Noninvasive Breast Brachytherapy Research Articles

Mammographically guided noninvasive breast brachytherapy: Preoperative partial breast radiotherapy markedly improves targeting accuracy and decreases irradiated volume

PurposeMammographically based noninvasive image-guided breast brachytherapy (NIBB) partial breast irradiation (PBI) is ideally suited for preoperative treatment. We hypothesize that delivering NIBB PBI to the preoperative tumor volume compared with the postoperative lumpectomy bed would simplify target identification and allow for a reduction in irradiated volume along each orthogonal axis. Methods and MaterialsPatients with invasive breast cancer treated with NIBB PBI at our institution were identified. Preoperative NIBB treatments were modeled along orthogonal craniocaudal and mediolateral axes with an applicator encompassing the gross lesion plus a 1 cm clinical target volume margin. Preoperative treatment volumes were calculated along each axis using the selected applicator surface area multiplied by the preoperative mammogram separation. The actual applicator size and breast separation from the first fraction of postoperative treatment was used to calculate the postoperative treatment volume. Paired -test was used to compare the preoperative and postoperative treatment separation, area, and volume for each patient. ResultsForty-eight patients with Stage I–II breast cancer had imaging and treatment data available for review. Along the axis, the mean preoperative treatment volume was significantly less than the mean postoperative treatment volume (116 cm 3 vs. 204 cm 3, respectively; p < 0.0001). Similarly, along the mediolateral axis, the mean preoperative treatment volume was significantly less than the mean postoperative treatment volume (125 cm 3 vs. 216 cm 3, respectively; p < 0001). ConclusionsBased on our retrospective comparison, PBI delivered using NIBB to the preoperative tumor may reduce the volume of healthy breast tissue receiving radiation as compared with NIBB to the postoperative tumor bed.

Novel and programmatic improvements to the workflow associated with the AccuBoost breast brachytherapy procedure

PurposeWhile the noninvasive breast brachytherapy (NIBB) treatment procedure, known as AccuBoost, for breast cancer patients is well established, the treatment quality can be improved by the efficiency of the workflow delivery. A formalized approach evaluated the current workflow through failure modes and effects analysis and generated insight for developing new procedural workflow techniques to improve the clinical treatment process. Methods and MaterialsAccuBoost treatments were observed for several months while gathering details on the multidisciplinary workflow. A list of possible failure modes for each procedure step was generated and organized by timing within the treatment process. A team of medical professionals highlighted procedural steps that unnecessarily increased treatment time, as well as introduced quality deficiencies involving applicator setup, treatment planning, and quality control checks preceding brachytherapy delivery. Procedural improvements and their impact on the clinical workflow are discussed. ResultsThe revised clinical workflow included the following key procedural enhancements. Prepatient arrival: Improvement of prearrival preparation requires advance completion of dose calculation documentation with patient-specific setup data. Patient arrival pretreatment: Physicists carry out dwell time calculations and check the plan, while the therapist concurrently performs several checks of the ensuing hardware configuration. Treatment: An electronic method to export the associated HDR brachytherapy paperwork to the electronic medical record system with electronic signatures and captured approvals was generated. Posttreatment: The therapist confirms the applicators were appropriately positioned, and treatment was delivered as expected. ConclusionsThe procedural improvements reduced the overall treatment time, improved consistency across users, and eased performance of this special procedure for all participants.

Analysis of Outcomes Using Hypofractionated Tumor Bed Boost Combined With Hypofractionated Whole Breast Irradiation for Early-stage Breast Cancer

IntroductionTumor bed boost improves local control and is an important part of breast-conserving therapy. Data on the use of a hypofractioned tumor bed boost are needed. We performed a retrospective analysis of patients treated with hypofractionated whole breast irradiation (WBI) and hypofractionated boost to examine acute and delayed outcomes. Materials and MethodsWe examined the records of patients treated with hypofractionated WBI and tumor bed boost after lumpectomy for Stage 0 to II breast cancer. Local control, toxicity, and cosmetic outcome were evaluated. Patient, tumor, and treatment characteristics were evaluated including excision volume, surgical technique, surgical complications, chemotherapy, endocrine therapy administration, radiation dose, fractionation, and technique. ResultsA total of 143 patients received hypofractionated WBI with hypofractionated boost between 2010 and 2015. The median follow-up was 16.8 months. The median patient age was 65 years. Patient stage was 0, I, and II in 25%, 68%, and 7%, respectively. All patients received hypofractionated WBI with 42.5 Gy in 16 fractions. Sixty-one percent of women received a boost regimen of 2.66 Gy/fraction for 3 fractions. Boost techniques included noninvasive breast brachytherapy, electrons, 3-dimensional conformal radiation therapy, or a combination of techniques. Acute skin reaction was grade 1 in 65% and grade 2 in 32%. Good or excellent cosmetic outcome was achieved in 94% of patients. Subcutaneous fibrosis was the most common delayed toxicity in 19%, of which 86% was grade 1. There were no local recurrences. ConclusionsHypofractionated tumor bed boost is well-tolerated with a low rate of toxicity and high rate of good-to-excellent cosmetic outcome.

