Ultra-hypofractionated whole breast radiotherapy as adyuvant treatment for early breast cancer

Radiotherapy is an essential treatment in the local control of breast cancer. Standard treatment is currently carried out in 15 daily sessions. At present, following the results of the phase III Fast-Foward trial and in view of the situation triggered by COVID-19, the number of sessions has been reduced to 5. We present the data of our series to evaluate the results of the extreme hypofractionation scheme as a radiotherapy treatment for breast cancer at the Multihospital Clinical Unit of Radiation Oncology of Aragón (UCMORA). Materials and Methods After implantation, 115 patients were treated with 3D conformal radiotherapy between April 2020 and May 2021 at UCMORA using the extreme hypofractionation scheme (26 Gy at 5.2 Gy per fraction in 5 fractions). Demographic, tumor, dosimetric and toxicity characteristics were analyzed. Results The mean age was 63.5 years. 53 patients were treated at the Lozano Blesa Clinical Universitary Hospital and 62 at the Miguel Servet Universitary Hospital, in total 59 right and 56 left breasts. The predominant histology was infiltrating ductal carcinoma (84.3%), followed by infiltrating lobular carcinoma (10.4%), ductal carcinoma in situ (4.3%) and mucinous (0.9%). 51.7% were luminal A, 39.1% luminal B, 1.8% Her2 positive and 7.8% triple negative. In relation to staging, we found 4pTis, 8pT1a, 45pT1b, 58pT1c, 2Nx, 8N0, 1Nmi and 13N1a. Only 45% had acute toxicity at one month after the end of treatment, predominantly G1 radiodermatitis (86.6%), followed by G2 (11.2%) and G3 (2.2%). When analyzing the dose-volume histograms, values were obtained for ipsilateral lung V8 between 1.32 and 21.2%, for the heart, in case of left breast a median for V1.5 of 8.2% and 1.05% for V7;in case of right breast the median Dmed for the heart was 0.5Gy (Figure Presented) Conclusion Ultra-hypofractionated whole breast radiotherapy as a radiation treatment for breast cancer is well tolerated, reduces costs and number of sessions, while increasing comfort for patients.

Dermal recall effect in breast radiotherapy patients after vaccine administration

Purpose or Objective The dermal recall phenomenon is an increase in the sensitivity of stem cells in the area of the treatment field and may lead to increased acute toxicity. Afterwards, the recall effect has been described in those patients who have been vaccinated against COVID during radiotherapy treatment. Our objective has been to observe if we are facing a dermal recall phenomenon after the administration of the vaccine in patients who are on the course of radiotherapy. Materials and Methods Coinciding with the vaccination campaign against SARS-CoV-2 in oncological patients, which began in our environment in March 2021, we have collected data on radiodermatitis that have been presented by 42 patients after the end of radiation therapy treatment for breast cancer Results The percentage of patients vaccinated were as follows: 57% (24/ 42 patients) Of which 6/24 patients received the vaccine dose during radiation therapy Of the 42 patients treated with radiation therapy, 3 had a degree 3 dermal toxicity. These 3 patients were given the vaccine during radiotherapy treatment, which accounts for 50% of the patients vaccinated during radiotherapy. Note that of the 845 patients treated with hypofractionation radiotherapy since 2016 only 0.23% have presented grade 3 acute radiodermatitis, versus 7% of the patients who have been vaccinated during radiotherapy Conclusion We estimate that most likely, the vaccine carries a greater risk of skin toxicity mediated by the dermal recall phenomenon but that does not mean that the administration of the vaccine should be contraindicated, but more closely warn patients who receive the vaccine during radiation therapy.

RT with hyperthermia in recurrent and radiation-induced sarcomas: preliminary results of NCT04398095

Purpose or Objective The role of perioperative treatment in radiation-induced and in-field recurrent sarcomas (RIS/IFRS) is unknown. Reirradiation may be associated with a risk of significant toxicity;thus, it is rarely used. We hypothesized that the combination of preoperative or definitive 12x 3 Gy radiotherapy (RT) with or without integrated 3.5 Gy to 42 Gy boost combined with regional hyperthermia twice a week will enable satisfactory local control without significant late toxicity in patients with RIS/IFRS. Materials and Methods A prospective phase II, single-arm clinical trial was conducted. We included patients with locally advanced RIS/IFRS without distant metastases. Treatment combined three weeks of radiotherapy, four fractions per week, 3 or 3.5 Gy per fraction, with regional hyperthermia, followed by surgery or observation. The choice of the boost or no-boost regimen was based on resectability (Figure 1). The intervention would be deemed tolerable if significant RT-related (grade 3+ CTCAE 5.0) late adverse events occur in less than 20% of patients. We planned to enroll 20 patients based on Wilson’s method for calculation of confidence intervals. (Figure Presented) Results We recruited 20 patients. All patients completed the treatment without interruptions. Eight of them had RIS whereas twenty were diagnosed with IFRS. Patients’ characteristics were provided in Table 1. Twelve patients from planned 15 underwent surgery. Two patients with potentially resectable tumors did not undergo surgery due to COVID-related reasons. One patient preferred not to undergo surgery after the preoperative no-boost regimen. The remaining five patients were deemed unresectable at the enrollment and received the simultaneous boost. In five patients who underwent resection, we observed extensive pathological response according to the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group recommendations for pathological examination and reporting, namely grade A in two cases and grade C in three cases. In four patients we observed complete radiological response. The median follow-up was 13 months. In 14 patients we noted mild or moderate radiation dermatitis. One patient experienced grade 2 gastrointestinal toxicities. From the late toxicities, we observed restricted limb mobility (grade 1) in one patient and chronic skin ulceration (grade 2) in one patient. None of the patients who developed grade 3 or higher late toxicity. Two patients who received the no-boost regimen and did not undergo resection developed local progression. One patient experienced borderline local relapse after surgery. None of the patients who received the boost regimen developed local progression. Three patients developed distant metastases. One patient was lost to follow-up. (Figure Presented) Conclusion Preliminary data suggest that the tolerance of the regimen is acceptable;however, data regarding late toxicity may change during the follow-up period. Boost may play a significant role in achieving local control in non-resected tumors.