Hypofractionated Versus Conventional Fractionated Radiotherapy After Breast-Conserving Surgery in the Modern Treatment Era: A Multicenter, Randomized Controlled Trial From China

Effect of jaw width in jaw tracking mode on the radiotherapy dose of partial arc VMAT in patients undergoing left breast-conserving surgery

To analyze the effect of jaw width in jaw tracking mode on the dose of radiotherapy partial arc VMAT (P-VMAT) for patients undergoing left breast-conserving surgery and to explore the best jaw width as the initial inverse optimization parameter. Twenty patients who underwent left breast-conserving surgery were randomly selected. Six groups of P-VMAT plans were designed (named Plan0, Plan0.3, Plan0.6, Plan0.9, Plan-0.3, and Plan-0.6). The width of the jaw of each plan was changed in 0.3 cm steps along the X direction (from - 0.6 to 0.9 cm) according to the beginning of the half beam (Plan0). The PTV coverage, conformity index (CI), homogeneity index (HI), monitor units (MU) and organs at risk (OARs) dose were evaluated by repeated measurement data analysis of variance between plan0 and the other plans. Additionally, the correlations between CI, HI, MU and OARs to change in jaw width were analyzed using Spearman's bivariate correlation analysis. The PTV dose distributions of Plan-0.3 and Plan-0.6, which have smaller jaw widths than those of Plan0, did not meet the clinical requirements. CI, HI and MU were correlated with jaw width (r = 0.554, -0.501, -0.641, p < 0.05, respectively). The V5, V10, V20, V40, Dmean and Dmax of the heart were correlated with jaw width (r = 0.288, 0.284, 0.191, -0.27, 0.186, -0.245, p < 0.05, respectively). The V2.5, V5, V10, V20, V40 and Dmean of the left lung (Lung-L) were correlated with jaw width (0.298, 0.421, 0.516, 0.391, -0.241, 0.356, p < 0.05, respectively). Among all the plans to ensure PTV target coverage, Plan0 had the lowest clinical indicators for the heart and Lung-L (p < 0.05, respectively). The internal boundary of the jaw set as 0 cm (Plan0) represents the optimal jaw width for the initial optimization of the plan design. This method is the simplest and most effective for radiotherapy treatment planning for breast-conserving surgery for breast cancer as well as allows ideal dose distribution.

Low-dose moderate hypofractionated radiotherapy for indolent non-Hodgkin lymphoma: a multicentre, single-arm, phase 2 trial

BACKGROUND

Radiotherapy for indolent non-Hodgkin lymphoma has evolved to optimise the definitive dose while minimising toxicity. We aimed to assess the activity and safety of a hypofractionated low-dose radiotherapy regimen of 12 Gy in four fractions in patients with indolent non-Hodgkin lymphoma.

METHODS

This multicentre, single-arm, phase 2 trial study enrolled patients from four hospitals in China. Patients aged 18 years or older with newly diagnosed or relapsed stage I-IV indolent non-Hodgkin lymphoma (follicular lymphoma, marginal zone lymphoma, and low-grade lymphoma) and an Eastern Cooperative Oncology Group performance status of 0-3 were eligible. Patients underwent involved-site radiotherapy at a dose of 12 Gy in four fractions. The primary endpoint was the complete response rate 6 months after radiotherapy. All analyses were performed in the intention-to-treat population. This trial was registered with ClinicalTrials.gov, NCT05543070, with a four-month delay due to the COVID-19 pandemic; recruitment is complete and follow-up is ongoing.

FINDINGS

Between May 8, 2022, and Nov 8, 2023, 71 patients (with 73 target sites) were enrolled (median age 55 years [IQR 48-65]; 29 [41%] male and 42 [59%] female; and all were Asian). With a median follow-up of 19 months (IQR 16-22), the 6-month complete response was 95% (95% CI 87-98; 69 of 73 sites). The most common acute adverse events were grade 1 lymphopenia (20 [28%] of 71 patients) and grade 1 nausea (14 [19%] of 73 sites). The sole grade 3 or higher adverse event was grade 3 lymphopenia (eight [11%] of 71 patients). No treatment-related deaths were noted.

INTERPRETATION

The regimen of 12 Gy in four fractions is safe and shows promising activity as a local treatment for patients with indolent non-Hodgkin lymphoma. Given the retrospective registration of the trial, further studies evaluating the efficacy of this strategy are warranted.

FUNDING

The Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, the National High Level Hospital Clinical Research Funding, and the Beijing Hope Run Special Fund of Cancer Foundation of China.

Mepitel® film versus standard care for the prevention of skin toxicity in breast cancer patients treated with adjuvant radiotherapy: A randomized controlled trial

Background & purpose

Radiotherapy plays a key role in breast cancer treatment however, radiation-induced dermatitis can impact on treatment delivery and patient quality of life.The primary outcome was to compare Mepitel® Film versus standard treatment in preventing radiotherapy skin toxicity onset.

Methods

A multicentre randomised controlled phase III study compared standard treatment (aqueous-urea cream - Excipial U hydrolotion applied at the beginning of radiotherapy and antiseptic cream - Flammazine or Ialugen Plus applied at the onset of moist desquamation) versus Mepitel® Film in patients with breast cancer undergoing post-operative radiotherapy. The primary outcome was the proportion of moist desquamation (RTOG score ≥ 2) in the experimental and control groups.

Results

During the study (2016-2020), 161 patients were randomized, 154 (95.7 %) were evaluable. Skin toxicity Radiation Therapy Oncology Group (RTOG) score ≥ 2 was observed in 9.5 % and 13.9 % of experimental and control groups respectively (Relative Risk = 0.68, 95 %CI 0.28-1.66; p = 0.393). RTOG scores > 0 were 90.5 % and 94.9 % in experimental and control groups respectively (Relative Risk = 0.95, 95 %CI 0.87-1.04; p = 0.294).Multivariable analysis, controlled for age, diabetes, BMI and smoking exposure, showed a risk reduction of RTOG > 0 of 38 % (HR = 0.62 95 %CI 0.49-0.96, p = 0.028), and a risk reduction of RTOG > 1 of 33 % (HR = 0.67 95 %CI 0.26-1.76, p = 0.420) in the experimental group.The median time to recovery from RTOG grade > 0 toxicity was 17 and 32 days for experimental and control groups, respectively (p = 0.027). At multivariable analysis, time to recovery was 38 % faster in the experimental group (HR = 1.38 95 %CI (0.99-1.93) p = 0.059).

Conclusions

Although the study did not demonstrate a statistically significant reduction in RTOG > 2 skin toxicity, there was evidence of a reduction in the rate of skin toxicity and an improvement in time to recovery. The device was well tolerated by patients.

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.

Efficacy and Safety of Hypofractionated Radiotherapy With a Simultaneous Integrated Boost and With a Sequential Boost After Breast-Conserving Surgery

PURPOSE

The objective of this study was retrospectively to compare the efficacy and safety of hypofractionated radiotherapy (HFRT) with a simultaneous integrated boost (SIB) or with a sequential boost (SB) after breast-conserving surgery in patients diagnosed with early breast cancer.

