Hypofractionated whole breast irradiation after conservative surgery for patients aged less than 60 years: a multi-centre comparative study

Factors Associated with Late Local Radiation Toxicity after Post-Operative Breast Irradiation

Purpose. To assess determinants associated with late local radiation toxicity in patients treated for breast cancer. Methods. A systematic review was performed. All studies reporting ≥2 variables associated with late local radiation toxicity after treatment with postoperative whole breast irradiation were included. Cohort studies, randomized controlled trials, and cross-sectional studies were eligible designs. Study characteristics and definitions of determinants and outcome measures were extracted. If possible, the measure of association was extracted. Results. Twenty-one studies were included in this review. Six out of seven studies focused on the association between radiotherapy (boost) dose or irradiated breast volume and late radiation toxicity found significant results. Tumor bed boost was associated with late radiation toxicity, fibrosis, and/or edema in six out of twelve studies. Lower age was associated with late breast toxicity in one study, while in another study, higher age was significantly associated with breast fibrosis. Also, no association between age and late radiation toxicity was found in eight out of twelve studies. Similar inconsistent results were found in the association between late radiation toxicity and other patient-related factors (i.e., breast size, diabetes mellitus) and surgical and systemic treatment-related factors (i.e., complications after surgery, chemotherapy, and time between surgery and radiotherapy). Conclusion. In modern 3D radiotherapy, radiotherapy (boost) dose and volume are—like in 2D radiotherapy—associated with late local radiation toxicity, such as breast fibrosis and edema. Treatment de-escalation, for example, partial breast irradiation in selected patients might be important to decrease late local toxicity without compromising locoregional control and survival.

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.

Can we treat with radiation breast cancer patients with covid-19 infection? Results from a prospective study

Purpose

The coronavirus disease 2019 (covid-19) caused by the severe acute respiratory syndrome coronavirus 2 (Sars-Cov-2) is at the origin of a global pandemic. This pandemic has prompted the current health system to reorganize and rethink the care offered by health establishments. We report the early and late toxicity in patients infected with covid-19 treated at the same time for early-stage breast cancer.

Material and methods

This is a monocentric prospective study of patients treated in our hospital between March and June 2020 who were diagnosed with covid-19 infection. The inclusion criteria were to be irradiated for early-stage breast cancer and to have a positive covid diagnosis on a polymerase chain reaction (PCR) test and/or a lung computed tomography (CT) scan and/or suggestive clinical symptoms. All of them needed 6 months follow-up clinic after the end of the radiotherapy with clinical examination, mammogram, as well as CT scan to evaluate the lung status. Radiotherapy consisted of breast or chest wall irradiation with or without lymph node irradiation, with protocols adapted to pandemic situation. The treatment-related toxicity was graded according to the Common Toxicology Criteria for Adverse Events (version 4.03).

Results

All 350 patients treated for early-stage breast cancer were studied. Of them, 16 presented clinical symptoms of covid-19 infection, and of them 12 had clinical, CT scan and PCR confirmation. This entire cohort of 12 patients with median age of 56 years (range: 42–72 years) underwent their radiotherapy. During the radiotherapy, nine patients presented radiodermatitis: eight grade 1 (66%) and one grade 2 (8%). Two patients with lymph nodes irradiation presented grade 2 oesophagitis. Late toxicity was evaluated 6 months after the end of the radiotherapy, and there was no radiation or covid lung sequel on the CT scans. One patient presented covid-related dyspnoea, and two had fibrosis.

Conclusion

The half-year follow-up of prospective covid-19 cohort, treated for early-stage breast cancer demonstrated an acceptable toxicity profile with few low-grade adverse events. It seems that the covid-19 infection does not appear to increase the side effects of radiotherapy. Therefore radiotherapy should not be delayed.

Radiodermatitis and Fibrosis in the Context of Breast Radiation Therapy: A Critical Review

Simple Summary

Skin toxicity is the main complication during irradiation in the management of early-stage breast cancer. In some cases, it may cause treatment to stop. These toxicities may be acute (mainly radiodermatitis) and/or late (mainly fibrosis). Their understandings, their mechanisms of occurrence, as well as their management is indispensable in order to improve the management of these patients. Through this study we propose to provide a clear picture of these toxicities in relation to the modalities of radiotherapy, advances in their quantification, and management to help practitioners improve their knowledge and clinical practices on this topic.

Abstract

Background: Radiation therapy has been progressively improved in order to maintain a satisfactory tumour response, while reducing toxicity. We will review the incidence of radiodermatitis and fibrosis according to the various radiation and fractionation techniques. We will then focus on the various methods used to manage, prevent, and quantify this toxicity. Method: More than 1753 articles were identified using the various search terms. We selected 53 articles to answer the questions addressed in this study according to criteria set in advance. Result: The literature reports lower acute toxicity with IMRT compared to 3DCRT, but no significant differences in terms of late toxicities. Partial breast irradiation appears to be less effective in terms of local control with a higher rate of late toxicity. Intra operative radiation therapy appears to provide good results in terms of both local control and late toxicity. The hypofractionation has equivalent efficacy and safety to the normofractionated regimen, but with lower rates of radiodermatitis and fibrosis. The adddition of a boost, particularly a sequential boost, increases the risk of fibrosis and radiodermatitis during treatment. Conclusion: The development of IMRT has significantly reduced acute toxicity and has improved tolerability during treatment. Modified fractionation has reduced treatment time, as well as adverse effects.

Assessment of planning reproducibility in three-dimensional field-in-field radiotherapy technique for breast cancer: impact of surgery-simulation interval

The three-dimensional field-in-field (3-D FIF) technique for radiotherapy is an advanced, state-of-the-art method that uses multileaf collimators to generate a homogeneous and conformal dose distribution via segmental subfields. The purpose of this study is to evaluate the dosimetric reproducibility of 3-D FIF plans using the original simulation computed tomography (iCT) scans and re-simulation CT (rCT) scans for whole breast irradiation (WBI) schedule. This study enrolled a total of 34 patients. The study population underwent iCT scans for standard WBI and took rCT scans after 45 Gy of WBI for cone down boost plans. The dosimetric parameters (V_105%, V_103%, V_100%, V_98%, V_95%, V_90%, V_50%), plan quality indices (conformity index, homogeneity index) and clinical parameters (isocenter-breast axis, isocenter-lung axis, soft tissue volumes within radiation field, lung volumes within radiation field) were assessed. The median time interval from surgery to iCT was 33 days and from iCT to rCT was 35 days. All dosimetric parameters exhibited statistically significant differences between iCT and rCT among cohorts with a surgery-iCT interval of < 60 days. Homogeneity index showed a statistically significant increase from iCT to rCT among all cohorts. Soft tissue volumes (p = 0.001) and isocenter-breast axis (p = 0.032) exhibited statistically significant differences among cohorts with surgery-iCT interval < 60 days. Regarding the reproducibility of the 3-D FIF WBI plans, significant changes were observed in dosimetric and clinical factors, particularly in study cohorts with a surgery-simulation interval < 60 days. The main contributing factor of these transitions seemed to be the changes in volume of the soft tissue within the WBI field. Further confirmative studies are necessary to determine the most suitable timing and technique for WBI.