Survival and toxicity after breast-conserving surgery and external beam reirradiation for localized ipsilateral breast tumour recurrence: A population-based study.

PURPOSE: Breast-conserving surgery followed by reirradiation for a localized ipsilateral breast tumour relapse may increase the radiation dose delivered to the heart and result in a greater risk of cardiac adverse events. This study aimed to compare the incidence of cardiac mortality in patients treated for a localized ipsilateral breast tumour relapse, either with breast-conserving surgery followed by reirradiation or with total mastectomy between 2000 and 2020. MATERIALS AND METHODS: All patients treated for a primary non-metastatic breast cancer with breast-conserving surgery and adjuvant radiotherapy were identified in the Surveillance, Epidemiology, and End Results (SEER) program database, and those who subsequently experienced a localized ipsilateral breast tumour relapse treated with breast-conserving surgery and reirradiation ("BCS+ReRT" group, n=239) or with total mastectomy ("TM" group, n=3127) were included. The primary objective was to compare the cardiac mortality rate between the patients who underwent breast-conserving surgery followed by reirradiation and total mastectomy. Secondary endpoints were overall survival and cancer specific survival. RESULTS: Cardiac mortality was significantly higher in patients treated with breast-conserving surgery followed by reirradiation (hazard ratio [HR]: 2.40, 95% confidence interval [95% CI]: 1.19-4.86, P=0.006) in univariate analysis; non-statistically significant differences were observed after adjusting for age, laterality and chemotherapy on multivariate analysis (HR: 1.96, 95% CI: 0.96-3.94, P=0.067), age being the only confounding factor. A non-statistically significant difference towards lower overall survival was observed in patients who had breast-conserving surgery followed by reirradiation compared with those who underwent total mastectomy (HR: 1.37, 95% CI: 0.98-1.90, P=0.066), and no differences were observed in terms of cancer specific survival (HR: 1.01, 95% CI: 0.56-1.82, P=0.965). CONCLUSION: In this study, the incidence of cardiac mortality was low, and breast-conserving surgery followed by reirradiation did not independently increased the risk of cardiac mortality for a localized ipsilateral breast tumour relapse.

Dosimetric feasibility study ("proof of concept") of refractory ventricular tachycardia radioablation using proton minibeams.

PURPOSE: Preclinical data demonstrated that the use of proton minibeam radiotherapy reduces the risk of toxicity in healthy tissue. Ventricular tachycardia radioablation is an area under clinical investigation in proton beam therapy. We sought to simulate a ventricular tachycardia radioablation with proton minibeams and to demonstrate that it was possible to obtain a homogeneous coverage of an arrhythmogenic cardiac zone with this technique. MATERIAL AND METHODS: An arrhythmogenic target volume was defined on the simulation CT scan of a patient, localized in the lateral wall of the left ventricle. A dose of 25Gy was planned to be delivered by proton minibeam radiotherapy, simulated using a Monte Carlo code (TOPAS v.3.7) with a collimator of 19 0.4 mm-wide slits spaced 3mm apart. The main objective of the study was to obtain a plan ensuring at least 93% of the prescription dose in 93% of the planning target volume without exceeding 110% of the prescribed dose in the planning target volume. RESULTS: The average dose in the planning treatment volume in proton minibeam radiotherapy was 25.12Gy. The percentage of the planning target volume receiving 93% (V93%), 110% (V110%), and 95% (V95%) of the prescribed dose was 94.25%, 0%, and 92.6% respectively. The lateral penumbra was 6.6mm. The mean value of the peak-to-valley-dose ratio in the planning target volume was 1.06. The mean heart dose was 2.54Gy versus 5.95Gy with stereotactic photon beam irradiation. CONCLUSION: This proof-of-concept study shows that proton minibeam radiotherapy can achieve a homogeneous coverage of an arrhythmogenic cardiac zone, reducing the dose at the normal tissues. This technique, ensuring could theoretically reduce the risk of late pulmonary and breast fibrosis, as well as cardiac toxicity as seen in previous biological studies in proton minibeam radiotherapy.

Management of second ipsilateral breast tumor event: An advocacy for a randomized trial.

