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

NOVEMBER, A Phase 2 Trial of a 9-Day Course of Whole Breast Radiation Therapy With a Simultaneous Lumpectomy Boost for Early-Stage Breast Cancer

PURPOSE/OBJECTIVES

A phase 2 prospective noninferiority trial evaluating a novel 9 fraction course of whole breast radiation and simultaneous lumpectomy boost.

MATERIALS AND METHODS

Tis and T1-3N0 patients enrolled to receive 3420 cGy radiation to the breast with 3960 cGy to the lumpectomy cavity. The primary endpoint was averaged photographic cosmetic scores at 24 months with a hypothesis of >70% good to excellent cosmetic breast scoring 24 months after completing radiation, assuming a baseline excellent/good cosmetic scoring of 80% with an 80% power, α = 0.1.

RESULTS

From 2018 to 2020, with institutional review board approval, 103 patients were enrolled. Patients had mostly invasive ductal carcinoma (75%), tumor size ≤ 2cm (88%), negative margins (92%), no lympho-vascular invasion (80%), and estrogen receptor positive (85%). Patients had a mean age of 59.5 years (33-82). With a mean follow-up of 51 months, there were no local recurrences and 1 patient with both regional (axilla) and distant (brain) recurrence. Twenty-four-month post-radiation therapy (RT) cosmetic photos were 68% excellent/good, and 32% fair/poor. The null hypothesis was not rejected with one-sided 95% exact binomial confidence interval of 59.1% (59.1%-100%). There were no reported late ≥grade 3 radiation toxicity events and only 4 patients with late grade 2 events. Patient-reported outcomes utilizing the Breast-Q survey revealed breast satisfaction in 85% of women.

CONCLUSIONS

We demonstrate an effective novel 9 fraction whole breast + lumpectomy boost radiation schedule. This trial uses one of the shortest published radiation schedules for a lumpectomy boost. Although we did not meet our prespecified cosmetic endpoint, no significant cosmetic change from baseline was seen in 80% of patients. We demonstrate excellent local control, and patient-reported satisfaction with low RT-related toxicity. We hope to move this concept forward in a randomized trial against the 5-day United Kingdom (UK) Fast Forward regimen, inclusive of a simultaneous lumpectomy cavity boost.

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.

Impact of Consensus Guidelines, Clinical Trials, and COVID-19 on Fractionation Practices for Node-negative Intact Breast Cancer

OBJECTIVE

To evaluate whether hypofractionated radiotherapy (HF-RT) in node-negative intact breast cancer significantly increased after guideline updates, trial publications, and COVID-19.

METHODS

Patients with node-negative breast cancer undergoing lumpectomy and adjuvant RT were identified in the National Cancer Database. Receiving ≥25 and <50 Gy in 5-20 fractions defined HF-RT. Receiving 50 to 66 Gy in >20 fractions defined conventional RT (CF-RT). Patient characteristics were compared with X 2 testing. Joinpoint analysis identified when fractionation significantly changed. Variables associated with HF-RT were identified by univariate and multivariate (MVA) logistic regression. Two-sided P -value <0.05 was significant.

RESULTS

Patients meeting criteria totaled 236,336; 54.8% received CF-RT and 45.2% HF-RT. HF-RT and 5-fraction RT significantly increased after 2015 and 2019, respectively ( P <0.05). On MVA, HF-RT was positively associated with: age older than or equal to 65 years (OR 2.14, P <0.001); private insurance (OR 1.27, P =0.03); treatment in Midwest (OR 1.66, P <0.001) or Western United States (US) (OR 3.77, P <0.001); distance ≥50 miles (OR 1.16, P =0.001); later year of diagnosis (OR 1.44, P <0.001); and partial breast irradiation (OR 2.08, P <0.001). HF-RT was negatively associated with: community (OR 0.49, P <0.001) or integrated network (0.55, P <0.001) centers; grade 2 (OR 0.83, P <0.001) or 3 (OR 0.49, P <0.001), hormone receptor negative (OR 0.66, P <0.001), and HER2+ (OR 0.74, P <0.001) disease; positive surgical margins (OR 0.61, P <0.001); and presence of lympho-vascular invasion (OR 0.86, P <0.001).

