Hypofractionated Versus Standard Fractionated Radiotherapy in Patients With Early Breast Cancer or Ductal Carcinoma In Situ in a Randomized Phase III Trial: The DBCG HYPO Trial

Tolerance of Adjuvant Ultrahypofractionated Whole-Breast Radiation Therapy Employing Moderately Hypofractionated Sequential Boost: A Single Institution Analysis

Purpose

This analysis evaluates early and intermediate treatment tolerance in a prospective observational cohort study of patients who underwent adjuvant ultrahypofractionated whole-breast radiation therapy (uhWBRT), with or without moderately hypofractionated sequential boost, following breast-conserving surgery.

Methods and Materials

uhWBRT was introduced in our department in March 2020. Data from 436 patients with breast tumors not requiring lymphatic irradiation were analyzed, including 376 with invasive carcinomas (pT1-pT3) and 60 with ductal carcinoma in situ. The mean age was 62 years (range, 26-85). Acute reactions (Common Terminology Criteria for Adverse Events v4.03) were assessed at radiation therapy completion and after 2 to 3 weeks. Late effects and patient-reported outcomes (Late Effects in Normal Tissues-Subjective, Objective, Management and Analytic and Harvard for Cosmesis) were evaluated at 6 months after radiation therapy and annually thereafter. The prescribed uhWBRT dose was 26 Gy in 5 daily fractions. A sequential boost of 10.0 to 12.5 Gy in 4 to 5 daily fractions was administered to 338 patients (77.5%), while 98 (22.5%) did not receive a boost.

Results

Acute toxicity grades 0, 1, and 2 were observed in 29.8%, 59.9%, and 10.3% of patients, respectively, at radiation therapy completion and 52.1%, 40.8%, and 7.2% of patients at 2 to 3 weeks after radiation therapy. Grade 2 late effects were identified in 5.3%, 2.0%, 1.8%, 1.1%, and 0%, and grade 3 late effects were identified in 1.5%, 2.3%, 0.9%, 0%, and 0% of patients at 6 months, 1 years, 2 years, 3 years, and 4 years. Patient-reported outcomes for cosmesis were rated as good or excellent in 97.7% of patients. After a mean follow-up of 18 months (median 14, range, 0-48), 1 local failure, 2 nodal failures, and 9 distant relapses were detected. Three deaths were reported, all nontumor-related.

Conclusions

Early and intermediate results indicate that the treatment schedules, including the moderately hypofractionated boost, are safe and well tolerated, with acute toxicity rates comparable to those in the FAST-Forward trial. Although our study follow up is relatively short, our findings indicate that uhWBRT, with or without a moderately hypofractionated boost, is safe and well tolerated.

The 2024 Assisi think tank on breast cancer: Focus on the use of a tumour bed boost after breast conserving therapy

At the Fifth Assisi Think Tank Meeting (ATTM) on breast cancer, one key topic was the role of tumor bed boost in invasive breast cancer and ductal carcinoma in situ. The need for a tumor bed boost after whole breast irradiation is controversial. A literature review assessed boost indications, target volume definition, techniques, dose fractionation, and ongoing trials. Findings indicated that while a boost halves the risk of local recurrence at 10 years, it also leads to worsened cosmetic outcomes and increased fibrosis without improving overall survival. Therefore, we would recommend to omit the boost if the estimated reduction in local recurrence at 10 years is less than 3 %, and to apply shared decision-making with patients, if the boost is expected to reduce the local recurrence rate with >3 % at 10 years. Future research will focus on identifying patient subgroups that can safely omit the boost and improving boost volume precision.

Radiation-induced heart disease in breast cancer patients: a narrative review of epidemiology, risk factors, radiotherapy parameters, and prevention

BACKGROUND

Breast cancer is the most prevalent cancer in women worldwide; nevertheless, the prognosis is good, with a 5-year overall survival of 80-90%. Therefore, it becomes crucial to strive for high quality of life after cure by minimizing treatment-related toxicity. One such concern is radiation-induced heart disease, which remains a significant focus of ongoing investigations.

PURPOSE

The aim of this review is to summarize current knowledge on radiation-induced heart disease in breast cancer patients by giving an overview of its epidemiology, risk factors, radiation parameters related to its development, solutions in radiation practice, and prevention. The goal is to raise awareness and maximize prevention of radiation-induced heart disease.

METHODS

The PubMed database was screened for articles published between January 2013 and November 2023 related to the keywords , , , and . Moreover, by screening the literature lists of these publications, additional articles were added.

RESULTS

Ninety-four relevant papers remained for final review.

CONCLUSION

Radiation-induced heart disease is a rare complication after breast cancer radiotherapy and represents a clinical spectrum of various cardiovascular conditions. Several heart-sparing techniques have been developed, and more attention has been paid to early diagnosis and prevention of radiation-induced heart disease. However, further research remains important to refine radiotherapy techniques and deepen our understanding for improved prevention and treatment of this condition in the future. This clinical review summarizes the existing evidence and literature on radiation-induced heart disease following modern breast cancer radiotherapy, offering clinical guidance for physicians.

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.

Early toxicity of moderately hypofractionated radiation therapy in breast cancer patients receiving locoregional irradiation: First results of the UNICANCER HypoG-01 phase III trial

PURPOSE

To investigate early adverse events (AEs) in HypoG-01, a randomised, controlled, multicentre, non-inferiority phase 3 trial comparing toxicity and efficacy of adjuvant loco-regional moderately hypofractionated radiation therapy versus 2 Gy daily radiation therapy.

METHODS

Women ≥ 18 years with T1-3 N0-3 M0 breast cancer were randomised 1:1 after surgery +/- systemic therapy to receive either 40 Gy/15 fractions (3-week-RT) or 50 Gy/25 fractions (5-week-RT) +/-tumour-bed boost. AEs at baseline, end of treatment, and 6-month follow-up were graded using CTCAEV4.0, LENT/SOMA and Harris 4-point scales. Competing risk analysis for cumulative incidence of AEs, worst grade dermatitis according to risk factors, and cosmetic assessment were performed in the intention-to-treat (ITT) population.

RESULTS

From September 2016 to March 2020, 29 sites enrolled 1265 women. The ITT population included 1260 patients (3-week-RT: 631, 5-week-RT: 629). The proportion of patients with maximum grade ≥ 2 AEs were 284 (45 %) in 3-week-RT and 326 (51.8 %) in 5-week-RT. Overall, 88 (7 %) grade 3, one grade 4 and no grade 5 AEs were observed. Reported AEs were mostly dermatitis, fatigue, and pain, numerically lower in 3-week-RT than 5-week-RT. Grade ≥ 2 dermatitis was more frequent in patients receiving a tumour-bed boost or with BMI > 30 but numerically less frequent with 3-week-RT than 5-week-RT even in those subgroups. Of the 552 patients with breast-conserving surgery who completed cosmetic evaluation at M6, 88.4 % had excellent to good cosmetic results with no imbalance between groups.

CONCLUSION

Early AEs were mild and do not raise safety concerns for 3-week-RT in women receiving nodal RT.

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.

