Low dose anti-inflammatory radiotherapy for the treatment of pneumonia by covid-19: a proposal for a multi-centric prospective trial

Background COVID-19 is a highly contagious viral infection with high morbidity that is draining health resources The biggest complication is pneumonia, which has a serious inflammatory component, with no standardized treatment Low-dose radiation therapy (LD-RT) is non-invasive and has anti-inflammatory effects that can interfere with the inflammatory cascade, thus reducing the severity of associated cytokine release and might be useful in the treatment of respiratory complications caused by COVID-19 Study Design and Methods This multicentric prospective clinical trial seeks to evaluate the efficacy of bilateral lung LD-RT therapy as a treatment for interstitial pneumonia in patients with COVID-19 for improving respiratory function This prospective study will have 2 phases: I) an exploratory phase enrolling 10 patients, which will assess the feasibility and efficacy of low-dose lung irradiation, evaluated according to an increase in the PaO2/FiO2 ratio of at least 20% at 48-72h with respect to the pre-irradiation value If a minimum efficiency of 30% of the patients is not achieved, the study will not be continued II) Non-randomized comparative phase in two groups: a control group, which will only receive pharmacological treatment, and an experimental arm with pharmacological treatment and LD-RT It will include 96 patients, the allocation will be 1: 2, that is, 32 in the control arm and 64 in the experimental arm The primary end-point will be the efficacy of LD-RT in patients with COVID-19 pneumonia according to an improvement in PaO2/FiO2 Secondary objectives will include the safety of bilateral lung LD-RT, an improvement in the radiology image, overall mortality rates at 15 and 30 days after irradiation and characterizing anti-inflammatory mechanisms of LD-RT by measuring the level of expression of adhesion molecules, anti-inflammatory cytokines and oxidative stress mediators Trial registration: ClinicalTrial gov NCT-04380818https://clinicaltrials gov/ct2/show/NCT04380818?term=RADIOTHERAPY&cond=COVID&draw=2&rank=4 Short running title: low-dose radiotherapy for COVID-19 pneumonia