CONCLUSIONS

HF-RT in node-negative intact breast cancer increased after 2015, coinciding with US and European guideline updates. Five-fraction RT increased after 2019, coinciding with COVID-19 and FAST-Forward trial results.

Impact of Hypofractionated Radiation Protocols on Reducing Travel Burden and Improving Patient Satisfaction: When Less Is More

PURPOSE

Despite rising cancer incidence and mortality in Saudi Arabia, access to radiotherapy (RT) services is limited in some regions. This study aimed to examine the travel burdens of RT patients and assess the benefits of hypofractionated RT (HFRT).

METHODS

This multicenter retrospective study included patients with breast cancer (BC) and prostate cancer (PC) treated with HFRT (26 Gy/5 fractions for BC and 60 Gy/20 fractions for PC) between 2020 and 2024. Patient data were collected from electronic records, and an online questionnaire assessed experiences and financial burdens. Google Maps determined the shortest driving distance from patients' residences to our RT center. Descriptive statistics compared accommodation, transportation costs, and time expenditure for shorter versus longer RT courses.

RESULTS

A survey of 153 out of 187 patients (average age 57 years for BC, 70 years for PC) revealed significant travel burdens. Notably, 43% traveled from outside Jeddah, averaging 415 km, compared with 17.9 km for those within Jeddah. HFRT offered substantial transportation cost-savings, estimated at $101 in US dollars (USD) for patients with BC (an additional $133 (USD) for those outside Jeddah) and $213 (USD) for patients with PC (an additional $320 (USD) for those outside Jeddah). Median accommodation cost-savings were $733 (USD) for BC and $1,600 (USD) for PC. Median time-savings were 9.25 hours for BC and 30 hours for PC. All patients were satisfied with the treatment duration, with 42% preferring the shorter hospital stay and 8% citing financial reasons.

CONCLUSION

Patients with cancer in Saudi Arabia travel significant distances for RT. HFRT using shorter RT courses reduces patient-related costs, enhances satisfaction, and may improve access by addressing logistical challenges.

Six-Year Results From a Prospective Phase 2 Trial of 10-Fraction Hypofractionated Radiation Therapy in Locally Advanced Breast Cancer

PURPOSE

We report the 6-year results of a phase 2 study on hypofractionated radiation therapy targeting the primary and regional lymph nodes in 10 fractions.

METHODS AND MATERIALS

A schedule of 34 Gy/10 fractions/2 weeks to the whole breast/chest wall and the draining lymph nodes was used. Both acute and late toxicities were collected. All patients but those who underwent mastectomy without reconstruction or with temporary expander were asked to rate their cosmetic outcome according to the Harvard scale. Toxicity was assessed weekly during radiation therapy (RT) and then at each follow-up (fup) examination. Cancer-related endpoints were evaluated from the date of RT start to the diagnosis of local relapse/distant metastases or the last fup.

RESULTS

From February 2015 to March 2019, 59 women (median age, 60 years and IQR, 48.3-68.8 years) with stage II to IIIA breast cancer who underwent axillary dissection and conservative surgery (83%) or mastectomy (17%) were accrued. One patient was lost to fup immediately after the end of RT. At the median fup of 77.11 months (range, 24-102 months), the cumulative incidence of any grade locoregional late toxicity estimated with the Kaplan-Meier method is 43.4% (95% CI) (30.0% and 46.1% for patients undergone mastectomy and lumpectomy, respectively). Peak-2 events have been observed for fibrosis (1 patient, 1.7%), telangiectasia (1 patient, 1.7%), and lymphoedema (1 patient, 1.7%). One patient (1.7%) experienced grade 3 breast retraction at 36 months fup. The cosmetic outcome resulted in being excellent, good, fair, and poor in 61.7%, 25%, 7.6%, and 5.7%, respectively. At 72 months, the specific-disease-free survival was 96.5%; distant metastasis-free survival and overall survival rates were 88% and 94.4%, respectively.

CONCLUSIONS

Our results support the activity of a 10-fractions hypo-RT schedule targeting the primary site as well as the draining lymph node stations after surgery for locally advanced breast cancer.

