite brachytherapy trial.

BACKGROUND: We present a 4-year update on the efficacy, cosmetic results, and complications of MammoSite breast brachytherapy in patients enrolled in the American Society of Breast Surgeons registry trial. METHODS: A total of 1,449 breasts in 1,440 patients with early stage breast cancer undergoing breast-conserving therapy were treated with adjuvant, accelerated partial breast irradiation (APBI) (34 Gy in 3.4-Gy fractions) delivered with the MammoSite device. The median follow-up period for the entire group was 36.1 months. RESULTS: The 3-year actuarial rate of ipsilateral breast tumor recurrence was 2.15%. The 3-year actuarial rate of axillary recurrence was .36%. Complication rates were as follows: infection, 9.5%; seroma, 26.8% (symptomatic seroma, 12.7%); and fat necrosis, 2.0%. The percentages of breasts with good or excellent cosmetic results were as follows: 12 months, 95%; 24 months, 94%; 36 months, 94%; and 48 months, 91%. CONCLUSIONS: Locoregional control, complications, and cosmetic outcomes from MammoSite APBI at the 4-year update are acceptable and similar to results seen with other forms of APBI.

Three-year analysis of treatment efficacy, cosmesis, and toxicity by the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation (APBI).

BACKGROUND: This report presents 3 years of data on treatment efficacy, cosmetic results, and toxicities for patients enrolled on the American Society of Breast Surgeons MammoSite (Cytyc, Bedford, Mass) Breast Brachytherapy Registry Trial. METHODS: A total of 1440 patients (1449 cases) with early stage breast cancer who were undergoing breast-conserving therapy were treated with the MammoSite device to deliver accelerated partial breast irradiation (APBI) (34 Gy in 3.4 Gy fractions). Of these, 1255 (87%) cases had invasive breast cancer (IBC; median size = 10 mm), and 194 (13%) cases had ductal carcinoma in situ (DCIS; median size = 8 mm). Median follow-up was 30.1 months. RESULTS: Twenty-three (1.6%) cases developed an ipsilateral breast tumor recurrence (IBTR) for a 2-year actuarial rate of 1.04% (1.11% for IBC and 0.59% for DCIS). No variables were associated with IBTR. Six (0.4%) patients developed an axillary failure. The percentages of breasts with good to excellent cosmetic results at 12 (n = 980), 24 (n = 752), 36 (n = 403), and 48 months (n = 67 cases) were 95%, 94%, 93%, and 93%, respectively. Breast seromas were reported in 23.9% of cases (30% in open-cavity implants and 19% in closed-cavity implants). Symptomatic seromas occurred in 10.6% of cases, and 1.5% of cases developed fat necrosis. A subset analysis of the first 400 consecutive cases enrolled was performed (352 with IBC, 48 DCIS). With a median follow-up of 37.5 months, the 3-year actuarial rate of IBTR was 1.79%. CONCLUSIONS: Treatment efficacy, cosmesis, and toxicity 3 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI with similar follow-up.

Multi-institutional experience using the MammoSite radiation therapy system in the treatment of early-stage breast cancer: 2-year results.

PURPOSE: To present a retrospective multi-institutional experience of patients treated with the MammoSite radiation therapy system (RTS). METHODS AND MATERIALS: Nine institutions participated in a pooled analysis of data evaluating the clinical experience of the MammoSite RTS for delivering accelerated partial breast irradiation. Between 2000 and 2004, 483 patients were treated with the MammoSite RTS to 34 Gy delivered in 10 fractions. Treatment parameters were analyzed to identify factors affecting outcome. RESULTS: Median follow-up was 24 months (minimum of 1 year). Overall, infection was documented in 9% of patients, but the rate was only 4.8% if the catheter was placed after lumpectomy. Six patients (1.2%) experienced an in-breast failure; four failures occurred remote from the lumpectomy site (elsewhere failure). Cosmetic results were good/excellent in 91% of patients. Treatment parameters identified as significant on univariate analysis were tested in multivariate regression analysis. The closed-cavity placement technique significantly reduced the risk of infection (p = 0.0267). A skin spacing of <6 mm increased the risk of severe acute skin reaction (p = 0.0178) and telangiectasia (p = 0.0280). The use of prophylactic antibiotics reduced the risk of severe acute skin reaction (p < 0.0001). The use of multiple dwell positions reduced the risk of severe hyperpigmentation (p = 0.0278). Infection was associated with an increased risk of fair or poor overall cosmesis (p = 0.0009). CONCLUSIONS: In this series of patients, the MammoSite RTS seems to have acceptable toxicity rates and cosmetic outcomes, comparable to those with whole-breast radiotherapy. On the basis of these data, the closed-cavity placement technique, use of prophylactic antibiotics, use of multiple dwell positions, and a minimum skin spacing of 6 mm seem to improve patient outcome.

Initial outcomes for patients treated on the American Society of Breast Surgeons MammoSite clinical trial for ductal carcinoma-in-situ of the breast.

