Feasibility and Safety of the "One-Week Breast Radiation Therapy" Program.

AIMS: FAST-Forward and UK-FAST-trials have demonstrated the safety and efficacy of five-fraction breast adjuvant radiation therapy (RT) and have become the standard of care for selected early breast cancer patients. In response to the additional burden caused by the COVID-19 pandemic, we implemented "One-Week Breast RT," an innovative program delivering five-fraction whole breast RT in a complete 5-day workflow. The primary objective of this study was to demonstrate the feasibility and safety of our program. The secondary objective was to evaluate cosmetic results. MATERIAL AND METHODS: A total of 120 patients treated from February 2021 to March 2022, received whole breast RT without lymph node irradiation nor boost, with 26 Gy in five fractions over one week. Inverse planning with restricted optimization parameters offers systematic deep inspiration breath-hold aimed to provide treatment plans compliant with FAST-Forward recommendations. Toxicity and cosmetic evaluations were prospectively registered prior (pre-RT), at the end (end-RT), and 6 months after RT (6 months) based on Common Terminology Criteria for Adverse Events v. 4.03 and Harvard scale. RESULTS: With a median age of 70 years (interquartile range (IQR): 66-74) and a median follow-up of 6 months (IQR: 6.01-6.25), most patients (93.3%) completed their RT in one week from baseline to the end of the treatment consultation. The most common acute toxicities (at end-RT) were skin-related: radio-dermatitis (72%), induration (35%), hyperpigmentation (8%), and breast edema (16%). The rate of radio-dermatitis decreased from end-RT to 6 months (71.7% vs 5.4%, P< 0.001). No patient experienced grade ≥3 toxicity. At 6 months, cosmetic results were generally good or excellent (94.1%). CONCLUSION: This study confirms the feasibility and acute safety of the "One-Week Breast RT" in real life. Favorable toxicity profiles and good cosmetic outcomes are in line with FAST-Forward results. A prospective national cohort, aimed at decreasing treatment burden, maintaining safety, efficacy, and improving RT workflow efficiency with longer follow-up is ongoing.

[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.

Subclinical left ventricle impairment following breast cancer radiotherapy: Is there an association between segmental doses and segmental strain dysfunction?

BACKGROUND: Cardiotoxicity following breast cancer radiotherapy (RT) represents one of the most redoubtable toxicities. The Global longitudinal strain measurement (GLS) based on 2D speckle tracking imaging (STI) allows detection of left ventricular (LV) dysfunction at a subclinical stage. The aim of this prospective study was to detect patients at risk of cardiotoxicity using echocardiographic parameters and to determine the association between segmental RT doses and early cardiac toxicity. MATERIAL AND METHODS: The STI was performed prior to RT and at 3, 6 and 12 months after. The association between subclinical LV dysfunction, defined as a reduction of GLS more than 10% from the initial value, radiation doses to different LV segments and non-radiation factors were performed based on multivariate analyses. RESULTS: From June 2017 to August 2018, a total of 103 female patients were included. Sixty patients had left sided RT. Seven patients (7.8%) developed a GSL impairment. The segmental alterations predominated in the anteroseptal and apical LV segments. The mean Dmean in altered segments was significantly higher than in non-altered segments (6.7 ± 8.8Gy-7.8 ± 8.9Gy vs 4.9 ± 7.9-5.4 ± 8.2Gy; p < 0.05). Age > 55 years and obesity were important confounding factors that should be considered during radiotherapy planning. CONCLUSION: The results of our study show that radiation dose is correlated with the subclinical LV segments' alteration. Global heart delineation seems to be insufficient during the breast radiotherapy planning. Segmental delineation of the LV may be an interesting alternative to limit segmental doses and to reduce the risk of subclinical alterations. A mean dose of 5Gy could be proposed in exposed heart segment.