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Shaitelman SF, Anderson BM, Arthur DW, Bazan JG, Bellon JR, Bradfield L, Coles CE, Gerber NK, Kathpal M, Kim L, Laronga C, Meattini I, Nichols EM, Pierce LJ, Poppe MM, Spears PA, Vinayak S, Whelan T, Lyons JA. Partial Breast Irradiation for Patients With Early-Stage Invasive Breast Cancer or Ductal Carcinoma In Situ: An ASTRO Clinical Practice Guideline. Pract Radiat Oncol 2024; 14:112-132. [PMID: 37977261 DOI: 10.1016/j.prro.2023.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE This guideline provides evidence-based recommendations on appropriate indications and techniques for partial breast irradiation (PBI) for patients with early-stage invasive breast cancer and ductal carcinoma in situ. METHODS ASTRO convened a task force to address 4 key questions focused on the appropriate indications and techniques for PBI as an alternative to whole breast irradiation (WBI) to result in similar rates of ipsilateral breast recurrence (IBR) and toxicity outcomes. Also addressed were aspects related to the technical delivery of PBI, including dose-fractionation regimens, target volumes, and treatment parameters for different PBI techniques. The guideline is based on a systematic review provided by the Agency for Healthcare Research and Quality. Recommendations were created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength. RESULTS PBI delivered using 3-dimensional conformal radiation therapy, intensity modulated radiation therapy, multicatheter brachytherapy, and single-entry brachytherapy results in similar IBR as WBI with long-term follow-up. Some patient characteristics and tumor features were underrepresented in the randomized controlled trials, making it difficult to fully define IBR risks for patients with these features. Appropriate dose-fractionation regimens, target volume delineation, and treatment planning parameters for delivery of PBI are outlined. Intraoperative radiation therapy alone is associated with a higher IBR rate compared with WBI. A daily or every-other-day external beam PBI regimen is preferred over twice-daily regimens due to late toxicity concerns. CONCLUSIONS Based on published data, the ASTRO task force has proposed recommendations to inform best clinical practices on the use of PBI.
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Affiliation(s)
- Simona F Shaitelman
- Department of Breast Radiation Oncology, University of Texas MD - Anderson Cancer Center, Houston, Texas.
| | - Bethany M Anderson
- Department of Radiation Oncology, University of Wisconsin, Madison, Wisconsin
| | - Douglas W Arthur
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia
| | - Jose G Bazan
- Department of Radiation Oncology, City of Hope Comprehensive Cancer Center, Duarte, California
| | - Jennifer R Bellon
- Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, Massachusetts
| | - Lisa Bradfield
- American Society for Radiation Oncology, Arlington, Virginia
| | - Charlotte E Coles
- Department of Oncology, University of Cambridge, Cambridge, United Kingdom
| | - Naamit K Gerber
- Department of Radiation Oncology, New York University Grossman School of Medicine, New York, New York
| | - Madeera Kathpal
- Department of Radiation Oncology, Duke University Wake County Campus, Raleigh, North Carolina
| | - Leonard Kim
- Department of Radiation Oncology, MD - Anderson Cancer Center at Cooper, Camden, New Jersey
| | - Christine Laronga
- Department of Breast Oncology, Moffitt Cancer Center, Tampa, Florida
| | - Icro Meattini
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Elizabeth M Nichols
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Lori J Pierce
- Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Matthew M Poppe
- Department of Radiation Oncology, Huntsman Cancer Institute, Salt Lake City, Utah
| | - Patricia A Spears
- Patient Representative, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Shaveta Vinayak
- Department of Medical Oncology, University of Washington, Seattle, Washington
| | - Timothy Whelan
- Department of Oncology, McMaster University, Hamilton, Ontario, Canada
| | - Janice A Lyons
- Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Cleveland, Ohio
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Ravani LV, Calomeni P, Wang M, Deng D, Speers C, Zaorsky NG, Shah C. Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: a Kaplan-Meier-derived patient data meta-analysis. Breast Cancer Res Treat 2024; 203:1-12. [PMID: 37736843 DOI: 10.1007/s10549-023-07112-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 08/24/2023] [Indexed: 09/23/2023]
Abstract