METHODS

This study enrolled a total of 343 patients diagnosed with T1-2N0-1 breast cancer who had undergone breast-conserving surgery followed by whole-breast irradiation (WBI) without nodal irradiation, between March 2018 and April 2021. Out of 343 patients, 176 (51.3%) received HFRT-SIB treatment, totaling 15 sessions, while the remaining 167 (48.7%) received HFRT-SB treatment, totaling 18 sessions. Demographic characteristics, skin toxicity, radiation pneumonia, and myelosuppression, were compared in the two groups. Three-year local progression free survival (LPFS) rates were determined using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

The median follow-up time was 39.7 months (range 24.3-61.3 months). Toxicities rates did not differ significantly in the HFRT-SIB and HFRT-SB groups, including rates of grade 2 skin toxicity (14.8% vs. 13.8%, p = 0.721), Grade 2 radiation pneumonia (2.8% vs. 3.6%, p = 0.355), grades 1, 2 and 3 myelosuppression (12.5%, 5.7% and 1.1%, respectively, vs. 9.6%, 7.8%, and 1.2%, respectively; p = 0.744). Three-year cumulative LPFS rates were similar in the HFRT-SIB and HFRT-SB groups (99.3% vs. 98.6%, p = 0.52). Regional nodal recurrences were observed in one patient in the HFRT-SIB group (after 27.4 months) and in two patients in the HFRT-SB group (after 29.4 and 56.4 months), and a local recurrence was observed in one patient in the latter group after 36.0 months. One patient in the HFRT-SIB group was diagnosed with distant metastases to bone, and one patient in the HFRT-SB group was diagnosed with distant metastases to the liver.

CONCLUSION

Similar efficacy and safety of HFRT-SIB and HFRT-SB after breast-conserving surgery in patients with early-stage (T1-2N0-1) breast cancer. Longer-term follow-up is required to further compare their efficacy.

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.

Patient-Reported Outcomes Between Whole-Breast Plus Regional Irradiation and Whole-Breast Irradiation Only in pN1 Breast Cancer After Breast-Conserving Surgery and Taxane-Based Chemotherapy: A Randomized Phase 3 Clinical Trial (KROG 17-01)

PURPOSE

The role of regional node irradiation (RNI) with whole-breast irradiation (WBI) in patients with pN1 breast cancer receiving taxane-based adjuvant chemotherapy is not well defined. The KROG 1701 trial, a phase 3, multicenter, noninferiority study, aimed to compare the disease-free survival between WBI+RNI and WBI alone in this patient cohort. Comprehensive patient-reported outcomes (PROs) collected at multiple timepoints are reported.

METHODS AND MATERIALS

The trial (NCT03269981) enrolled patients with pN1 breast cancer after breast-conserving surgery and taxane-based adjuvant chemotherapy, allocating them to receive either WBI+RNI or WBI only. PROs were assessed using European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaires Core 30and breast cancer-specific module 23 modules at baseline, during radiation therapy, and at subsequent follow-up intervals of 3 to 6 months, and annually up to 4 years.

RESULTS

From April 2017 to December 2021, 840 patients were enrolled; 777 received intervention as assigned, and 750 completed baseline PRO questionnaires (387 in WBI+RNI, 363 in WBI only). All PRO domains showed improvements over time (P < .001). During radiation therapy, the WBI+RNI group reported greater fatigue and nausea. Higher arm symptom scores were observed in the WBI+RNI group 3 months post-treatment (P = .030). No other significant PRO domain differences, including arm/breast symptoms, were observed between the 2 groups.

CONCLUSIONS

In patients with pN1 breast cancer treated with taxane-based chemotherapy, adding RNI to WBI resulted in minor, temporary declines in specific PRO domains, but these differences were not clinically significant. This indicates that overall patient experience between WBI+RNI and WBI is comparable, supporting the safety and patient tolerability of both treatments.

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.

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.

Prognostic value of lymphocytes in patients with breast cancer receiving radiotherapy after breast-conserving surgery: A post hoc analysis of a phase III randomized trial

PURPOSE

To evaluate the prognostic value of peripheral lymphocyte count (PLC) in the breast cancer patients after breast-conserving surgery (BCS) with radiotherapy (RT).

METHODS AND MATERIALS

This post hoc analysis was performed using data of 628 patients from a phase III, randomized controlled trial comparing hypofractionated RT (HFRT) with conventional fractionated RT (CFRT) after BCS. PLCs were obtained before, during, and after RT until the 1-year follow-up. The optimal cut-off PLCs were determined using the maxstat package in R. Survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test.

RESULTS

A total of 275 (46.1 %) patients developed lymphopenia during RT, among them, 17 (2.8 %) had grade 3 lymphopenia and no one developed grade 4 lymphopenia. With a median follow-up of 110.8 months, patients with pre-RT PLCs of < 1.77 × 109/L had a significantly lower 10-year breast cancer-specific survival (BCSS) rate (P = 0.013) and overall survival (OS) rate (P = 0.026). Patients with a nadir PLC of < 1.35 × 109/L had a significantly poorer 10-year OS rate (P = 0.048). Multivariate analysis showed that a pre-RT PLC of < 1.77 × 109/L was an independent factor influencing BCSS and OS, while the effect of the nadir PLC did not remain significant. Neither PLC nor lymphopenia recovery at post-RT 1, 3, and 6 months and 1 year was associated with survival.

CONCLUSIONS

Radiation-induced lymphopenia in patients with breast cancer after BCS tends to be mild. The lower pre-RT PLC predicted poorer survival.

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.

Hypofractionation for Regional Nodal Irradiation in Breast Cancer: Best of Both the Worlds

Locoregional radiotherapy play an important role in controlling the disease after surgery in patients with breast cancer. Radiotherapy schedules vary from conventional fraction to hypofractionation. The purpose of this review is to get an insight into the data on regional nodal irradiation (RNI) with hypofractionation in patients with breast cancer. This systematic review was constructed in accordance with Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) framework. Electronic databases such as PubMed, Cochrane and EMBASE were searched from January 1, 2023 to March 31, 2023 to identify studies published in English language on hypofractionated RNI in post mastectomy patients. The search was carried out with the National Library of Medicine's Medical Subject Heading (MeSH) terms like "regional nodal irradiation," "hypofractionated" and "hypofractionation in breast cancer" with different Boolean operators (and/or). A manual search of reference lists of included articles was also performed to make sure there were no additional cases unidentified from the primary search. Studies deemed potentially eligible were identified and assessed by same independent reviewers to confirm eligibility. RNI data are mainly from a randomized study from Beijing and pooled data from START trials. There are also data from retrospective and single institutional studies and a few phase II studies with limited number of patients using different dose fractionations and techniques of radiotherapy. Doses used in these trials ranged from 26-47.7 Gy in 5-19 fractions over 1-4 weeks. Grade ≥ 2 pulmonary fibrosis and lymphedema rate ranged from 2%-7.9% and 3%-19.8% respectively. Grade ≥ 2 shoulder dysfunction and brachial plexopathy ranged from 0.2%-28% and 0%-< 1%, respectively. Late effects with a dose range of 26-40 Gy delivered in 5 to 15 fractions over 1-3 weeks were less/similar to conventional fraction. Current data showed lower/similar rates of toxicity with hypofractionated RNI compared with conventional fractionation RNI. Doses of 26 Gy to 40 Gy delivered in 5 to 15 fractions over 1-3 weeks are safe for RNI. With limited data, ultra-hypofractionation 26 Gy/5 fractions/1 week also seems to be safe. However, long-term outcome is awaited and many trials are going on to address its efficacy and safety.

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.

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.

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.

Feasibility of Intraoperative Radiotherapy Tumor Bed Boost in Patients with Breast Cancer after Neoadjuvant Chemotherapy

PURPOSE

This study aimed to assess the feasibility and safety of administering intraoperative radiotherapy (IORT) as a boost during breast-conserving surgery (BCS) following neoadjuvant chemotherapy for patients at high risk of breast cancer recurrence.

MATERIALS AND METHODS

Patients who underwent neoadjuvant chemotherapy received a single 20-Gy dose of IORT during BCS, followed by external beam radiotherapy 4-6 weeks after surgery.