Treatment Planning Using the TG-43 Hybrid Technique for HDR Non-Invasive Breast Brachytherapy Applicators

Treatment Planning Using the TG-43 Hybrid Technique for HDR Non-Invasive Breast Brachytherapy Applicators

Updated feasibility and reproducibility results of multi-institutional study of noninvasive breast tumor bed boost

PurposeTo report updated feasibility and reproducibility results for high-dose-rate noninvasive breast brachytherapy (NIBB) for tumor bed boost with whole breast radiation therapy (WBRT) in the setting of expanded patient and treatment facility number. Methods and MaterialsFifteen independent community-based and academic centers reported 518 early-stage breast cancer patients from July 2007 to February 2015 on a privacy-encrypted online data registry. All patients' treatment included lumpectomy followed by combination of WBRT and NIBB. NIBB was completed with commercially available (AccuBoost, Billerica, MA) mammography-based system using high-dose-rate 192Ir emissions along orthogonal axes. Harvard scale was used to grade cosmesis. ResultsTotal patient cohort had median followup of 12 months (1–75 months) with subset of 268 having available cosmesis. Greater than 2- and 3-year followup was 29% and 14%, respectively. Entire cohort had 97.4% excellent/good (E/G) breast cosmesis and freedom from recurrence of 97.6% at the final followup. WBRT timing with respect to NIBB delivery demonstrated no statistically significant difference in E/G cosmesis. Achieved E/G cosmesis rate was also not statistically significant (χ2p-value = 0.86) between academic and community institutions with 97.8% vs. 96.6%. ConclusionsNIBB represents an alternative method for delivery of breast tumor cavity boost that has shown feasibility in a diverse group of both academic and community-based practices with reproducible early cosmesis and tumor control results. Recommendations are updated noting ideal timing of boost delivery likely to be before or early during WBRT given equal cosmesis and less documented treatment discomfort.

A Multi-Institutional Study of Feasibility, Implementation, and Early Clinical Results With Noninvasive Breast Brachytherapy for Tumor Bed Boost

To evaluate the feasibility, implementation, and early results of noninvasive breast brachytherapy (NIBB) for tumor bed boost with whole breast radiation therapy (WBRT). NIBB is a commercially available (AccuBoost, Billerica, MA) mammography-based, brachytherapy system in which the treatment applicators are centered on the planning target volume (PTV) to direct (192)Ir emissions along orthogonal axes. A privacy-encrypted online data registry collected information from 8 independent academic and community-based institutions. Data were from 146 consecutive women with early-stage breast cancer after lumpectomy and WBRT receiving boost with NIBB between July 2007 and March 2010. Toxicity and cosmesis were graded according to the Common Toxicity Criteria (v. 3.0) and the Harvard scale. Median follow-up was 6 months (1-39 months). Grade 1-2 skin toxicity was observed in 64%, 48%, and 21% during the acute (1-3 weeks), intermediate (4-26 weeks), and late-intermediate (>26 weeks) periods. There was no Grade 4 toxicity. At 6 months, for the entire cohort, cosmesis was excellent/good in 62%/38%. The subset receiving NIBB before WBRT had cosmetic scores of 32% and 63%, whereas during WBRT, 58% and 37% were rated as excellent and good, respectively. Breast compression was scored as "uncomfortable" in 12%, 29%, and 59% when NIBB was delivered before, during, or after WBRT. For each patient, the fraction-to-fraction variability in PTV was low. Skin flash was associated with a higher proportion of excellent cosmesis (58% vs. 42%) relative to having the applicator all within breast tissue. These data indicate that NIBB is feasible and can be consistently implemented in a broad array of practice settings. Preliminary evaluation suggests that NIBB is associated with acceptably mild normal tissue toxicity and favorable early cosmesis. The application of NIBB before WBRT may be associated with better patient tolerance at the expense of less favorable cosmetic outcome.

Dose Modeling of Noninvasive Image-Guided Breast Brachytherapy in Comparison to Electron Beam Boost and Three-Dimensional Conformal Accelerated Partial Breast Irradiation

To perform dose modeling of a noninvasive image-guided breast brachytherapy (NIIGBB) for comparison to electrons and 3DCRT. The novel technology used in this study is a mammography-based, noninvasive breast brachytherapy system whereby the treatment applicators are centered on the planning target volume (PTV) to direct (192)Ir emissions along orthogonal axes. To date, three-dimensional dose modeling of NIIGBB has not been possible because of the limitations of conventional treatment planning systems (TPS) to model variable tissue deformation associated with breast compression. In this study, the TPS was adapted such that the NIIGBB dose distributions were modeled as a virtual point source. This dose calculation technique was applied to CT data from 8 patients imaged with the breast compressed between parallel plates in the cranial-caudal and medial-lateral axes. A dose-volume comparison was performed to simulated electron boost and 3DCRT APBI. The NIIGBB PTV was significantly reduced as compared with both electrons and 3DCRT. Electron boost plans had a lower D(min) than the NIIGBB technique but higher V(100), D(90), and D(50). With regard to PTV coverage for APBI, the only significant differences were minimally higher D(90), D(100), V(80), and V(90), with 3DCRT and D(max) with NIIGBB. The NIIGBB technique, as compared with electrons and 3D-CRT, achieved a lower maximum dose to skin (60% and 10%, respectively) and chest wall/lung (70-90%). NIIGBB achieves a PTV that is smaller than electron beam and 3DCRT techniques. This results in significant normal tissue sparing while maintaining dosimetric benchmarks to the target tissue.

Design of a Skin Dose-Sparing Non-Invasive Breast Brachytherapy Applicator

Design of a Skin Dose-Sparing Non-Invasive Breast Brachytherapy Applicator

Three-dimensional Dose Modeling of the AccuBoost Mammography-based Image Guided Non-invasive Breast Brachytherapy System for Partial Breast Irradiation

Three-dimensional Dose Modeling of the AccuBoost Mammography-based Image Guided Non-invasive Breast Brachytherapy System for Partial Breast Irradiation