Quality of Decision Making in Radiation Oncology

High-quality decision making in radiation oncology requires the careful consideration of multiple factors. In addition to the evidence-based indications for curative or palliative radiotherapy, this article explores how, in routine clinical practice, we also need to account for many other factors when making high-quality decisions. Foremost are patient-related factors, including preference, and the complex interplay between age, frailty and comorbidities, especially with an ageing cancer population. Whilst clinical practice guidelines inform our decisions, we need to account for their applicability in different patient groups and different resource settings. With particular reference to curative-intent radiotherapy, we explore decisions regarding dose fractionation schedules, use of newer radiotherapy technologies and multimodality treatment considerations that contribute to personalised patient-centred care.

Prolonged interval hypofractionated radiotherapy facilitates better antitumor immunity

PURPOSE

To evaluate the impact of hypofractionated radiotherapy (Hypo-RT) with different interfraction intervals on tumor growth, immune response, and synergistic effects with anti-PD-1 immunotherapy.

METHODS

The mouse MC38 colon cancer model was utilized. Various radiation regimens were designed to investigate the effects of fraction interval and fraction size on tumor growth, immune mobilization, and combination effects with anti-PD-1 immunotherapy.

RESULTS

For a fixed-dose experiment, the 6 × 5 Gy for every other day (qod) regimen demonstrated an equivalent effect on tumor growth compared to the 6 × 5 Gy once daily (qd) regimen, while the 6 × 5 Gy for twice weekly (biw) regimen failed to inhibit tumor growth. Both qod and biw regimens induced an enhanced immune response, unlike the qd regimen. For a fixed biologically equivalent dose experiment, 6 × 5 Gy qod, 4 × 7 Gy biw, and 2 × 11 Gy once weekly (qw) regimens exhibited similar tumor suppression to the 12 × 3 Gy qd regimen. The long-interval Hypo-RT regimens significantly mobilized host immunity, whereas 12 × 3 Gy qd did not. The peripheral and intratumoral T cells increased as the fraction interval and size increased. All Hypo-RT regimens combined with anti-PD-1 immunotherapy demonstrated higher intratumoral CD8 + T cells and more effective tumor growth delay compared to the 12 × 3 Gy qd regime.

CONCLUSIONS

The current study suggested that a prolonged inter-fraction interval with an increased fraction size in Hypo-RT may be a promising option to balance the therapeutic effect on tumor and immune activation.

Efficacy Analysis of Hypofractionated Radiotherapy for Oligometastatic Tumors: A Retrospective Study

INTRODUCTION

Metastasis remains a major cause of death among patients with malignant tumors. Radiotherapy is one of the main modalities of cancer treatment. The rapid development of radiotherapy technology has enabled the widespread application of hypofractionated radiotherapy (HFRT) in clinical practice. This study aimed to evaluate the effect of HFRT on the survival and safety of patients with oligometastatic tumors.

METHODS

We conducted a retrospective study that involved 65 patients with well-controlled primary tumors and 1-5 metastatic foci treated at the study site between January 2020 and December 2022. Patients were aged >18 years and had a ≥ 6-month life expectancy. The patients received standard treatments plus HFRT for all metastatic foci. The dose fractionation regimen was adjusted according to the location and size of the patient's metastatic foci. The planning gross tumor volume of HFRT was 82.93 cm3 (range: 10.12-562.80 cm3), and the radiation dose range was 20 Gy/5 F-60 Gy/15 F. Progression-free survival (PFS), overall survival (OS), local control rates, and incidence of adverse events of the patients were observed.

RESULTS

Among the 65 patients, the median follow-up time, PFS, and OS were 26 months (95% CI: 0.80-37.50), 15 months (95% CI: 9.36-20.64), and 28 months (95% CI: 16.71-39.29), respectively. The 1- and 2-year PFS were 53.8% and 40.0%, respectively, while the 1- and 2-year OS rates were 73.8% and 56.9%, respectively. In total, 13.8%, 55.4%, 20.0%, and 13.8% of patients showed complete response, partial response, stable disease, and progressive disease, respectively. Four patients developed grade 3 or worse adverse events, and no treatment-related deaths occurred.

CONCLUSIONS

HFRT showed favorable clinical efficacy and safety in patients with oligometastatic tumors, generally achieving a good OS rate. Further randomized trials should be conducted.

Exploring the feasibility of preoperative tumor-bed boost, oncoplastic surgery, and adjuvant radiotherapy schedule in early-stage breast cancer: a phase II clinical trial

BACKGROUND

Oncoplastic breast-conserving surgery (OBCS) improves satisfaction in patients who would fare otherwise sub-optimal cosmetic outcomes while bringing challenges in tumor-bed identification during adjuvant radiotherapy. The ultra-hypofractionated breast radiotherapy further shortens treatment sessions from moderately hypofractionated regimens. To circumscribe the difficulty in tumor-bed contouring and the additional toxicity from larger boost volumes, the authors, propose to move forward with the boost session preoperatively from the adjuvant radiation part. Thus, the present study aims to evaluate the feasibility of a new treatment paradigm of preoperative primary-tumor boost before breast-conserving surgery (BCS) or OBCS followed by adjuvant ultra-hypofractionated whole-breast irradiation (u-WBRT) for patients with early-stage breast cancer.

METHODS

There was a phase II study. Patients younger than 55 years old, with a biopsy confirmed mono-centric breast cancer, without lymph node involvement were enrolled. A preoperative primary-tumor boost was given by a single 10 Gy in 1 fraction, and BCS or OBCS was conducted within 2 weeks afterwards. Adjuvant u-WBRT (26 Gy/5.2 Gy/5 f) was given in 6 weeks postoperatively without any boost, after the full recovery from surgery. Surgical complications and patient-reported outcomes, as assessed via Breast-Q questionnaires, were documented. A propensity score matching approach was employed to identify a control group at a 1:1 ratio for BREAST-Q outcomes comparison.

RESULTS

From May 2022 to September 2023, 36 patients were prospectively enrolled. Surgical complications were observed in seven cases (19.4%), including three cases with Clavien-Dindo (CD) grade 1-2 and four cases with CD grade 3 complications. All but four patients (11.1%) started the planned u-WBRT within 1 week after the predefined due dates postoperatively (≤49 days). Four patients (11.1%) developed grade 2 radiodermatitis after chemotherapy initiation. Compared to the study group, the control patients reported higher scores in chest physical well-being ( P =0.045) and in their attitudes towards arm swelling ( P =0.01). No significant difference was detected in the other of domains (Satisfaction with Breasts, Sexual and Psychosocial Well-Being, and Adverse Effects of Radiation). With a median follow-up period of 9.8 months (2.4-18.9 months), none had any sign of relapse.

CONCLUSION

This Phase II clinical trial confirmed the technical and safety feasibility of a novel radiation schedule in patients undergoing BCS or OBCS. According to the BREAST-Q questionnaire, patients who underwent novel radiation schedules reported lower satisfaction in chest physical well-being. A randomized controlled trial is necessary to further investigate these findings. Additionally, long-term follow-up is required to assess oncological outcomes.

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.

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.

Reproducibility and stability of voluntary deep inspiration breath hold and free breath in breast radiotherapy based on real-time 3-dimensional optical surface imaging system

BACKGROUND

The aim of this study was to evaluate the inter-fraction reproducibility and intra-fraction stability of breast radiotherapy using voluntary deep-inspiration breath hold (DIBH) and free breathing (FB) based on an optical surface imaging system (OSIS).

