The UK Standardisation of Breast Radiotherapy (START) Trial A of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial

Geriatric determinants of curative radiotherapy scheme choice for older adults with breast cancer treatment compliance and tolerance: Results from the GERABEL study

INTRODUCTION

Chronological and functional aging complicates care in older patients, and therapeutic decisions need to consider individual needs to minimise morbidity and mortality. Therapeutic decisions should be guided by a multidisciplinary geriatric assessment, allowing a complete assessment of physical and functional performance. In this context, the GERABEL study aimed to orientate the irradiation strategy based on a detailed oncogeriatric assessment in women more than 70 years old with breast cancer.

MATERIALS AND METHODS

This was a multicentre clinical trial conducted between January 2017 and June 2021. The oncogeriatric assessment comprised seven questionnaires (activities of daily living [ADL], instrumental ADL, Mini-Mental State Examination, mini Geriatric Depression Scale, Mini-Nutritional Assessment, Cumulative Illness Rating Scale-Geriatric, and Timed Up and Go) to determine a predictive score. Irradiation regimen was assigned according to oncogeriatric score: normofractionated - NF (score range, 160-200), hypofractionated - HF (score range, 159-120), or high-dose hypofractionated - HDHF (score ≤ 119). Endpoints were the overall tolerance to treatment, using the oncogeriatric score as a proxy at six months post-treatment, and compliance.

RESULTS

After oncogeriatric assessment at baseline, 177 patients were treated with a NF regimen, 24 with a HF regimen, and four with a HDHF regimen. Tolerance was excellent in the three groups, as no decrease of more than 20 % in the oncogeriatric score was noted at six months post-treatment. More generally, 68 % and 73 % of patients reported an improvement of the oncogeriatric score at two months and six months post-treatment, respectively. Only four treatment interruptions were observed and quality-of-life was well-conserved. In the hypo fractionated groups, short-term toxicities were not increased and no impact was noted on compliance.

DISCUSSION

Decision-making guidance for irradiation schemes in breast cancer according to oncogeriatric determinants was successful in older patients, who tolerated treatment well and, overall, had a preserved general condition.

Size Matters: Predicting Surgical Site Infection After Whole Breast Radiotherapy in the Era of Hypofractionation

Objectives: Few studies have analyzed surgical site infections associated with hypofractionated RT. The purpose of this study was to identify risk factors for surgical site infections with a particular focus on volumetric parameters that reflect the size of the volumes treated, including tumors, surgical cavities, and breasts. Methods: A total of 145 early breast cancer patients who were surgically staged 0-II undergoing hypofractionated RT on the whole breast were retrospectively reviewed. Tumor size (cm) was measured from surgical pathology. Surgical cavity volume (cc) and breast volume (cc) were calculated by segmenting each axial slice of simulation CT. The cavity-to-breast ratio (%) was calculated as surgical cavity volume/breast volume × 100. Results: The incidence of surgical site infection was 4.8% at a median of 6.3 months after the completion of RT. In univariate analysis, tumor size (OR 2.01, p = 0.025), surgical cavity volume (OR 1.03, p = 0.013), cavity-to-breast ratio (OR 1.29, p = 0.005), and BMI (OR 1.23, p = 0.014) were significantly associated with surgical site infection. In multivariate analysis, the cavity-to-breast ratio (OR 1.24, p = 0.039) remained significantly associated with surgical site infection. Conclusions: This study highlights the importance of volumetric parameters, specifically the cavity-to-breast ratio, as significant predictors of surgical site infection in a pure cohort of early breast cancer patients undergoing breast-conserving surgery and hypofractionated RT. Tailored approaches, including the use of prophylactic antibiotics, prophylactic aspiration, and close follow-up, may reduce the morbidity associated with surgical site infection and prevent the potential compromise of tumor outcomes.

Evaluating MicroRNAs as diagnostic tools for lymph node metastasis in breast cancer: Findings from a systematic review and meta-analysis

Lymph node metastasis (LNM) significantly affects the prognosis and clinical management of breast cancer (BC) patients. This systematic review and meta-analysis aim to identify microRNAs (miRNAs) associated with LNM in BC and evaluate their potential diagnostic and prognostic value. Following PRISMA guidelines, a comprehensive literature search was conducted in PubMed, Web of Science, and SCOPUS databases, to assess the role of miRNAs in LNM BC. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool was used to evaluate the quality of included studies. A total of 84 miRNAs were identified as differentially expressed in BC patients with LNM. Of these, a meta-analysis was performed in two microRNAs that were present in at least 3 different articles with a coherent expression direction: miR-155 and miR-34a. The meta-analysis returned a pooled a Log2 fold change of 1.50 for miR-155 (upregulated) and -0.53 for miR-34a (downregulated) with no evidence of publication bias, and a low risk of bias and applicability concerns. To conclude, this study names miR-155 and miR-34a as potential diagnostic biomarkers for LNM in BC, although further experimental validation is necessary to confirm these findings and develop non-invasive diagnostic tools for clinical use.

Ultra-hypofractionated 5-fraction radiation therapy for early breast cancer into whole breast and regional nodes: experience in a tertiary hospital

INTRODUCTION

Post-surgery radiotherapy to the breast and regional lymph nodes decreases locoregional tumour recurrence and related mortality. The FAST-Forward approach, with 5 daily fractions, shows non-inferiority to the conventional 15-fraction scheme with similar safety. Authors suggest Simultaneous Integrated Boost (SIB) for the tumour bed and regional nodal irradiation (RNI) for comparable toxicity.

OBJECTIVES AND PURPOSES

To describe acute and delayed toxicity in adjuvant radiotherapy patients using FAST-Forward scheme with SIB and analyze associations with patient characteristics.

MATERIALS AND METHODS

An observational, descriptive, retrospective study on 120 early breast cancer patients (pT1-3, pN0-1, M0), treated with surgery and adjuvant radiotherapy using the FAST-Forward scheme with SIB at our center. Some also received RNI. Study conducted from June 2021 to October 2023.

RESULTS

Median age: 55 years (range 30-86). Main histological type: infiltrating ductal carcinoma (80%), with Luminal A as predominant molecular subtype (58.5%). Stage IA tumours (61%), pT1c (40%), G2 (50%). Treatment included: neoadjuvant chemotherapy (18.3%), adjuvant chemotherapy (23.5%), hormonal treatment (82.5%), surgery (99%). Radiotherapy with SIB in 90% of conservative surgeries with a median dose 30 Gy (range: 29-33.6). There was no significant association between acute/chronic toxicity and SIB found. However, there was increased risk of acute induration with neoadjuvant chemotherapy. Adjuvant chemotherapy was linked to significant rates of acute and delayed hyperpigmentation. The acute toxicity in first 6 months post-radiotherapy was only G1. The most frequent late toxicities were G1 indurations, edema, hyperpigmentation.

CONCLUSIONS

The FAST-Forward scheme with SIB and RNI in 5 daily fractions seems well-tolerated without severe acute or delayed toxicity.

Navigating through recent evidence on locoregional breast cancer radiotherapy: an initiative by the scientific association of Swiss radiation oncology

PURPOSE

Breast cancer (BC) is the most prevalent cancer in women and radiotherapy (RT) is an integral part of its treatment. High-level evidence guides clinical decisions, but given the abundance of guidelines, a need to navigate within the evidence has been identified by the board of the Scientific Association of Swiss Radiation Oncology (SASRO). A pilot project was initiated aiming to create an overview of recent clinically relevant evidence for BC RT, to make it easily available to (radiation) oncologists and radiation oncologists in training.

METHODS

A panel of 10 radiation oncology experts for BC RT, one expert in BC surgery, and one expert in BC medical oncology critically reviewed the relevant literature. The panel comprehensively represented different geographical regions of Switzerland as well as university, cantonal, and private institutions. We sought to create a consensual overview of the most relevant questions in BC RT today, accompanied by the most recent and relevant available evidence.

RESULTS

From January 2023 to January 2024, the panel met four times to review and work on an initial draft. The final draft was reviewed and accepted by all panelists. We hereby publish this work to make it available to international audiences. After publication, the work will be made available to all SASRO members on the SASRO website. This work is to be updated every 2 years.

CONCLUSION

The identified need was addressed with a successful pilot project and will be further expanded upon in other tumor pathologies.

Early-Stage Breast Cancer: A Critical Review of Current and Emerging Practice

Breast-conserving surgery followed by adjuvant radiation to reduce the risk of ipsilateral breast tumor recurrence is the mainstay of treatment for early-stage breast cancer (ESBC). However, improved understanding of the heterogeneity of the clinical and molecular characteristics of ESBC has led to greater efforts to personalize approaches to treatment. Furthermore, advances in the understanding of the radiobiology of breast cancer have led to several practice-changing trials on the effectiveness and tolerability of moderate and ultrahypofractionated radiation. Here, we review the recent evidence and ongoing research in the radiotherapeutic management of ESBC, including the use of boost for high-risk disease and opportunities for accelerated fractionation, partial breast irradiation, and radiation omission for low-risk disease. We also discuss how molecular profiling can inform decision-making and new opportunities for primary radiation therapy and reirradiation.

Breast induration and irradiated volume in the DBCG HYPO trial: The impact of age, smoking, and boost

PURPOSE

To investigate the association between irradiated breast volume and grade 2-3 breast induration three years after radiotherapy in the phase III Danish Breast Cancer Group HYPO trial randomizing patients ≥ 41 years to whole breast irradiation (WBI) with 40 Gy/15fr versus 50 Gy/25fr.

METHODS

Treatment plans were available for all Danish patients. Associations between frequency of induration and irradiated volume, age, smoking status, and boost were assessed by logistic regression. A sequential boost was given to patients < 50 years or in case of a narrow (<2 mm) resection margin.