PURPOSE Partial breast irradiation (PBI) and intraoperative radiation (IORT) represent alternatives to whole breast irradiation (WBI) following breast conserving surgery. However, data is mixed regarding outcomes. We therefore performed a pooled analysis of Kaplan-Meier-derived patient data from randomized trials to evaluate the hypothesis that PBI and IORT have comparable long-term rates of ipsilateral breast tumor recurrence as WBI. METHODS In February, 2023, PubMed, EMBASE and Cochrane Central were systematically searched for randomized phase 3 trials of early-stage breast cancer patients undergoing breast-conserving surgery with PBI or IORT as compared to WBI. Time-to-event outcomes of interest included ipsilateral breast tumor recurrence (IBTR), overall survival (OS) and distant disease-free survival (DDFS). Statistical analysis was performed with R Statistical Software. RESULTS Eleven randomized trials comprising 15,460 patients were included; 7,675 (49.6%) patients were treated with standard or moderately hypofractionated WBI, 5,413 (35%) with PBI and 2,372 (15.3%) with IORT. Median follow-up was 9 years. PBI demonstrated comparable IBTR risk compared with WBI (HR 1.20; 95% CI 0.95-1.52; p = 0.12) with no differences in OS (HR 1.02; 95% CI 0.90-1.16; p = 0.70) or DDFS (HR 1.15; 95% CI 0.81-1.64; p = 0.43). In contrast, patients treated with IORT had a higher IBTR risk (HR 1.46; 95% CI 1.23-1.72; p < 0.01) compared with WBI with no difference in OS (HR 0.98; 95% CI 0.84-1.14; p = 0.81) or DDFS (HR 0.91; 95% CI 0.76-1.09; p = 0.31). CONCLUSION For patients with early-stage breast cancer following breast-conserving surgery, PBI demonstrated no difference in IBTR as compared to WBI while IORT was inferior to WBI with respect to IBTR.
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Affiliation(s)
| | - Pedro Calomeni
- University of Sao Paulo Medical School, São Paulo, Brazil
| | - Ming Wang
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Daxuan Deng
- Department of Public Health Sciences, Penn State University College of Medicine, Hershey, PA, USA
| | - Corey Speers
- Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Nicholas G Zaorsky
- Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Chirag Shah
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA
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Shumway DA, Corbin KS, Farah MH, Viola KE, Nayfeh T, Saadi S, Shah V, Hasan B, Shah S, Mohammed K, Riaz IB, Prokop LJ, Murad MH, Wang Z. Partial breast irradiation compared with whole breast irradiation: a systematic review and meta-analysis. J Natl Cancer Inst 2023; 115:1011-1019. [PMID: 37289549 PMCID: PMC10483267 DOI: 10.1093/jnci/djad100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/21/2023] [Accepted: 05/23/2023] [Indexed: 06/10/2023] Open
Abstract
BACKGROUND Early-stage breast cancer is among the most common cancer diagnoses. Adjuvant radiotherapy is an essential component of breast-conserving therapy, and several options exist for tailoring its extent and duration. This study assesses the comparative effectiveness of partial-breast irradiation (PBI) compared with whole-breast irradiation (WBI). METHODS A systematic review was completed to identify relevant randomized clinical trials and comparative observational studies. Independent reviewers working in pairs selected studies and extracted data. Randomized trial results were pooled using a random effects model. Prespecified main outcomes were ipsilateral breast recurrence (IBR), cosmesis, and adverse events (AEs). RESULTS Fourteen randomized clinical trials and 6 comparative observational studies with 17 234 patients evaluated the comparative effectiveness of PBI. PBI was not statistically significantly different from WBI for IBR at 5 years (RR = 1.34, 95% CI = 0.83 to 2.18; high strength of evidence [SOE]) and 10 years (RR = 1.29, 95% CI = 0.87 to 1.91; high SOE). Evidence for cosmetic outcomes was insufficient. Statistically significantly fewer acute AEs were reported with PBI compared with WBI, with no statistically significant difference in late AEs. Data from subgroups according to patient, tumor, and treatment characteristics were insufficient. Intraoperative radiotherapy was associated with higher IBR at 5, 10, and over than 10 years (high SOE) compared with WBI. CONCLUSIONS Ipsilateral breast recurrence was not statistically significantly different between PBI and WBI. Acute AEs were less frequent with PBI. This evidence supports the effectiveness of PBI among selected patients with early-stage, favorable-risk breast cancer who are similar to those represented in the included studies.