BACKGROUND: The MammoSite device was designed as a breast brachytherapy applicator and is currently used to deliver accelerated partial breast irradiation (APBI). We hypothesized that APBI delivered with the MammoSite device would be well tolerated and be associated with a good cosmetic outcome in patients with ductal carcinoma-in-situ (DCIS). METHODS: From 2002 to 2004, 191 patients with DCIS were enrolled in a registry trial to assess the MammoSite applicator. Fifteen patients were excluded from analysis because of device- or patient-related factors; 7 patients were excluded after receiving a radiotherapy boost, thus leaving 169 patients available for study. Follow-up information was available for 158 patients. The average length of follow-up was 7.35 months. Forty-three patients had at least 1 year of follow-up. RESULTS: Skin spacing for the MammoSite applicator was as follows: < 5 mm, 3 patients (1.78%); 5 to 7 mm, 18 patients (10.65%); and > or = 7 mm, 148 patients (87.57%). Patients with a device-to-skin distance of > or = 7 mm had the best cosmetic result. Patients with a device-to-skin distance of > or = 7 mm also had a lower incidence of radiation dermatitis. Data on 43 patients who were followed up for at least 1 year confirmed these findings. Additional adverse events were primarily related to skin changes, with breast infections occurring in five patients (3.16%). No patient in the study has experienced a recurrence. CONCLUSIONS: APBI delivered via MammoSite is well tolerated in patients with DCIS, and the lowest toxicity was obtained in patients with the greatest device-to-skin distance. Long-term follow-up data regarding patient satisfaction, cosmesis, and efficacy are needed and will be determined from a recently opened large randomized study.

First analysis of patient demographics, technical reproducibility, cosmesis, and early toxicity: results of the American Society of Breast Surgeons MammoSite breast brachytherapy trial.

BACKGROUND: Eighty-seven institutions participated in a Registry Trial that was designed to collect data on the clinical use of the MammoSite breast brachytherapy catheter for delivering breast irradiation. Patient demographics, technical reproducibility, cosmesis, and early toxicity were evaluated. METHODS: From May 4, 2002 through July 30, 2004, 1419 patients with Stage 0, I, or II breast carcinoma who were undergoing breast-conserving therapy were enrolled on the trial. The device was placed in 1403 of these patients. The 1237 patients (87% of enrolled patients) who received accelerated partial breast irradiation (APBI) (34 grays prescribed to 1.0 cm in 10 fractions; 95% of patients who received APBI) constituted the study population; 86% of those patients (1068) had Stages I-II breast carcinoma (median tumor size, 10 mm), and 14% of those patients (169) had Stage 0 breast carcinoma. Ninety-one percent of the patients with invasive carcinoma (977 of 1068 patients) had negative lymph node status, and 99% of all patients had negative margins. The median patient age was 65 years. Systemic chemotherapy alone was administered to 79 patients with invasive carcinoma (7%), hormone therapy was administered to 501 patients (45%), and both were administered to 39 patients (4%). The median follow-up was 5 months. RESULTS: Five hundred fifty-four catheters (45%) were placed with an open cavity at the time of lumpectomy, and 683 catheters (55%) were placed with a closed cavity after lumpectomy. Skin spacing ranged from 2 mm to 75 mm (median, 10 mm). In 89% of patients, there was a minimum balloon-to-skin distance of 7 mm (2% of patients had distances < 5 mm). In terms of cosmetic assessment, 95% of patients (1030 of 1084 patients) who had a cosmetic assessment had a good/excellent result (last follow-up visit). Cosmetic results at 12 months were good/excellent in 92% of 248 evaluable patients. The median skin spacing (> or = 7 mm vs. < 7 mm) was associated significantly with a good/excellent cosmetic result (96.1% vs. 86.8%; P = 0.0001) overall and at 6 months (P = 0.006). Increasing skin spacing was associated with a good/excellent cosmetic result as a continuous variable (P < 0.0001). In total, 92 of 1140 evaluable patients (8.1%) developed an infection in the breast, which was device-related in 5.3% of patients (60 of 1140 patients). Good/excellent cosmetic results were noted in 86% of these patients (last follow-up visit). Fifteen of 442 evaluable patients (3.4%) developed a radiation recall reaction. Good/excellent cosmetic results were noted in 93% of these patients at their last follow-up visit. One local recurrence (0.1%) was reported (new primary carcinoma). CONCLUSIONS: Clinical evaluation of the ability of the MammoSite breast brachytherapy catheter to deliver APBI demonstrated acceptable technical reproducibility between multiple institutions and use in appropriate groups of patients. Cosmetic results at 12 months (92% good/excellent) were comparable to those reported with whole-breast RT. Early toxicity rates (infections, radiation recall) appeared to be acceptable.

Postoperative ultrasound-guided percutaneous placement of a new breast brachytherapy balloon catheter.

BACKGROUND: The optimal technique and timing for the implantation of a recently developed breast brachytherapy balloon catheter (MammoSite; Proxima Therapeutics, Alpharetta, Georgia) have not been well defined. We hypothesized that placing this postoperatively, utilizing percutaneous ultrasound-guided placement, would be preferable. METHODS: Patients who met eligibility requirements for breast brachytherapy were implanted with the MammoSite device utilizing percutaneous ultrasound-guided technique. Additionally, to study optimal timing, a historical cohort of patients operated upon for breast cancer by two of the authors were analyzed to compare the intraoperative and postoperative candidacy for MammoSite placement. RESULTS: Twenty-one of 23 patients successfully completed brachytherapy after implantation, with only 2 (9%) requiring catheter removal secondary to unfavorable balloon positioning. There were no serious complications. Of 343 historical patients with breast cancer, 137 were intraoperative candidates for brachytherapy, but final postoperative histology disqualified 40 (29%). CONCLUSIONS: Implantation of the MammoSite brachytherapy device is optimally performed postoperatively, after the final pathology is defined, utilizing ultrasound-guided percutaneous technique.