RESULTS

RT plans from 1,333 patients were analyzed with 178 (13 %) having grade 2-3 induration. 1135 patients had only WBI. For this group, induration was correlated with irradiated breast volume for patients ≥ 65 years (n = 343, 10 %/22 % for small/large irradiated volumes, p = 0.005) but not for patients aged 50-64 years (n = 792, 11 % for both small and large volumes, p = 0.82). Smoking doubled the frequency irrespective of irradiated volume and age. All patients < 50 years (n = 156) had a boost. A volume effect was found for this group (5 %/21 % induration for small/large volume, p = 0.002). 42 patients ≥ 50 years had a boost and 14 (33 %) had grade 2-3 induration, however, with a p-value > 0.05 due to the few numbers of patients.

CONCLUSION

A relationship between irradiated breast volume and 3-year frequency of breast induration was found for patients ≥ 65 years, whilst not for patients aged 50-64 years. Smoking doubled the risk of induration irrespective of volume and age. A dose-induration relationship was seen for boost patients < 50 years.

"When Less is More": Paradigm Shifts in Radiation Treatment for Early-Stage Breast Cancer

OPINION STATEMENT

Recent advancements in the treatment of early-stage breast cancer have significantly shifted the radiotherapy landscape. Traditionally, the standard of care included lumpectomy followed by endocrine therapy and 3-5 weeks of adjuvant radiation targeting the entire unilateral breast. This review summaries modern trials, emphasizing data reported since 2019 that have changed radiation treatment paradigms. Ultra-hypofractionated treatment regimens have enabled radiation oncologists to deliver the total radiation dose in as few as 5 treatments over 1 week for select patients. Partial breast irradiation, treating only the breast tissue nearest to the lumpectomy cavity, has also emerged as an effective and well-tolerated treatment. Furthermore, a growing body of evidence supports the safety of omitting radiation completely for certain older adults with low-risk disease. Ongoing research in areas such as precision cancer care, treatment de-escalation, and toxicity prevention and management reflects a broader shift toward shared decision-making in medicine and individually tailored treatment paradigms. As research progresses, treatment options will continue to evolve. Advances in radiation oncology will give the oncology team a growing array of tools to custom treatment plans to individual patient risks and toxicity concerns. Knowledge of radiation advances should be used to facilitate shared decisions with patients about the balance of treatment efficacy, toxicity, and quality of life, with the ultimate goal of promoting high-quality, personalized, and patient-centered cancer care.

Radiation Pneumonitis After Partial Breast Irradiation

This case presentation describes development of symptomatic radiation pneumonitis in a healthy woman who underwent partial breast irradiation with deep inspiration breath hold for early stage breast cancer meeting all published dose constraints. Risk factors for, diagnosis and management of radiation pneumonitis are discussed in detail. Radiation pneumonitis is rare, ranging from <1% to 1.5% (when regional nodal irradiation is included). Partial breast irradiation spares breast tissue, but may not spare lung tissue better than whole breast irradiation, depending upon treatment technique such as prone positioning. Dose constraints for normal and target structures from published trials are reviewed, however data specifically relating to pneumonitis in partial breast trials are limited.

Toxicity Evaluation of Dose-Escalation in Hypofractionated Regional Nodal Irradiation for Breast Cancer: A Retrospective Study

PURPOSE

Regional nodal irradiation (RNI) to the axilla and supraclavicular area presents distinct toxicities, such as lymphedema and shoulder stiffness, compared with whole-breast irradiation. There is insufficient evidence on the safety of dose-escalation in hypofractionated RNI. We aimed to evaluate and compare toxicity rates in patients with breast cancer who received hypofractionated RNI with and without dose-escalation.

METHODS AND MATERIALS

We retrospectively analyzed 381 patients with breast cancer treated with hypofractionated RNI between March 2015 and February 2017. Patients received either the standard-dose to the regional nodal area (43.2 Gy/16 fx; 48.7 Gy3.5 equivalent dose [EQD2], 2 Gy equivalent dose with α/β= 3.5 Gy) or dose-escalation with a median dose of 54.8 Gy3.5 EQD2 (range, 51.7-60.9 Gy3.5 EQD2), depending on clinical and pathologic nodal stage. Toxicity rates of lymphedema and shoulder stiffness were assessed, and statistical analyses were conducted to identify associated factors.

RESULTS

The median follow-up time was 32.3 months (5.7-47.0 months). After radiation therapy, 71 (18.6%) patients developed lymphedema, and 48 (12.6%) developed shoulder stiffness. Patients who received dose-escalation exhibited significantly higher rates of lymphedema (32.1% vs 14.8%; odds ratio, 2.72, P = .0004) and shoulder stiffness (23.8% vs 9.4%; odds ratio, 2.01, P = .0205) compared with the standard-dose group. Moreover, dose-escalation showed a tendency to increase the severity of lymphedema and shoulder stiffness.

CONCLUSIONS

Patients who received dose-escalation in hypofractionated RNI face a higher risk of developing lymphedema and shoulder stiffness compared with those who received standard-dose hypofractionated RNI. Therefore, it is crucial to implement close and frequent monitoring for early detection, along with timely rehabilitation interventions for these patients.

Uptake of ultra-hypofractionated radiation therapy following breast-conserving surgery among patients with early-stage breast cancer: a multi-institutional questionnaire survey

BACKGROUND

In patients with early-stage breast cancer following breast surgery, ultra-hypofractionated (UHF) breast/chest wall radiation therapy (RT) has been shown to be non-inferior to a moderate-hypofractionated (MHF) regimen, with a minimal risk of breast induration, in the FAST-Forward trial, and UHF is now becoming the standard regimen in Europe. Herein, we aimed to investigate Japanese patients' attitudes toward the UHF regimen.

METHODS

A questionnaire-based survey was conducted at 13 RT centers in nine prefectures across Japan. All patients underwent breast-conserving surgery, followed by either conventional fractionation (2 Gy/fr) or MHF (2.66 Gy/fr) whole-breast irradiation (WBI) with or without a tumor bed boost. The questionnaire consisted of 13 questions mainly addressing quality-of-life during RT. Key questions included an 11-point scale (0-10) for rating the patients' enthusiasm for the UHF regimen and prioritization of the following treatment-related effects: treatment efficacy, acute/late adverse effects, physical/emotional/financial burden, and breast cosmesis. The patient and treatment characteristics were assessed by a physician.

RESULTS

In total, 247 questionnaires were administered between November 2022 and June 2023. The age distribution was as follows: < 50:50 s:60 s: ≥ 70 = 59 (24%):76 (30%):63 (26%):49 (20%). Sixty-nine percent of patients rated their enthusiasm for the UHF regimen at ≥ 6 out of 10 points (45% rated 10/10). Treatment efficacy was the highest priority for most patients (89%), whereas breast cosmesis the lowest priority (53%).

CONCLUSIONS

Patients' enthusiasm for UHF-WBI was observed across the cohort. These results could motivate researchers and clinicians to introduce UHF regimens in clinical practice.

Single preoperative radiation therapy with delayed surgery for low-risk breast cancer: Oncologic outcome, toxicity and cosmesis of the SPORT-DS phase I trial

BACKGROUND

A novel approach using single-fraction preoperative partial breast irradiation (PBI) for low-risk breast cancer is under study. We sought to investigate the rate of pathologic response (pR), toxicities and cosmetic results related to this new treatment strategy.

METHODS

Women of 65 years or older with stage I unifocal luminal A breast cancer were eligible for inclusion in this phase I prospective trial. Patients received a single 20 Gy dose of PBI followed by breast-conserving surgery (BCS) 3 months later. The primary endpoint was the pR rate, and the secondary endpoints were radiation therapy-related toxicity and cosmetic results.

RESULTS

Thirteen patients were treated, with a median age of 71. Eleven patients (84.6 %) had pR with a median residual cellularity of 1 % (range: 0-10 %). At median follow-up of 48.5 months, no recurrences or cancer-related deaths were recorded. Acute radiation therapy-related toxicity were limited to grade 1 dermatitis and breast pain. At the 1-year follow-up, there were one grade 2 fat necrosis and two grade 3 toxicities (wound infection and hematoma). Only grade 1 toxicities remained at 2 years, but one grade 2 toxicity (fibrosis/induration) developed by the 3-year follow-up. Three-year patient-reported cosmetic outcomes were good or excellent in 60 % of patients.

CONCLUSIONS

Single-fraction preoperative PBI preceding BCS for low-risk breast cancer is feasible, relatively well tolerated and leads to a high level of pR. The 3-month interval after PBI seems to place surgery in a post-radiation inflammatory phase. Further delay between PBI and surgery could improve pR and cosmetic outcome. NCT03917498.

Practice-changing trials on breast cancer

There is new data in the fractionation modalities and these are the really the practice-changing trials of last years: can we use hypo fractionated whole breast radiotherapy in patients presented with ductal carcinoma in situ? Can we realize hypofractionated whole breast radiotherapy with simultaneous integrated boost? What about hypofractionated irradiation after mastectomy with reconstruction? Can we do hypofractionation to lymph nodes without risk of increased toxicity? The purpose of this work is to respond with the last evidence-based recently presented or published data.

IORT-photon boost plus hypofractionated whole breast irradiation in patients with breast cancer after primary systemic treatment: feasibility, safety and clinical results

AIM

To assess for the first time the safety and feasibility of combining photon-intraoperative radiotherapy (ph-IORT) with hypofractionated whole breast irradiation (h-WBI) in patients referred to primary systemic therapy (PST).

