Hypofractionated Whole-Breast Irradiation in Women Less Than 50 Years Old Treated on 4 Prospective Protocols

Potential of MRI in Assessing Treatment Response After Neoadjuvant Radiation Therapy Treatment in Breast Cancer Patients: A Scoping Review

The objective of this scoping review is to evaluate the potential of Magnetic Resonance Imaging (MRI) and to determine which of the available MRI techniques reported in the literature are the most promising for assessing treatment response in breast cancer patients following neoadjuvant radiotherapy (NRT). Ovid Medline, Embase, CINAHL, and Cochrane databases were searched to identify relevant studies published from inception until March 13, 2023. After primary selection, 2 reviewers evaluated each study using a standardized data extraction template, guided by set inclusion and exclusion criteria. A total of 5 eligible studies were selected. The positive and negative predictive values for MRI predicting pathological complete response across the studies were 67% to 88% and 76% to 85%, respectively. MRI's potential in assessing postradiotherapy tumor sizes was greater for volume measurements than uni-dimensional longest diameter measurements; however, overestimation in surgical tumor sizes was observed. Apparent diffusion coefficient (ADC) values and Time to Enhance (TTE) was seen to increase post-NRT, with a notable difference between responders and nonresponders at 6 months, indicating a potential role in assessing treatment response. In conclusion, this review highlights tumor volume measurements, ADC, and TTE as promising MRI metrics for assessing treatment response post-NRT in breast cancer. However, further research with larger cohorts is needed to confirm their utility. If MRI can accurately identify responders from nonresponders to NRT, it could enable a more personalized and tailored treatment approach, potentially minimizing radiation therapy related toxicity and enhancing cosmetic outcomes.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

Evidence-based guidelines for hypofractionated radiation in breast cancer: conclusions of the Catalan expert working group

Introduction

Daily, moderate hypofractionation has become standard treatment for breast cancer following breast-conserving surgery, although substantial variation exists in its use. This paper describes the generation of consensus-based recommendations for the utilisation of this therapy at the healthcare system level and compares these to American Society for Radiation Oncology (ASTRO) guidelines.

Materials and methods

Consensus-based guidelines were developed in three steps, including a systematic literature review and involvement of radiation oncologists specialising in breast cancer in Catalonia: (a) creation of a working group and evidence review; (b) consideration of the levels of evidence and agreement on the formulation of survey questions; and (c) performance of survey and development of consensus-based recommendations. Results were compared to the ASTRO recommendations.

Results

Consensus was above 80% for 10 of the 14 survey items. Experts supported hypofractionated radiotherapy for all breast cancer patients aged 40 years or more; with invasive carcinoma and breast-conserving surgery; without radiation of lymph nodes; and regardless of the tumour size, histological grade, molecular subtype, breast size, laterality, other treatment characteristics, or need for a boost. Over half favoured its use in all situations, even where available scientific evidence is insufficient. The resulting recommendations and the quality of the evidence are comparable to those from ASTRO, despite some differences in the degree of consensus.

Conclusion

Specialists agree that hypofractionation is the standard treatment for breast cancer following breast-conserving surgery, but some specific areas require a higher level of evidence before unequivocally extending indications.

Expert Discussion: Hypofractionated Radiation Therapy - Standard for All Indications?

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Toxicity and Cosmetic Outcome of Breast Irradiation in Women with Breast Cancer and Autoimmune Connective Tissue Disease: The Role of Fraction and Field Size

PURPOSE

Hypofractionation has historically been underused among breast cancer patients with connective tissue diseases given a theoretical risk of increased toxicity and their overall underrepresentation in clinical trials that established hypofractionation as standard of care. We aim to compare the rates of toxicity in patients with autoimmune connective tissue diseases treated with conventionally fractioned radiation therapy (CF-RT) and hypofractionated radiation therapy (HF-RT) including accelerated partial breast irradiation.

METHODS

A total of 1983 patients treated with breast conservation between 2012 and 2016 were reviewed for diagnosis of autoimmune disease. Univariate analysis using binary logistic regression was performed to evaluate the effect of disease and treatment variables on acute and late toxicity. Multivariate analyses using Cox regression models were used to evaluate the independent associations between covariates and the primary end points. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for reach risk group.