METHODS

Seventeen patients (510 breath-hold sessions) treated using a field-in-field (FiF) technique and twenty patients (600 breath-free sessions) treated with a volume-modulated arc therapy (VMAT) technique were included in this retrospective study. All the patients were positioned with the guidance of CBCT and OSIS, and also monitored with OSIS throughout the whole treatment session. Eight setup variations in three directions were extracted from the treatment reports of OSIS for all sessions and were subsequently manually introduced to treatment plans, resulting in a total of 296 perturbed plans. All perturbed plans were recalculated, and the dose volume histograms (DVH) for the target and organs at risk (OAR) were analyzed.

RESULTS

The OSIS and CBCT for both DIBH and FB treatments showed a good agreement of less than 0.30 cm in each direction. The intra-fraction respiratory motion data during DIBH were -0.06 ± 0.07 cm, 0.12 ± 0.15 cm, and 0.12 ± 0.12 cm in the lateral, longitudinal, and vertical directions, respectively; for FB, the respiratory motion data were -0.02 ± 0.12 cm, 0.08 ± 0.18 cm, and 0.14 ± 0.20 cm, respectively. For the target, DIBH plans were more sensitive to setup errors; the mean deviations in D95 for CTV were 39.78 Gy-40.17 Gy for DIBH and 38.46 Gy-40.52 Gy for FB, respectively. For the OARs, the mean deviations of V10, V20, and Dmean to the heart; V5, V20, and Dmean to the ipsilateral lung; and Dmean to the breast were lower for the FB plan compared with the DIBH plan.

CONCLUSION

Based on OSIS, our results indicate that both DIBH and FB can provide good reproducibility in the inter-fractions and stability in the intra-fractions. When the patient respiratory motion is large, the FB technology has greater possibility for the undercoverage of the target volume, while DIBH technology is more likely to result in increases in dose to OARs (the lung, heart, and contralateral breast).

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.

Re-Evaluating the Omission of Radiation Therapy in Low-Risk Patients With Early-Stage Breast Cancer

Traditionally, management of early-stage breast cancer has required adjuvant radiation therapy following breast conserving surgery, due to decreased local recurrence and breast cancer mortality. However, over the past decade, there has been an increasing emphasis on potential overtreatment of patients with early-stage breast cancer. This has given rise to questions of how to optimize deintensification of treatment in this cohort of patients while maintaining clinical outcomes. A multitude of studies have focused on identification of a subset of patients with invasive breast cancer who were at low risk of local recurrence based on clinicopathologic features and therefore suitable for RT omission. These studies have failed to identify a subset that does not from RT with respect to local control. Several ongoing trials are evaluating alternative approaches to deintensification while focusing on tumor biology. With regards to ductal carcinoma in situ (DCIS), the role of RT has been questioned since breast conservation was utilized. Paralleling invasive disease studies, studies have sought to use clinicopathologic features to identify low risk patients suitable for RT omission but have failed to identify a subset that does not from RT with respect to local control. Use of new assays in patients with DCIS may represent the ideal approach for risk stratification and appropriate deintensification. At this time, when considering deintensification, individualizing treatment decisions with a focus on shared decision making is paramount.

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.

Optimising inter-patient image registration for image-based data mining in breast radiotherapy

Background and purpose

Image-based data mining (IBDM) requires spatial normalisation to reference anatomy, which is challenging in breast radiotherapy due to variations in the treatment position, breast shape and volume. We aim to optimise spatial normalisation for breast IBDM.

Materials and methods

Data from 996 patients treated with radiotherapy for early-stage breast cancer, recruited in the REQUITE study, were included. Patients were treated supine (n = 811), with either bilateral or ipsilateral arm(s) raised (551/260, respectively) or in prone position (n = 185). Four deformable image registration (DIR) configurations for extrathoracic spatial normalisation were tested. We selected the best-performing DIR configuration and further investigated two pathways: i) registering prone/supine cohorts independently and ii) registering all patients to a supine reference. The impact of arm positioning in the supine cohort was quantified. DIR accuracy was estimated using Normalised Cross Correlation (NCC), Dice Similarity Coefficient (DSC), mean Distance to Agreement (MDA), 95 % Hausdorff Distance (95 %HD), and inter-patient landmark registration uncertainty (ILRU).

Results

DIR using B-spline and normalised mutual information (NMI) performed the best across all evaluation metrics. Supine-supine registrations yielded highest accuracy (0.98 ± 0.01, 0.91 ± 0.04, 0.23 ± 0.19 cm, 1.17 ± 1.18 cm, 0.51 ± 0.26 cm for NCC, DSC, MDA, 95 %HD, and ILRU), followed by prone-prone and supine-prone registrations. Arm positioning had no significant impact on registration performance. For the best DIR strategy, uncertainty of 0.44 and 0.81 cm in the breast and shoulder regions was found.

Conclusions

B-spline algorithm using NMI and registered supine and prone cohorts independently provides the most optimal spatial normalisation strategy for breast IBDM.

A nomogram with Nottingham prognostic index for predicting locoregional recurrence in breast cancer patients

Background

The Nottingham prognostic index (NPI) has been shown to negatively impact survival in breast cancer (BC). However, its ability to predict the locoregional recurrence (LRR) of BC remains still unclear. This study aims to determine whether a higher NPI serves as a significant predictor of LRR in BC.

Methods

In total, 238 patients with BC were included in this analysis, and relevant clinicopathological features were collected. Correlation analysis was performed between NPI scores and clinicopathological characteristics. The optimal nomogram model was determined by Akaike information criterion. The accuracy of the model's predictions was evaluated using receiver operating characteristic curves (ROC curves), calibration curves and goodness of fit tests. The clinical application value was assessed through decision curve analysis.

Results

Six significant variables were identified, including age, body mass index (BMI), TNM stage, NPI, vascular invasion, perineural invasion (P<0.05). Two prediction models, namely a TNM-stage-based model and an NPI-based model, were constructed. The area under the curve (AUC) for the TNM-stage- and NPI-based models were 0.843 (0.785,0.901) and 0.830 (0.766,0.893) in training set and 0.649 (0.520,0.778) and 0.728 (0.610,0.846) in validation set, respectively. Both models exhibited good calibration and goodness of fit. The F-measures were 0.761vs 0.756 and 0.556 vs 0.696, respectively. Clinical decision curve analysis showed that both models provided clinical benefits in evaluating risk judgments based on the nomogram model.

Conclusions

a higher NPI is an independent risk factor for predicting LRR in BC. The nomogram model based on NPI demonstrates good discrimination and calibration, offering potential clinical benefits. Therefore, it merits widespread adoption and application.

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.

Impact of the COVID-19 Pandemic on Hypofractionated Radiation Therapy Use for Breast Cancer in Japan: A Nationwide Study

Purpose

Hypofractionated radiation therapy (RT) was recommended for several cancer sites to reduce outpatient visits during the COVID-19 pandemic. This study aimed to identify the impact of the pandemic on hypofractionated RT for breast cancer in Japan.

Methods and Materials

The monthly number of courses for hypofractionated and conventional RTs was counted using sample data sets from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, a nationwide database accumulating insurance claims data comprehensively. Changes in the number of hypofractionated and conventional RTs were estimated using an interrupted time-series analysis.