METHODS

From March 2019 to December 2020, patients referred for breast conservative surgery (BCS) after PST in our institution were prospectively included in the present trial. PST was prescribed to all patients according the ESMO-SEOM guidelines. Once the PST was completed, BCS was discussed in the multidisciplinary tumor board (MTB). 20 Gy were prescribed to the surface of the applicator of an Intrabeam®photon-IORT during BCS. h-WBI (40.5 Gy/2.67 Gy/15frx) was planned to be administered 3-5w after BCS. All patients were treated with hWBI VMAT-Rapid-Arc&Daily Exac-Trac-IGRT. The primary end points of the study were feasibility and safety (grade 3 toxicity rate CTCAE.5.0-scale) of the proposed treatment protocol. The secondary end points included cosmetic results (Harvard Scale), local relapse rate and overall survival.

RESULTS

Thirty-five patients were included in the trial. The median age was 54 years. Tumor size was > 2 cm in all cases. Eighteen patients were N + (51.4%). There was no disease progression during PST. All patients received the planned 20 Gy-ph-IORT boost at the time of BCS and the proposed h-WBI. 31/35 (88,6%) patients started h-WBI within the predefined time period (3-5w after BCS). No patient showed ≥ G3 acute toxicity 3 months after the end of h-WBI. No ≥ G3 late toxicity was observed at 12 months of follow-up and thereafter. Cosmetic results were scored excellent/good in 26 patients (74.2%). After a median follow-up of 52 months, a TNBC patient locally relapsed at 13 months of follow-up.

CONCLUSION

We demonstrated for the first time that ph-IORT + hWBI is feasible and safe in patients referred to BCS after PST.

Breast Cancer Adjuvant Radiotherapy and Chemotherapy Sequencing: Sequential, Concomitant, or What Else? A Comprehensive Review of the Adjuvant Combinations Journey

Background: To date, in breast cancer (BC) treatment, adjuvant chemotherapy (A-CT) has preceded adjuvant radiotherapy (A-RT). In the last twenty years, the adjuvant treatment of BC has quickly evolved due to better knowledge of its molecular biology, genetic profile, and α/β ratio of 3/4 Gy for tumor and normal tissue radiosensitivity. Thus, new schedules with hypofractionated radiotherapy have been tested, and a third generation of A-CT has been introduced, raising the question of whether it is time to rethink the sequencing between these two approaches. Methods: In the last 20 years, many attempts have been made worldwide to optimize the best sequencing strategy between these two approaches in terms of sequential CT-RT and RT-CT and concomitant and sandwich modalities using drugs and schedules. This paper presents a comprehensive review of the state of the art, analyzing all the available studies to assess the sequencing between A-CT and A-RT with different generations of chemotherapy schedules. Results: More than 8000 patients from 30 studies treated with adjuvant chemotherapy and whole breast radiotherapy who were enrolled in randomized, retrospective, and prospective studies were analyzed. Sequential, concomitant, and sandwich modalities of chemotherapy with conventional or hypofractionated RT schedules from the most important studies were included. The most used sequence was adjuvant chemotherapy followed by conventional or hypofractionated radiotherapy. In the concomitant approach, i.v. CMF has been the most important adopted schedule, while the concomitant use of anthracyclines and taxanes with conventional or hypofractionated radiotherapy has been found to be more toxic. One study analyzed the benefit in terms of reducing adjuvant treatment time with upfront hypofractionated radiotherapy and third-generation chemotherapy. Conclusions: At present, the best sequencing strategy has not yet been defined. This comprehensive review is a journey among the most important randomized, retrospective, and prospective studies that highlights the past, current, and novel time sequencing proposals between A-CT and A-RT to assess the state of the art and provide useful information for future adjuvant approaches in breast cancer treatment.

OPAR: A Randomized Trial of Partial Breast Irradiation in Five Fractions Once Daily for Early Breast Cancer

PURPOSE

Previous studies suggest that external-beam partial breast irradiation (PBI) delivered twice a day can lead to increased adverse cosmesis (AC). The objective of our trial was to determine whether two regimens for PBI given once daily over 1 week resulted in acceptable AC to inform a phase III trial.

METHODS

Patients age ≥50 years with invasive breast cancer or ductal carcinoma in situ, ≤3 cm in size treated by lumpectomy with negative axillary nodes were randomly assigned to external-beam PBI of 30 Gy or 27.5 Gy, each given in five fractions once daily. The primary outcome was AC (fair or poor) by photographic assessment at 2 years. Secondary outcomes included AC assessed by nurse at 2 years, by patient self-assessment at 3 years, and late toxicity. On the basis of a 17% risk of AC with whole-breast irradiation, the upper bound of a two-sided 90% CI, 23% was set as the tolerance margin (OPAR, ClinicalTrials.gov identifier: NCT02637024).

RESULTS

In total, 142 patients were randomly assigned to 30 Gy and 139 to 27.5 Gy. The median follow-up was 5 years. The mean age was 65 years, and the mean tumor size was 1.2 cm. Both schedules met acceptability criteria by photographic assessment (AC, 12.1% [90% CI, 8.2 to 17.6] for 30 Gy and 15.2% [90% CI, 10.8 to 21.1] for 27.5 Gy) and by nurse assessment. AC by patient self-assessment exceeded the 90% CI for the 30 Gy regimen. At 5 years, 16 (11.3%, 90% CI, 7.6 to 16.4) patients treated with 30 Gy and eight (5.8%, 90% CI, 3.3 to 9.9) patients treated with 27.5 Gy were observed to have grade 2 or more late toxicity.

CONCLUSION

According to the study design, 30 Gy and 27.5 Gy resulted in acceptable cosmetic outcomes. In light of recent studies, a lower dose was chosen for the phase III trial.

Postoperative complications of hypofractionated and conventional fractionated radiation therapy in patients with implant-based breast reconstruction: A systematic review and meta-analysis

INTRODUCTION

Post-mastectomy radiation therapy is an important component of adjuvant therapy for high-risk patients. However, radiation to reconstructed breasts can cause various complications. Recently, hypofractionated (HF) protocols have been adopted in several countries. Here, we aimed to assess the impact of HF protocols on implant-reconstructed breasts through a meta-analysis and systematic review of the currently available literature.

METHODS

Records published until August 2023 were systematically searched in PubMed, Cochrane Library, and EMBASE databases. Keywords included hypofractionation radiotherapy, mastectomy, and breast reconstruction. Studies that utilized HF and conventional fractionation (CF) after prosthetic reconstruction were selected. Due to the rarity of events in outcomes, Mantel-Haenszel's odds ratios were calculated using a fixed-effect model to compare the complication rates between HF and CF groups. For analysis with high heterogeneity, a random effect model was used.

RESULTS

Seven articles with 924 implant reconstructions, in which 506 (54.8 %) underwent HF were included. HF patients received 43.8 Gy on average, while CF patients received 51.2 Gy. Mean follow-up ranged from 10.6 to 35 months. Seven studies were included in the meta-analysis. HF groups had a significantly lower risk of capsular contracture (OR 0.25, 95 % CI 0.11-0.55), major revision surgery (OR 0.19, 95 % CI 0.05-0.80), and wound dehiscence (OR 0.24, 95 % CI 0.07-0.78) compared to CF groups. The risks of other complications were not statistically significant.

CONCLUSION

This study indicates that HF protocols are associated with fewer complications than CF protocols in implant-reconstructed patients. These findings suggest that the application of HF PMRT in implant-reconstructed patients with breast cancer is plausible.

Neuropilin-2-expressing breast cancer cells mitigate radiation-induced oxidative stress through nitric oxide signaling

The high rate of recurrence after radiation therapy in triple-negative breast cancer (TNBC) indicates that novel approaches and targets are needed to enhance radiosensitivity. Here, we report that neuropilin-2 (NRP2), a receptor for vascular endothelial growth factor (VEGF) that is enriched on subpopulations of TNBC cells with stem cell properties, is an effective therapeutic target for sensitizing TNBC to radiotherapy. Specifically, VEGF/NRP2 signaling induces nitric oxide synthase 2 (NOS2) transcription by a mechanism dependent on Gli1. NRP2-expressing tumor cells serve as a hub to produce nitric oxide (NO), an autocrine and paracrine signaling metabolite, which promotes cysteine-nitrosylation of Kelch-like ECH-associated protein 1 (KEAP1) and, consequently, nuclear factor erythroid 2-related factor 2-mediated (NFE2L2-mediated) transcription of antioxidant response genes. Inhibiting VEGF binding to NRP2, using a humanized mAb, results in NFE2L2 degradation via KEAP1, rendering cell lines and organoids vulnerable to irradiation. Importantly, treatment of patient-derived xenografts with the NRP2 mAb and radiation resulted in significant tumor necrosis and regression compared with radiation alone. Together, these findings reveal a targetable mechanism of radioresistance, and they support the use of NRP2 mAb as an effective radiosensitizer in TNBC.

The role of medical physics experts in clinical trials: A guideline from the European Federation of Organisations for Medical Physics

The EFOMP working group on the Role of Medical Physics Experts (MPEs) in Clinical Trials was established in 2010, with experts from across Europe and different areas of medical physics. Their main aims were: (1) To develop a consensus guidance document for the work MPEs do in clinical trials across Europe. (2) Complement the work by American colleagues in AAPM TG 113 and guidance from National Member Organisations. (3) To cover external beam radiotherapy, brachytherapy, nuclear medicine, molecular radiotherapy, and imaging. This document outlines the main output from this working group. Giving guidance to MPEs, and indeed all Medical Physicists (MP) and MP trainees wishing to work in clinical trials. It also gives guidance to the wider multidisciplinary team, advising where MPEs must legally be involved, as well as highlighting areas where MPEs skills and expertise can really add value to clinical trials.

Randomised controlled trials on radiation dose fractionation in breast cancer: systematic review and meta-analysis with emphasis on side effects and cosmesis

OBJECTIVE

To provide a comprehensive assessment of various fractionation schemes in radiation therapy for breast cancer, with a focus on side effects, cosmesis, quality of life, risks of recurrence, and survival outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (from inception to 23 October 2023).

