Use Of Accelerated Partial Breast Irradiation Research Articles

Adjuvant Hypofractionated Whole Breast Irradiation (WBI) vs. Accelerated Partial Breast Irradiation (APBI) in Postmenopausal Women with Early Stage Breast Cancer: 5Years Update of the HYPAB Trial

Therapeutical strategies in breast cancer are continuously updating. Recent researches assessed the possibility of irradiating only the surgical bed in selected patients (Partial Breast Irradiation, PBI). In 2014 we designed a study to evaluate toxicity and cosmesis of APBI using Volumetric Modulated Arc Therapy-Rapid Arc compared with hypofractionated whole breast irradiation (WBI). We present here the 5-years updated data. HYPAB was a single-institution randomized trial that recruited 172 patients from 2015 to 2018. Patients underwent conserving surgery and were randomized to either adjuvant WBI (40.5Gy/15 fractions with simultaneous boost to 48 Gy to tumoral bed) or APBI (30Gy/5 fractions), both delivered with VMAT-RA technique. Clinical evaluation was performed during the first visit, once a week during radiotherapy and during follow up. Cosmesis was assessed using the Harvard Scale for Breast Cosmesis. At the time of the analysis 161 patients were eligible, 53% in the WBI and 47% in the APBI group, with a median follow-up of 67 months. Most common late skin toxicities were G1 fibrosis (32%) and oedema (28%) and were higher in the WBI group; no G3 toxicities were observed. Cosmesis was rated poor in only 6 cases. 147 patients had no evidence of disease at the last follow-up, and no patients died of the disease. Mature results confirm the safety and efficacy of APBI in selected early stage breast cancer patients. Late toxicity is improved in the APBI arm at the cost of a slight increase in local relapse. Further studies are ongoing to better elucidate the use of APBI as a de-escalation approach.

Assessment of Eligibility and Utilization of Accelerated Partial Breast Irradiation in Korean Breast Cancer Patients (KROG 22-15).

We investigated the proportions of patients eligible for accelerated partial breast irradiation (APBI) among those with pT1-2N0 breast cancer, based on the criteria set by the American Society for Radiation Oncology (ASTRO), the Groupe Européen de Curiethérapie and the European Society for Radiotherapy and Oncology (GEC-ESTRO), the American Brachytherapy Society (ABS), and the American Society of Breast Surgeons (ASBS). Additionally, we analyzed the rate of APBI utilization among eligible patients. Patients diagnosed with pT1-2N0 breast cancer in 2019 were accrued in four tertiary medical centers in Korea. All patients had undergone breast conserving surgery followed by radiotherapy, either whole breast irradiation or APBI. To determine which guideline best predicts the use of APBI in Korea, the F1 score and Matthews Correlation Coefficient (MCC) were determined for each guideline. A total of 1,251 patients were analyzed, of whom 196 (15.7%) underwent APBI. The percentages of eligible patients identified by the ASTRO, GEC-ESTRO, ABS, and ASBS criteria were 13.7%, 21.0%, 50.5%, and 63.5%, respectively. APBI was used to treat 54.4%, 37.2%, 27.1%, and 23.7% of patients eligible by the ASTRO, GEC-ESTRO, ABS, and ASBS criteria, respectively. The ASTRO guideline exhibited the highest F1 score (0.76) and MCC (0.67), thus showing the best prediction of APBI utilization in Korea. The proportion of Korean breast cancer patients who are candidates for APBI is substantial. The actual rate of APBI utilization among eligible patients may suggest there is a room for risk-stratified optimization in offering radiation therapy.

Effectiveness and safety of intraoperative radiotherapy (IORT) with low-energy X-rays (INTRABEAM®) for accelerated partial breast irradiation (APBI).

To evaluate treatment outcomes in patients with early-stage breast cancer (ESBC) treated with targeted intraoperative radiation therapy (IORT) administered as accelerated partial breast irradiation (APBI). Between December 2014 and May 2019, 50 patients diagnosed with ESBC were treated with a 50 kilovoltage (kV) X-ray source with a single dose of 20Gy using the Intrabeam® radiotherapy delivery system. All patients were followed prospectively to assess local control (LC), disease-free survival (DFS), cancer-specific survival (CSS), overall survival (OS), radiation-induced toxicity, and cosmetic outcomes. We also evaluated the prognostic implications of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Median follow-up was 53months. Mean patient age was 70years. The mean duration of radiation delivery was 22.25min. Two patients developed a recurrence. One death was recorded. Elevated pretreatment NLR levels were a significant risk factor for mortality (p = 0.0026). The most common treatment-related toxicities were breast induration (30%) and seroma (18%). Five-year LC, DFS, CSS, and OS rates were 97.1%, 93.9%, 100%, and 94.4%, respectively. Cosmesis was excellent or good in most cases (94%). These findings confirm the effectiveness of a single dose of 20Gy of IORT with the Intrabeam device as APBI. The toxicity profile was good with excellent cosmesis. These results provide further support for the clinical use of APBI in well-selected patients.

