RT info:eu-repo/semantics/doctoralThesis T1 Radioterapia a dosis bajas en el manejo de la neumonía por Covid-19 A1 Sanmamed Salgado, Noelia A2 Universidad de Valladolid. Escuela de Doctorado K1 COVID-19 K1 Radiotherapy K1 Radioterapia K1 Pneumonia K1 Neumonía K1 3201.12 Radioterapia AB Since 2019 the world has been facing the COVID-19 pandemic. More than 173.6 million cases have been registered so far, with approximately 3.7 million deaths according to the World Health Organization. Spain has been one of the European countries most affected by COVID-19, with more than 3.5 million infected and 80,000 deaths. Although most patients have a mild illness, in the first waves of the pandemic, before the spread of vaccines, about 5% developed severe acute respiratory syndrome. Initially, mortality of patients hospitalised with COVID-19 ranged from 4% to 54%, depending on risk factors such as age. Many treatment options were explored in this setting with limited impact. Low-dose radiotherapy (LD-RT) has been used for decades to treat benign inflammatory disease because of its known anti-inflammatory effect at doses of 0.5 to 1.0 Gy. Recently, experimental studies found that LD-RT regulates lung inflammation and shifts macrophages towards an anti-inflammatory profile (increasing IL-10 and decreasing pro-inflammatory substances such as interferon gamma and IL-6). These results provided preclinical support for clinical trial design. Here we present the results of our prospective single-arm Low-Dose Radiation Therapy in the Management of COVID-19 Pneumonia (LOWRAD- Cov19; ClinicalTrials.gov registry NCT04420390). Patients over 50 years of age, with a diagnosis of COVID-19 (confirmed by PCR), bilateral lung involvement on CT and need for supplemental oxygen were included. Treatment consisted of 1.0 Gy in a single session on both lungs. The primary objective of this study was to assess the effect of LD-RT evaluated by respiratory function and radiological response criteria on days +3 and +7 after treatment. Forty-one patients (63% male) were included; seven of them (17%) were admitted to the ICU. Forty-two per cent experienced respiratory improvement on day +3 after LD-RT treatment compared to baseline (p < 0.01), as well as an improvement in the extent of lung involvement between baseline and day +7 CT (p = 0.002) and between day +3 and day +7 CT (p = 0.002). This rapid recovery allowed these patients to be discharged early (median days from LD-RT to discharge 11 days). None of the patients had any treatment-related toxicity.Several phase I/II studies of LD-RT for COVID-19 pneumonia have been published in the last year, proposing LD-RT as a safe and potentially beneficial treatment. The results of this study are in agreement with the other published studies. Based on these results, randomised studies would be needed to establish the real clinical efficacy of LD-RT in patients with COVID-19 pneumonia. YR 2021 FD 2021 LK https://uvadoc.uva.es/handle/10324/60185 UL https://uvadoc.uva.es/handle/10324/60185 LA spa NO Escuela de Doctorado DS UVaDOC RD 25-dic-2024