Results

The number of hypofractionated RT courses gradually increased before the pandemic in contrast to that of conventional RT courses, which gradually decreased. However, conventional RT remained outnumbered by hypofractionated RT throughout the observation period. After the outbreak of the pandemic, the use of hypofractionated RT significantly increased in April 2020 (1312 courses; 95% CI, 801-1823) but decreased in October 2020 (-601; 95% CI, -1111 to -92). Subgroup analysis by age and the number of beds in medical institutions revealed similar trends.

Conclusions

Although conventional RT for breast cancer has been gradually replaced by hypofractionated RT, it remains predominant. The use of hypofractionated RT increased briefly early in the COVID-19 pandemic; however, this increase was not sustained, unlike in other countries. Considering the benefits of hypofractionated RT for breast cancer, its use should be encouraged in Japan.

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.

French national survey on breast cancer care: caregiver and patient views

PURPOSE

To improve the quality of care for patients with breast cancer, an analysis of the health-care pathway, considering feedback from both health-care practitioners (HCPs) and patients, is needed.

METHODS

Between 2020 and 2022, we conducted a survey at French breast cancer centers and analyzed information from questionnaires completed by HCPs and patients. We collected information on center organization, diagnostic processes, treatment decisions and modalities, supportive care, patient advocacy groups, and work issues.

RESULTS

Twenty-three breast cancer centers were included and questionnaires completed by 247 HCPs and 249 patients were analyzed. The centers closely followed the legal French framework for cancer treatments, which includes formal diagnostic announcements, multidisciplinary tumor boards, personalized treatment summaries, and supportive care access. HCPs and patients were satisfied with the time to diagnosis (≤ 2 weeks as evaluated by 75% of patients), time to surgery (mean 61 days), time between surgery and chemotherapy (mean 47 days), and time between surgery and radiotherapy (mean 81 days). Fertility preservation counseling for women under 40 years of age was systematically offered by 67% of the HCPs. The majority (67%) of the patients indicated that they had received a personalized treatment summary; the topics discussed included treatments (92%), tumor characteristics (84%), care pathways (79%), supportive care (52%), and breast reconstruction (33%). Among HCPs, 44% stated that reconstructive surgery was offered to all eligible patients and 57% and 45% indicated coordination between centers and primary care physicians for adverse effects management and access to supportive care should be improved, for chemotherapy and radiotherapy, respectively. Regarding patient advocacy groups, 34% of HCPs did not know whether patients had contact and only 23% of patients declared that they had such contact. For one-third of working patients, work issues were not discussed. Twenty-eight percent of patients claimed that they had faced difficulties for supportive care access. Among HCPs, 13% stated that a formal personalized survivorship treatment program was administered to almost all patients and 37% almost never introduced the program to their patients. Compliance to oral treatments was considered very good for 75-100% of patients by 62% of HCPs.

CONCLUSIONS

This study provides an updated analysis of breast cancer care pathways in France. Overall, the initial processes of diagnosis, announcement, and treatment were swift and were in agreement with the best care standards. No barriers to accessing care were identified. Based on the study findings, we proposed several strategies to improve the quality of care for patients in supportive care, coordination with primary care physicians, reconstructive surgery, and fertility preservation access.

Ultrahypofractionation in postoperative radiotherapy for breast cancer: A single-institution retrospective cohort series

BACKGROUND

The 'FAST-forward', study published in April 2020, demonstrated the effectiveness of an extremely hypofractionated radiotherapy schedule, delivering the total radiation dose in five sessions over the course of 1 week. We share our department's experience regarding patients treated with this regimen in real-world clinical settings, detailing outcomes related to short-term toxicity and efficacy.

METHODS

A descriptive observational study was conducted on 160 patients diagnosed with breast cancer. Between July 2020 and December 2021, patients underwent conservative surgery followed by a regimen of 26 Gy administered in five daily fractions.

RESULTS

The median age was 64 years (range: 43-83), with 82 patients (51.3%) treated for left-sided breast cancer, 77 patients (48.1%) for right-sided breast cancer, and 1 instance (0.6%) of bilateral breast cancer. Of these, 66 patients had pT1c (41.3%), 70.6% were infiltrative ductal carcinomas, and 11.3% were ductal carcinoma in situ. Most tumours exhibited intermediate grade (41.9%), were hormone receptor positive (81.3%), had low Ki-67 (Ki-67 < 20%; 51.9%) and were Her 2 negative (85%). The majority of surgical margins were negative (99.4%). Among the patients, 72.5% received hormonotherapy, and 23.8% received chemotherapy. Additionally, 26 patients (16.3%) received an additional tumour boost following whole breast irradiation (WHBI) of 10 Gy administered in five sessions of 2 Gy over a week. The median planning target volume (PTV) was 899 cm3 (range: 110-2509 cm3). Early toxicity was primarily grade I radiodermatitis, affecting 117 patients (73.1%). During a median follow-up of 15 months (range: 3.9-28.77), only one patient experienced a local relapse, which required mastectomy.

CONCLUSIONS

The implementation of this highly hypofractionated regimen in early-stage breast cancer appears feasible and demonstrates minimal early toxicity. However, a more extended follow-up duration would be required to evaluate long-term toxicity and efficacy accurately.

Assessing Response to PSMA Radiopharmaceutical Therapies with Single SPECT Imaging at 24 Hours After Injection

Understanding the relationship between lesion-absorbed dose and tumor response in 177Lu-PSMA-617 radiopharmaceutical therapies (RPTs) remains complex. We aimed to investigate whether baseline lesion-absorbed dose can predict lesion-based responses and to explore the connection between lesion-absorbed dose and prostate-specific antigen (PSA) response. Methods: In this retrospective study, we evaluated 50 patients with 335 index lesions undergoing 177Lu-PSMA-617 RPT, who had dosimetry analysis performed on SPECT/CT at 24 h after cycles 1 and 2. First, we identified the index lesions for each patient and measured the lesion-based absorbed doses. Lesion-based response was calculated after cycle 2. Additionally, PSA50 response (a decline of 50% from baseline PSA) after cycle 2 was also calculated. The respective responses for mean and maximum absorbed doses and prostate-specific membrane antigen (PSMA) volumetric intensity product (VIP-PSMA) at cycles 1 and 2 were termed SPECTmean, SPECTmaximum, and SPECTVIP-PSMA, respectively. Results: Of the 50 patients reviewed, 46% achieved a PSA50 response after cycle 2. Of the 335 index lesions, 58% were osseous, 32% were lymph nodes, and 10% were soft-tissue metastatic lesions. The SPECT lesion-based responses were higher in PSA responders than in nonresponders (SPECTmean response of 46.8% ± 26.1% vs. 26.2% ± 24.5%, P = 0.007; SPECTmaximum response of 45% ± 25.1% vs. 19% ± 27.0%, P = 0.001; SPECTVIP-PSMA response of 49.2% ± 30.3% vs. 14% ± 34.7%, P = 0.0005). An association was observed between PSA response and SPECTVIP-PSMA response (R 2 = 0.40 and P < 0.0001). A limited relationship was found between baseline absorbed dose measured with a 24-h single time point and SPECT lesion-based response (R 2 = 0.05, P = 0.001, and R 2 = 0.03, P = 0.007, for mean and maximum absorbed doses, respectively). Conclusion: In this retrospective study, quantitative lesion-based response correlated with patient-level PSA response. We observed a limited relationship between baseline absorbed dose and lesion-based responses. Most of the variance in response remains unexplained solely by baseline absorbed dose. Establishment of a dose-response relationship in RPT with a single time point at 24 h presented some limitations.