Five-year results of accelerated partial breast irradiation: A single-institution retrospective review of 289 cases

PurposeThe purpose of the study was to describe our institutional experience with accelerated partial breast irradiation (APBI) using multicatheter brachytherapy with high-dose-rate. We report 5-year survival outcomes, cosmesis, and treatment-related toxicity. Methods and MaterialsThis included a retrospective review of patients who underwent breast-conserving surgery followed by APBI at our institution from 2004 to 2017. ResultsA total of 289 patients were evaluated. Median followup was 72 months. Median age was 70 years. APBI was the only primary treatment in 86.2% of cases with early-stage breast cancer and a second conservative treatment in 13.8%. The implant was performed postoperatively in 213 patients (73.7%) and intraoperatively in 76 (26.3%). The most common radiation schemes were 10 fractions of 3.4 Gy and eight fractions of 4 Gy. Elderly or frail patients (10%) received a single 16 Gy dose. Of the 289 patients, 215 met Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology criteria for APBI; in this group, late side effects included Grade 2 (G2) fibrosis (14.8%), skin discoloration at the catheter points (8.8%), and telangiectasia (0.5%). The cosmetic result was considered excellent or good in 88.3% of cases. Five-year local control, disease-free, cancer-specific, and overall survival rates were 98.9%, 96.7%, 99.1%, and 95.6%, respectively. ConclusionsLocal control and survival outcomes at 5 years of followup in this group of well-selected patients were excellent, with low rates of treatment-related toxicity. These findings confirm the safety and effectiveness of APBI, even in elderly and frail patients. These results provide further support for the clinical use of APBI in suitable patients.

High-dose interstitial brachytherapy for accelerated partial-breast irradiation in clinical practice: Preliminary results from a tertiary cancer center in India

Introduction: Over the past several years, there has been growing interest in the use of accelerated partial-breast irradiation (APBI) as an alternative to whole-breast radiation in properly selected patients. The use of multicatheter interstitial brachytherapy (MIB) for APBI is increasing due to better availability of expertise and experience than other forms of APBI. The use of APBI outside the framework of a clinical trial has markedly increased. We report the efficacy and safety of APBI through high-dose-rate (HDR) MIB for early-stage breast cancer. Materials and Methods: Between 2008 and 2017, 20 prospectively selected patients with early-stage breast cancer received APBI using MIB following breast-conserving surgery. The mean age was 62.85 years (range: 41–80). Mean size of the tumor was 2.04 cm. The dose of 34 Gy in 10 fractions given twice daily (3.4 Gy) over 5 days was delivered to the tumor bed plus a 2-cm margin. The mean follow-up was 57.75 months (range: 12–100). Ten (50%) patients received adjuvant chemotherapy. Thirteen (65%) patients received hormonal therapy. Results: A total of 18 (90%) patients reported having excellent-to-good cosmesis, while 2 (10%) had fair-to-poor cosmesis. All patients (100%) were clinically controlled at follow-up, i.e., no locoregional recurrence. Only three (15%) had distant metastasis on follow-up. Conclusion: APBI using HDR-MIB was associated with excellent local control, acceptable toxicity, and cosmesis for early-stage breast cancer patients.