RESULTS

The median follow-up duration was 31.0 months (range, 18.0-59.0 months). Initial tumor sizes had a median of 2.6 cm (range: 0.8-5.3 cm), reducing to 0.3 cm (range: 0-4.0 cm) after neoadjuvant chemotherapy. The most common neoadjuvant chemotherapy regimen was doxorubicin and cyclophosphamide, followed by paclitaxel (n=42, 73.7%). Among 57 patients who received neoadjuvant chemotherapy before BCS and IORT, 2 patients (3.5%) required secondary surgery to achieve negative resection margins due to initially positive margins. Regional lymph node irradiation was performed in 37 (64.9%) patients. There was no grade 3 or higher adverse events, with 4 patients (7.0%) experiencing grade 2 acute radiation dermatitis and 3 (5.3%) having less than grade 2 breast edema. Binary correlation analysis did not reveal statistically significant associations between applicator size or radiation therapy modality and the risk of treatment-related toxicity. Furthermore, chi-square analysis showed that the grade of treatment-related toxicity was not associated with the fractionated regimen (p=0.375).

CONCLUSION

Most patients successfully received IORT as a tumor bed boost after neoadjuvant chemotherapy. Thus, IORT may be a safe and feasible option for patients with advanced-stage breast cancer receiving neoadjuvant chemotherapy.

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.

Autologous breast reconstruction in low- and middle-income countries (LMICs): a systematic review of current practices and challenges

INTRODUCTION

Efforts to improve global healthcare persist, yet LMICs face challenges accessing surgical care, especially breast reconstruction amidst rising breast cancer cases. This review evaluates the present state and challenges of autologous breast reconstruction in low- and middle-income countries (LMICs).

EVIDENCE ACQUISITION

Utilizing the PRISMA guidelines and the Cochrane Collaboration's standards, databases such as EMBASE, MEDLINE, Cochrane, PubMed, and Google Scholar were examined for studies on breast reconstruction in LMICs (based on the World Bank's 2022-2023 definitions) up to August 2022. Articles and case reports focusing on autologous reconstruction following breast cancer surgery in these regions were incorporated.

EVIDENCE SYNTHESIS

From an initial 288 articles, 19 met the criteria after thorough assessment. These articles documented 4899 patient cases from LMICs, with the breakdown being: 11 on LD flaps, nine on TRAM flaps, eight on DIEP flaps, two on TDAP flaps, and one on TMG flap. Flap necrosis emerged as the prevalent complication in four studies.

CONCLUSIONS

While autologous breast reconstruction presents superior aesthetic benefits without notable long-term economic setbacks, its adoption in LMICs is limited. This is partly due to the domination of implant-based methods among patients and surgeons, selected due to convenience. The scarcity of concrete evidence and standardized metrics in LMICs clouds the understanding of this procedure. Despite its advantages, awareness is low, necessitating more training and awareness campaigns. Uniform reporting, quality data, and financial analysis can provide a comprehensive LMIC understanding, aiding future research.

VMAT with DIBH in hypofractionated radiotherapy for left-sided breast cancer after breast-conserving surgery: results of a non-inferiority clinical study

The purpose of this study was to show the safety of volumetric modulated arc therapy (VMAT) with deep inspiration breath-hold (DIBH) in hypofractionated radiotherapy for left-sided breast cancer after breast-conserving surgery in a clinical setting. Twenty-five Japanese women, aged 20-59 years, who were enrolled in this prospective non-inferiority study received VMAT under the condition of DIBH with 42.4 Gy/16 fractions for whole-breast irradiation (WBI) ± boost irradiation for the tumor bed to show the non-inferiority of VMAT with DIBH to conventional fractionated WBI with free breathing. The primary endpoint was the rate of occurrence of radiation dermatitis of Grade 3 or higher or pneumonitis of Grade 2 or higher within 6 months after the start of radiotherapy. This study was registered with UMIN00004321. All of the enrolled patients completed the planned radiotherapy without interruption. The evaluation of adverse events showed that three patients (12.0%) had Grade 2 radiation dermatitis. There was no other Grade 2 adverse event and there was no patient with an adverse event of Grade 3 or higher. Those results confirmed our hypothesis that the experimental treatment method is non-inferior compared with our historical results. There was no patient with locoregional recurrence or metastases. In conclusion, VMAT under the condition of DIBH in hypofractionated radiotherapy for left-sided breast cancer after breast-conserving surgery can be performed safely in a clinical setting.

A Beam Angle Selection Method to Improve Plan Robustness Against Position Error in Intensity-Modulated Radiotherapy for Left-Sided Breast Cancer

PURPOSE

We report a dosimetric study in whole breast irradiation (WBI) of plan robustness evaluation against position error with two radiation techniques: tangential intensity-modulated radiotherapy (T-IMRT) and multi-angle IMRT (M-IMRT).

METHODS

Ten left-sided patients underwent WBI were selected. The dosimetric characteristics, biological evaluation and plan robustness were evaluated. The plan robustness quantification was performed by calculating the dose differences (Δ) of the original plan and perturbed plans, which were recalculated by introducing a 3-, 5-, and 10-mm shift in 18 directions.

RESULTS

M-IMRT showed better sparing of high-dose volume of organs at risk (OARs), but performed a larger low-dose irradiation volume of normal tissue. The greater shift worsened plan robustness. For a 10-mm perturbation, greater dose differences were observed in T-IMRT plans in nearly all directions, with higher ΔD98%, ΔD95%, and ΔDmean of CTV Boost and CTV. A 10-mm shift in inferior (I) direction induced CTV Boost in T-IMRT plans a 1.1 (ΔD98%), 1.1 (ΔD95%), and 1.7 (ΔDmean) times dose differences greater than dose differences in M-IMRT plans. For CTV Boost, shifts in the right (R) and I directions generated greater dose differences in T-IMRT plans, while shifts in left (L) and superior (S) directions generated larger dose differences in M-IMRT plans. For CTV, T-IMRT plans showed higher sensitivity to a shift in the R direction. M-IMRT plans showed higher sensitivity to shifts in L, S, and I directions. For OARs, negligible dose differences were found in V20 of the lungs and heart. Greater ΔDmax of the left anterior descending artery (LAD) was seen in M-IMRT plans.

CONCLUSION

We proposed a plan robustness evaluation method to determine the beam angle against position uncertainty accompanied by optimal dose distribution and OAR sparing.

Quality assurance in a phase III, multicenter, randomized trial of POstmastectomy radioThErapy in Node posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL): a planning benchmark case

PURPOSE

To report the planning benchmark case results of the POTENTIAL trial-a multicenter, randomized, phase 3 trial-to evaluate the value of internal mammary nodal (IMN) irradiation for patients with high-risk breast cancer.

METHODS

All participating institutions were provided the outlines of one benchmark case, and they generated radiation therapy plans per protocol. The plans were evaluated by a quality assurance team, after which the institutions resubmitted their revised plans. The information on beams arrangement, skin flash, inhomogeneity corrections, and protocol compliance was assessed in the first and final submission.

RESULTS

The plans from 26 institutions were analyzed. Some major deviations were found in the first submission. The protocol compliance rates of dose coverage for the planning target volume of chest wall, supraclavicular fossa plus axilla, and IMN region (PTVim) were all significantly improved in the final submission, which were 96.2% vs. 69.2%, 100% vs. 76.9%, and 88.4% vs. 53.8%, respectively. For OARs, the compliance rates of heart Dmean, left anterior descending coronary artery V40Gy, ipsilateral lung V5Gy, and stomach V5Gy were significantly improved. In the first and final submission, the mean values of PTVim V100% were 79.9% vs. 92.7%; the mean values of heart Dmean were 11.5 Gy vs. 9.7 Gy for hypofractionated radiation therapy and 11.5 Gy vs. 11.0 Gy for conventional fractionated radiation therapy, respectively.

CONCLUSION

The major deviations were corrected and protocol compliance was significantly improved after revision, which highlighted the importance of planning benchmark case to guarantee the planning quality for multicenter trials.

A novel, multi-active emollient for the prevention of acute radiation dermatitis in breast cancer patients: a randomized clinical trial

PURPOSE

To investigate the efficacy of a novel, multi-active emollient in preventing and managing acute radiation dermatitis (ARD) in breast cancer patients undergoing moderate hypofractionated (HF) radiotherapy (RT) compared to standard of care.