Dosimetric Correlation of Acute Radiation Dermatitis in Patients With Breast Cancer Undergoing Hypofractionated Proton Beam Therapy Using Pencil Beam Scanning

PURPOSE

Pencil-beam scanning (PBS) is a modern delivery technique used in proton beam therapy (PBT) to reduce normal tissue reactions. No dosimetric correlation between dermatitis and PBS has been reported for breast cancer. The current study aimed to investigate the factors associated with grade 2 or higher dermatitis in patients with breast cancer undergoing PBT using PBS.

METHODS

The medical data of 42 patients with breast cancer who underwent adjuvant radiotherapy between December 2019 and September 2023 were reviewed. All patients received hypofractionated radiotherapy (HFRT), either 26 Gy (relative biological effectiveness [RBE])/five fractions or 40.05 or 43.5 Gy (RBE)/15 fractions, for the whole breast/chest wall with or without nodal irradiation. The duration of acute radiation dermatitis was defined as within 90 days from the start of radiotherapy. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate analyses of the actuarial rates of grade 2-3 dermatitis.

RESULTS

Twenty-two (52.4%) and 20 (47.6%) patients were diagnosed with grade 1 and 2 dermatitis, respectively. Multivariate analysis revealed a clinical target volume (CTV) ≥ of 320 cc (p = 0.035) and a skin dose of D10cc ≥ 38.3 Gy (RBE) (p = 0.009) as independent factors of grade 2 dermatitis. The 10-week cumulative grade 2 dermatitis rates were 88.2%, 39.4%, and 8.3% (p < 0.001) for patients with both high, either high, and neither high CTV and D10cc, respectively.

CONCLUSION

To the best of our knowledge, this is the first study on dosimetric correlations for dermatitis in patients with breast cancer who underwent hypofractionated PBT using PBS. In the era of HFRT, skin dose modulation using PBS may reduce the incidence of dermatitis.

Essential requirements for reporting radiation therapy in breast cancer clinical trials: An international multi-disciplinary consensus endorsed by the European Society for Radiotherapy and Oncology (ESTRO)

The European Society for Radiotherapy and Oncology (ESTRO) has advocated the establishment of guidelines to optimise precision radiotherapy (RT) in conjunction with contemporary therapeutics for cancer care. Quality assurance in RT (QART) plays a pivotal role in influencing treatment outcomes. Clinical trials incorporating QART protocols have demonstrated improved survival rates with minimal associated toxicity. Nonetheless, in routine clinical practice, there can be variability in the indications for RT, dosage, fractionation, and treatment planning, leading to uncertainty. In pivotal trials reporting outcomes of systemic therapy for breast cancer, there is limited information available regarding RT, and the potential interaction between modern systemic therapy and RT remains largely uncharted. This article is grounded in a consensus recommendation endorsed by ESTRO, formulated by international breast cancer experts. The consensus was reached through a modified Delphi process and was presented at an international meeting convened in Florence, Italy, in June 2023. These recommendations are regarded as both optimal and essential standards, with the latter aiming to define the minimum requirements. A template for a case report form (CRF) has been devised, which can be utilised by all clinical breast cancer trials involving RT. Optimal requirements include adherence to predefined RT planning protocols and centralised QART. Essential requirements aim to reduce variations and deviations from the guidelines in RT, even when RT is not the primary focus of the trial. These recommendations underscore the significance of implementing these practices in both clinical trials and daily clinical routines to generate high-quality data.

Hypofractionated whole breast IMRT with HDR brachytherapy boost in early-stage breast cancer: Long-term results from a single-center

INTRODUCTION/OBJECTIVES

The addition of a boost to the lumpectomy bed after whole-breast (WB) radiotherapy plays a key role in the treatment of patients with breast cancer (BC). The clinical benefits of a boost with high-dose-rate brachytherapy (HDR-BT) after conventional fractionation is supported by a large body of evidence. However, few studies have described its outcomes after a hypofractionated scheme.

MATERIALS AND METHODS

We included all patients treated with adjuvant WB-IMRT in 15 sessions followed by a single-session HDR-BT boost with local anesthesia on an outpatient basis.

RESULTS

Between 2009 and 2017, 638 patients with early-stage BC were treated according to the aforementioned protocol after breast-conserving surgery. Median follow-up was 6 years (4-11). Despite the low incidence of side effects and their slightness, we did identify an impact of breast volume on the risk of acute radiodermatitis, fibrosis, pain and edema. However, we did not identify any relationship between the volume in cubic centimeters of the BT-implant with acute or long-term side effects. 2.2% patients had an actual local relapse, 2.4% a 2nd primary in the same breast and 2.39% were diagnosed with contralateral BC. Event-free survival at 11 years was 85.5% with an overall survival of 95.7%.

CONCLUSION

Adjuvant hypofractionated whole-breast IMRT followed by a single dose HDR-BT boost has a low incidence of acute and chronic toxicity and excellent oncological outcomes. However, it may be worthwhile to intensify self-care protocols and surveillance in women with large breasts who may be at increased risk of side effects.

Methodological guide for assessing the carbon footprint of external beam radiotherapy: A single-center study with quantified mitigation strategies

Background and purposes

Data on the carbon footprint of external beam radiotherapy (EBRT) are scarce. Reliable and exhaustive data, including a detailed carbon inventory, are needed to determine effective mitigation strategies.

Materials and methods

This study proposes a methodology for calculating the carbon footprint of EBRT and applies it to a single center. Mitigation strategies are derived from the carbon inventory, and their potential reductions are quantified whenever possible.

Results

The average emission per treatment and fraction delivered was 489 kg CO₂eq and 27 kg CO₂eq, respectively. Patient transportation (43 %) and the construction and maintenance of linear accelerators (LINACs) and scanners (17 %) represented the most significant components. Electricity, the only energy source used, accounted for only 2 % of emissions.Derived mitigation strategies include a data deletion policy (reducing emissions in 30 years by 12.5 %), geographical appropriateness (-12.2 %), transportation mode appropriateness (-9.3 %), hypofractionation (-5.9 %), decrease in manufacturers' carbon footprint (-5.2 %), and an increase in machine durability (-3.5 %).

Conclusion

Our findings indicate that a significant reduction in the carbon footprint of a radiotherapy unit can be achieved without compromising the quality of care.This study provides a methodology and a starting point for comparison and proposes and quantifies mitigation strategies, paving the way for others to follow.

The Japanese breast cancer society clinical practice guidelines for radiation treatment of breast cancer, 2022 edition

The Breast Cancer Clinical Practice Guidelines, organized by the Japanese Breast Cancer Society (JBCS), were published in 2022. We present the English version of the Radiation Therapy (RT) section of the guidelines. The JBCS formed a task force to update the 2018 version of the JBCS Clinical Practice Guidelines. The Background Questions (BQs) contain the standard treatments for breast cancer in clinical practice, whereas the Clinical Questions (CQs) address daily clinical questions that remain controversial. Future Research Questions (FRQs) explore the subjects that are considered important issues, despite there being insufficient data for inclusion as CQs. The task force selected the 12 BQs, 8 CQs, and 6 FRQs for the RT section. For each CQ, systematic literature reviews and meta-analyses were conducted according to the Minds Manual for Guideline Development 2020, version 3.0. The recommendations, strength of recommendation, and strength of evidence for each CQ were determined based on systematic reviews and meta-analyses, and finalized by voting at the recommendation decision meeting.

