Acute skin toxicity of conventional fractionated versus hypofractionated radiotherapy in breast cancer patients receiving regional node irradiation: the real-life prospective multicenter HYPOBREAST cohort.

BACKGROUND: Large-scale trials have shown that hypofractionated adjuvant breast radiotherapy was as effective in terms of survival and local control as conventional fractionated radiotherapy, and acute toxicity was reduced with hypofractionated radiotherapy. However, there is a lack of data about the toxicity of breast with regional nodal irradiation (RNI). The aim of this study was to assess the effect of fractionation on radiation-related acute skin toxicity in patients receiving RNI in addition to whole-breast or chest wall irradiation, using real-life data. METHODS: We conducted a prospective, multicenter cohort study with systematic computerized data collection integrated into Mosaiq®. Three comprehensive cancer centers used a standardized form to prospectively collect patient characteristics, treatment characteristics and toxicity. RESULTS: Between November 2016 and January 2022, 1727 patients were assessed; 1419 (82.2%) and 308 (17.8%) patients respectively received conventional fractionated and hypofractionated radiation therapy. Overall, the incidence of acute grade 2 or higher dermatitis was 28.4% (490 patients). Incidence was lower with hypofractionated than with conventional fractioned radiation therapy (odds ratio (OR) 0.34 [0.29;0.41]). Two prognostic factors were found to increase the risk of acute dermatitis, namely 3D (vs IMRT) and breast irradiation (vs chest wall). CONCLUSION: Using real-life data from unselected patients with regional nodal irradiation, our findings confirm the decreased risk of dermatitis previously reported with hypofractionated radiation therapy in clinical trials. Expansion of systematic data collection systems to include additional centers as well as dosimetric data is warranted to further evaluate the short- and long-term effects of fractionation in real life.

New photobiomodulation device for prevention and cure of radiotherapy-induced oral mucositis and dermatitis: results of the prospective Safe PBM study.

PURPOSE: The study aims to assess the feasibility, safety, and tolerability of CareMin650, a new photobiomodulation device, in patients treated by radiotherapy (RT) and to collect preliminary data on efficacy for prevention and treatment of oral mucositis (OM) and radiation dermatitis (RD). METHODS: Safe PBM is a French, multicentric, prospective, non-comparative study which include patients with head and neck cancer (H&NC, cohort A) or breast cancer (BC, cohort B) treated in prophylactic (cohorts A1 and B1) or curative setting (cohort A2 and B2). Prophylactic treatment was administered from D1 to end of RT, at a dose of 3 J/cm2. Curative treatment started when a grade 1 to grade 3 lesion had occurred and was pursued until end of RT. Primary endpoint was incidence of device-related adverse events (AEs). OM and RD lesions were graded according to CTCAE V3. RESULTS: Overall, 72 patients were included (22, 9, 23, and 18 in cohorts A1, A2, B1, and B2, respectively). No device-related AE was reported after 1312 CareMin650 sessions. In cohorts A1 and B1, median time to first OM or RD lesion was 20 days. One BC patient developed G3 RD after completion of RT and discontinuation of CareMin650. Four H&NC patients developed G3 OM. In cohorts A2 and B2, lesions improved or stabilized in 71% of patients. Rates of satisfaction were high among patients and users. CONCLUSION: CareMin650 is feasible, safe, and well tolerated for preventive or curative treatment of OM and RD in cancer patients treated with RT. Preliminary efficacy results are promising.

A Practical Approach to the Management of Radiation-Induced Hemorrhagic Cystitis.

Radiation-induced hemorrhagic cystitis (HC) is a complication of pelvic radiotherapy, mainly for prostate and uterine cancers. In the acute phase, patients feel urinary urgency and bladder pain. This phase is reversible after radiotherapy. In the chronic stage, an irritative syndrome is coupled with hematuria during the 2-10 years following radiotherapy. Cystoscopy shows white and frosted mucosa with telangiectasia. The incidence is estimated at 5 % or less. It is suggested that the radiation oncologist reviews the dosimetry plan to validate that the lesions coincide with significant radiation exposure confirming diagnosis of radiation-induced HC. The treatment for HC is first symptomatic, with bladder lavage, clot evacuation, coagulation via cystoscopy and blood transfusions if necessary. Subsequently, hyaluronic acid bladder instillation can be done with little toxicity. Hyperbaric oxygen therapy delivers pure oxygen to patients in a pressurized cabin, promoting angio-neogenesis and lowering hypoxia to the irradiated tissues. The clinical response rate is estimated to be around 80 %. Nevertheless, this approach is limited by the low availability, and length of treatment. While surgery remains an effective treatment for HC, it is the last option because of the high morbidity and mortality risks. Prospective studies need to be conducted to identify and evaluate new interventions, particularly for HC.