STUDY SELECTION

Included studies were randomised controlled trials focusing on conventional fractionation (CF; daily fractions of 1.8-2 Gy, reaching a total dose of 50-50.4 Gy over 5-6 weeks), moderate hypofractionation (MHF; fraction sizes of 2.65-3.3 Gy for 13-16 fractions over 3-5 weeks), and/or ultra-hypofractionation (UHF; schedule of only 5 fractions).

DATA EXTRACTION

Two independent investigators screened studies and extracted data. Risk of bias and quality of evidence were assessed using the Cochrane Collaboration's tool and the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach, respectively.

DATA SYNTHESIS

Pooled risk ratios (RRs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using a random effects model. Heterogeneity was analysed using Cochran's Q test and I2 statistic. Network meta-analysis was used to integrate all available evidence.

MAIN OUTCOME MEASURES

The pre-specified primary outcome was grade ≥2 acute radiation dermatitis and late radiation therapy related side effects; secondary outcomes included cosmesis, quality of life, recurrence, and survival metrics.

RESULTS

From 1754 studies, 59 articles representing 35 trials (20 237 patients) were assessed; 21.6% of outcomes showed low risk of bias, whereas 78.4% had some concerns or high risk, particularly in outcome measurement (47.4%). The RR for grade ≥2 acute radiation dermatitis for MHF compared with CF was 0.54 (95% CI 0.49 to 0.61; P<0.001) and 0.68 (0.49 to 0.93; P=0.02) following breast conserving therapy and mastectomy, respectively. Hyperpigmentation and grade ≥2 breast shrinkage were less frequent after MHF than after CF, with RRs of 0.77 (0.62 to 0.95; P=0.02) and 0.92 (0.85 to 0.99; P=0.03), respectively, in the combined breast conserving therapy and mastectomy population. However, in the breast conserving therapy only trials, these differences in hyperpigmentation (RR 0.79, 0.60 to 1.03; P=0.08) and breast shrinkage (0.94, 0.83 to 1.07; P=0.35) were not statistically significant. The RR for grade ≥2 acute radiation dermatitis for UHF compared with MHF was 0.85 (0.47 to 1.55; P=0.60) for breast conserving therapy and mastectomy patients combined. MHF was associated with improved cosmesis and quality of life compared with CF, whereas data on UHF were less conclusive. Survival and recurrence outcomes were similar between UHF, MHF, and CF.

CONCLUSIONS

MHF shows improved safety profile, cosmesis, and quality of life compared with CF while maintaining equivalent oncological outcomes. Fewer randomised controlled trials have compared UHF with other fractionation schedules, but its safety and oncological effectiveness seem to be similar with short term follow-up. Given the advantages of reduced treatment time, enhanced convenience for patients, and potential cost effectiveness, MHF and UHF should be considered as preferred options over CF in appropriate clinical settings, with further research needed to solidify these findings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023460249.

Stereotactic body radiotherapy using CyberKnife versus interstitial brachytherapy in accelerated partial breast irradiation on left-sided breast: A comparison of dosimetric characteristics and preliminary clinical results

INTRODUCTION

We compared the dosimetric characteristics of the target and organs at risk (OARs) as well as the preliminary clinical outcomes between two accelerated partial breast irradiation (APBI) techniques.

METHODS

Forty-four patients diagnosed with left-sided early breast cancer who underwent APBI using either interstitial brachytherapy (IB) or stereotactic body radiation therapy (SBRT) with CyberKnife (CK) were retrospectively reviewed. The dosimetric parameters of the target and OARs were compared. Preliminary clinical outcomes, including tumor control and acute toxicity, were analyzed.

RESULTS

Treatment plans with CK demonstrated a better cardiac dose-sparing effect. Radiation doses to the heart at V150cGy for the CK and IB groups were 24.4 % and 60.4 %, respectively (p < 0.001), while the mean heart doses for the CK and IB groups were 107.4 cGy and 204 cGy, respectively (p < 0.001). The heart D1c.c. and the ipsilateral lung received a lower dose in the IB group, without any significant differences. The median follow-up time in the CK and IB groups was 28.6 and 61.3 months, respectively. No patients died from either breast cancer or cardiac events during follow-up. A locoregional recurrence event at the neck occurred in one patient within the IB group.

CONCLUSIONS

APBI planned by CK was shown to have a better dose-sparing effect on the heart, as well as better conformity and homogeneity to the target. CK is a non-invasive treatment which showed minimal acute toxicity and promising tumor control.

Computational Model Based on Optical Coherence Tomography (OCT) Skin Scanning to Identify and Quantify Acute Radiation Dermatitis (ARD): A Prospective Diagnostic Study

BACKGROUND

Acute radiation dermatitis (ARD) is the most widely reported radiotherapy-induced adverse event. Currently, there is no objective or reliable method to measure ARD.

OBJECTIVE

Our main objective was to identify and quantify the effects of radiotherapy with a computational model using optical coherence tomography (OCT) skin scanning. Secondary objectives included determining the ARD impact of different radiotherapeutic schemes and adjuvant topical therapies.

METHODS

We conducted a prospective, single-center case series study in a tertiary referral center of patients with breast cancer who were eligible for whole breast radiotherapy (WBRT).

RESULTS

A total of 39 women were included and distributed according to the radiotherapeutic schemes (15, 20, and 25 fractions). A computational model was designed to quantitatively analyze OCT findings. After radiotherapy, OCT scanning was more sensitive revealing vascularization changes in 84.6% of the patients (vs 69.2% of the patients with ARD by clinical examination). OCT quantified an increased vascularization at the end of WBRT (P<.05) and a decrease after 3 months (P=.032). Erythematous skin changes by OCT were more pronounced in the 25-fraction regime.

CONCLUSION

An OCT computational model allowed for the identification and quantification of vascularization changes on irradiated skin, even in the absence of clinical ARD. This may allow the design of standardized protocols for ARD beyond the skin color of the patients involved.

Increase in Hypofractionated Radiation Therapy Among Patients with Invasive Breast Cancer or Ductal Carcinoma In Situ: Who is Left Behind?

PURPOSE

We aimed to update the trend of hypofractionated whole-breast irradiation (HF-WBI) use over time in the US and examine factors associated with lack of HF-WBI adoption for patients with early-stage invasive breast cancer (IBC) or ductal carcinoma in situ (DCIS) undergoing a lumpectomy.

METHODS AND MATERIALS

Among patients who underwent a lumpectomy, we identified 928,034 patients with early-stage IBC and 330,964 patients with DCIS in the 2004 to 2020 National Cancer Database. We defined HF-WBI as 2.5-3.33 Gy/fraction to the breast and conventionally fractionated WBI as 1.8-2.0 Gy/fraction. We evaluated the trend of HF-WBI utilization using a generalized linear model with the log link and binomial distribution. Factors associated with HF-WBI utilization were assessed using multivariable logistic regression in patients diagnosed between 2018 and 2020.

RESULTS

Among patients with IBC, HF-WBI use has significantly increased from 0.7% in 2004 to 63.9% in 2020. Similarly, HF-WBI usage among patients with DCIS has also increased significantly from 0.4% in 2004 to 56.6% in 2020. Black patients with IBC were less likely than White patients to receive HF-WBI (adjusted odds ratio [AOR] 0.81; 95% CI, 0.77-0.85). Community cancer programs were less likely to administer HF-WBI to patients with IBC (AOR, 0.80; 95% CI, 0.77-0.84) and to those with DCIS (AOR, 0.87; 95% CI, 0.79-0.96) than academic/research programs. Younger age, positive nodes, larger tumor size, low volume programs, and facility location were also associated with lack of HF-WBI adoption in both patient cohorts.

CONCLUSIONS

HF-WBI utilization among postlumpectomy patients has significantly increased from 2004 to 2020 and can finally be considered standard of care in the US. We found substantial disparities in adoption within patient and facility subgroups. Reducing disparities in HF-WBI adoption has the potential to further alleviate health care costs while improving patients' quality of life.

Computational Model Based on Optical Coherence Tomography (OCT) Skin Scanning to Identify and Quantify Acute Radiation Dermatitis (ARD): A Prospective Diagnostic Study

BACKGROUND

Acute radiation dermatitis (ARD) is the most widely reported radiotherapy-induced adverse event. Currently, there is no objective or reliable method to measure ARD.

OBJECTIVE

Our main objective was to identify and quantify the effects of radiotherapy with a computational model using optical coherence tomography (OCT) skin scanning. Secondary objectives included determining the ARD impact of different radiotherapeutic schemes and adjuvant topical therapies.

METHODS

We conducted a prospective, single-center case series study in a tertiary referral center of patients with breast cancer who were eligible for whole breast radiotherapy (WBRT).

RESULTS

A total of 39 women were included and distributed according to the radiotherapeutic schemes (15, 20, and 25 fractions). A computational model was designed to quantitatively analyze OCT findings. After radiotherapy, OCT scanning was more sensitive revealing vascularization changes in 84.6% of the patients (vs 69.2% of the patients with ARD by clinical examination). OCT quantified an increased vascularization at the end of WBRT (P<.05) and a decrease after 3 months (P=.032). Erythematous skin changes by OCT were more pronounced in the 25-fraction regime.

CONCLUSION

An OCT computational model allowed for the identification and quantification of vascularization changes on irradiated skin, even in the absence of clinical ARD. This may allow the design of standardized protocols for ARD beyond the skin color of the patients involved.

Expenditures and Use of Hypofractionated Radiation Therapy Treating Breast Cancer Among Medicare Advantage Enrollees, 2009 to 2017

Purpose

Technology advances in cancer care have paralleled rapidly increasing expenditures in radiation therapy. The use and costs of shorter cancer radiation therapy offer potential utility in clinical practice. We evaluate use and expenditures of Medicare Advantage (MA) beneficiaries receiving hypofractionated whole breast irradiation (HF-WBI) compared with conventionally fractionated whole breast irradiation (CF-WBI) in the United States and examine the relationship of patient characteristics with HF-WBI use.