Shared decision making with breast cancer patients - does it work? Results of the cluster-randomized, multicenter DBCG RT SDM trial

BACKGROUND AND PURPOSE

Shared decision making (SDM) is a patient engaging process advocated especially for preference-sensitive decisions, such as adjuvant treatment after breast cancer. An increasing call for patient engagement in decision making highlights the need for a systematic SDM approach. The objective of this trial was to investigate whether the Decision Helper (DH), an in-consultation patient decision aid, increases patient engagement in decisions regarding adjuvant whole breast irradiation.

MATERIAL AND METHODS

Oncologists at four radiotherapy units were randomized to practice SDM using the DH versus usual practice. Patient candidates for adjuvant whole breast irradiation after breast conserving surgery for node-negative breast cancer were eligible. The primary endpoint was patient-reported engagement in the decision process assessed with the Shared Decision Making Questionnaire (SDM-Q-9) (range 0-100, 4 points difference considered clinical relevant). Other endpoints included oncologist-reported patient engagement, decisional conflict, fear of cancer recurrence, and decision regret after 6 months.

RESULTS

Of the 674 included patients, 635 (94.2%) completed the SDM-Q-9. Patients in the intervention group reported higher level of engagement (median 80; IQR 68.9 to 94.4) than the control group (71.1; IQR 55.6 to 82.2; p < 0.0001). Oncologist-reported patient engagement was higher in the invention group (93.3; IQR 82.2 to 100) compared to control group (73.3; IQR 60.0 to 84.4) (p < 0.0001).

CONCLUSION

Patient engagement in medical decision making was significantly improved with the use of an in-consultation patient decision aid compared to standard. The DH on adjuvant whole breast irradiation is now recommended as standard of care in the Danish guideline.

Radiotherapy for breast cancer

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

Physician- and Patient-Reported Outcomes of the MC1635 Phase 3 Trial of Ultrahypofractionated Versus Moderately Hypofractionated Adjuvant Radiation Therapy After Breast-Conserving Surgery

PURPOSE

Our aim was to report physician- and patient-reported outcomes of patients with localized breast cancer treated with moderate versus ultrahypofractionated whole breast irradiation (WBI) after breast-conserving surgery (BCS).

METHODS AND MATERIALS

Between February 2018 and February 2020, patients with localized breast cancer (pT0-3 pN0-1 M0) were offered participation in a phase 3 randomized clinical trial assessing adjuvant moderate hypofractionation (MHF) to 40 Gy in 15 fractions versus ultrahypofractionation (UHF) to 25 Gy in 5 fractions after BCS, with an optional simultaneously integrated boost. Toxicities, cosmesis, and quality of life were assessed at baseline, end of treatment (EOT), and 3 months, 1 year, 2 years, and 3 years from irradiation using validated metric tools.

RESULTS

One hundred seven patients were randomized to MHF (n = 54) or UHF (n = 53) adjuvant WBI. The median follow-up was 42.8 months. Grade 2 radiation dermatitis was experienced by 4 patients (7.4%) in the MHF arm and 2 patients (3.7%) in the UHF arm at EOT (P = .726). No grade 3 or higher toxicities were observed. Deterioration of cosmesis by physician assessment was observed in 2 (6.7%) patients treated in the UHF arm and 1 (1.9%) patient treated in the MHF arm at EOT (P = .534), whereas at 3 months, only 1 (1.8%) patient treated in the MHF arm demonstrated deterioration of cosmesis (P = .315). At EOT, 91% and 94% of patients reported excellent/good cosmesis among those treated with MHF and UHF regimens, respectively (P = .550). At 3 months, more patients within the MHF arm reported excellent/good cosmesis compared with those in the UHF arm (100% vs 91%; P = .030). However, the difference in patient-reported cosmesis disappeared at the 1-, 2-, and 3-year time points.

CONCLUSIONS

UHF WBI showed similar treatment-related late toxicities and similar provider-scored cosmesis compared with MHF radiation in patients treated adjuvantly after BCS.

Practice of Tumor Bed Boost in Patients after Oncoplastic Breast-Conserving Surgery

The practice of boost to the tumor bed after treatment with oncoplastic breast-conserving surgery (BCS) remains variable. Using a survey, the present study evaluated the current practice of tumor bed boost administered in women after oncoplastic BCS. Actively practicing radiation oncologists across India were sent a questionnaire on the practice of adjuvant whole-breast radiotherapy and tumor bed boost after oncoplastic BCS via email and encouraged to participate. Of the 54 radiation oncologists who participated, most (98.1%) used a linear accelerator for radiotherapy. Hypofractionation was preferred by 59.26%, standard fractionation by 7.41%, and the remaining selected the fractionation strategy based on various patient factors. In addition, 83.33% participants reported that they always planned tumor boost, 51.85% preferred photons for the boost, and 75.93% administered sequential boost. The most common dose for the boost was 12.5 Gy in five fractions (40.74%). Most participants (77.78%) revealed that they used a combination of methods for identifying the tumor bed. With respect to clip placement, most surgeons (96%) at the participants' centers placed ≥ 4 clips at the tumor site, with both the base and margins being preferred by surgeons (81.48%) for placement. Finally, 12.96% participants revealed that the surgeons always involved them during surgical planning, whereas 7.4% participants reported that they always included the surgeons during radiotherapy planning, suggesting that radiation oncologists and oncoplastic surgeons do not involve each other during surgical and radiotherapy planning, possibly leading to suboptimal treatment. This may be attributed to the absence of guidelines regarding boost practices after oncoplastic BCS.

Safe dose escalation and reduction of the fraction number of uterine cervical brachytherapy using a gel spacer in the rectovaginal and vesicouterine septum: A planning study

PURPOSE

To evaluate the possibility of dose escalation and reduction of fraction number in cervical brachytherapy using a gel spacer.

MATERIAL AND METHODS

Twenty patients with uterine cervical cancer treated with image-guided adaptive brachytherapy (IGABT) were selected. Hyaluronic acid gel injection (HGI) was performed in the rectovaginal and vesicouterine septum for 10 patients. The other ten patients were not with HGI. Both groups were treated with IGABT involving tandem/ovoid or cylindrical applicators along with additional interstitial needles. Dose distributions approved by radiation oncologists were retrospectively analyzed, and a dose summation of 45 Gy/25 of external beam radiation therapy and IGABT was performed. Dose constraints for D2cc of bladder, rectum, and sigmoid were 80, 70, and 70 Gy, respectively. Equivalent dose in 2-Gy fractions calculations used α/β = 10 Gy for high-risk clinical target volume (CTVHR) D90 and α/β = 3 Gy for organs at risks (OARs). As a planning study, dose distribution rescaling was conducted to deliver as much dose to CTVHR D90 as possible within the dose constraint limitation for OARs when IGABT was performed for four, three, and two fractions in both groups.