For a second ipsilateral breast tumor event, salvage mastectomy is the standard of care while second conservative treatment is a possible option. However, level 1 proofs are missing, leading to perform salvage mastectomy for patients who could receive second conservative treatment and consequently avoid psychological/quality of life salvage mastectomy deleterious impacts. A phase 3 randomized trial comparing salvage mastectomy to second conservative treatment is needed. Here we discuss what would be to us the optimal design of such trial to confirm the non-inferiority between the two salvage options, with a focus on methodological aspects in terms of patient characteristics and statistical issues.

Radiation therapy of the primary tumour and oligometastatic sites in patients with breast cancer with synchronous metastases: A literature review.

De novo metastatic breast cancer represents 5 to 8% of all breast cancers (2500 new cases per year in France). Systemic treatment is the cornerstone of treatment, whereas radiation therapy usually has a palliative intent. Advances in systemic and local treatments (surgery and radiation therapy) have substantially improved overall survival. In the recent breast cancer statistics in the United States, the 5-year relative survival for patients diagnosed during 2012-2018 was 29% for stage IV (Breast Cancer Statistics). Thus, an increasing proportion of metastatic breast cancers present a prolonged complete response to systemic therapy, which raises the question of the impact of local treatment on patient survival. Radiation therapy has shown its value for early breast cancer, but its place in the local management of the primary tumour or oligometastatic sites for de novo metastatic breast cancer remains under debate. This article is a literature review assessing the role of radiation therapy directed to the primary tumour and oligometastatic sites of breast cancer in patients with synchronous metastases, in order to highlight clinicians in their therapeutic decision.

[Rare tumours of the breast]. / Tumeurs rares du sein.

Breast tumours are the most common tumours in women but represent a very heterogeneous group. On the one hand, there are ductal and lobular carcinomas of the breast, representing 90% of tumours, whose clinicopathologic characteristics are well known. On the other hand, there are rare breast tumours, each of which represents less than 1% that limits their study through large cohorts. The objective of this work was to collect, update and synthesize knowledge on these rare tumours. A literature review was performed on the Medline and Google Scholar databases. We present here a selection of several rare tumours, providing updated data at the epidemiological, histopathological, genetic, clinical and radiographic, prognostic and therapeutic levels, taking into account the place of radiotherapy. Each tumour histology is unique and has its own characteristics, the management must therefore be adapted as much as possible and decided in a multidisciplinary meeting.

Radiation therapy in the thoracic region: Radio-induced cardiovascular disease, cardiac delineation and sparing, cardiac dose constraints, and cardiac implantable electronic devices.

Radiation therapy in the thoracic region may deliver incidental ionizing radiation to the surrounding healthy structures, including the heart. Radio-induced heart toxicity has long been a concern in breast cancer and Hodgkin's lymphoma and was deemed a long-term event. However, recent data highlight the need to limit the dose to the heart in less favorable thoracic cancers too, such as lung and esophageal cancers in which incidental irradiation led to increased mortality. This article will summarize available cardiac dose constraints in various clinical settings and the types of radio-induced cardiovascular diseases encountered as well as delineation of cardiac subheadings and management of cardiac devices. Although still not completely deciphered, heart dose constraints remain intensively investigated and the mean dose to the heart is no longer the only dosimetric parameter to consider since the left anterior descending artery as well as the left ventricle should also be part of dosimetry constraints.

Late hepatic toxicity after breast cancer intensity-modulated radiotherapy using helicoidal tomotherapy.