ESTRO-ACROP guideline: Interstitial multi-catheter breast brachytherapy as Accelerated Partial Breast Irradiation alone or as boost – GEC-ESTRO Breast Cancer Working Group practical recommendations

PurposeThis consensus statement from the Breast Cancer Working Group of Groupe Européen de Curiethérapie of European Society for Radiotherapy and Oncology (GEC-ESTRO) aims at generating practical guidelines for multi-catheter image-guided brachytherapy in the conservative management of breast cancer patients used for either Accelerated Partial Breast Irradiation (APBI) or for a breast boost. MethodsRecent advances in techniques of multi-catheter brachytherapy were summarized and all the relevant literature was reviewed by a panel of experts. Panel members of the GEC-ESTRO experts participated in a series of conferences, supplemented their clinical experience, were surveyed to determine their current practices and patterns, performed a literature review, and formulated recommendations for implementing APBI with multi-catheter brachytherapy, focusing on treatment planning issues, catheter insertion, dosimetry and quality assurance. This document was reviewed and approved by the full panel, the GEC-ESTRO executive board and by the ACROP (Advisory Committee on Radiation Oncology Practice). ResultsThree-dimensional (3D) treatment planning, catheter insertion techniques, dosimetry and methods of quality assurance for APBI and boost with multi-catheter image-guided brachytherapy after breast conserving surgery are described. Detailed recommendations for daily practice including dose constraints are given. ConclusionsRecent standards and guidelines for the use of APBI with different multi-catheter image-guided brachytherapy techniques have been defined. Different techniques are used to insert the catheters. Guidelines are mandatory to assure precise catheter insertion for coverage of the target volume and to guarantee high-quality dosimetry. The same rules apply for brachytherapy based boost irradiation for breast cancer after whole breast irradiation as well as for partial breast re-irradiation.

Nation-Scale Adoption of Shorter Breast Radiation Therapy Schedules Can Increase Survival in Resource Constrained Economies: Results From a Markov Chain Analysis

Hypofractionated whole breast irradiation and accelerated partial breast irradiation (APBI) offer women options for shorter courses of breast radiation therapy. The impact of these shorter schedules on the breast cancer populations of emerging economies with limited radiation therapy resources is unknown. We hypothesized that adoption of these schedules would improve throughput in the system and, by allowing more women access to life-saving treatments, improve patient survival within the system. We designed a Markov chain model to simulate the different health states that a postlumpectomy or postmastectomy patient could enter over the course of a 20-year follow-up period. Transition rates between health states were adapted from published data on recurrence rates. We used primary data from a tertiary care hospital in Lahore, Pakistan, to populate the model with proportional use of mastectomy versus breast conservation and to estimate the proportion of patients suitable for APBI. Sensitivity analyses on the use of APBI and relative efficacy of APBI were conducted to study the impact on the population. The shorter schedule resulted in more women alive and more women remaining without evidence of disease (NED) compared with the conventional schedule, with an absolute difference of about 4% and 7% at 15years, respectively. Among women who had lumpectomies, the chance of remaining alive and with an intact breast was 62% in the hypofractionation model and 54% in the conventional fractionation model. Increasing throughput in the system can result in improved survival, improved chances of remaining without evidence of disease, and improved chances of remaining alive with a breast. These findings are significant and suggest that adoption of hypofractionation in emerging economies is not simply a question of efficiency and cost but one of access to care and patient survivorship.

Practical Implications of the Publication of Consensus Guidelines by the American Society for Radiation Oncology: Accelerated Partial Breast Irradiation and the National Cancer Data Base

To examine utilization trends of accelerated partial breast irradiation (APBI) in the American College of Surgeons' National Cancer Database and changes in APBI use after the 2009 publication of the American Society for Radiation Oncology (ASTRO) guidelines. A total of 399,705 women were identified who were diagnosed from 2004 to 2011 with nonmetastatic invasive breast cancer or ductal carcinoma in situ who were treated with breast-conserving surgery and radiation therapy to the breast. Patients were divided by the type of treatment received (whole breast irradiation or APBI) and by suitability to receive APBI as defined by the ASTRO guidelines. Logistic regression was applied to study APBI use overall and within guideline categorization, and a multivariable model was created to determine predictors of treatment with brachytherapy-based APBI based on guideline categorization. For all patients, APBI use increased, from 3.8% in 2004 to 10.6% in 2011 (P<.0001). Overall rates of APBI utilization were higher among "suitable" than "cautionary"/"unsuitable" patients (14.8% vs 7.1%, P<.0001). The majority of APBI treatment was delivered using brachytherapy, for which use peaked in 2008. Starting in 2009, among "suitable" patients, utilization of APBI via brachytherapy plateaued, whereas for "cautionary"/"unsuitable" patients, treatment with brachytherapy-based APBI declined and then plateaued. Use of APBI across all patient groups increased from 2004 through 2008. After publication of the ASTRO APBI guidelines in 2009, rates of brachytherapy-based APBI treatment plateaued among "suitable" patients and declined and then plateaued among "cautionary"/"unsuitable" patients. Our study highlights how large national databases can be used to assess national trends in radiation use in response to the publication of guidelines.