METHODSA

A monocentric, open-label, randomized clinical trial (RCT) with breast cancer patients receiving moderate HF (dose: 40.05-55.86 Gy, fractions: 15-21) was conducted between January 2022 and May 2023. The experimental group received the novel emollient, while the control group received the standard skin care. Patients applied the skin care products twice daily during the complete RT course. The primary outcome was the severity of ARD at the final RT session measured by the modified Radiation Therapy Oncology Group (RTOG) criteria. Secondary outcomes included patient symptoms, quality of life (QoL), and treatment satisfaction.

RESULTS

A total of 100 patients with 50 patients per group were enrolled. In the control group, 50% of the patients developed RTOG grade 1 ARD and 48% grade 2 or higher, while in the experimental group, the severity of ARD was significantly lower with 82% grade 1 and 16% grade 2 ARD (P = .013, χ2-test). The frequency and severity of xerosis were significantly lower in the experimental compared to the control group (Ps ≤ .036, Mann Whiney U test). The impact of ARD on the QoL was low, and treatment satisfaction was high in both groups, with no significant difference.

CONCLUSION

This RCT shows that the novel, multi-active emollient significantly reduced the ARD RTOG grade. Research in a more diverse patient population is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04929808 (11/06/2021).

Hypofractionated radiotherapy compared with conventionally fractionated radiotherapy to treat initial distant metastases in nasopharyngeal carcinoma: A multicenter, prospective, randomized, phase II trial

BACKGROUND AND PURPOSE

To investigate the safety and efficacy of hypofractionated plus chemotherapy in patients with initially distant metastatic nasopharyngeal carcinoma (mNPC).

MATERIALS AND METHODS

Between May 2014 and June 2020, 35 patients initially diagnosed with mNPC were enrolled on prospective trial. The enrolled patients were assigned randomly to receive either hypofractionated plus chemotherapy (HFRT) or conventionally fractionated radiotherapy plus chemotherapy (CFRT). 60 Gy over 25 fractions was administered to the HFRT group (n = 17) and 69.96 Gy over 33 fractions was administered to the CFRT group (n = 18), both groups five times each week.Progression free survival (PFS) comprised the primary endpoint. Overall survival (OS), locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), and acute and late toxicity comprised the secondary endpoints.

RESULTS

Twenty-eight patients (seven were excluded) were enrolled. The 2-year PFS was 33.3% (HFRT group) versus 30.0% (CFRT group) (stratified hazard ratio (HR):1.09; 95% confidence interval (CI): 0.45-2.65, P = 0.843). The 2-year OS was 66.7% (HFRT group) versus with 62.5% (CFRT group) (stratified HR, 0.88; 95% CI; 0.31-2.51, P = 0.806). All patients experienced acute grade 1 or 2, skin toxicity, oral mucositis, difficulty swallowing, xerostomia, but no acute grade 3 or 4 toxicities. All patients had grade 1 late xerostomia. Two patients experienced hearing loss in the HFRT group (one grade 1 and one grade 3), and three patients experienced grade 1 hearing loss in the CFRT group. One patient developed mucosal necrosis in the HFRT group.

CONCLUSION

Improving the balance between severe late toxicities and local control by appropriately reducing the total dose but increasing the fractionated dose has marked clinical significance for those patients.

Recent advances progress in radiotherapy for breast cancer after breast-conserving surgery: a review

Adjuvant radiotherapy after breast-conserving surgery has become an integral part of the treatment of breast cancer. In recent years, the development of radiotherapy technology has made great progress in this field, including the comparison of the curative effects of various radiotherapy techniques and the performance of the segmentation times. The choice of radiotherapy technology needs to be co-determined by clinical evidence practice and evaluated for each individual patient to achieve precision radiotherapy. This article discusses the treatment effects of different radiotherapy, techniques, the risk of second cancers and short-range radiation therapy techniques after breast-conserving surgery such as hypo fractionated whole breast irradiation and accelerated partial breast irradiation. The choice of radiotherapy regimen needs to be based on the individual condition of the patient, and the general principle is to focus on the target area and reduce the irradiation of the normal tissues and organs. Short-range radiotherapy and hypofractionated are superior to conventional radiotherapy and are expected to become the mainstream treatment after breast-conserving surgery.

Radiotherapy refusal in breast cancer with breast-conserving surgery

BACKGROUND

Although radiotherapy after breast-conserving surgery has been the standard treatment for breast cancer, some people still refuse to undergo radiotherapy. The aim of this study is to identify risk factors for refusal of radiotherapy after breast-conserving surgery.

METHODS

To investigate the trend of refusing radiotherapy after breast-conserving surgery in patients with breast cancer using the Surveillance, Epidemiology, and End Results database. The patients were divided into radiotherapy group and radiotherapy refusal group. Survival results were compared using a multivariate Cox risk model adjusted for clinicopathological variables. Multivariate logistic regression was used to analyze the influencing factors of patients refusing radiotherapy after breast-conserving surgery and a nomogram model was established.

RESULTS

The study included 87,100 women who underwent breast-conserving surgery for breast cancer between 2010 and 2015. There were 84,948 patients (97.5%) in the radiotherapy group and 2152 patients (2.5%) in the radiotherapy refusal group. The proportion of patients who refused radiotherapy after breast-conserving surgery increased from 2.1% in 2010 to 3.1% in 2015. The Kaplan-Meier survival curve showed that radiotherapy can improve overall survival (p < 0.001) and breast cancer specific survival (p < 0.001) in the patients with breast-conserving surgery. The results of multivariate logistic regression showed that age, income, marital status, race, grade, stage, subtype and chemotherapy were independent factors associated with the refusal of radiotherapy.

CONCLUSIONS

Postoperative radiotherapy can improve the benefits of breast-conserving surgery. Patients with old age, low income, divorce, white race, advanced stage, and no chemotherapy were more likely to refuse radiotherapy.

Moderately hypofractionated post-operative radiation therapy for breast cancer: preferences amongst radiation oncologists from countries in Latin America and the Caribbean

Background

The safety and effectiveness of moderately hypofractionated post-operative radiation therapy for breast cancer were demonstrated by several trials. This study aimed to evaluate the current patterns of practice and prescription preference about moderately hypofractionated post-operative radiation therapy to assess possible aspects that affect the decision-making process regarding the use of fractionation in breast cancer patients in Latin America and the Caribbean (LAC). We also aimed to identify factors that can restrain the utilization of moderately hypofractionated post-operative radiation therapy for breast cancer.

Materials an methods

Radiation oncologists from LAC were invited to contribute to this study. A 38-question survey was used to evaluate their opinions.

Results

A total of 173 radiation oncologists from 13 countries answered the questionnaire. The majority of respondents (84.9%) preferred moderately hypofractionated post-operative radiation therapy as their first choice in cases of whole breast irradiation. Whole breast plus regional nodal irradiation, post-mastectomy (chest wall and regional nodal irradiation) without reconstruction, and post-mastectomy (chest wall and regional node irradiation) with reconstruction hypofractionated post-operative radiation therapy was preferred by 72.2% 71.1%, and 53.7% of respondents, respectively. Breast cancer stage, and flap-based breast reconstruction were the factors associated with absolute contraindications for the use of hypofractionated schedules.

Conclusion

Even though moderately hypofractionated post-operative radiation therapy for breast cancer is considered a new standard to the vast majority of the patients, its unrestricted application in clinical practice across LAC still faces reluctance.

Hypofractionated whole breast irradiation in association with hypofractionated or normofractionated boost to the tumor bed in early breast cancer: tolerance and efficacy analysis

BACKGROUND

The boost to the tumor bed improves local control in breast cancer and it is an important part of the breast conserving therapy. However, information about the use of a hypofractionated boost is sparse, thus further studies are needed. We conducted a retrospective study with the aim of comparing hypofractionated boost (HB) and normofractionated boost (NB) on skin toxicity and local control.