Methods and Materials

We performed a retrospective analysis of radiation therapy in MA beneficiaries using private employer-sponsored insurance claims for a pooled cross-sectional evaluation from 2009 to 2017. The study population included female MA beneficiaries with early-stage breast cancer treated with lumpectomy and whole breast irradiation.

Results

A total of 9957 women received HF-WBI, and 18,920 received CF-WBI. Older age, greater distance from home to treatment facility, and a higher proportion of college graduates in the community of residence were associated with increased HF-WBI use. Mean insurer-paid radiation therapy expenditures were significantly lower for HF-WBI versus CF-WBI (adjusted difference, $4113; 95% CI, $4030-$4,197). Mean patient out-of-pocket expenditure for HF-WBI was $426 less than that of CF-WBI. Across US states, geographic variation existed in the ratio of costs for HF-WBI relative to CF-WBI (range, 0.41-0.87).

Conclusions

HF-WBI use among MA beneficiaries with breast cancer has dramatically increased over time, surpassing CF-HBI as the dominant form of radiation therapy. HF-WBI clinical adoption has outpaced any continual cost decrease, despite wide variation across US states for this shorter radiation therapy treatment. As MA enrollment continues to expand, identifying the drivers of HF-WBI use and the sources of variation in costs of HF-WBI will help direct the quality of cancer care delivered to Medicare beneficiaries.

Qualitative exploration of patients' experiences with Intrabeam TARGeted Intraoperative radioTherapy (TARGIT-IORT) and External-Beam RadioTherapy Treatment (EBRT) for breast cancer

OBJECTIVE

To gather a deep qualitative understanding of the perceived benefits and impacts of External-Beam RadioTherapy (EBRT) and TARGeted Intraoperative radioTherapy (TARGIT-IORT) using Intrabeam to assess how the treatments affected patient/care partner experiences during their cancer treatment and beyond.

DESIGN AND PARTICIPANTS

A patient-led working group was established to guide study design and to help validate findings. Patients with experience of receiving EBRT or TARGIT-IORT were purposively sampled by Hampshire Hospitals NHS Foundation Trust. These patients had been offered both regimens as per their clinical features and eligibility. Semistructured interviews were conducted with 29 patients and care partners with lived experience of either EBRT (n=12, 5-day FAST-Forward regimen and n=3, 3-week regimen) or TARGIT-IORT (n=14). Thematic analysis was then carried out by two coders generating 11 themes related to EBRT or TARGIT-IORT.

SETTING

Semistructured interviews were conducted virtually via Zoom during February and March 2023.

RESULTS

A number of procedural grievances were noted among EBRT patients. EBRT was perceived as being disruptive to normal routines (work, home and travel) and caused discomfort from side effects. TARGIT-IORT was perceived by patients and care partners as the safer option and efficient with minimal if any disruptions to quality of life. The need for timely accessible information to reduce anxieties was noted in both cohorts.

CONCLUSIONS

This qualitative study found that patients perceived EBRT as being greatly disruptive to their lives. In contrast, the one-off feature of TARGIT-IORT given while they are asleep during surgery gives them the feeling of stamping out the cancer without conscious awareness. These insights can help healthcare staff and policy-makers further justify the incorporation of the treatment favoured by these patient perceptions (TARGIT-IORT) more widely in routine practice. Further research is planned to explore TARGIT-IORT in more diverse populations and in the 35 countries where it is an established treatment option.

Preoperative Magnetic Resonance Guided Single-Dose Partial Breast Irradiation: 5-Year Results of the Prospective Single-Arm ABLATIVE Trial

PURPOSE

Preoperative partial breast irradiation (PBI) can increase accuracy of target volume definition and decrease irradiated volumes compared with postoperative PBI. In the ABLATIVE trial (NCT02316561), 15 of 36 patients achieved pathologic complete response 6 to 8 months after preoperative PBI and breast-conserving surgery (BCS). We now present the 5-year results.

METHODS AND MATERIALS

The ABLATIVE trial is a Dutch prospective cohort study conducted in 4 hospitals. Women aged ≥50 years with unifocal, nonlobular breast cancer, estrogen receptor-positive, HER2-negative, and a tumor negative sentinel node were treated between 2015 and 2018 with preoperative single-dose PBI followed by BCS after 6 or 8 months. The primary endpoint was pathologic complete response. Secondary endpoints were annually evaluated oncological outcomes, toxicity, cosmetic outcome (assessed by patients and physicians), and quality of life.

RESULTS

Thirty-six patients were treated with BCS 6 (n = 15) and 8 (n = 21) months following PBI. Median tumor size was 13 mm (IQR 9-16 mm). After a median follow-up of 5.5 years (IQR, 5.1-6.0), 2 (6%) patients had ipsilateral breast events and 2 (6%) distant metastases. The 5-year overall survival was 94% (95% CI, 87-100). The 5-year cumulative incidence of clinician-reported grade 1/2 breast fibrosis and breast discomfort/pain were 94%/6% and 75%/6%, respectively. The proportion of patients (very) satisfied with the cosmetic results was 89% at baseline and 78% at 5 years. Cosmetic results evaluated using the BCCT.core software were excellent or good in all patients. The 4-year median global quality of life score was 83 (IQR, 67-92), similar to baseline (83; IQR, 75-83; P = .42).

CONCLUSIONS

Preoperative single-dose PBI and BCS may be an oncologically safe treatment with mild late toxicity and no decline in cosmetic results and quality of life during 5 years of follow-up. This means that preoperative instead of standard postoperative irradiation has the potential to challenge the current clinical practice.

Radiation-induced dermatitis among breast cancer patients undergoing adjuvant radiotherapy in Ghana

The aim of the study was to investigate radiation-induced epidermal desquamation among breast cancer patients undergoing radiotherapy with 6MV linac and Co-60 teletherapy units. METHOD: Quantitative data was collected using self-administered closed ended questionnaires addressing the desquamation in relation to some patient-and treatment-related factors. The Radiation Therapy Oncology Group (RTOG) criteria for acute skin toxicity was used to grade the toxicity. Chi square and logistic regression analyses were respectively used to test statistical significance and evaluate the effects of the various factors on radiation induced epidermal desquamation RESULTS: Majority of the participants had high BMIs (overweight: 39.5 %; obese: 50 %). Patients with BMI ≥ 25 kg/m2 presented with wet desquamation (RTOG grade 2). A chi-square analysis showed a significant difference (p = 0.02) between BMI and severity of desquamation. There was no significant difference between type of treatment machine and cumulative incidence dose of desquamation (p= 0.251). The logistic regression analysis showed that patients who had undergone mastectomy (OR = 0.562) were less likely to develop wet desquamation (RTOG grade 2) on the Co-60 machine within the 20-30 Gy threshold (OR=0.981) compared to those on the linear accelerator. Patients with lower BMI (OR = 0.412,[ < 25 vs ≥30]; OR = 0.286, [25-29.9 vs ≥30]) were also less likely to develop wet desquamation compared to those with higher BMI. CONCLUSION: Radiation-induced epidermal desquamation is a common side effect of breast cancer patients undergoing radiotherapy. BMI has an effect on the severity of desquamation experienced during breast irradiation.

Hypofractionated versus Conventional Postmastectomy Irradiation for Breast Cancer: Comparison of Acute Skin Toxicity

Purpose

Breast cancer is the leading cause of cancer mortality among women. Radiotherapy can reduce recurrence and prolong survival of patients accepting breast-conserving surgery (BCS). This study aims to compare acute skin reactions in patients receiving hypofractionated versus conventional radiotherapy at a single institution and to summarize the relevant influencing factors.

Methods

This study analyzed 152 patients who underwent either hypofractionated or conventional whole-breast irradiation (WBI) after BCS. Acute skin toxicity was assessed according to the Radiation Therapy Oncology Group (RTOG) criteria. Predictive factors for acute skin toxicity were identified using multivariate analysis and visualized using a forest spot.

Results

Grade 0 reactions occurred in 75.34% vs 70.89%, grade 1 in 16.44% vs 15.19%, grade 2 in 8.22% vs 12.66%, and grade 3 in 0% vs 1.27% of patients receiving hypofractionated and conventional WBI, respectively. There was no statistically significant difference in acute skin reaction in patients treated with hypofractionated radiation compared with conventional radiation (P = 0.62). Multivariate analysis revealed that metastatic lymph nodes (P = 0.021), whole-breast planning target volume (PTV-WB) (P < 0.001), and tumor bed planning target volume (PTV-TB) (P = 0.002) were significantly correlated with higher rates of acute skin toxicity.

Conclusion

Hypofractionated WBI demonstrated similar acute skin adverse reactions compared to conventional WBI. These findings indicate that hypofractionated radiotherapy offers comparable tolerance, equivalent curative effect, convenience, and economic benefits, supporting its clinical promotion.

Breast Cancer Adjuvant Radiotherapy in Up-Front to Chemotherapy: Is There a Worthwhile Benefit? A Preliminary Report

Purpose

We administered a new breast cancer (BC) adjuvant therapy sequence that delivered postoperative radiotherapy (PORT) before chemotherapy (CT). Our aim was to assess the gain in time to start PORT and the G2-G3 acute-subacute toxicity rate of whole breast adjuvant hypofractionated radiotherapy (AH-RT) administered up-front to the third-generation adjuvant CT (A-CT) in high-risk nodal positive BC in a preliminary report at 2 years.

Methods

This retrospective study analysed the duration of treatment and safety of AH-RT administered up-front to A-CT in high-risk nodal positive BC patients (pts). Data on 45 pts treated between 2022-2023 were collected. All pts underwent the third-generation A-CT after AH-RT 15-5 fractions with or without a boost. Acute toxicity was scored according to CTCAE v5.0 for skin, pulmonary, and cardiac adverse events. Univariate and multivariate analyses were conducted to assess significant prognosticators for skin/lung/heart acute toxicities in the AH-RT 5-15 fractions arms and CT (p < 0.005).