Did the adoption of accelerated partial-breast irradiation reduce the noncompliance with adjuvant radiation in lumpectomy patients?

BackgroundThe underutilization of radiation therapy after breast-conserving surgery in early-stage breast cancer patients has been attributed to the inconvenience and potential side effects of whole-breast radiation treatment regimens. Accelerated partial-breast irradiation (APBI) involves twice-daily treatments more than 4 to 5 days, which could potentially improve convenience and adherence for women undergoing treatment. MethodsWe studied local therapies in about one-third of a million female breast cancer patients who were diagnosed between January 2000 and June 2011. ResultsWe found that the use of APBI brachytherapy increased rapidly from .2% in 2000 to about 3.1% in 2008 and leveled off after 2009. The increased use of APBI did not reduce the percentage of early-stage breast cancer patients who improperly forego radiation (about 14% over the whole study period). ConclusionsNoncompliance with adjuvant radiation is still common when shortened radiation therapy becomes increasingly accessible.

Breast Conservation Therapy Utilizing Partial Breast Brachytherapy for Early-stage Cancer of the Breast

Accelerated partial breast irradiation (APBI) is a convenient alternative to whole-breast irradiation, as less overall time is needed for completion. The use of APBI outside the framework of large prospective clinical trials has markedly increased. To our knowledge, no high-volume, community-based breast program has published their experience with APBI. The records of 93 consecutive patients who underwent APBI utilizing Mammosite Radiation Therapy System from 2005 to 2010 at Saint Luke's Cancer Institute in Kansas City, MO, were retrospectively reviewed. The Kaplan-Meier method was used to estimate the ipsilateral breast recurrence rate and recurrence-free survival. Median age at diagnosis was 63 years (range, 45 to 86 y) and mean follow-up was 29 months. Patient stratification ASTRO consensus classifications for APBI was 37% suitable, 57% cautionary, and 6% unsuitable. The 3-year breast control rate was 98.7%. Three-year overall recurrence-free survival was 94.4%, and 3-year mastectomy-free survival was 97.4%. Using univariate analysis, no tumor or patient factors were associated with ipsilateral breast recurrence. However, tumor grade (P<0.05), stage (P=0.04), estrogen receptor status (P<0.001), progesterone receptor status (P<0.001), tumor size (P<0.001), and ASTRO suitability criteria (P=0.027) were associated with overall recurrence-free survival. No differences were observed when outcomes of patients with ductal carcinoma in situ were compared with those with invasive disease. In our high-volume community-based program, APBI outcomes are comparable with those reported from large academic institutions. We also found relationships between tumor stage, grade, negative estrogen receptor status, and ASTRO suitability criteria with overall recurrence rates. The continued careful application of APBI in appropriately selected patients appears warranted until phase III trials comparing this modality to whole-breast irradiation have matured.

Predictors of Adverse Cosmetic Outcome in the RAPID Trial: An Exploratory Analysis

To evaluate factors associated with adverse cosmesis outcome in breast cancer patients randomized to accelerated partial breast irradiation (APBI) using 3-dimensional conformal radiation therapy or whole-breast irradiation in the RAPID (Randomized Trial of Accelerated Partial Breast Irradiation) trial. Subjects were trial participants with nurse-assessed global cosmetic scores at baseline and at 3years. Adverse cosmesis was defined as a score of fair or poor. Cosmetic deterioration was defined as any adverse change in score from baseline to 3years. The analysis is based on data from the previously reported interim analysis. Logistic regression models were used to assess the association ofrisk factors for these outcomes among all patients and those treated with APBI only. Clinicopathologic characteristics were similar between subjects randomized to APBI (n=569) or whole-breast irradiation (n=539). For all subjects, factors associated with adverse cosmesis at 3years were older age, central/inner tumor location, breast infection, smoking, seroma volume, breast volume, and use of APBI; factors associated with cosmetic deterioration were smoking, seroma volume, and use of APBI (P<.05). For APBI subjects, tumor location, smoking, age, and seroma volume were associated with adverse cosmesis (P<.05), and smoking was associated with cosmetic deterioration (P=.02). An independent association between the V95/whole-breast volume ratio and adverse cosmesis (P=.28) or cosmetic deterioration (P=.07) was not detected. On further exploration a V95/whole-breast volume ratio <0.15 was associated with a lower risk of cosmetic deterioration (p=.04), but this accounted for only 11% of patients. In the RAPID trial, a number of patient tumor and treatment-related factors, including the use of APBI, were associated with adverse cosmesis and cosmetic deterioration. For patients treated with APBI alone, the high-dose treatment volume was not independently associated with an adverse cosmetic outcome, and a useful clinical threshold could not be identified.