MATERIALS AND METHODS

A total of 96 women with early breast cancer undergoing breast-conserving surgery and hypofractionated whole breast irradiation (WBI) were retrospectively analyzed divided into hypofractionated boost group and conventional fractionation boost group. Forty-nine patients were treated with NB with 16 Gy in 8 fractions and 47 patients were treated with HB with 13.35 Gy in 5 fractions. We examined acute and chronic toxicity with CTCAE version 5.

RESULTS

The median follow-up was 49.5 months (26-67). Median age was 57 years (36-82). Sixty-six patients (68.7%) were younger than 60 years at the time of boost and 30 (31.2%) were older than 60 years who received the boost due to poor prognostic factors. No differences were found between the two groups in terms of patient, tumor or treatment characteristics. Grade 2 acute skin toxicity was 6.3% in the NB group and 4.2% in the HB group. Chronic skin induration was 4.2% in the NB group and 1% in the HB group. They did not show grade 3 skin toxicity. There were also no differences in acute or late skin toxicity between the two groups. No local recurrences were evidenced.

CONCLUSIONS

Hypofractionated WBI associated with HB treatment is a viable option in the management of conservative breast therapy given the good tolerance and similar local control.

Radiation-Induced Hypothyroidism in Patients With Breast Cancer After Hypofractionated Radiation Therapy: A Prospective Cohort Study

PURPOSE

Our objective was to assess the incidence and risk factors of radiation-induced hypothyroidism (RHT) after adjuvant hypofractionated radiation therapy (RT) in patients with breast cancer.

METHODS AND MATERIALS

Eligible patients with breast cancer who were treated with hypofractionated RT were prospectively evaluated. Thyroid function tests were performed before and at regular times after RT. RHT was defined as twice elevated serum thyroid-stimulating hormone (TSH) with decreased or normal free thyroxin after RT. The patient, tumor, and treatment factors were evaluated for possible associations with the risk of RHT.

RESULTS

Five hundred patients were analyzed. All patients underwent chest wall/breast with or without regional nodal irradiation. Among them, 369 (73.8%) patients received supraclavicular nodal radiation (SCRT). Eighty-two (16.4%) patients had elevated TSH before RT. At a median follow-up of 21.9 months, 131 (26.2%) patients developed RHT, and 59 (11.8%) patients received thyroid hormone-replacement therapy. Patients with SCRT had a significantly increased 2-year cumulative incidence of RHT compared with patients without SCRT (31.5% and 11.4%, P<.001). The peak incidence of RHT occurred around 6 to 12 months after RT. Multivariate analysis revealed that elevated baseline TSH and increased thyroid mean dose (Dmean) were independent risk factors for developing RHT. After adjusted for baseline TSH, there was a nonlinear relationship between thyroid Dmean and the risk of RHT. Dmean >21 Gy was the threshold value for predicting RHT (hazard ratio, 2.2; P<.001).

CONCLUSIONS

The incidence of RHT was high in patients with breast cancer. Thyroid function test should be started no later than 6 months after RT. We recommend that the Dmean of the thyroid should be kept lower than 21 Gy for hypofractionated RT.

Radiation Therapy for Low-Risk Breast Cancer: Whole, Partial, or None?

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.The following case represents a relatively common clinical scenario of a postmenopausal female patient who presents with low-risk, estrogen receptor-positive/progesterone receptor-positive/human epidermal growth factor receptor 2-negative, early-stage, left-sided breast cancer to discuss the role of postoperative radiation (RT) following wide local excision (WLE) and sentinel node biopsy. The spectrum of choices, ranging from omission of RT, accelerated partial breast irradiation (PBI), whole-breast radiation therapy, and the nuances of various dose/fractionation regimens for each option, are discussed in the context of the Danish Breast Cancer Study Group (DBCSG) PBI trial published in this issue, with additional review of other key trials that inform these treatment recommendations. After consideration of the clinical-pathologic features in the framework of the existing data and an in-depth discussion taking into consideration the patient's preferences/goals, the decision was made to deliver moderately hypofractionated RT (40 Gy/15 fractions) to a PBI volume, in concordance with the DBCSG-PBI trial.

Journey to hypofractionation in radiotherapy for breast cancer: critical reviews for recent updates

Historical conventional fractionated radiation therapy (RT) for breast cancer consisted of 1.8-2.0 Gy per fraction with a total dose of 45-60 Gy over 5-7 weeks. Based on radiobiological characteristics, a low α/β is suspected of breast cancer resulting in sensitivity to higher dose per fraction (2.5-3.0 Gy). Over the past 10 years, multiple clinical trials support the application of shorter treatment regimen with hypofractionated RT (HypoRT). Recently, ultra-HypoRT with 5 fractions showed favorable outcomes. Although the safety and efficacy of HypoRT has been supported by high-quality randomized trials, there are still some worries and doubts around HypoRT from radiation oncologists. However, the radiation oncology community have now reached an important timepoint for adopting HypoRT during the COVID-19 pandemic. The aim of this review is to provide an overview of HypoRT in breast cancer based on prospective randomized trials and discuss the special consideration regarding HypoRT.

Effectiveness of hypofractionated and normofractionated radiotherapy in a triple‐negative breast cancer model

Breast cancer (BC) is one of the most diagnosed malignant carcinomas in women with a triple-negative breast cancer (TNBC) phenotype being correlated with poorer prognosis. Fractionated radiotherapy (RT) is a central component of breast cancer management, especially after breast conserving surgery and is increasingly important for TNBC subtype prognosis. In recent years, moderately hypofractionated radiation schedules are established as a standard of care, but many professionals remain skeptical and are concerned about their efficiency and side effects. In the present study, two different triple-negative breast cancer cell lines, a non-malignant breast epithelial cell line and fibroblasts, were irradiated daily under normofractionated and hypofractionated schedules to evaluate the impact of different irradiation regimens on radiation-induced cell-biological effects. During the series of radiotherapy, proliferation, growth rate, double-strand DNA break-repair (DDR), cellular senescence, and cell survival were measured. Investigated normal and cancer cells differed in their responses and receptivity to different irradiation regimens, indicating cell line/cell type specificity of the effect. At the end of both therapy concepts, normal and malignant cells reach almost the same endpoint of cell count and proliferation inhibition, confirming the clinical observations in the follow-up at the cellular level. These result in cell lines closely replicating the irradiation schedules in clinical practice and, to some extent, contributing to the understanding of growth rate or remission of tumors and the development of fibrosis.

Hypofractionated versus conventional intensity-modulated radiation irradiation (HARVEST-adjuvant): study protocol for a randomised non-inferior multicentre phase III trial

INTRODUCTION

Short course regimen has become the major trend in the field of adjuvant radiotherapy for patients with breast cancer. Hypofractionated radiotherapy (HF-RT) regimen of 40-42.5 Gy in 15-16 fractions has been established as a preferred option for whole breast irradiation. However, few evidences of hypofractionated regional nodal irradiation (RNI), especially involving internal mammary nodes (IMNs), could be available during the era of intensity-modulated radiation therapy (IMRT). Against this background, we design this trial to explore the hypothesis that HF-RT regimen involving RNI (including infraclavicular, supraclavicular nodes and IMNs) will be non-inferior to a standard schedule by using IMRT technique.

METHODS AND ANALYSIS

This is an open-label randomised, non-inferior, multicentre phase III trial. Patients with breast cancer with an indication for RNI after breast conserving surgery or mastectomy are randomised at a ratio of 1:1 into the following two groups: hypofractionated regimen of 2.67 Gy for 16 fractions or conventional regimen of 2 Gy for 25 fractions. The dose was prescribed to ipsilateral chest wall or whole breast and RNI (including infraclavicular, supraclavicular nodes and IMNs, lower axilla if indicated). The trial plans to enrol a total of 801 patients and all patients will be treated using IMRT technique. The primary endpoint is 5-year locoregional recurrence. The secondary endpoints include 5-year distant metastasis free survival, invasive recurrence-free survival, overall survival, accumulative acute radiation-induced toxicity and accumulative late radiation-induced toxicity, cosmetic outcomes and quality of life.