RESULTS

The median CTVHR D90 was >80 Gy in the non-HGI group and >85 Gy in the HGI group for virtual two and three fractions. Rectum D2cc was significantly lower in the HGI group for three fractions (p < 0.01).

CONCLUSIONS

In the HGI group, adequate dose delivery to CTVHR could be achieved with a reduced IGABT fraction number while meeting the dose constraints of OARs.

Hype or hope? A review of challenges in balancing tumor control and treatment toxicity in breast cancer from the perspective of the radiation oncologist

The aim of this article is to discuss the challenges and new strategies in managing breast cancer patients, with a specific focus on radiation oncology and the importance of balancing oncologic outcomes with quality of life and post-treatment morbidity. A comprehensive literature review was conducted to identify advances in the management of breast cancer, exploring de-escalation strategies, hypofractionation schemes, predictors and tools for reducing toxicity (radiation-induced lymphocyte apoptosis, deep inspiration breath-hold, adaptive radiotherapy), enhancer treatments (hyperthermia, immunotherapy) and innovative diagnostic modalities (PET-MRI, omics). Balancing oncologic outcomes with quality of life and post-treatment morbidity is crucial in the era of personalized medicine. Radiotherapy plays a critical role in the management of breast cancer patients. Large randomized trials are necessary to generalize some practices and cost remains the main obstacle for many innovations that are already applicable.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Digital breast tomosynthesis versus X-ray of the breast specimen for intraoperative margin assessment: A randomized trial

BACKGROUND

Involved resection margins after breast conserving surgery (BCS) often require a re-operation with increased patient anxiety and risk of impaired cosmesis. We investigated the number of re-operations due to involved resection margins after BCS comparing digital breast tomosynthesis(DBT) with X-ray for intraoperative margin evaluation. Furthermore, we assessed the diagnostic accuracy of these methods to predict histopathological margin status. Finally, we evaluated risk factors for re-operation.

METHODS

In this randomized, non-blinded study, 250 invasive breast cancer patients were randomized (1:1), whereof 241 were analyzed intraoperatively with either DBT (intervention, n = 119) or X-ray (standard, n = 122). Pearson's chi-squared test, Fisher's exact test, t-test, logistic and ordinal regression analysis was used as appropriate.

RESULTS

No difference was found in the number of re-operations between the DBT and X-ray group (16.8 % vs 19.7 %, p = 0.57), or in diagnostic accuracy to predict histopathological margin status (77.5 %, CI: 68.6-84.9 %) and (67.3 %, CI: 57.7-75.9 %), respectively. We evaluated 5 potential risk factors for re-operation: Ductal carcinoma in situ (DCIS) outside tumor, OR = 9.4 (CI: 4.3-20.6, p < 0.001); high mammographic breast density, OR = 6.1 (CI: 1.0-38.1, p = 0.047); non-evaluable margins on imaging, OR = 3.8 (CI: 1.3-10.8, p = 0.016); neoadjuvant chemotherapy, OR = 3.0 (CI: 1.0-8.8, p = 0.048); and T2 tumor-size, OR = 2.6 (CI: 1.0-6.4, p = 0.045).

CONCLUSIONS

No difference was found in the number of re-operations or in diagnostic accuracy to predict histopathological margin status between DBT and X-ray groups. DCIS outside the tumor showed the highest risk of re-operation. Intraoperative methods with improved visualization of DCIS are needed to obtain tumor free margins in BCS.

Optimizing Clinical Implementation of Hypofractionation: Comprehensive Evidence Synthesis and Practical Guidelines for Low- and Middle-Income Settings

The global cancer burden, especially in low- and middle-income countries (LMICs), worsens existing disparities, amplified by the rising costs of advanced treatments. The shortage of radiation therapy (RT) services is a significant issue in LMICs. Extended conventional treatment regimens pose significant challenges, especially in resource-limited settings. Hypofractionated radiotherapy (HRT) and ultra-hypofractionated/stereotactic body radiation therapy (SBRT) offer promising alternatives by shortening treatment durations. This approach optimizes the utilization of radiotherapy machines, making them more effective in meeting the growing demand for cancer care. Adopting HRT/SBRT holds significant potential, especially in LMICs. This review provides the latest clinical evidence and guideline recommendations for the application of HRT/SBRT in the treatment of breast, prostate, and lung cancers. It emphasizes the critical importance of rigorous training, technology, stringent quality assurance, and safety protocols to ensure precise and secure treatments. Additionally, it addresses practical considerations for implementing these treatments in LMICs, highlighting the need for comprehensive support and collaboration to enhance patient access to advanced cancer care.

Hypofractionated Radiotherapy in Gynecologic Malignancies-A Peek into the Upcoming Evidence

Radiotherapy (RT) has a fundamental role in the treatment of gynecologic malignancies, including cervical and uterine cancers. Hypofractionated RT has gained popularity in many cancer sites, boosted by technological advances in treatment delivery and image verification. Hypofractionated RT uptake was intensified during the COVID-19 pandemic and has the potential to improve universal access to radiotherapy worldwide, especially in low-resource settings. This review summarizes the rationale, the current challenges and investigation efforts, together with the recent developments associated with hypofractionated RT in gynecologic malignancies. A comprehensive search was undertaken using multiple databases and ongoing trial registries. In the definitive radiotherapy setting for cervical cancers, there are several ongoing clinical trials from Canada, Mexico, Iran, the Philippines and Thailand investigating the role of a moderate hypofractionated external beam RT regimen in the low-risk locally advanced population. Likewise, there are ongoing ultra and moderate hypofractionated RT trials in the uterine cancer setting. One Canadian prospective trial of stereotactic hypofractionated adjuvant RT for uterine cancer patients suggested a good tolerance to this treatment strategy in the acute setting, with a follow-up trial currently randomizing patients between conventional fractionation and the hypofractionated dose regimen delivered in the former trial. Although not yet ready for prime-time use, hypofractionated RT could be a potential solution to several challenges that limit access to and the utilization of radiotherapy for gynecologic cancer patients worldwide.

Optimal adjuvant therapy in older (≥70 years of age) women with low-risk early-stage breast cancer

Older women are under-represented in breast cancer (BC) clinical trials, and treatment guidelines are primarily based on BC studies in younger women. Studies uniformly report an increased incidence of local relapse with omission of breast radiation therapy. Review of the available literature suggests very low rates of distant relapse in women ≥70 years of age. The incremental benefit of endocrine therapy in decreasing rate of distant relapse and improving disease-free survival in older patients with low-risk BC remains unclear. Integration of molecular genomic assays in diagnosis and treatment of estrogen receptor positive BC presents an opportunity for optimizing risk-tailored adjuvant therapies in ways that may permit treatment de-escalation among older women with early-stage BC. The prevailing knowledge gap and lack of risk-specific adjuvant therapy guidelines suggests a compelling need for prospective trials to inform selection of optimal adjuvant therapy, including omission of adjuvant endocrine therapy in older women with low risk BC.

Contouring variation affects estimates of normal tissue complication probability for breast fibrosis after radiotherapy

BACKGROUND

Normal tissue complication probability (NTCP) models can be useful to estimate the risk of fibrosis after breast-conserving surgery (BCS) and radiotherapy (RT) to the breast. However, they are subject to uncertainties. We present the impact of contouring variation on the prediction of fibrosis.