PURPOSE: Helical tomotherapy (HT) is a rotational intensity-modulated radiation therapy (IMRT) technique that allows target conformal irradiation and efficient organs at risk (OAR) sparing in the case of complex target volumes and specific anatomic considerations, but increases the "low-dose bath" to non-target volumes. The aim of this study was to analyze the delayed hepatotoxicity after rotational IMRT (HT) radiation therapy for non-metastatic breast cancer. PATIENTS AND METHODS: This single-center retrospective study included all non-metastatic breast cancer patients with a normal pre-radiotherapy biological hepatic function who were treated with tomotherapy between January 2010 and January 2021 and for whom the dosimetric parameters for the whole liver were assessable. A logistic regression analysis was employed. The selected covariates for the multivariate analysis were those with a P-value that was less or equal to 0.20 in the univariate analysis. RESULTS: Forty-nine patients were included in this study: 11 patients (22%) received Trastuzumab for 1 year in tumors with an HER2-expression; 27 patients (55%) received radiation therapy for cancer of the right or bilateral breasts; 43 patients (88%) received lymph node irradiation and 41 patients (84%) received a tumor bed boost. Mean and maximum doses to the liver were 2.8Gy [0.3-16.6] and 26.9Gy [0.7-51.7], respectively. With a median follow-up after irradiation was 5.4 years (range, 6 to 115 months), 11 patients (22%) had developed delayed low grade biological hepatic abnormalities: all patients had grade 1 delayed hepatotoxicity; 3 patients (6%) had additional grade 2 delayed hepatotoxicity. There was no hepatotoxicity at grade 3 or higher. According to the univariate and multivariate analysis, Trastuzumab was a significant predictive variable of late biological hepatotoxicity (OR=4.4 [1.01-20.18], P=0.04). No other variable was statistically associated with delayed biological hepatotoxicity. CONCLUSION: Delayed hepatotoxicity after multimodal non-metastatic breast cancer management including rotational IMRT was negligible. Consequently, the liver doesn't have to be considered like an organ-at-risk in the analysis of breast cancer radiotherapy but future prospectives studies are needed to confirm these findings.

[Radiotherapy and targeted therapy for the management of breast cancer: A review]. / Radiothérapie et thérapie ciblée pour la prise en charge du cancer du sein : mise au point.

The purpose of this study was to review the current knowledge regarding combinations of the most commonly used targeted therapies or those under development for the management of breast cancer with radiation therapy. Several studies have shown that the combination of radiation therapy and tamoxifen increased the risk of radiation-induced lung toxicity; therefore, the two modalities are generally not given concurrently. The combination of HER2 inhibitors (trastuzumab, pertuzumab) and radiation therapy appeared to be safe. However, trastuzumab emtansine (T-DM1) should not be given concomitantly with brain radiation therapy because this combination may increase the risk of brain radionecrosis. The combination of radiation therapy with other new targeted therapies such as new selective estrogen receptor modulators (SERDs), lapatinib, cell cycle inhibitors, immune checkpoint inhibitors, or molecules acting on DNA damage repair seems feasible but has been mainly evaluated on retrospective or prospective studies with small numbers of patients. Moreover, there is a great heterogeneity between these studies regarding the dose and fractionation used in radiotherapy, the dosage of systemic treatments and the sequence of treatments used. Therefore, the combination of these new molecules with radiotherapy should be proposed sparingly, under close monitoring, pending the ongoing prospective studies cited in this review.

Long-term efficacy and tolerance of a technique for postmastectomy electron beam radiation therapy of the unreconstructed chest wall and lymph node areas for non-metastatic breast cancers.