ETHICS AND DISSEMINATION

The study has been approved by the Ethical Committee of Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine (version 2018-95-3) and approvals from ethical committee of each participating centre have also been obtained. Research findings will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03829553.

Cost containment analysis and access to treatment associated with adopting hypofractionated radiation therapy from the Brazilian perspective

Background

Estimates show that breast cancer, the leading cause of cancer death in females worldwide, will continue to increase in incidence, highlighting the need for increased treatment capacity. While postoperative radiation therapy (RT) is commonly used to reduce recurrence and mortality, research has shown that moderately hypofractionated radiation therapy (HFRT) and 5-fraction HFRT are equally safe and effective and can reduce treatment costs. This study aimed to compare the cost of conventional RT (50Gy/25), moderately HFRT (40.05Gy/15), and 5-fraction HFRT (26Gy/5) for breast cancer patients in Brazil.

Methods

The cost of each RT regimen was calculated using the International Atomic Energy Agency's Radiotherapy Cost Estimator Tool. The potential annual savings were then estimated by applying the cost of each regime to the 2020 Brazilian cancer incidence rates.

Findings

The average costs per patient for 25 fractions, 15 fractions, and 5 fractions are $2,699.20, $1,711.98, and $929.81, respectively. The annual cost savings associated with treating 70% of patients with 15 fraction HFRT and 30% of patients with 5 fraction HFRT as compared to treating all patients with 25 fraction RT is $72,929,315.40. The estimated annual productivity of 1 LINAC machine for 25 fractions, 15 fractions, and 5 fractions is 338, 647, and 1,310 patients, respectively.

Interpretation

The cost analysis revealed decreased patients' costs and potential for increased EBRT access associated with HFRT in the Brazilian perspective.

Funding

None.

Outcomes and toxicity following post-operative hypofractionated radiotherapy to the regional nodes and the breast or the chest wall in locally advanced breast cancer

OBJECTIVES

We aimed to analyze the impact of a 3-week schedule of HypoFractionated (HF) radiotherapy (RT) after axillary dissection and breast surgery, in terms of safety and efficacy in patients with locally advanced breast cancer (BC).

METHODS

Eligible patients were females with Stage IIA - IIIC BC who underwent axillary dissection and breast surgery, either quadrantectomy or mastectomy. HF RT was delivered in 15 or 16 fractions for a total dose of 40.05 Gy or 42.56 Gy, respectively, to the clavicular nodal region along with the whole breast (HF WBRT) or the chest wall (HF PMRT), according to the type of surgery. Locoregional recurrence (LRR), distant metastases-free survival (DMFS), overall survival (OS) and acute and late treatment-related toxicities were estimated.

RESULTS

57 patients with a median age of 60 years (32-85) were retrospectively analyzed. 34 (60%) of patients underwent breast conservative surgery in the form of quadrantectomy and 23 (40%) were offered radical mastectomy. All patients underwent hypofractionated regional nodal irradiation (HF RNI). 34 (60%) of them underwent HF WBRT, while 23 (40%) received HF PMRT.At a median follow-up of 80 months (30-113), the 7-year LRR-free survival was 93% (95% CI, 74%-95%). The same features for DMFS and OS were 76% (95% CI, 52%-78%) and 67% (95% CI, 50%-80%), respectively. Only one (2%) patient experienced G3 acute skin toxicity. No grade ≥2 late toxicity was observed.

CONCLUSION

Our study shows that HF RNI with HF RT to the whole breast or the chest wall after breast surgery is safe and effective in patients with locally advanced BC. Longer follow-up is needed to strengthen further analyses on late toxicity and clinical outcomes.

ADVANCES IN KNOWLEDGE

This paper adds to the evidence that post-operative RNI with WBRT or PMRT can be safely and effectively delivered with 3-week HF regimen. Locally advanced BC patients can be offered HF RT to the regional nodes and the breast or the chest wall regardless the type of surgery.

Is Clinical Research Serving the Needs of the Global Cancer Burden? An Analysis of Contemporary Global Radiation Therapy Randomized Controlled Trials

PURPOSE

Randomized controlled trials (RCTs) are the cornerstone of delivering sustained improvements in cancer outcome. To inform radiation therapy research policy and prioritization, we analyze the radiation therapy RCT landscape including comparison with trials of systemic therapies over the same period, with a specific focus on funding and disparities across income settings.

METHODS AND MATERIALS

This retrospective cohort study identified all phase 3 RCTs evaluating anticancer therapies published from 2014 to 2017. RCTs were classified according to anticancer modality and country of origin. Descriptive statistics were used to compare key characteristics of radiation therapy RCT studies according to study design characteristics, tumor types evaluated, types of intervention appraised, treatment intent and main funding sources.

RESULTS

The study cohort included 694 RCTs of which 64 were radiation therapy RCTs (9%) compared with 601 systemic therapy RCTs (87%). Among all radiation therapy RCTs, 47% of them focused on 2 areas of evaluation: (1) combining radiation therapy with systemic agents (25%) and (2) changes in dose fractionation (22%). The most common cancers studied were head and neck (22%), lung (22%), and breast (14%), with cervical cancer trials representing only 3% of the cohort. Among the radiation therapy RCTs, 33% of them met their primary endpoint, and 62% assessed interventions in the curative setting compared with 31% in systemic therapy RCTs. For their country locations, 77% of radiation therapy RCTs took place in high-income countries, 13% in low-and-middle-income countries, and 11% in both high-income and low-and-middle-income countries. For funding, 17% of radiation therapy RCTs received funding from industry compared with 79% of systemic therapy RCTs.

CONCLUSIONS

This study highlights the need for greater investment in radiation therapy RCTs and the need to look at the disparities in conducting RCTs globally. The study emphases the urgent need for more capacity building for cancer clinical trials in low-and-middle-income countries and more sustainable funding sources.

Clinical Outcomes of Hypofractionated Whole Breast Irradiation in Early-Stage, Biologically High-Risk Breast Cancer

PURPOSE

Adoption of hypofractionated whole breast irradiation (WBI) for patients with early-stage, biologically high-risk breast cancer remains relatively low. We compared clinical outcomes of conventionally fractionated versus moderately hypofractionated WBI in this patient population.

METHODS

We queried a prospectively maintained database for patients with early-stage (T1-2, N0, M0) breast cancer who received whole breast irradiation with either conventional fractionation (CWBI) or moderate hypofractionation (HWBI) at a single institution. We included only patients with biologically high-risk tumors (defined as either ER/PR/HER-2 negative, HER-2 amplified, and/or patients with a high-risk multi-gene assay) who received systemic chemotherapy. Inverse probability of treatment weighting (IPTW) was used to compare treatment cohorts and to estimate 5-year time to event endpoints. Hazard ratios (HR) and 95% CI were determined based on Cox Proportional Hazards Model.

RESULTS

We identified 300 patients, of whom 171 received CWBI and 129 received HWBI. There was a statistically significant difference in median age at diagnosis, 59 years for CWBI vs 63 years for HWBI (p = 0.004), and in median follow-up time, 97 months for CWBI vs 55 months for HWBI (p < 0.001). After accounting for differences in patient and tumor characteristics with IPTW, we found similar 5-year freedom from local recurrence (HR 0.76, 95% CI 0.14-4.1), freedom from regional recurrence (HR 3.3, 95% CI 0.15-69), freedom from distant metastasis (HR 3.9, 95% CI 0.86-17), and disease-free survival (HR 0.84, 95% CI 0.3-2.4), between those treated with CWBI and those treated with HWBI. Results were similar among each of the three high-risk subtypes.