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Affiliation(s)
- Dean A Shumway
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Kimberly S Corbin
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Magdoleen H Farah
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Kelly E Viola
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Tarek Nayfeh
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Samer Saadi
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Vishal Shah
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Bashar Hasan
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Sahrish Shah
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Khaled Mohammed
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
| | - Irbaz Bin Riaz
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
| | - Larry J Prokop
- Library Public Services, Mayo Clinic, Rochester, MN, USA
| | - M Hassan Murad
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | - Zhen Wang
- Mayo Clinic Evidence-Based Practice Center, Rochester, MN, USA
- Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
- Division of Health Care Delivery Research, Mayo Clinic, Rochester, MN, USA
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Recent Advances in Optimizing Radiation Therapy Decisions in Early Invasive Breast Cancer. Cancers (Basel) 2023; 15:cancers15041260. [PMID: 36831598 PMCID: PMC9954587 DOI: 10.3390/cancers15041260] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023] Open
Abstract
Adjuvant whole breast irradiation after breast-conserving surgery is a well-established treatment standard for early invasive breast cancer. Screening, early diagnosis, refinement in surgical techniques, the knowledge of new and specific molecular prognostic factors, and now the standard use of more effective neo/adjuvant systemic therapies have proven instrumental in reducing the rates of locoregional relapses. This underscores the need for reliably identifying women with such low-risk disease burdens in whom elimination of radiation from the treatment plan would not compromise oncological safety. This review summarizes the current evidence for radiation de-intensification strategies and details ongoing prospective clinical trials investigating the omission of adjuvant whole breast irradiation in molecularly defined low-risk breast cancers and related evidence supporting the potential for radiation de-escalation in HER2+ and triple-negative clinical subtypes. Furthermore, we discuss the current evidence for the de-escalation of regional nodal irradiation after neoadjuvant chemotherapy. Finally, we also detail the current knowledge of the clinical value of stromal tumor-infiltrating lymphocytes and liquid-based biomarkers as prognostic factors for locoregional relapse.
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Goldberg M, Bridhikitti J, Khan AJ, McGale P, Whelan TJ. A Meta-Analysis of Trials of Partial Breast Irradiation. Int J Radiat Oncol Biol Phys 2023; 115:60-72. [PMID: 36155214 DOI: 10.1016/j.ijrobp.2022.09.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 02/09/2023]
Abstract
PURPOSE Partial breast irradiation (PBI) is the delivery of radiation therapy (RT) limited to the tumor bed after breast conserving surgery. The results of recent trials of PBI compared with whole breast irradiation (WBI) have suggested conflicting results with respect to local control and toxicity. The purpose of this meta-analysis was to assess effectiveness of PBI and to compare the different techniques. METHODS AND MATERIALS A meta-analysis of aggregate data from published randomized trials was performed to examine the effectiveness of PBI compared with WBI in patients with invasive breast cancer and ductal carcinoma in situ. Relevant data were extracted. The primary outcome was any ipsilateral breast event (invasive or noninvasive). Secondary outcomes included acute and late toxicity. The results of randomized trials were pooled using a fixed effects model and the inverse variance method. RESULTS Fifteen trials involving 16,474 patients were identified. The majority of enrolled patients were >60 years of age and had T1N0 grade 1 to 2 disease treated with hormone therapy. The percent of ipsilateral breast events was higher in patients treated with PBI compared with WBI (5.0% vs 2.8%; risk ratio [RR], 1.72; 95% confidence interval [CI], 1.47-2.02). Heterogeneity (P = .0002) was observed between the 4 PBI techniques: external beam RT without computed tomography (CT) planning (RR, 2.06; 95% CI, 1.36-3.12); brachytherapy (RR, 1.21; 95% CI, 0.65-2.25); intraoperative RT (RR, 2.79; 95% CI, 2.08-3.73); and external beam RT with CT planning (RR, 1.25; 95% CI, 0.99-1.58). When external beam RT without CT planning and intraoperative RT trials were excluded, the percent of ipsilateral breast events was 3.3% versus 2.6%, respectively (RR, 1.25; 95% CI, 1.00-1.55; P = .05), and no heterogeneity was observed (P = .92). Overall, acute toxicity was less with PBI, and the effect on late toxicity varied by technique. CONCLUSIONS Overall, WBI was more effective than PBI, but the effectiveness of PBI was technique related. PBI was less effective when given by external beam RT without CT planning or intraoperative therapy. Although PBI given by multicatheter brachytherapy or external beam RT with CT planning tended to be statistically less effective than WBI, the absolute difference between groups for ipsilateral breast events was very small (<1%), supporting these approaches for women considering PBI.
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Affiliation(s)
- Mira Goldberg
- Department of Oncology, McMaster University, Hamilton, Ontario, Canada; Division of Radiation Oncology, Juravinski Cancer Centre at Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Jidapa Bridhikitti
- Division of Radiation Oncology, Department of Radiology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand
| | - Atif J Khan
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Paul McGale
- Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Timothy J Whelan
- Department of Oncology, McMaster University, Hamilton, Ontario, Canada; Division of Radiation Oncology, Juravinski Cancer Centre at Hamilton Health Sciences, Hamilton, Ontario, Canada.
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Shah C, Leonardi MC. Accelerated Partial Breast Irradiation: An Opportunity for Therapeutic De-escalation. Am J Clin Oncol 2023; 46:2-6. [PMID: 36255336 DOI: 10.1097/coc.0000000000000945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Partial breast irradiation (PBI) has been demonstrated to have comparable outcomes to whole breast irradiation based on multiple randomized trials with long-term follow-up. However, despite the strength of the data available, PBI remains underutilized despite being an appropriate option for many women diagnosed with early-stage breast cancer. This is significant, as PBI offers the potential to reduce toxicities and shorten treatment duration without impacting outcomes; in addition, for low-risk patients, PBI alone is being investigated as an alternative to endocrine therapy alone. Modern PBI can be delivered with multiple techniques, and advances in treatment planning have allowed for improved therapeutic ratios compared with earlier techniques; one such approach is utilizing stereotactic body radiation therapy approaches allowing for smaller target margins and therefore lower breast doses. Moving forward, studies are ongoing evaluating the use of radiation alone including PBI as compared with endocrine therapy alone, with prospective studies evaluating stereotactic body radiation therapy.
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Affiliation(s)
- Chirag Shah
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH
| | - Maria C Leonardi
- Department of Radiotherapy, IEO European Institute of Oncology, IRCCS, Milano, Italy
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Effectiveness and safety of intraoperative radiotherapy (IORT) with low-energy X-rays (INTRABEAM ®) for accelerated partial breast irradiation (APBI). Clin Transl Oncol 2022; 24:1732-1743. [PMID: 35305245 DOI: 10.1007/s12094-022-02823-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 02/22/2022] [Indexed: 10/18/2022]
Abstract
PURPOSE 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). METHODS 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 20 Gy 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). RESULTS Median follow-up was 53 months. Mean patient age was 70 years. The mean duration of radiation delivery was 22.25 min. 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%). CONCLUSION These findings confirm the effectiveness of a single dose of 20 Gy 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.