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.

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.

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.

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.

Therapeutic Management in Elderly Male Breast Cancer Patients: A Scoping Review

PURPOSE OF REVIEW

Male breast cancer (MBC) is a rare entity which often arises in elderly people. Aim of this review is to evaluate the principal issues related to MBC in elderly, because the therapeutic management of disease is not only related to the biological behavior of the tumor, but also to the comorbidities and frailty of older population. A scoping literature review was performed on Pubmed and Cochrane Database using the following keywords: therapeutic management/ male/ breast cancer/ elderly patients. Papers published before 2000, not edited in English or French language, or not related to the main topic, were excluded. Only articles related to therapeutic issues in MBC and including more than 10 elderly (≥ 65 years) patients were selected for the qualitative outcome analysis.

RECENT FINDINGS

36 papers regarding surgery, radiotherapy, systemic therapy, racial disparities and therapeutic management in retrospective series of MBC in elderly were examined in details. MBC has a different biological behavior and a poorer prognosis than female, especially in cases with positive nodes at diagnosis. Elderly MBC patients have often larger tumors in more advanced stages at the time of diagnosis compared with younger patients. In spite of the advanced tumors at presentation, older patients present often cancers with more favorable biological characteristics, but they receive less guideline-concordant curative treatments (as adequate lymph node staging or adjuvant radiation therapy) compared to women. Moreover, racial differences in treatment of older MBC were observed. Therapeutic management of MBC in elderly patients is a subject rarely addressed in literature. Our review highlighted differences in the treatment and in guidelines-concordance for elderly MBC patients. Adequate geriatric assessment and use of therapeutic schemes adapted to age and comorbidities can avoid under/overtreatment, contributing to a better standard of care in this frail population.

Sequential or simultaneous-integrated boost in early-stage breast cancer patients: trade-offs between skin toxicity and risk of compromised coverage

PURPOSE

To determine the dosimetric effects of set-up errors on boost coverage, and compares skin toxicity of sequential and simultaneous boost techniques for left-sided breast cancer.

MATERIALS AND METHODS

This retrospective study included 23 early-stage breast cancer cases. Single isocenter HFWBI-SIB(s-SIB), single isocenter HFWBI-SB(s-SB) and dual isocenter HFWBI-SB(d-SB) were planing. Rotations of 0.5°, 1°, and 2° coupled with translationals of 0.5 mm, 1.0 mm, and 2.0 mm were applied along three orthogonal axes. The dose to 95% of the PTV (D95) and the volume covered by 95% of the prescribed dose (V95) were evaluated using GEE univariate analysis to determine how PTV coverage was related to 1/CIRTOG, PTVboost volume, PTVboost separation to isocenter. The relationship between the high-dose regions within the PTVbreast and Ratio_V was evaluated using univariate analysis.

RESULTS

The s-SIB had optimal target coverage and lower high-dose volume, but it increased the risk of compromised coverage to tumor bed. For the s-SB technique, V95 exceeded 95% under all setup errors. At 2.0° coupled with 2.0 mm, s-SIB and d-SB exhibited V95 values below 95% in 34.8% and 8.7% of cases, respectively. At other setup errors, both s-SIB and d-SB demonstrated V95 values greater than 95%. Notably, high-dose regions such as V105%, V107%, and V110% within the PTVbreast across the three techniques displayed a significant correlation with Ratio_V.

CONCLUSION

Simultaneous-integrated boost for early-stage breast cancer can reduce skin toxicity compared to sequential techniques but with the risk of compromising tumor bed coverage.

An observational study comparing the dosimetry and clinical effects of conventional versus hypofractionated radiotherapy in elderly patients of early breast cancer

INTRODUCTION

Hypofractionated radiation therapy after Breast Conserving Surgery in patients of early breast carcinoma results in equivalent clinical outcome but better cosmesis as compared to conventional therapy. In this study we have compared the dosimetry and clinical outcome between Hypofractionated and Conventional whole breast radiation followed by boost therapy after patients had undergone breast conserving surgery for early breast cancer.