CONCLUSION

Our data support the use of moderately hypofractionated whole breast irradiation in patients with early-stage, biologically high-risk breast cancer.

Ultra-Hypofractionated vs. Moderate Fractionated Whole Breast Three Dimensional Conformal Radiotherapy during the COVID-19 Pandemic

Background and Objectives: Reducing time of treatment during COVID-19 outbreaks has been recommended by the leading Radiation Oncology societies. Still minimizing radiation induced tissue toxicity is one of the most important issues in breast cancer patients. The study aimed to investigate compliance, clinical and dosimetry normal tissue toxicity, and cosmetic results between moderated and ultra-fractionated regimes for breast cancer patients during COVID-19 pandemic. Materials and Methods: This pilot prospective randomized study included 60 patients with early breast cancer after preserving surgery, 27 patients advocated to ultra-hypofractionated whole-breast three dimensional (3D) conformal radiotherapy of 26 Gy in 5 fractions over 1 week and 33 patients with moderate fractionated breast 3D conformal radiotherapy patients between March 2020 and July 2020, during the COVID pandemic outbreak. The compliance to treatment, dosimetric parameters, acute and late skin toxicity, subcutaneous tissue toxicity, cosmetic results and clinical follow up for 18 months for the two regimes were analyzed and compared. Results: When two regimes were compared 5 fraction group had significantly lower prevalence of newly infected cases of SARS-CoV-2 and thus delayed/interrupted treatment (p = 0.05), comparable grade 1 CTCAE v5, acute skin toxicity (p = 0.18), Grade 1 Radiation Morbidity Scoring Scheme (RESS) subcutaneous tissue toxicity (p = 0.18), Grade 1 RESS late skin toxicity (p = 0.88) and cosmetic results (p = 0.46). Dosimetric results reveled that patients in 5 fraction group received significantly lower median ipsilateral lung doses (p < 0.01) in addition to left breast cancer patients that received significantly lower median heart dose (p < 0.01) and median left anterior descending artery (LAD) dose (p < 0.01). Conclusion: Ultra-hypofractionated radiotherapy for breast cancer is comparable to moderate hypofractionation regimen regarding grade 1 acute skin toxicity, grade 1 subcutaneous tissue toxicity, late skin toxicity and cosmetic results. Application of ultra-hypofractionated radiotherapy with significantly lower radiation doses for lung and heart could be crucial in reducing the risk of acute/late pulmonary and heart radiation-induced toxicity.

Multicenter, Randomized, Phase III Trial of Short-Term Radiotherapy Plus Chemotherapy Versus Long-Term Chemoradiotherapy in Locally Advanced Rectal Cancer (STELLAR)

PURPOSE

To ascertain if preoperative short-term radiotherapy followed by chemotherapy is not inferior to a standard schedule of long-term chemoradiotherapy in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

Patients with distal or middle-third, clinical primary tumor stage 3-4 and/or regional lymph node-positive rectal cancer were randomly assigned (1:1) to short-term radiotherapy (25 Gy in five fractions over 1 week) followed by four cycles of chemotherapy (total neoadjuvant therapy [TNT]) or chemoradiotherapy (50 Gy in 25 fractions over 5 weeks, concurrently with capecitabine [chemoradiotherapy; CRT]). Total mesorectal excision was undertaken 6-8 weeks after preoperative treatment, with two additional cycles of CAPOX (intravenous oxaliplatin [130 mg/m², once a day] on day 1 and capecitabine [1,000 mg/m², twice a day] from days 1 to 14) in the TNT group and six cycles of CAPOX in the CRT group. The primary end point was 3-year disease-free survival (DFS).

RESULTS

Between August 2015 and August 2018, a total of 599 patients were randomly assigned to receive TNT (n = 302) or CRT (n = 297). At a median follow-up of 35.0 months, 3-year DFS was 64.5% and 62.3% in TNT and CRT groups, respectively (hazard ratio, 0.883; one-sided 95% CI, not applicable to 1.11; P < .001 for noninferiority). There was no significant difference in metastasis-free survival or locoregional recurrence, but the TNT group had better 3-year overall survival than the CRT group (86.5% v 75.1%; P = .033). Treatment effects on DFS and overall survival were similar regardless of prognostic factors. The prevalence of acute grade III-V toxicities during preoperative treatment was 26.5% in the TNT group versus 12.6% in the CRT group (P < .001).

CONCLUSION

Short-term radiotherapy with preoperative chemotherapy followed by surgery was efficacious with acceptable toxicity and could be used as an alternative to CRT for locally advanced rectal cancer.

Addressing the problem of overtreatment in breast cancer

INTRODUCTION

As breast cancer treatment options have multiplied and biologic diversity within breast cancer has been recognized, the use of the same treatment strategies for patients with early-stage and favorable disease, and for those with biologically aggressive disease, has been questioned. In addition, as patient-reported outcome measures have called attention to the morbidity of many common treatments, and as the cost of breast cancer care has continued to increase, reduction in the overtreatment of breast cancer has assumed increasing importance.

AREAS COVERED

Here we review selected aspects of surgery, radiation oncology, and medical oncology for which scientific evidence supports de-escalation for invasive carcinoma and ductal carcinoma in situ, and assess strategies to address overtreatment.

EXPERT OPINION

The problems of breast cancer overtreatment we face today are based on improved understanding of the biology of breast cancer and abandonment of the 'one-size-fits-all' approach. As breast cancer care becomes increasingly complex, and as our knowledge base continues to increase exponentially, these problems will only be magnified in the future. To continue progress, the move must be made from advocating the maximum-tolerated treatment to advocating the minimum-effective one.

Targeting the PI3K/AKT/mTOR pathway in epithelial ovarian cancer, therapeutic treatment options for platinum-resistant ovarian cancer

The survival rates for women with ovarian cancer have shown scant improvement in recent years, with a 5-year survival rate of less than 40% for women diagnosed with advanced ovarian cancer. High-grade serous ovarian cancer (HGSOC) is the most lethal subtype where the majority of women develop recurrent disease and chemotherapy resistance, despite over 70%-80% of patients initially responding to platinum-based chemotherapy. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway regulates many vital processes such as cell growth, survival and metabolism. However, this pathway is frequently dysregulated in cancers including different subtypes of ovarian cancer, through amplification or somatic mutations of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), amplification of AKT isoforms, or deletion or inactivation of PTEN. Further evidence indicates a role for the PI3K/AKT/mTOR pathway in the development of chemotherapy resistance in ovarian cancer. Thus, targeting key nodes of the PI3K/AKT/mTOR pathway is a potential therapeutic prospect. In this review, we outline dysregulation of PI3K signaling in ovarian cancer, with a particular emphasis on HGSOC and platinum-resistant disease. We review pre-clinical evidence for inhibitors of the main components of the PI3K pathway and highlight past, current and upcoming trials in ovarian cancers for different inhibitors of the pathway. Whilst no inhibitors of the PI3K/AKT/mTOR pathway have thus far advanced to the clinic for the treatment of ovarian cancer, several promising compounds which have the potential to restore platinum sensitivity and improve clinical outcomes for patients are under evaluation and in various phases of clinical trials.

Prospective Comparison of Hypofractionated Versus Normofractionated Intensity-Modulated Radiotherapy in Breast Cancer: Late Toxicity Results of the Non-Inferiority KOSIMA Trial (ARO2010-3)

Purpose

To compare the late toxicity profile of hypofractionation and normofractionation for whole-breast radiotherapy in breast cancer (BC) patients after conserving surgery.

Methods

Sixty-year-old or older patients with pTis-pT3, pN0-pN1a, M0 BC were recruited and stratified to hypofractionated (arm R-HF) or normofractionated (arm L-NF) intensity-modulated radiotherapy (IMRT), for right- and left-sided BC, respectively, in this single-center, non-randomized, non-inferiority trial. A boost was allowed if indicated. The primary outcome was the cumulative percentage of patients developing grade III fibrosis, grade I telangiectasia, and/or grade II hyperpigmentation after 2 years, with a pre-specified non-inferiority margin of 15% increase from an expected 2-year toxicity rate of 20%.