Accelerated partial breast irradiation.

Local therapies to treat newly diagnosed breast cancer include a lumpectomy with radiation therapy or a mastectomy. The 20-year data from studies about the safety and efficacy of lumpectomy with full-breast radiation therapy support the safety of this regimen and its role to decrease the risk of ipsilateral recurrence and increase long-term survivorship of women with breast cancer. Accelerated partial breast irradiation (APBI) provides radiation therapy to the tumor bed but spares the remaining breast tissue. APBI accelerates the time required to complete the therapy regimen, with a range of one intraoperative session to five consecutive days compared to five to seven weeks. Several techniques exist to administer APBI, including the insertion of a balloon into the lumpectomy space. Of interest is the widespread use of APBI in community and academic settings that has preceded outcomes of large, randomized clinical trials. Because of selection bias in a number of small, single-institution, nonrandomized studies, published data are of limited value to ensure APBI as a standard of care.

Prospective Multicenter Trial Evaluating Balloon-Catheter Partial-Breast Irradiation for Ductal Carcinoma in Situ

To determine outcomes of accelerated partial-breast irradiation (APBI) with MammoSite in the treatment of ductal carcinoma in situ (DCIS) after breast-conserving surgery. We conducted a prospective, multicenter trial between 2003 and 2009. Inclusion criteria included age >18 years, core needle biopsy diagnosis of DCIS, and no prior breast cancer history. Patients underwent breast-conserving surgery plus MammoSite placement. Radiation was given twice daily for 5 days for a total of 34 Gy. Patients were evaluated for development of toxicities, cosmetic outcome, and ipsilateral breast tumor recurrence (IBTR). A total of 41 patients (42 breasts) completed treatment in the study, with a median follow up of 5.3 years. Overall, 28 patients (68.3%) experienced an adverse event. Skin changes and pain were the most common adverse events. Cosmetic outcome at 6 months was judged excellent/good by 100% of physicians and by 96.8% of patients. At 12 months, 86.7% of physicians and 92.3% of patients rated the cosmetic outcome as excellent/good. Overall, 4 patients (9.8%) developed an IBTR (all DCIS), with a 5-year actuarial rate of 11.3%. All IBTRs were outside the treatment field. Among patients with IBTRs, the mean time to recurrence was 3.2 years. Accelerated partial-breast irradiation using MammoSite seems to provide a safe and cosmetically acceptable outcome; however, the 9.8% IBTR rate with median follow-up of 5.3 years is concerning. Prospective randomized trials are necessary before routine use of APBI for DCIS can be recommended.

Utilization of accelerated partial-breast irradiation (APBI) and guideline concordance: Analysis of the National Cancer Database.

54 Background: ASTRO published a consensus statement on patient suitability for APBI treatment to guide physician practice. The purpose of this study was to examine utilization trends of APBI in the American College of Surgeons’ National Cancer Database and to assess changes in APBI use following publication of the ASTRO guidelines in 2009. Methods: A total of 337,910 women were identified who were diagnosed from 2004 to 2010 with non-metastatic invasive breast cancer or ductal carcinoma in situ who were treated with breast conserving surgery and radiation therapy (RT) to the breast. Patients were divided by the type of treatment received (whole breast irradiation (WBI) or APBI) and by suitability to receive APBI as defined by the ASTRO Consensus Statement. Logistic regression was applied to study APBI use overall and within consensus statement categorization. All p-values are two-sided. Results: For all patients, APBI usage increased as an alternative to WBI over time, from 3.8% in 2004 to 10.8% in 2008, with a subsequent decline to 9.9% in 2010, due to a decline in APBI use for “cautionary”/“unsuitable” patients (p&lt;0.0001). Overall rates of APBI utilization were higher among “suitable” than “cautionary”/“unsuitable” patients (range 6.9% to 16.9% vs. 3.1% to 7.8%, p&lt;0.0001). Among all patients, the most common modality of delivering APBI was brachytherapy (82%), followed by external beam RT (17%) and intraoperative RT (1.0%). For both “suitable” and “cautionary”/“unsuitable” patients, factors associated with treatment with APBI included treatment after 2004 (p&lt;0.0001), well differentiated histology (p&lt;.0001), and smaller tumor size (p&lt;0.0001). For “cautionary”/“unsuitable” patients, those with grossly negative tumor margins were more likely to receive APBI, as were “suitable” patients treated at an academic or comprehensive community cancer program compared to a community cancer program (both p&lt;0.0001). Conclusions: The highest absolute rate of use of APBI was seen in the group considered “suitable” by ASTRO guidelines. Although significant increases have also been seen among less suitable cohorts, these rates have declined since the publication of the ASTRO guidelines in 2009.