Results

A reduction in the time to PORT initiation and overall adjuvant treatment time was recorded. RT was initiated 5 median weeks after surgery, and A-CT was performed 9 median weeks after surgery. The median duration of the entire adjuvant treatment was 35 weeks after surgery. At 6 months mean follow-up, no significant differences in G2-G3 toxicity were noted between the different hypofractionated RT arms, irrespective of the CT schedules, irradiated volumes, or boost (SIB or sequential) in univariate and multivariate analyses. In the multivariate analysis, no significant effects in CT schedules and AH-RT 5-15 arms for skin/lung acute toxicities (p = 0.077 and p = 0.68; 0.67 and 0.87, respectively) were recorded.

Conclusion

As a new PORT approach in BC, AH-RT up-front to the third-generation A-CT appeared safe with a low acute toxicity profile, providing an advantage in shortening the time from surgery to PORT initiation and the overall adjuvant treatment time.

Are We Missing Acute Toxicities Associated With Hypofractionated Breast Irradiation? A Report From a Large Multicenter Cohort Study

PURPOSE

The efficacy and long-term safety of hypofractionated whole breast irradiation (HF-WBI) have been established through multiple randomized trials, yet data about acute toxicities remain more limited. Since 2013, our group has prospectively collected acute toxicity data from weekly treatment evaluations and additional assessment after completion. In 2016, we intentionally shifted the posttreatment assessment follow-up visit from 1 month to 2 weeks to evaluate for missed acute toxicity occurring in that immediate posttreatment window. Here, we report whether 2-week follow-up has resulted in increased detection of acute toxicities compared with 4-week follow-up.

METHODS AND MATERIALS

We prospectively compared acute toxicity for patients treated with HF-WBI between January 1, 2013, and August 31, 2015 (4 week follow-up cohort) to patients treated between January 1, 2016, and August 31, 2018 (2 week follow-up cohort). Analyses included a multivariable model that adjusted for other factors known to correlate with toxicity. We prospectively defined acute toxicity as maximum breast pain (moderate or severe rating) and/or occurrence of moist desquamation reported 7 days before the completion of radiation therapy (RT) until 42 days after completion.

RESULTS

A total of 2689 patients who received postlumpectomy radiation and boost were analyzed; 1862 patients in the 2-week follow-up cohort and 827 in the 4-week follow-up cohort. All acute toxicity measures assessed were statistically similar between follow-up cohorts when compared in an unadjusted fashion. Overall acute composite toxicity was 26.4% and 27.7% for patients in the 4-week follow-up and 2-week follow-up cohorts, respectively. Overall acute composite toxicity remained similar between follow-up cohorts in a multivariable, adjusted model and was significantly related to patient's age, body mass index, smoking status, and treatment technique (intensity-modulated RT vs 3-dimensional conformal radiation therapy) but not follow-up cohort.

CONCLUSIONS

An earlier posttreatment follow-up for HF-WBI patients did not reveal a significant increased incidence of acute toxicities at 2 weeks compared with 4 weeks. This study provides physicians and patients with additional data on the safety and tolerability of HF-WBI for early stage breast cancer.

Implementation of ultra-hypofractionated radiotherapy schedules for breast cancer during the COVID-19 pandemic in the Netherlands

Background and purpose

The COVID-19 pandemic resulted in an accelerated recommendation to use five-fraction radiotherapy schedules, according to the FAST- and FAST-Forward trial. In this study, trends in the use of different radiotherapy schedules in the Netherlands were studied, as well as the likelihood of receiving five fractions.

Materials and methods

Data from the NABON Breast Cancer Audit-Radiotherapy and Netherlands Cancer Registry was used. Women receiving radiotherapy for their primary invasive breast cancer or DCIS between 01-01-2020 and 31-12-2021 were included. Logistic regression was used to investigate the association between patient-, tumour-, treatment-, and radiotherapy institution-related characteristics and the likelihood of receiving five fractions in tumours meeting the FAST and FAST-Forward criteria.

Results

Detailed information about radiotherapy treatment was available for 9,392 tumours. Shortly after the start of the COVID-19 pandemic, i.e. April 2020, 19% of the tumours being treated with radiotherapy received five fractions of 5.2 or 5.7 Gray (Gy). While only 3% of the tumours received five fractions in March 2020. The usage of five fractions increased to 26% in December 2021. Partial breast irradiation, compared to whole breast irradiation, was significantly associated with the administration of five fractions, as well as radiotherapy delivered in an academic radiotherapy institution compared to an independent institution.

Conclusion

The start of the COVID-19 pandemic was associated with the early use of ultra-hypofractionated radiotherapy schedules. After publication of the trials, and mainly after the recommendation by the national radiotherapy society, the implementation further increased. These schedules were not yet used in all patients meeting the eligibility criteria for the FAST- or FAST-Forward trial.

A nationwide study of breast reconstruction after mastectomy in patients with breast cancer receiving postmastectomy radiotherapy: comparison of complications according to radiotherapy fractionation and reconstruction procedures

BACKGROUND

We examined the patterns of breast reconstruction postmastectomy in breast cancer patients undergoing postmastectomy radiotherapy (PMRT) and compared complications based on radiotherapy fractionation and reconstruction procedures.

METHODS

Using National Health Insurance Service (NHIS) data (2015-2020), we analysed 4669 breast cancer patients with PMRT and reconstruction. Using propensity matching, cohorts for hypofractionated fractionation (HF) and conventional fractionation (CF) were created, adjusting for relevant factors and identifying grade ≥3 complications.

RESULT

Of 4,669 patients, 30.6% underwent HF and 69.4% CF. The use of HF has increased from 19.4% in 2015 to 41.0% in 2020. Immediate autologous (32.9%) and delayed two-stage implant reconstruction (33.9%) were common. Complication rates for immediate (N = 1286) and delayed two-stage (N = 784) reconstruction were similar between HF and CF groups (5.1% vs. 5.4%, P = 0.803, and 10.5% vs. 10.7%, P = 0.856, respectively) with median follow-ups of 2.5 and 2.6 years. HF showed no increased risk of complications across reconstruction methods.

CONCLUSION

A nationwide cohort study revealed no significant difference in complication rates between the HF and CF groups, indicating HF for reconstructed breasts is comparable to CF. However, consultation regarding the fractionation for reconstructed breast cancer patients may still be necessary.

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

Geographic and Physician-Level Variation in the Use of Hypofractionated Radiation Therapy for Breast Cancer in the U.S.: A Cross-Classified Multilevel Analysis

Purpose

We aimed to assess geographic and physician-level variation for hypofractionated whole-breast irradiation (HF-WBI) use for early-stage breast cancer patients in the United States. We further evaluated the association between HF-WBI use and demographic factors after accounting for these variations.

Methods and Materials

We performed a retrospective study of early-stage breast cancer patients using private employer-sponsored insurance claims from 2008 to 2017. Patients were clustered according to geographic level and by radiation oncologist. Bayesian cross-classified multilevel logistic models were used to examine the geographic heterogeneity and variation of radiation oncologists simultaneously. Intracluster correlation coefficient (ICC) and median odds ratios (MOR) were calculated to quantify the variation at different levels. We also used the cross-classified model to identify patient demographic factors associated with receiving HF-WBI.

Results

The study included 79,747 women (74.0%) who received conventionally fractionated whole-breast irradiation (CF-WBI) and 27,999 women (26.0%) who underwent HF-WBI. HF-WBI adoption increased significantly across time (2008-2017). The variation in HF-WBI utilization was attributed mostly to physician-level variability (MOR = 2.59). The variability of HF-WBI utilization across core-based statistical areas (CBSAs) (MOR = 1.55) was found to be the strongest among all geographic classifications. After accounting for variability in both CBSAs and radiation oncologists, age, receiving chemotherapy, and several community-level factors, including distance from home to facility, community education level, and racial composition, were found to be associated with HF-WBI utilization.

Conclusion

This study demonstrated geographic and physician-level heterogeneity in the use of HF-WBI among early-stage breast cancer patients. HF-WBI utilization was also found to be associated with patient and community-level characteristics. Given observed physician-level variability, intervention through continuing medical education could help doctors to better understand the advantages of HF-WBI and promote the adoption of HF-WBI in the U.S. Influence of physician-level characteristics on HF-WBI utilization merits further study.

Hypofractionated radiotherapy with simultaneous tumor bed boost (Hi-RISE) in breast cancer patients receiving upfront breast-conserving surgery: study protocol for a phase III randomized controlled trial

BACKGROUND

The effectiveness and safety of moderately hypofractionated radiotherapy (HFRT) in patients undergoing breast-conserving surgery (BCS) has been demonstrated in several pivotal randomized trials. However, the feasibility of applying simultaneous integrated boost (SIB) to the tumor bed and regional node irradiation (RNI) using modern radiotherapy techniques with HFRT needs further evaluation.

METHODS

This prospective, multi-center, randomized controlled, non-inferiority phase III trial aims to determine the non-inferiority of HFRT combined with SIB (HFRTsib) compared with conventional fractionated radiotherapy with sequential boost (CFRTseq) in terms of five-year locoregional control rate in breast cancer patients undergoing upfront BCS. A total of 2904 participants will be recruited and randomized in a 1:1 ratio into the HFRTsib and CFRTseq groups. All patients will receive whole breast irradiation, and those with positive axillary nodes will receive additional RNI, including internal mammary irradiation. The prescribed dose for the HFRTsib group will be 40 Gy in 15 fractions, combined with a SIB of 48 Gy in 15 fractions to the tumor bed. The CFRTseq group will receive 50 Gy in 25 fractions, with a sequential boost of 10 Gy in 5 fractions to the tumor bed.