Results

The Median follow-up was 4.93 (0.57-8.65) years for R-HF and 5.02 (0.65-8.72) years for L-NF (p=0.236). The median age was 68 (60-83 and 60-80) years, respectively. In total, 226 patients were recruited (107 for R-HF and 119 for L-NF), with 100 and 117 patients suitable for assessment, respectively. A boost was delivered in 51% and 53% of each arm, respectively. Median PTV volumes were 1013.6 (273-2805) cm3 (R-HF) and 1058.28 (315-2709) cm3 (L-NF, p=0.591). The 2-year primary endpoint rate was 6.1% (95% CI 1.3-11.7, n=5 of 82) and 13.3% (95% CI 7-20.2, n=14 of 105), respectively (absolute difference -7.2%, one-sided 95% CI ∞ to -0.26, favoring R-HF). No local recurrence-free- or overall-survival differences were found.

Conclusion

In this prospective non-randomized study, hypofractionation did not have higher toxicity than normofractionated whole-breast IMRT.

Hypofractionated Whole-Breast Irradiation Focus on Coronary Arteries and Cardiac Toxicity-A Narrative Review

Breast cancer is the most common cancer among women worldwide, which is often treated with radiotherapy. Whole breast irradiation (WBI) is one of the most common types of irradiation. Hypo-fractionated WBI (HF-WBI) reduces the treatment time from 5 to 3 weeks. Recent radiobiological and clinical evidence recommended the use of HF-WBI regardless of the age or stage of disease, and it is proven that hypo-fractionation is non-inferior to conventional fractionation regimen irradiation. However, some studies report an increased incidence of heart-related deaths in the case of breast irradiation by hypo-fractionation, especially in patients with pre-existing cardiac risk factors at the time of treatment. Due to the new technical possibilities of radiotherapy techniques, HF-WBI can reduce the risk of cardiac toxicity by controlling the doses received both by the heart and by the anatomical structures of the heart. The radiobiological “double trouble”, in particular “treble trouble”, for hypo-fractionated regimen scan be avoided by improving the methods of heart sparing based on image-guided irradiation (IGRT) and by using respiration control techniques so that late cardiac toxicity is expected to be limited. However, long-term follow-up of patients treated with HF-WBI with modern radiotherapy techniques is necessary considering the progress of systemic therapy, which is associated with long-term survival, and also the cardiac toxicity of new oncological treatments. The still unknown effects of small doses spread in large volumes on lung tissue may increase the risk of second malignancy, but they can also be indirectly involved in the later development of a heart disease. It is also necessary to develop multivariable radiobiological models that include histological, molecular, clinical, and therapeutic parameters to identify risk groups and dosimetric tolerance in order to limit the incidence of late cardiac events. MR-LINAC will be able to offer a new standard for reducing cardiac toxicity in the future, especially in neoadjuvant settings for small tumors.

Moderately hypofractionated post-operative radiation therapy for breast cancer: Systematic review and meta-analysis of randomized clinical trials

Introduction

We provide a critical assessment regarding current evidence for the use of moderately hypofractionated irradiation for patients with breast cancer. The aim of the study was to summarize the available evidence regarding outcomes after moderately hypofractionated compared with conventional radiation doses in the post-operative treatment of patients with breast cancer.

Material and methods

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and LILACS databases were searched until March 25, 2021. All randomized phase 3 clinical trials that compared moderately hypofractionated with conventional radiation doses in the post-operative treatment of patients with breast cancer were selected. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

Results

Eight clinical trials satisfied the eligibility criteria and were the focus of the analysis. A total of 12,139 breast cancer patients was randomly assigned for moderately hypofractionated compared with conventional irradiation. Meta-analysis of the trials regarding local recurrence, loco-regional recurrence, disease-free survival, and overall survival outcomes did not demonstrate any significant difference between moderately hypofractionated irradiation and conventional radiation doses groups. The rate of severe side effects was low in both groups; acute and late side effects and cosmesis were similar or even tended to be lower after moderately hypofractionated than after conventional irradiation.

Conclusions

Moderately hypofractionated is at least as effective and safe as conventional radiation irradiation regimens and should be considered as a treatment option for most, if not all, breast cancer patients.

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Evidence for the use of moderately hypofractionated RT (MHRT) for breast cancer.

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Meta-analysis of clinical trials.

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MHRT is at least as safe and effective as conventionally fractionated regimens.

Implicaciones de la pandemia en la radioterapia para el cáncer de mama. Radioterapia hipofraccionada

La pandemia por el nuevo coronavirus (SARS-CoV-2) ha puesto a prueba los sistemas de salud de todo el mundo, de una forma tan apremiante que no se veía hace muchos años. Las implicaciones en la atención en salud no afectan únicamente a los pacientes con la COVID-19, sino que son transversales a todas las enfermedades. Específicamente en cáncer de mama, los esquemas de radioterapia hipofraccionada constituyen una alternativa válida y segura que ayuda a disminuir la exposición de las pacientes al nuevo virus, la congestión de las instituciones de salud y los costos propios de los tratamientos oncológicos especializados. En este artículo, se realizó una revisión de la literatura más relevante sobre los regímenes acortados de radioterapia en cáncer de mama: hipofraccionamiento e hipofraccionamiento extremo, y sobre su equivalencia con el fraccionamiento estándar. Al final, se destacan las recomendaciones de diferentes sociedades científicas y expertos internacionales, para considerar esquemas de radioterapia hipofraccionados, a propósito de la contingencia de salud mundial.

Disease Control After Hypofractionation Versus Conventional Fractionation for Triple Negative Breast Cancer: Comparative Effectiveness in a Large Observational Cohort

PURPOSE

Questions remain about whether moderately hypofractionated whole-breast irradiation is appropriate for patients with triple-negative breast cancer.

METHODS AND MATERIALS

Using the prospective database of a multicenter, collaborative quality improvement consortium, we identified patients with node-negative, triple-negative breast cancer who received whole-breast irradiation with either moderate hypofractionation or conventional fractionation. Using inverse probability of treatment weighting (IPTW), we compared outcomes using the Kaplan-Meier product-limit estimation method with Cox regression models estimating the hazard ratio for time-to-event endpoints between groups.

RESULTS

The sample included 538 patients treated at 18 centers in 1 state in the United States, of whom 307 received conventionally fractionated whole-breast irradiation and 231 received moderately hypofractionated whole-breast irradiation. The median follow-up time was 5.0 years (95% confidence interval [CI], 4.77-5.15 years). The 5-year IPTW estimates for freedom from local recurrence were 93.6% (95% CI, 87.8%-96.7%) in the moderate hypofractionation group and 94.4% (95% CI, 90.3%-96.8%) in the conventional fractionation group. The hazard ratio was 1.05 (95% CI, 0.51-2.17; P = .89). The 5-year IPTW estimates for recurrence-free survival were 87.8% (95% CI, 81.0%-92.4%) in the moderate hypofractionation group and 88.4% (95% CI 83.2%-92.1%) in the conventional fractionation group. The hazard ratio was 1.02 (95% CI, 0.62-1.67; P = .95). The 5-year IPTW estimates for overall survival were 96.6% (95% CI, 92.0%-98.5%) in the moderate hypofractionation group and 93.4% (95% CI, 88.7%-96.1%) in the conventional fractionation group. The hazard ratio was 0.65 (95% CI, 0.30-1.42; P = .28).

CONCLUSIONS

Analysis of outcomes in this large observational cohort of patients with triple-negative, node-negative breast cancer treated with whole-breast irradiation revealed no differences by dose fractionation. This adds evidence to support the use of moderate hypofractionation in patients with triple-negative disease.