Clinical Experience Using Accelerated Partial Breast Irradiation for Ductal Carcinoma In Situ

To the Editor:Breast-conserving therapy (BCT) has becomestandard care as an alternative to mastectomy in thetreatment of most women with early stage 0, I, and IIbreast cancer (1). BCT includes tumor excision bymeans of lumpectomy followed by a course of dailyfractions of external beam radiation therapy to thewhole breast (45–50 Gy), which can be, and often is,followed by a boost to the tumor bed with an addi-tional 6–10 fractions, which achieves a total dose of60–64 Gy. These treatments typically span 5–7 weeks.Studies looking at the patterns of failure and localrecurrence for patients with breast cancer found thatthe majority (about 90%) of early breast local recur-rences occurred at the site of the original primarytumor (2). This observation and the desire to shortenthe treatment times led to the idea of using acceleratedpartial breast irradiation (APBI), which concentratesthe dose of radiation at the site of the lumpectomycavity and simultaneously limits the dose to otherstructures. This type of therapy is typically given over5 days, which not only reduces the toxicity of irradia-tion but also reduces the total treatment time.Results from trials studying the efficacy of APBIhave been encouraging, in that multiple techniqueshave been effective in maintaining excellent local con-trol and cosmetic outcomes with minimal toxicity(3–6). Several phase III randomized studies of APBIare under way; in addition, we are awaiting the resultsof the National Surgical Adjuvant Breast and BowelProject B 39/Radiation Therapy Oncology Group0413 protocol (B-39) large phase III trial that com-pares ABPI to whole breast irradiation (WBI) in earlystage breast cancer, which is finishing accrual in thenear future (7–10).Ductal carcinoma in situ (DCIS) comprises approxi-mately 25% of all cases of breast cancer diagnosedeach year (1). The National Comprehensive CancerNetwork (NCCN) guidelines continue to recommendBCT with standard adjuvant WBI as a category 1 rec-ommendation for DCIS (11). This recommendation isbased on the results of multiple randomized controlledtrials (12,13) demonstrating the efficacy of this com-bined modality approach. Specifically, these studiesreport an approximate 50% relative risk reduction inlocal control with the addition of adjuvant RT. Nosubgroup of patients with DCIS has proved not tobenefit from postoperative radiotherapy (14,15). In2002, DCIS was included as acceptable for APBI inthe American Society for Breast Surgeons (ASBS)guidelines. The APBI Consensus Statement Task Forceof the American Society for Radiation Oncology(ASTRO) classifies the subset of patients with pureDCIS as “cautionary,” with a recommended tumorcutoff size of 3 cm (16). Recent publications haveshown excellent 5-year follow-up results in patientswith DCIS treated with APBI (17–20).At our institutions we have noted low recurrencerates and excellent or good cosmesis outcomes in100% of the patients treated with APBI after breastconservation surgery (BCS) for patients with DCIS.This letter is in response to requests from brachythera-py specialists to publicize institution-specific dataregarding the use of APBI to treat breast cancer. Wehave now treated over 40 patients with stage 0 breastcancer treated with BCS and adjuvant APBI. Allpatients had biopsy-proven DCIS, and three patientsalso had an invasive component along with DCIS.With a median follow-up was 27 months (range,0–72 months, the overall and cause-specific survivalrates were 95% and 100%, respectively. The24-month actuarial ipsilateral breast tumor recurrence(IBTR) rate was 2.5%, with one patient having arecurrence. Another patient developed a contralateral

Accelerated Partial Breast Irradiation for Early-Stage Breast Cancer: Controversies and Current Indications for Use