PURPOSE: To evaluate the long-term tolerance and outcome of patients irradiated with an electron beam technique used since 2007 on the chest wall and lymph node areas after mastectomy for non-metastatic locally advanced breast carcinoma. PATIENTS AND METHODS: All patients irradiated with an improved electron beam technique after mastectomy for non-metastatic breast carcinoma between 2007 and 2011 at Institut Curie (France) were included in this descriptive study. The technique has already been described in other studies, as has its 5-year tolerance and non-inferiority compared to photon irradiation. Acute and chronic toxicity were collected using CTCAE v 3.0. A clinical examination was carried out each week during the radiotherapy and at each 6 months consultation with one mammogram per year at the Institut Curie for at least 5 years. The patients then continued to be followed either at the Institut Curie or in private practice with a good transmission of outpatient consultations, thanks to a system of forms to be completed and integrated into the electronic files. Quantitative and qualitative data are defined by mean and proportion. Statistical comparisons were made by computer using the Chi2 test and Fisher's exact test for categorical variables. Recurrence-free survival was defined as the time between the end of treatment and the date of recurrence or death. Overall survival was defined in the same way without taking into account recurrences. Patients who did not report any events were censored at the date of last news. RESULTS: Of the 796 patients included, 51.3% had multifocal lesions, 10.1% had triple negative status, and 18.8% displayed overexpression of the Her2 receptor, 196 (24.6%) patients received neoadjuvant chemotherapy and 208 (26.1%) systemic treatment during radiotherapy (chemotherapy or targeted therapy); 514 (64.6%) had at least one positive lymph node. The internal mammary chain (IMC) was irradiated in 85.6% of cases, the supraclavicular areas in 88.3% of cases, the infraclavicular in 77.9% of cases and the axillary area in 14.9% of cases. With a median follow-up of 113 months (range: 2-164 months), locoregional recurrence-free survival and overall 10-year survival was respectively 94.02%, (95% CI: 92.13-98.94) and 79.84% (95% CI: 76.83-82.97). Median survival was not reached. In the long term, 29.6% of patients had telangiectasias (grade 1: 23.3%, grade 2: 5.2%, grade 3: 1.1%). There were 279 patients (35.1%) with secondary breast reconstruction on average 21 months after all treatments. IMC irradiation was not associated with a majority of pulmonary toxicity. Thirty-five patients developed chronic heart disease after radiotherapy, 30 of whom had received anthracyclines and 9 had received traztuzumab. Three of these reported a coronary ischaemic event, including 2 irradiated on the left and 1 on the right, the 4 were irradiated in the vicinity of the IMC and the other lymph node areas, but presented many other cardiovascular risk factors (between 2 and 4). During follow-up, 4.9% of patients had a contralateral recurrence (n=39) and 5.5% had a second non-breast cancer (n=44), of the 6 bronchopulmonary cancers diagnosed, none appeared to be related to chest wall radiotherapy. CONCLUSION: This study confirms that the improved postmastectomy electron beam radiation therapy technique is well-tolerated after nearly 10 years of follow-up.

[Biological, preclinical and clinical aspects of the association between radiation therapy and CDK4/6 inhibitors]. / Aspects biologiques, précliniques et cliniques de l'association de radiothérapie et d'inhibiteur de CDK 4/6.

Several clinical studies have shown that CDK4/6 inhibitors (CDK4/6i) improve survival in patients with metastatic or locally advanced HR-positive, HER-2-negative breast cancer (BC). The aim of this review was to synthesize the biological, preclinical and clinical aspects of the treatment of BC with CDK4/6i, with a focus on the combination of CDK4/6i and radiotherapy. The DNA damage induced after exposure of cells to ionizing radiation activates control pathways that inhibit cell progression in the G1 and G2 phases and induce a transient delay in progression in the S phase. These checkpoints are in particular mediated by cyclin-dependent kinases (CDK) 4/6 activated by cyclin D1. Several preclinical studies have shown that CDK4/6i could be used as radiosensitizers in non-small cell lung cancer, medulloblastoma, brainstem glioma and breast cancer. CDK4/6 inhibition also protected against radiation-induced intestinal toxicities by inducing redistribution of quiescent intestinal progenitor cells, making them less radiosensitive. Clinical data on the combination of CDK inhibitors and radiotherapy for both locoregional and metastatic irradiation are based on retrospective data. Nevertheless, the most optimal therapeutic sequence would be radiotherapy followed by palbociclib. Pending prospective clinical trials, the concomitant combination of the two treatments should be done under close supervision.

Neutron brachytherapy in the modern era: Indications and evidence.

Hadrontherapy is a form of radiation therapy (RT) that relies on heavy particles, such as proton, heavy ions, or neutrons, to enhance anti-tumoral efficacy based on their specific dosimetric and radio-biological properties. Neutrons are characterized by specific radiobiological properties that might deserve greater consideration, including the high linear energy transfer and the low oxygen enhancement ratio. Neutron brachytherapy, relying on interstitial or intracavitary neutron sources, has been developed since the 1950s using Californium-252 (252Cf) as a mixed emitter of fission fast neutrons and γ-photos. However, the place of NBT in the era of modern radiation therapy is yet to be precisely defined. In this systematic review, we aim to provide an up-to-date analysis of current experience and clinical evidence of NBT in the XXI th century, by answering the following clinical questions: How is NBT currently delivered? What are the current efficacy data and tolerance profiles of NBT?

Supraventricular cardiac conduction system exposure in breast cancer patients treated with radiotherapy and association with heart and cardiac chambers doses.