DISCUSSION

This trial intends to assess the effectiveness and safety of SIB combined with HFRT in early breast cancer patients following BCS. The primary endpoint is locoregional control, and the results of this trial are expected to offer crucial evidence for utilizing HFRT in breast cancer patients after BCS.

TRIAL REGISTRATION

This trial was registered at ClincalTrials.gov (NCT04025164) on July 18, 2019.

The impact of the new ESTRO-ACROP target volume delineation guidelines for postmastectomy radiotherapy after implant-based breast reconstruction on breast complications

The European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) updated a new target volume delineation guideline for postmastectomy radiotherapy (PMRT) after implant-based reconstruction. This study aimed to evaluate the impact on breast complications with the new guideline compared to the conventional guidelines. In total, 308 patients who underwent PMRT after tissue expander or permanent implant insertion from 2016 to 2021 were included; 184 received PMRT by the new ESTRO-ACROP target delineation (ESTRO-T), and 124 by conventional target delineation (CONV-T). The endpoints were major breast complications (infection, necrosis, dehiscence, capsular contracture, animation deformity, and rupture) requiring re-operation or re-hospitalization and any grade ≥2 breast complications. With a median follow-up of 36.4 months, the cumulative incidence rates of major breast complications at 1, 2, and 3 years were 6.6%, 10.3%, and 12.6% in the ESTRO-T group, and 9.7%, 15.4%, and 16.3% in the CONV-T group; it did not show a significant difference between the groups (p = 0.56). In multivariable analyses, target delineation is not associated with the major complications (sHR = 0.87; p = 0.77). There was no significant difference in any breast complications (3-year incidence, 18.9% vs. 23.3%, respectively; p = 0.56). Symptomatic RT-induced pneumonitis was developed in six (3.2%) and three (2.4%) patients, respectively. One local recurrence occurred in the ESTRO-T group, which was within the ESTRO-target volume. The new ESTRO-ACROP target volume guideline did not demonstrate significant differences in major or any breast complications, although it showed a tendency of reduced complication risks. As the dosimetric benefits of normal organs and comparable oncologic outcomes have been reported, further analyses with long-term follow-up are necessary to evaluate whether it could be connected to better clinical outcomes.

Use of immobilisation bra for daily setup of patients with pendulous breasts undergoing radiotherapy

PURPOSE

A feasibility study to evaluate the Chabner XRT® Radiation Bra (CIVCO Radiotherapy & Qfix, Coralville, IA, USA) as a customised immobilisation device for patients with pendulous breasts undergoing radiotherapy was conducted.

METHODS

A total of 34 patients with large pendulous breasts were fitted with the Chabner XRT® Radiation Bra during RT. A mixed-method questionnaire was administered to both radiation therapists (RTTs) and patients. RTTs evaluated the effectiveness of the bra in setup. Patients appraised its comfort level and ease of wearing. Setup reproducibility was evaluated based on a departmental imaging protocol. Acute skin side effects were documented with photos and assessed using the Radiation Therapy Oncology Group (RTOG) classification.

RESULTS

Of the patients, 27 (79.4%) completed the questionnaire. 23 patients felt comfortable wearing the bra while 20 felt less exposed during treatment. Reproducibility was acceptable, with a median (range) setup error (isocentre) of 0.0 cm (-0.6 to 0.7 cm; left/right), -0.1 cm (-0.5 to 1.2 cm; posterior) and 0.2 cm (-0.5 to 0.9 cm; inferior) achieved based on matched field borders on skin. However, repeated setups and imaging were required for 3 patients due to large breast size (cups D-G; size 4-5). Minimal skin toxicity (grade 0-1) was observed. No grade ≥ 2 was reported. 10 RTTs completed the survey. Male RTTs (n = 4) were not confident in assisting patients with bra fitting. 8 RTTs agreed that although it was difficult to reproduce the breast tissue for treatment, it helped patients to maintain the treatment position.

CONCLUSION

Our study demonstrated the feasibility of using a customised bra which provided optimal setup reproducibility while maintaining minimal skin toxicity and patient comfort, especially the value-added modesty felt among Asian women during their breast cancer radiotherapy.

Immunotherapy and Radiation Therapy Sequencing in Breast Cancer: A Systematic Review

PURPOSE

In the past decade, immune checkpoint inhibitors (ICIs) have emerged as a treatment option for metastatic breast cancer (BC). More recently, ICIs have been approved in the perioperative setting. This has led to clinical scenarios where radiation therapy (RT) is given concurrently with ICIs. On the other hand, moderate and ultrahypofractionated schedules of RT are being widely adopted in the adjuvant setting, in addition to an increased use of metastasis-directed therapy. Furthermore, RT can modulate the tumor microenvironment and induce a systemic response at nonirradiated sites, an "abscopal effect." The amplification of antitumor immune response is used as the rationale behind the concomitant use of ICIs and RT. To date, there is a lack of literature on the optimal sequence, timing, dose/fractionation schema, and treated RT volumes with ICIs in patients with BC, especially in the era of ultrahypofractionation.

METHODS AND MATERIALS

We conducted a systematic review to delineate the reported treatment details, safety, and efficacy of combining ICI and RT in patients with BC. PubMed, Embase, and Cochrane CENTRAL were searched between 2014 and 2023. Data were extracted to assess the details of ICIs/RT delivery, safety, and efficacy.

RESULTS

Of the 12 eligible studies, 9 involved patients with metastatic BC. Most studies were phase 1/2, had a small sample size (range, 8-28), and were heterogenous in patient population and reported outcomes. The combination was reported to be safe. We identified 1 study in the perioperative setting, which did a posthoc analysis of safety/efficacy of ICIs in the adjuvant setting with receipt and pattern of RT.

CONCLUSIONS

In conclusion, there are limited data on the dose, timing, fractionation, and volumes of RT in both the adjuvant and metastatic setting in BC. Ongoing/future trials should collect and report such data on RT details, whenever RT is used in combination with ICIs.

Hypofractionated Partial Breast Irradiation With Intensity-Modulated Radiotherapy in Early Breast Cancer or Carcinoma In Situ: An Investigational Short-Term Analysis

PURPOSE

This study aimed to analyze the treatment outcomes and adverse effects of moderately hypofractionated partial breast irradiation (PBI) in patients with early breast cancer.

METHODS

In total, 473 patients with early breast cancer or carcinoma in situ were diagnosed with Tis or T1N0 disease and underwent PBI following breast-conserving surgery. All histologic tumor types, close surgical margins within 1 mm of the tumor, and multifocal tumors were included in this study. A radiation dose of 50 Gy in 20 fractions was delivered over 4 weeks using intensity-modulated radiotherapy technique. Dosimetric data, recurrence patterns, survival outcomes, and adverse events were retrospectively analyzed.

RESULTS

During a median follow-up of 28.9 months, seven patients (1.5%) experienced ipsilateral breast tumor recurrence (IBTR). Two patients had regional recurrence, four patients developed contralateral breast cancer, and no distant metastases were observed. The locoregional recurrence rate in the ipsilateral breast was 1.8%. Two deaths occurred during the follow-up period, but were not attributed to breast cancer. The 2-year disease-free survival and 2-year overall survival rates were was 94.0% and 99.8%, respectively. Acute adverse events occurred in 131 patients (27.1%), and were distributed among all grades, with only two patients (0.4%) experiencing grade 3 events. Late adverse events were noted in 16 patients (3.4%), and were distributed among all grades, including grade 3 events in four patients (0.8%). No grade 4 or 5 events were observed.

CONCLUSION

Hypofractionated PBI demonstrated favorable IBTR rates in patients with early breast cancer, with low incidence of acute and late toxicities in the short-term analysis.

Is FAST FORWARD the Way Forward in Radiotherapy for Locally Advanced Breast Cancer - Learnings From the COVID Pandemic

INTRODUCTION

Low middle-income countries (LMICs), including India, have paucity of external beam radiotherapy (RT) machines leading to prolonged wait times for RT. Delay in delivery of RT has been shown to adversely affect outcomes in locally advanced breast cancer (LABC). With the availability of results of multiple randomized controlled trials, hypofractionated RT delivered over 3 to 4 weeks became the standard of care in breast cancer RT.

METHODS

We conducted a retrospective audit of 172 LABC patients treated with ultrahypofractionated adjuvant RT (radiotherapy completed in 1 week) during the COVID pandemic. Log rank and Cox-regression model used for univariate and multi-variate analyses.

RESULTS

No patient developed grade 3 esophagitis. Grade 2 esophagitis requiring short term narcotic analgesics was seen in 12 (6.9%) patients. Grade 2 or higher toxicity peaked between 2 and 3 weeks after RT. The estimated 2 and 3- year recurrence free survival (RFS) for the cohort is 87.1 % and 81.4 %, respectively. The estimated 2 and 3-year overall survival for the cohort is 95% and 91.3%. On multivariate analysis, presence of extra-nodal extension was found to be an independent factor associated with worse RFS (P = .028).

CONCLUSIONS

FAST FORWARD protocol RT in LABC appears well tolerated.

Personalized Radiation Therapy for Breast Cancer

Breast cancer is diagnosed in nearly 3 million people worldwide. Radiation therapy is an integral component of disease management for patients with breast cancer, and is used after breast-conserving surgery or a mastectomy to reduce the risk of a local recurrence. The following review describes the methods used to personalize radiation therapy by optimizing patient selection, using advanced treatment techniques to lessen the radiation dose to normal organs, and using hypofractionation in order to shorten the duration of radiation treatment.