AIMS AND OBJECTIVES

1. Dosimetric analysis and toxicity assessment between conventional and Hypofractionated radiation therapy.2. Comparative analysis of late toxicity between two groups.

MATERIALS AND METHODS

In the department of Radiation Oncology in a Tertiary Care Hospital, 100 patients between the age group 65-75 years were selected as per inclusion criteria of the study and there were 60 patients in the conventional group and 40 in the hypofractionated group respectively. All the patients underwent treatment in Varian Truebeam Linear accelerator with appropriate radiation planning after undergoing Breast Conserving Surgery along with adjuvant chemotherapy when indicated.The conventional group received a dose of 50 Gy in 25# followed by boost of 10 Gy in 5 # and the hypofractionated arm received a dose of 42.5Gy in 16# followed by a boost of 12.5Gy in 5 # . The post-operative tumour cavity was irradiated along with axillary lymph nodes when indicated. All the patients in both arms were assessed for toxicity related to therapy and quality of life as per EORTC Q45 in 2 years following treatment completion. All statistical tests were done by SPSS version 23. Unpaired t-test was used for dosimetric comparison. Comparison of QOL and toxicity was done by Chi-square test respectively between two groups. A p-value of < 0.05 was taken to be significant.

RESULTS

At the end of 2 years, 54 patients in conventional group and 38 patients in hypofractionated group could be assessed respectively and rest in both groups had lost to follow-up due to logistical reasons. There was no significant difference in dosimetry between the two groups as per unpaired t-test (P value >0.05). In terms of Quality of Life assessment in two years following the completion of therapy the conventional arm had more toxicity than hypofractionated arm as per Chi-square test (P value <0.05). Chi-square test revealed patients who had conventional therapy had worse cosmetic outcome and increased incidence of myelotoxicity than in those who received hypofractionated therapy, both statistically significant (P value < 0.05). There was no incidence of locoregional relapse in either groups.

CONCLUSION

Hypofractionated whole breast Radiation therapy followed by boost therapy with can result in less toxicity and thus better cosmetic outcome and almost equal dosimetric results compared to Conventional Radiotherapy in patients after breast conserving surgery, thus comparatively increasing their quality of life.

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.

Optimization of the Dose-Volume Effect Parameter "a" in EUD-Based TCP Models for Breast Cancer Radiotherapy

IntroductionRadiotherapy treatment plans traditionally rely on physical indices like Dose-volume histograms and spatial dose distributions. While these metrics assess dose delivery, they lack consideration for the biological effects on tumors and healthy tissues. To address this, radiobiological models like tumor control probability (TCP) and Normal tissue complications probability (NTCP) are increasingly incorporated to evaluate treatment efficacy and potential complications. This study aimed to assess the predictive power of radiobiological models for TCP in breast cancer radiotherapy and provide insights into the model selection and parameter optimization.MethodsIn this retrospective observational study, two commonly used models, the Linear-Poisson and Equivalent uniform dose (EUD)-based models, were employed to calculate TCP for 30 patients. Different radiobiological parameter sets were investigated, including established sets from literature (G1 and G2) and set with an optimized "a" parameter derived from clinical trial data (a1 and a2). Model predictions were compared with clinical outcomes from the START trials.ResultsThe Linear-Poisson model with es lished parameter sets from the literature demonstrated good agreement with clinical data. The standard EUD-based model (a = -7.2) significantly underestimated TCP. While both models exhibited some level of independence from the specific parameter sets (G1 vs. G2), the EUD-based model was susceptible to the "a" parameter value. Optimization suggests a more accurate "a" value closer to -2.57 and -5.65.ConclusionThis study emphasizes the importance of clinically relevant radiobiological parameters for accurate TCP prediction and optimizing the "a" parameter in the EUD-based model based on clinical data (a1 and a2) improved its predictive accuracy significantly.

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.

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.