MATERIALS AND METHODS

280 breast cancer patients treated BCS-RT were included. Nine Clinical Target Volume (CTV) contours were created for each patient: i) CTV_crop (reference), cropped 5 mm from the skin and ii) CTV_skin, uncropped and including the skin, iii) segmenting the 95% isodose (Iso95%) and iv) 3 different auto-contouring atlases generating uncropped and cropped contours (Atlas_skin/Atlas_crop). To illustrate the impact of contour variation on NTCP estimates, we applied two equations predicting fibrosis grade ≥ 2 at 5 years, based on Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) models, respectively, to each contour. Differences were evaluated using repeated-measures ANOVA. For completeness, the association between observed fibrosis events and NTCP estimates was also evaluated using logistic regression.

RESULTS

There were minimal differences between contours when the same contouring approach was followed (cropped and uncropped). CTV_skin and Atlas_skin contours had lower NTCP estimates (-3.92%, IQR 4.00, p < 0.05) compared to CTV_crop. No significant difference was observed for Atlas_crop and Iso95% contours compared to CTV_crop. For the whole cohort, NTCP estimates varied between 5.3% and 49.5% (LKB) or 2.2% and 49.6% (RS) depending on the choice of contours. NTCP estimates for individual patients varied by up to a factor of 4. Estimates from "skin" contours showed higher agreement with observed events.

CONCLUSION

Contour variations can lead to significantly different NTCP estimates for breast fibrosis, highlighting the importance of standardising breast contours before developing and/or applying NTCP models.

Large scale experience of two ultrahypofractionated 5 fractions regimes after breast conserving surgery from a single centre

PURPOSE

Ultra-hypofractionation breast radiotherapy is a safe alternative to moderate hypofractionation. This study reports the results of two ultrahypofractionated regimens used in clinical practice in a high-volume radiotherapy center in terms of efficacy and of tolerance.

METHODS

we included all patients treated in an adjuvant setting with five fractions after breast conserving surgery (BCS), for a histologically-confirmed invasive or in situ breast carcinoma. Radiotherapy regimens after BCS were either a 5-week schedule with 5 weekly fractions of 5,7 Gy or a one-week schedule with 5 daily fractions of 5,2 Gy. Adverse events were recorded and local-relapse free survival (LRFS), locoregional-relapse free survival (LRRFS), metastasis-free survival (MFS), for breast-cancer specific survival (BCSS) and overall survival (OS) were evaluated.

RESULTS

Between December 2014 and December 2022, 396 patients (400 breasts) were treated with ultrahypofractionated radiotherapy. Five-year LRFS was 98.8% (95% confidence interval: 97.1%-100%), and 5-year OS was 96.0% (95%CI: 92.6-99.5%). Age was statistically associated with OS in univariate analysis (HR: 1.16, 95%CI: 1.04-1.42, p = .01). Four patients (1.0%) experienced acute grade 3 radiation-induced adverse events, and 8 patients (2.3%) acute grade 2 toxicities. Twenty-three patients (5.8%) experienced late toxicity, all of them being graded as grade 1. The use of the 5.7 Gy-weekly-fraction regimen and the delivery of a tumor bed boost were significantly associated with acute radiodermatitis (p < .01; p = .02; respectively) and late fibrosis (p < .01; p = .049; respectively).

CONCLUSIONS

ultrahypofractionated radiotherapy was associated with an excellent tumor control rate in our 'real-life' cohort with low-risk breast cancer patients. However, delivery of a tumor bed boost and using weekly 5.7-Gy fractions were associated with an increased risk of acute and late cutaneous toxicities.

Do Barrier Films Impact Long-Term Skin Toxicity following Whole-Breast Irradiation? Objective Follow-Up of Two Randomised Trials

Purpose: Hydrofilm, a polyurethane-based barrier film, can be used to prevent acute radiation dermatitis (RD) in adjuvant whole-breast irradiation (WBI) for breast cancer. This cost-effective prophylactic measure is currently being recommended to a growing number of patients, yet long-term safety data and its impact on late radiation-induced skin toxicity such as pigmentation changes and fibrosis have not been investigated. Methods: We objectively evaluated patients who were previously enrolled in either of two intrapatient-randomised (lateral versus medial breast halve) controlled trials on the use of Hydrofilm for RD prevention (DRKS00029665; registered on 19 July 2022). Results: Sixty-two patients (47.7% of the initial combined sample size) provided consent for this post-hoc examination, with a median follow-up time (range) of 58 (37-73) months. Following WBI, there was a significant increase in yellow skin tones of the entire breast when compared to baseline measurements before WBI (p < 0.001) and a significant increase of cutis, subcutis, and oedema thickness (p < 0.001, p < 0.001, and p = 0.004, respectively). At follow-up, there were no significant differences in either pigmentation changes or skin fibrosis between the Hydrofilm and standard of care breast halves. Conclusion: These data suggest that Hydrofilm can be safely used in the context of acute RD prevention, without affecting late side effects, supporting its widespread use.

Comparison of adverse events in partial- or whole breast radiotherapy: investigation of cosmesis, toxicities and quality of life in a meta-analysis of randomized trials

PURPOSE/OBJECTIVE

Adjuvant whole breast radiotherapy and systemic therapy are part of the current evidence-based treatment protocols for early breast cancer, after breast-conserving surgery. Numerous randomized trials have investigated the therapeutic effects of partial breast irradiation (PBI) compared to whole breast irradiation (WBI), limiting the treated breast tissue. These trials were designed to achieve equal control of the disease with possible reduction in adverse events, improvements in cosmesis and quality of life (QoL). In this meta-analysis, we aimed to investigate the differences between PBI and WBI in side effects and QoL.

MATERIAL/METHODS

We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect-sizes for available acute and late adverse events. Additionally, we evaluated cosmetic outcomes as well as general and breast-specific QoL using the EORTC QLQ-C30 and QLQ-BR23 questionnaires.

RESULTS

Sixteen studies were identified (n = 19,085 patients). PBI was associated with a lower prevalence in any grade 1 + acute toxicity and grade 2 + skin toxicity (OR = 0.12; 95% CI 0.09-0.18; p < 0.001); (OR = 0.16; 95% CI 0.07-0.41; p < 0.001). There was neither a significant difference in late adverse events between the two treatments, nor in any unfavorable cosmetic outcomes, rated by either medical professionals or patients. PBI-technique using EBRT with twice-daily fractionation schedules resulted in worse cosmesis rated by patients (n = 3215; OR = 2.08; 95% CI 1.22-3.54; p = 0.007) compared to WBI. Maximum once-daily EBRT schedules (n = 2071; OR = 0.60; 95% CI 0.45-0.79; p < 0.001) and IORT (p = 0.042) resulted in better cosmetic results grade by medical professionals. Functional- and symptom-based QoL in the C30-scale was not different between PBI and WBI. Breast-specific QoL was superior after PBI in the subdomains of "systemic therapy side effects" as well as "breast-" and "arm symptoms".

CONCLUSION

The analysis of multiple randomized trials demonstrate a superiority of PBI in acute toxicity as well breast-specific quality of life, when compared with WBI. Overall, late toxicities and cosmetic results were similar. PBI-technique with a fractionation of twice-daily schedules resulted in worse cosmesis rated by patients.