Purpose: To assess sinoatrial node (SAN) and atrioventricular node (AVN) doses for breast cancer (BC) patients treated with 3D-CRT and evaluate whether "large" cardiac structures (whole heart and four cardiac chambers) would be relevant surrogates. Material and methods: This single center study was based on 116 BCE patients (56 left-sided, 60 right-sided) treated with 3D-CRT without respiratory gating strategies and few IMN irradiations from 2009 to 2013. The heart, the left and right ventricles (LV, RV), the left and right atria (LA, RA) were contoured using multi-atlases for auto-segmentation. The SAN and the AVN were manually delineated using a specific atlas. Based on regression analysis, the coefficients of determination (R2) were estimated to evaluate whether "large" cardiac structures were relevant surrogates (R2 > 0.70) of SAN and AVN doses. Results: For left-sided BC, mean doses were: 3.60 ± 2.28 Gy for heart, 0.47 ± 0.24 Gy for SAN and 0.74 ± 0.29 Gy for AVN. For right-sided BC, mean heart dose was 0.60 ± 0.25 Gy, mean SAN dose was 1.57 ± 0.63 Gy (>85 % of patients with SAN doses > 1 Gy) and mean AVN dose was 0.51 ± 0.14 Gy. Among all "large" cardiac structures, RA appeared as the best surrogate for SAN doses (R2 > 0.80). Regarding AVN doses, the RA may also be an interesting surrogate for left-sided BC (R2 = 0.78), but none of "large" cardiac structures appeared as relevant surrogates among right-sided BC (all R2 < 0.70), except the LA for patients with IMN (R2 = 0.83). Conclusions: In BC patients treated 10 years ago with 3D-CRT, SAN and AVN exposure was moderate but could exceed 1 Gy to the SAN in many right-sided patients with no IMN-inclusion. The RA appeared as an interesting surrogate for SAN exposure. Specific conduction nodes delineation remains necessary by using modern radiotherapy techniques.

Multidisciplinary management and role of reirradiation in the treatment of a breast cancer patient with four locoregional recurrences.

Breast cancer is a frequent and sometimes fatal disease. The risk of locoregional recurrence has considerably decreased since the introduction of adjuvant treatments (radiotherapy, chemotherapy, hormone therapy). Nevertheless, some patients present a risk of multiple local recurrences. We report here the case of a patient who had four locoregional breast cancer recurrences. There is currently no validated biomarker that allows the prediction of recurrence. Salvage surgery, most often mastectomy, remains the recommended treatment for the management of these recurrences in the irradiated field. However, increasingly, depending on the patient's wishes and the technical possibilities of multiple surgeries, the question of a second conservative treatment and reirradiation arises. This type of management must in all cases be multidisciplinary and in specialized centers. Reirradiation must in any case try to give maximum priority to the protection of healthy tissue already irradiated.

Long-term follow-up results of intensity-modulated radiotherapy with helicoïdal tomotherapy for non-metastatic breast cancers: Single centre experience.

PURPOSE: Intensity-modulated radiotherapy with helical Tomotherapy is a novel radiation therapy technique, which may be beneficial in several features compared to traditional methods. Our aim was to evaluate the local control, overall survival, progression free survival and adverse events in breast cancer patients treated with this new technique. MATERIAL AND METHODS: This is retrospective analysis of patients irradiated with intensity-modulated radiotherapy with helical Tomotherapy. Overall survival and progression free survival curves were plotted with Kaplan-Meier method. We also analysed the overall survival and progression-free survival data by molecular subgroups. Long-term toxicity including skin, cardiac and pulmonary complications were also evaluated. Multivariant logistic regression analysis was performed to determine the predictors of the side effects. RESULTS: Between 2009-2015, 179 consecutive patients with 194 treated breasts were irradiated with intensity-modulated radiotherapy with helical Tomotherapy. The median follow-up were 65 months. The overall survival rate was 89.2% (95% confidence interval [95CI]: 83.5-95.4%), while disease-free survival rate was 85.4% (95CI: 80.2-91%). The Human epidermal growth factor receptor 2-positive patients had the best 5-year overall survival data of 95% (95CI: 85.9-100%). Long-term skin toxicity was the most common, seen in a total of 20.7% of the patients. CONCLUSION: Intensity-modulated radiotherapy with helical Tomotherapy could be safely used for adjuvant breast cancer irradiation in patients with complex anatomy and provides favourable long-term prognosis with acceptable late toxicity.