Contemporary Issues in Postmastectomy Radiotherapy: A Brief Review

Breast cancer is the one of the most common cancers and causes a significant disease burden. Currently, postmastectomy radiotherapy (PMRT) is indicated for breast cancer patients with higher risk of recurrence, such as those with positive surgical margins or high-risk breast cancer (T3 with positive lymph nodes, ≥4 positive lymph nodes or T4 disease). Whether PMRT should be used in intermediate-risk breast cancer (T3 with no positive lymph nodes or T1-2 with 1-3 positive lymph nodes) is contentious. Rates of breast reconstruction postmastectomy are increasing in countries like Australia, and PMRT usage in such settings is another area of active research. Ongoing trials are also assessing the safety and efficacy of hypofractionated PMRT, a clinical scenario now widely accepted for early-stage breast cancer. This brief review is unique in that it aims to examine three current and controversial aspects of the PMRT field (PMRT in intermediate-risk breast cancer, PMRT in conjunction with breast reconstruction and its hypofractionation). To achieve this aim, we discuss available and emerging literature and guidelines to offer insights important to the PMRT field. Current literature suggests that PMRT could play a role in improving the overall survival rate and in reducing locoregional recurrence in intermediate-risk breast cancer. In terms of recommending a timing or type of breast reconstruction best suited to the setting of PMRT, we found that individual patient preferences and circumstances need to be considered alongside a multidisciplinary approach. Research into PMRT hypofractionation safety and efficacy is ongoing and its place remains to be elucidated.

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.

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.

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.

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.

Preliminary results of hypofractionated radiotherapy in breast cancer in Chandigarh, India: single-centre, non-inferiority, open-label, randomised, phase 3 trial

BACKGROUND

Globally, most of the randomised trials with hypofractionation in patients with breast cancer have used 3-dimensional conformal radiotherapy technique (3D-CRT). As facilities for 3D-CRT technique may not be available in low-resource settings, there is a need to see if hypofractionation is feasible and safe with 2-dimensional (2-D) technique. In this study, we compared a 3-week radiation schedule with a 2-week schedule of hypofractionated radiotherapy in patients with breast cancer with 2-D technique.

METHODS

The current study was an open-label, randomised, phase 3 trial. Patients with breast cancer, stage I-III, post mastectomy or after breast conservative surgery who needed adjuvant locoregional radiotherapy were randomised in the Department of Radiotherapy & Oncology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh, India; to 34Gy in 10 fractions over 2 weeks (2-week arm) or 35Gy in 15 fractions over 3 weeks to the chest wall and 40Gy/15#/3wks to breast and supraclavicular fossa (3-week arm). Boost dose when indicated was 8-10Gy/2-4#/2-4 days in both the arms. Patients were planned on a 2-dimensional (2D) simulator with 2 tangential fields to breast/chest wall and incident supraclavicular fossa field. Acute toxicity was assessed using the Radiation Therapy Oncology Group (RTOG) grading scale. Assessments were carried out weekly during radiotherapy and at 4 weeks after treatment by the physician. Cosmetic outcome was assessed using the Harvard/National Surgical Adjuvant Breast and Bowel Project (NSABP)/RTOG scale. The toxicity rates between the two arms were compared using Fisher's exact tests. The trial was approved by institutional ethics committee and registered with ClinicalTrials.gov, number NCT04075058.

FINDINGS

This study included 1121 eligible patients from June 2015 to December 2020. Median follow-up was 35 months (6-84 months). Mean age was 48 years (24-75 years). The patient characteristics were comparable between the two arms except for more mastectomies in the 3-week arm and more node-positive patients in the 2-week arm. There were more oestrogen receptor-positive tumors in the 3-week arm. Acute skin toxicities were comparable between the two arms. Grade 2 and 3 skin toxicity was 100 (18%) and 82 (15%); and 16 (3%) and 12 (2%) in the 3-week and 2-week arm (p = 0.21), respectively. Cosmetic outcome was assessed as Excellent or Good for 89% of patients in the 3-week arm as compared to 94% in the 2-week arm (p = 0.004).

INTERPRETATION

The two radiation schedules were comparable in terms of acute skin toxicity. The cosmetic outcome was better with the 2-week schedule. The preliminary findings indicate 2-week radiotherapy schedule with 2-D technique was better than the 3-week schedule in patients with breast cancer. However, disease outcomes and late-term toxicities need to be further checked.

FUNDING

This study was funded by Science and Engineering Research Board (SERB), India.

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.