Radiation therapy options for early-stage breast cancer have evolved during the past 40 years. Several choices are currently available to certain patient subsets that allow radiation oncologists to individualize care. Multiple phase II and several phase III trials have been published that support the safety and efficacy of accelerated partial breast irradiation (APBI) as part of breast conservation in selected patients. In contrast, a recent large retrospective analysis of patients aged 67 or older who received brachytherapy for APBI has raised concerns about its effectiveness. As the radiation community awaits results from NSABP B-39/RTOG 0413, the largest randomized trial of whole breast radiation therapy (WBRT) versus APBI, to provide more conclusive data, many academic and private radiation oncology practices are utilizing APBI off-protocol to treat early-stage breast cancer patients. Because of this, the American Society for Radiation Oncology (ASTRO) published a consensus statement in 2009 to aid in proper patient selection (Table 1). Until more definitive data is garnered, we advocate strict adherence to these selection criteria to ensure optimal outcomes. Specifically, we caution against the use of APBI in lymph node-positive disease outside of a clinical trial. There is a paucity of comparative data to guide oncologists in selection of the best APBI delivery method. The current NSABP B-39/RTOG 0413 trial allows any of the three most common forms of delivery to be utilized (multicatheter interstitial brachytherapy, balloon intracavitary brachytherapy, and external beam 3D conformal therapy) and will be instrumental to compare outcome differences between these methods.

Should Ductal Carcinoma-in-situ (DCIS) Be Removed from the ASTRO Consensus Panel Cautionary Group for Off-protocol Use of Accelerated Partial Breast Irradiation (APBI)? A Pooled Analysis of Outcomes for 300 Patients with DCIS Treated with APBI

To analyze outcomes in patients with ductal carcinoma-in-situ (DCIS) treated with accelerated partial breast irradiation (APBI) within a pooled set of patients. A total of 300 women with DCIS underwent APBI between April 1993 and November 2010 as part of American Society of Breast Surgeons MammoSite Registry Trial (n=192) or at William Beaumont Hospital (n=108). Patients with pure DCIS <3cm (n=125) were assigned to the cautionary risk group per American Society of Radiation Oncology consensus panel guidelines for off-protocol use of APBI and analyzed compared to a pooled invasive suitable (n=653) risk group and pooled invasive suitable/cautionary (n=1,298) risk group. The rate of ipsilateral breast tumor recurrence (IBTR) for all 300 DCIS patients was 2.6% at 5years with no regional recurrences, while cause-specific survival was 99.5% and overall survival (OS) was 96.4%. When comparing the cautionary DCIS group to the invasive suitable/cautionary group, no difference in IBTR was noted (2.6 vs. 3.1%, P=0.90) with significant improvements in distant metastases (0 vs. 2.5 %, P=0.05), disease-free survival (98.5 vs. 94.4 %, P=0.05), and OS (95.7 vs. 90.8 %, P=0.03) noted for DCIS patients. When comparing cautionary DCIS patients to invasive suitable patients, no difference in IBTR were noted (2.6 vs. 2.4 %, P=0.76), while improved OS for DCIS patients was noted (95.7 vs. 90.9 %, P=0.02). This analysis of the largest cohort of patients with DCIS treated with APBI supports previously reported excellent outcomes; as a result of small numbers of events, further data are necessary to confirm these findings.

Comparison of survival and regional failure between accelerated partial breast irradiation and whole breast irradiation

PurposeTo compare rates of regional recurrence (RR) and overall survival (OS) between a pooled set of 1400 patients treated on the American Society of Breast Surgeons MammoSite (Hologic, Inc., Bedford, MA) Registry Trial to a cohort of 3600 patients treated with whole breast irradiation (WBI). Methods and MaterialsA total of 1440 women underwent accelerated partial breast irradiation (APBI) between 2002 and 2004 as part of the American Society of Breast Surgeons Registry Trial and a total of 3593 patients who received WBI were evaluated from the Surveillance Epidemiology and End Results database with treatment received between 1980 and 2009. A matched-pair analysis was performed based on age, receipt of hormonal therapy, chemotherapy, nodal status, and tumor size (1051 patients per arm). Rates of RR and OS were then analyzed for each group. ResultsAfter the match, no differences in patient characteristics were noted when tumor size was evaluated as a continuous variable. Rates of RR and OS were similar between the WBI and APBI groups. A Cox regression model found no difference between WBI and APBI with regard to RR; however, OS was improved in the APBI cohort (hazard ratio 0.008, p<0.0001). ConclusionsWith one of the largest patient populations to date comparing WBI and APBI, no difference in RR or OS was noted between WBI and APBI treatment. Until the publication of prospective Phase III trials, these data support the continued use of APBI on protocol and off protocol in appropriately selected patients.