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 56years (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.

Radiation dose to the low axilla in patients treated for early-stage breast cancer by locoregional intensity-modulated radiotherapy (IMRT).

PURPOSE: To determine the dose received by the low axilla during locoregional radiotherapy (RT) for early-stage breast cancer and to assess the impact of the treatment technique (three-dimensional conformal radiotherapy (3D-CRT) or rotational IMRT (VMAT) or helical tomotherapy (HT). MATERIALS AND METHODS: The dosimetric study was performed on patients receiving normofractionated (NFRT - 50Gy in 25 fractions) or hypofractionated (HFRT - 40Gy in 15 fractions) locoregional radiotherapy (breast or chest wall and internal mammary, supraclavicular and infraclavicular nodes±axillary nodes) by 3D-CRT or VMAT or HT at the Institut Curie Paris. Patients treated by breast-conserving surgery received a boost dose of 16Gy and 10Gy to the tumour bed, respectively. RESULTS: Sixty-eight patients treated by RT from February 2017 to January 2019 were studied. The mean dose received by the low axilla when it was not part of the target volume was 30.8Gy, 41.0Gy and 44.4Gy by 3D-CRT, VMAT and HT, respectively for NFRT and 24.2Gy, 33.0Gy and 34.9Gy, respectively, for HFRT. With NFRT, 4.1% of the axilla received 95% (V95) of the prescribed dose by 3D-CRT compared to 24.5% and 33.6% by VMAT and HT, respectively; with HFRT, V95 was 3.9%, 19.5% and 24.1%, respectively. CONCLUSION: The axilla receives a non-negligible dose during locoregional radiotherapy; this dose is greater when VMAT or HT are used. Prospective studies must be conducted to assess the impact of this axillary dose in terms of morbidity, which currently remains unknown.

[Patient selection and early tolerance of whole breast irradiation according to the "Fast Forward" protocol: Preliminary results]. / Sélection de patientes et tolérance précoce de l'irradiation mammaire selon le protocole « Fast Forward ¼ : résultats préliminaires.

PURPOSE: Moderate hypofractionated radiotherapy has become routine practice for a selected population of patients treated for early-stage breast cancer. In April 2020, the Fast Forward (FF) study was published which introduced another extreme hypofractionated radiotherapy regimen in five sessions over a week. The aim of this work is to evaluate the population of first patients in whom this regimen was used in our department, as well as the results in terms of early toxicity. MATERIAL AND METHODS: We retrospectively analysed all the patients treated in our department according to the Fast Forward protocol after establishing an institutional consensus regarding the selection of patients with breast cancer without indication for lymph node irradiation. All patients received breast-only irradiation at a total dose of 26Gy in five fractions according to protocol. All patients were treated by modern conformational techniques with planning large volume coverage between 95 and 100%. Acute toxicity of the treatment was assessed using the NCI CTC v4.0 scale and the general condition was assessed according to the WHO classification. RESULTS: Between August 2020 and May 2021, 30 patients were included, treated on the breast alone without complement on the tumour bed or irradiation of the lymph node areas. The median age of the patients was 80years (range: 60-85years) with performance status 2 in 27 cases (89%). Only one patient had metastatic disease (3%), one patient presented locally advanced and 28 (94%) patients had early stage disease. Three patients (10%) were treated in dorsal decubitus according to the "field in the field" technique and 27 patients (90%) in isocentric lateral decubitus, which made it possible to avoid the organs at risk such as the heart (average dose of less than 1Gy) and the lungs. The early toxicity observed was grade I radio dermatitis in 8 patients (27%). No grade 2 and 3 toxicity, as well as radiation-induced pain or lymphedema were observed. CONCLUSIONS: The results of this series of patients treated with hypofractionated radiotherapy according to the Fast Forward protocol on the breast alone with adapted techniques show that the protocol is feasible, with little early toxicity but a greater follow-up is necessary to assess long-term toxicity.