RESULTS

Ninety-two patients with autoimmune disease were identified. Median follow-up was 59 months. Of the patients 35% received CF-RT and 65% received HF-RT, of whom 70% received whole breast radiation (WBI) without regional nodal irradiation, 12% received WBI with regional nodal irradiation, and 18% received accelerated partial breast radiation. Patients who received CF-RT were significantly more likely to have autoimmune disease (AD) symptoms (78% vs 37%, P <.001), to be managed on disease-modifying antirheumatic drugs (DMARDs; 41% vs 15%, P = .013), and to have active autoimmune disease (84% vs 43%, P <.001). On multivariate analysis, HF-RT was associated with a significantly decreased odds of acute and late grade 2/3 toxicity compared with CF-RT fractionation (acute: OR 0.200, 95% CI 0.064-0.622, P = .005; late: OR 0.127, 95% CI 0.031-0.546, P = .005).

CONCLUSIONS

Hypofractionation including accelerated partial-breast irradiation is associated with less acute or late grade 2/3 toxicity in this population.

Breast Radiation Therapy Under COVID-19 Pandemic Resource Constraints-Approaches to Defer or Shorten Treatment From a Comprehensive Cancer Center in the United States

Purpose

Breast radiation therapy accounts for a significant proportion of patient volume in contemporary radiation oncology practice. In the setting of anticipated resource constraints and widespread community infection with SARS-CoV-2 during the COVID-19 pandemic, measures for balancing both infectious and oncologic risk among patients and providers must be carefully considered. Here, we present evidence-based guidelines for omitting or abbreviating breast cancer radiation therapy, where appropriate, in an effort to mitigate risk to patients and optimize resource utilization.

Methods and Materials

Multidisciplinary breast cancer experts at a high-volume comprehensive cancer center convened contingency planning meetings over the early days of the COVID-19 pandemic to review the relevant literature and establish recommendations for the application of hypofractionated and abbreviated breast radiation regimens.

Results

Substantial evidence exists to support omitting radiation among certain favorable risk subgroups of patients with breast cancer and for abbreviating or accelerating regimens among others. For those who require either whole-breast or postmastectomy radiation, with or without coverage of the regional lymph nodes, a growing body of literature supports various hypofractionated approaches that appear safe and effective.

Conclusions

In the setting of a public health emergency with the potential to strain critical healthcare resources and place patients at risk of infection, the parsimonious application of breast radiation therapy may alleviate a significant clinical burden without compromising long-term oncologic outcomes. The judicious and personalized use of immature study data may be warranted in the setting of a competing mortality risk from this widespread pandemic.

The efficacy and safety of hypofractionated radiotherapy with concurrent anti-HER-2 therapy following breast-conserving therapy for breast cancer

The purpose of this study was to report rates and severities of radiation-related toxicities and analyze disease-control outcomes in patients who have received hypofractionated whole breast radiation (HF) with concurrent trastuzumab with or without pertuzumab. We conducted a retrospective cohort study including women with stage I-III HER2-positive breast cancer who received HF at the University of Pennsylvania between 1/2005 and 5/2018 with concurrent trastuzumab with or without pertuzumab. Fractionation was 266 cGy daily to a total dose of 4256 cGy with or without a sequential tumor bed boost. Eighty patients were included in the cohort with a median follow-up time of 21.44 months. There was one grade 3 acute toxicity (fatigue) and no grade 3 late toxicities. 91% and 25% of patients experienced grade 1-2 acute and late skin reactions, respectively. An excellent-good cosmetic outcome was reported by 74% and 95% of patients and physicians, respectively. No patients experienced tumor recurrences, and the only death was due to a secondary cause. These results suggest that hypofractionated whole breast radiation administered concurrently with anti-HER-2 therapies is efficacious and has acceptable toxicity in early-stage breast cancer patients treated with lumpectomy. Continued follow-up is warranted to evaluate long-term outcomes.