Efficacy analysis of high-risk breast cancer patients treated with accelerated partial breast irradiation from a single institution.

111 Background: We present the results of an analysis of high-risk breast cancer patients as defined by the NSABP B-39/RTOG 0413 phase III trial, all treated with accelerated partial breast irradiation (APBI) from a single institution. Methods: Between July 1993 and August 2010, 130 patients with any combination of at least one of the high-risk features of estrogen receptor (ER) negativity, age &lt; 50, and/or axillary nodal positivity were treated with 1 of 3 forms of APBI. Sixty-seven patients were treated with interstitial needle-catheter brachytherapy, 44 balloon-based brachytherapy and 19 with 3D conformal external beam radiation therapy. Aside from the high-risk features, general eligibility criteria included infiltrating ductal carcinoma, with inclusion of invasive lobular and DCIS since 2003, margins &gt; 2 mm, and surgically staged axilla. One-hundred eighteen patients had one high-risk factor, 11 had two, and 1 had all three factors. The median tumor size was 12.0 mm with margins &gt; 2 mm in 80% of patients. Greater than 75% had T1 tumors and 50% were ER negative. Thirty-one percent of patients were node positive. Based upon the ASTRO Consensus Guidelines for use of APBI (2009) none of these patients were suitable, 38% cautionary and 62% were unsuitable. Results: Median age was 56.5 yrs (range 40-90). With a median follow-up of 5.3 yrs (0.02-16.9) the 5-yr actuarial local recurrence rate (LR) was 4.2%; regional recurrence (RR) was 2.1%. Median time to LR and RR were 1.2 and 2.8 yrs, respectively. On univariate analysis, the only factor significant for LR was a close/positive margin (p=0.031), as ER/PR, age, nodal status, tumor size, histology, grade, hormonal or chemotherapy were all NS. The 5-yr actuarial cause specific, disease-free, and overall survivals as well as distant metastasis were 94%, 91%, 90%, and 6.4%, respectively. Conclusions: This cohort of NSABP B-39/RTOG 0413 identified high-risk patients who have undergone APBI has yielded local-regional control rates and survival outcomes comparable to standard risk patients undergoing partial breast irradiation. Continued follow-up will be needed to assess the long-term efficacy of such high-risk breast cancer patients treated with APBI.

Abstract P4-11-16: Accelerated Partial Breast Irradiation for Ductal Carcinoma In Situ: An Analysis of the Susan G Komen Clinical Trial

Abstract Introduction In 2002 the Food and Drug Administration approved a device, MammoSite, that delivers accelerated partial breast irradiation (APBI). Our aim was to determine outcomes with MammoSite in the treatment of ductal carcinoma in situ (DCIS). Methods We conducted a prospective multi-center trial between 2003 and 2009. Inclusion criteria included age &amp;gt; 18 years, biopsy diagnosis of DCIS, and no prior breast cancer history. Patients underwent breast-conserving surgery plus MammoSite placement. Radiation was given twice daily for 5 days for a total of 34 Gy. Patients were evaluated for development of toxicities (according to the EROTC/RTOG Acute Radiation Morbidity Scoring Criteria), cosmetic outcome, and ipsilateral breast tumor recurrence (IBTR). Results We enrolled 45 patients into the study. APBI was not initiated in 5 patients due to inadequate distance from tumor cavity to the skin. Toxicities were observed in 30 patients (75%). Grade 1 toxicity was the most common (78%); most were subcutaneous and cutaneous changes. Cosmetic outcome at 12 months was reported as good to excellent in 93% of surgeon and 90% of patient responses. Median follow up was 36.5 months. Among treated patients, 4 (10%), developed an IBTR, (all DCIS). All IBTRs were outside the treatment field. Among patients with IBTRs the mean age was 49.8 years and the mean time to recurrence was 29.8 months. Conclusions APBI, using MammoSite, appears to provide a safe cosmetically acceptable outcome; however the 10% IBTR rate with median follow up of only 36.5 months is concerning. Randomized trials are necessary before use of APBI for DCIS. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-16.