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Haussmann J, Budach W, Strnad V, Corradini S, Krug D, Schmidt L, Tamaskovics B, Bölke E, Simiantonakis I, Kammers K, Matuschek C. Comparing Local and Systemic Control between Partial- and Whole-Breast Radiotherapy in Low-Risk Breast Cancer-A Meta-Analysis of Randomized Trials. Cancers (Basel) 2021; 13:2967. [PMID: 34199281 PMCID: PMC8231985 DOI: 10.3390/cancers13122967] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/09/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022] Open
Abstract
PURPOSE/OBJECTIVE The standard treatment for localized low-risk breast cancer is breast-conserving surgery, followed by adjuvant radiotherapy and appropriate systemic therapy. As the majority of local recurrences occur at the site of the primary tumor, numerous trials have investigated partial-breast irradiation (PBI) instead of whole-breast treatment (WBI) using a multitude of irradiation techniques and fractionation regimens. This meta-analysis addresses the impact on disease-specific endpoints, such as local and regional control, as well as disease-free survival of PBI compared to that of WBI in published randomized trials. MATERIAL AND METHODS We conducted a systematic literature review and searched for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was based on the published event rates and the effect sizes for available oncological endpoints of at least two trials reporting on them. We evaluated in-breast tumor recurrences (IBTR), local recurrences at the primary site and elsewhere in the ipsilateral breast, regional recurrences (RR), distant metastasis-free interval (DMFI), disease-free survival (DFS), contralateral breast cancer (CBC), and second primary cancer (SPC). Furthermore, we aimed to assess the impact of different PBI techniques and subgroups on IBTR. We performed all statistical analyses using the inverse variance heterogeneity model to pool effect sizes. RESULTS For the intended meta-analysis, we identified 13 trials (overall 15,561 patients) randomizing between PBI and WBI. IBTR was significantly higher after PBI (OR = 1.66; CI-95%: 1.07-2.58; p = 0.024) with an absolute difference of 1.35%. We detected significant heterogeneity in the analysis of the PBI technique with intraoperative radiotherapy resulting in higher local relapse rates (OR = 3.67; CI-95%: 2.28-5.90; p < 0.001). Other PBI techniques did not show differences to WBI in IBTR. Both strategies were equally effective at the primary tumor site, but PBI resulted in statistically more IBTRs elsewhere in the ipsilateral breast. IBTRs after WBI were more likely to be located at the primary tumor bed, whereas they appeared equally distributed within the breast after PBI. RR was also more frequent after PBI (OR = 1.75; CI-95%: 1.07-2.88; p < 0.001), yet we did not detect any differences in DMFI (OR = 1.08; CI-95%: 0.89-1.30; p = 0.475). DFS was significantly longer in patients treated with WBI (OR = 1.14; CI-95%: 1.02-1.27; p = 0.003). CBC and SPC were not different in the test groups (OR = 0.81; CI-95%: 0.65-1.01; p = 0.067 and OR = 1.09; CI-95%: 0.85-1.40; p = 0.481, respectively). CONCLUSION Limiting the target volume to partial-breast radiotherapy appears to be appropriate when selecting patients with a low risk for local and regional recurrences and using a suitable technique.
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Affiliation(s)
- Jan Haussmann
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
| | - Wilfried Budach
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
| | - Vratislav Strnad
- Department of Radiation Oncology, University Erlangen, 91054 Erlangen, Germany;
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital LMU (Ludwig Maximillian), 81377 Munich, Germany;
| | - David Krug
- Department of Radiation Oncology, University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
| | - Livia Schmidt
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
| | - Balint Tamaskovics
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
| | - Edwin Bölke
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
| | - Ioannis Simiantonakis
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
| | - Kai Kammers
- Division of Biostatistics and Bioinformatics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
| | - Christiane Matuschek
- Department of Radiation Oncology, Heinrich Heine University, 40225 Dusseldorf, Germany; (J.H.); (W.B.); (L.S.); (B.T.); (I.S.); (C.M.)
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