Radiotherapy for breast cancer

In early breast cancer, adjuvant moderately hypofractionated regimens are recommended for both whole breast, partial breast and locoregional irradiation which abbreviates the overall treatment time, as argued in this review. Gating is recommended as well as the use of a simultaneous integrated boost when indicated. A tangential field set-up is standard, however, for challenging cases volumetric modulated arc therapy techniques, or referral for proton therapy, may be considered. In the metastatic setting, stereotactic radiotherapy is a promising treatment option for oligometastatic disease.

Accelerated Partial Breast Irradiation Using 5 Daily Fractions: A Prospective, Phase 2, Multicenter Trial of Cosmetic Outcomes and Toxicity-ACCEL Final Results

PURPOSE

This study investigated the cosmetic degradation and toxicity for an accelerated partial breast irradiation (APBI) prescription delivered in 5 fractions over 1 week and compared the outcomes with those of whole breast irradiation (WBI).

METHODS AND MATERIALS

The trial was a multicenter, single-arm, phase 2 prospective cohort study. Eligible women 50 years of age or older with estrogen receptor-positive and human epidermal growth factor receptor 2-negative invasive ductal carcinoma or ductal carcinoma in situ after breast-conserving surgery received 27 Gy in 5 daily fractions of APBI. The primary endpoint was noninferiority of 2-year cosmesis using the RAPID trial's WBI arm as the control arm. A global consensus cosmetic score using a European Organisation for Research and Treatment of Cancer rating scale score of excellent, good, fair, or poor for each patient at baseline and 2 years was generated by a panel of 5 radiation oncologists using photographs of treated and untreated breasts.

RESULTS

From 2016 to 2019, 298 eligible women were enrolled. By the 2-year follow-up, 76 patients had been lost or withdrawn and 3 had died, resulting in 219 patients available for complete, 2-year photographic cosmetic evaluation. The median follow-up for all participants was 4.7 years (IQR, 3.8-5.5 years). No patient had a fair or poor cosmetic score at the 2-year evaluation. Cosmesis was better or unchanged for 97% of patients and worse for 3% (excellent to good), and no cosmetic failures occurred. The confidence intervals were 0.88 (0.86-0.90) and 1.00 (0.99-1.00) for the RAPID and ACCEL trials, respectively.

CONCLUSIONS

Cosmetic degradation with 5 daily treatments of the ACCEL trial's APBI intervention is noninferior to the WBI arm of the RAPID trial.

Ten-Year Results of Accelerated Partial-Breast Irradiation with Interstitial Multicatheter Brachytherapy after Breast-Conserving Surgery for Low-Risk Early Breast Cancer

Patients with an early carcinoma of the breast are commonly treated by breast-conserving surgery (BCS) and postoperative radiotherapy. Partial-breast irradiation has gained acceptance in the last few years. Between December 2008 and December 2017, 182 low-risk breast cancer patients treated by BCS in the four university hospitals of the province of Las Palmas and treated with APBI using interstitial multicatheter brachytherapy were included in this study. After a mean follow-up for survivors of 10 years, the treatment was shown to be safe, as no severe acute/late toxicity (grade ≥ 3) was observed. The 10-year IBTR was 1.7% (95%CI: 0.7-2.7%), and the cause-specific survival was 94.9% (95%CI: 93.2-96.6%). We suggest that multicatheter brachytherapy after BCS is safe and effective in early breast cancer patients.

Second Malignancy Probabilities in Patients With Breast Cancer Treated With Conventional Versus Hypofractionated External Beam Radiation Therapy in the Adjuvant Setting

AIMS

For women with breast cancer, seminal studies have shown that adjuvant hypofractionated external beam radiation therapy (hEBRT) maintains similar outcomes and may reduce overall costs compared with conventionally fractionated external beam radiation therapy (cEBRT). However, it is unclear whether hEBRT may be associated with differential risk of development of radiation-induced second malignancies compared with cEBRT. Because the occurrence of second malignancies is small, large databases may improve our understanding of the relative risk of second malignancies between hEBRT and cEBRT.

MATERIALS AND METHODS

Using the National Cancer Database, we carried out a retrospective cohort analysis of women diagnosed with non-metastatic, stage 0-III breast cancer from 2004 to 2017. All patients had a lumpectomy or mastectomy and a follow-up time of at least 60 months after diagnosis. The probability of second malignancies in women receiving adjuvant cEBRT or hEBRT was compared using multivariable logistic regression adjusting for sociodemographic, geographical, clinical and treatment factors, allowing for relative (but not absolute) comparison of second malignancy risk. Temporal sensitivity analyses stratified by year of diagnosis and length of follow-up time were also conducted.

RESULTS

Of the 125 228 women in our study, 115 576 (92.3%) received cEBRT and 9652 (7.71%) received hEBRT. The median age of the cohort was 60 (interquartile range 51-68) years at diagnosis and the median follow-up time was 99.61 (interquartile range 77.5-128.49) months. Upon adjusting for sociodemographic and clinical factors, patients who received hEBRT had no difference in relative risk than patients who received cEBRT (odds ratio 0.937, 95% confidence interval 0.869-1.010, P = 0.091). In analyses stratified by year of diagnosis, and stratified by length of follow-up, there was no difference in second malignancy probability between patients who completed hEBRT and patients who completed cEBRT.

CONCLUSIONS

In this analysis of over 120 000 women with non-metastatic breast cancer, hEBRT was not associated with different odds of developing second malignancies compared with cEBRT. Our findings may inform patient counselling in the choice of radiation regimens for breast cancer and further support the safety of hypofractionated regimens for breast cancer.

Evaluation of conventional IMRT and VMAT strategies for postmastectomy radiation therapy after immediate implant-based reconstruction using the new ESTRO-ACROP contouring guidelines

This study evaluated the usability of conventional templates based on the new contour guidelines of the European Society of Radiation and Oncology and Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) for treatment plans of postmastectomy radiotherapy after immediate implant-based reconstruction. Intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans generated with two different treatment planning systems (TPSs, Eclipse and Monaco) were examined. Six computed tomography scans of patients aged 35-54 years were retrospectively analysed who had undergone mastectomy and breast reconstruction using silicone implants after being diagnosed with left breast cancer. Six radiation oncologists participated in this study, and each of them contoured the target volume of one left breast using conventional contour (CTV-CONV) and new contour (CTV-ESTRO) methods. This study showed that compared with CTV-CONV, using CTV-ESTRO with objectives and cost functions similar to those of TPSs worsened the target volume coverage and increased the total number of monitor units. Considering the organs at risk, CTV-ESTRO tended to increase the mean dose delivered to the contralateral lung. It is concluded that the approach used for the new ESTRO-ACROP contour method cannot be applied in a manner similar to that for the conventional breast contour method, implying that the new ESTRO-ACROP contour method may require more time for improving plans for a given treatment.

The Impact of PM2.5 on Radiation-induced Pneumonitis in Patients With Breast Cancer

BACKGROUND/AIM

Exposure to particulate matter (PM) air pollution is known to adversely affect respiratory disease, but no study has examined its effect on radiation-induced pneumonitis (RIP) in patients with breast cancer.

PATIENTS AND METHODS

We conducted a retrospective review of 2,736 patients with breast cancer who received postoperative radiation therapy (RT) between 2017 and 2020 in a single institution. The distance between the PM measurement station and our institution was only 3.43 km. PM data, including PM2.5 and PM10, were retrieved from the open dataset in the official government database.

RESULTS

Overall incidence rate of RIP was 1.74%. After adjusting for age, RT technique, regional irradiation, fractionation and boost, the average value of PM2.5 was significantly associated with a higher risk of RIP (p=0.047) when patients received ≥20 fractions of RT. Specifically, PM2.5 ≥35 (μg/m3) showed a significantly higher risk of RIP (p=0.019) in patients with ≥20 fractions of RT.

CONCLUSION

This is the first study to reveal the association between PM2.5 and RIP in patients with breast cancer who received 20 fractions or more of postoperative RT. We demonstrated that high PM2.5 levels around the RT institution were associated with RIP, suggesting that reducing PM air pollution may be a modifiable risk factor.

Efficacy and safety analysis of hypofractionated and conventional fractionated radiotherapy in postoperative breast cancer patients

OBJECTIVES

In this meta-analysis, we conducted a comparative analysis of the safety and efficacy of hypofractionated and conventional fractionated radiotherapy in individuals who had undergone surgery for breast cancer.

METHODS

This study involved a systematic and independent review of relevant research articles published in reputable databases such as PubMed, Embase, Cochrane Library, and Web of Science. Two investigators conducted the review, which included studies published up to January 3, 2023. The quality of the eligible studies was evaluated and data were extracted using Review Manager software 5.4 (RevMan 5.4) to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The analysis comprised 35 studies and encompassed a collective sample of 18,246 individuals diagnosed with breast cancer. We did not find a statistically significant disparity in efficacy between conventional fractionated (CF) radiotherapy and hypofractionated (HF) radiotherapy regarding local recurrence (LR; OR = 0.91, 95% CI: 0.76-1.09, P = 0.30), disease-free survival (DFS; OR = 1.20, 95% CI: 1.01-1.42, P = 0.03), and overall survival (OS; OR = 1.08, 95% CI: 0.93-1.26, P = 0.28). Concerning safety, there was no significant difference between the HF and CF regimens in terms of breast pain, breast atrophy, lymphedema, pneumonia, pulmonary fibrosis, telangiectasia, and cardiotoxicity. However, the HF regimen resulted in lower skin toxicity (OR = 0.43, 95% CI: 0.33-0.55, P < 0.01) and improved patient fatigue outcomes (OR = 0.73, 95% CI: 0.60 - 0.88, P < 0.01).

CONCLUSIONS

Although there is no substantial difference in LR, DFS, OS, or many other side effects between the HF and CF regimens, the HF regimen reduces skin toxicity and relieves patient fatigue. If these two issues need to be addressed in clinical situations, the HF regimen may be a superior alternative to conventional radiotherapy in postoperative breast cancer patients.