Possibilities of low-dose radiation therapy in the treatment of intrapulmonary injuries caused by COVID-19 infection.

This paper examines the relevance of the use of a single irradiation of lungs in treatment of pneumonia caused by a new coronavirus infection. Clinical observations are presented that demonstrate perspectives in the treatment of this disease. Patients with severe pneumonia who were prescribed LD-RT (low-dose radiation therapy) at a dose of 0.5-1.5 Gy showed shorter recovery times and no complications. This method of treatment has shown its effectiveness in a number of studies from different countries, predicting success and economic benefits in its further use and study. A literature search containing information on relevant studies was carried out in PubMed, EMBASE, Web of Science and Google Scholar systems. Attention was focused on full-text articles given their general availability in a pandemic.Copyright © 2021 VIDAR Publishing House. All right reserved.

Low-dose radiation therapy suppresses viral pneumonia by enhancing broad-spectrum anti-inflammatory responses via transforming growth factor-ß production.

Low-dose radiation therapy (LDRT) can suppress intractable inflammation, such as that in rheumatoid arthritis, and is used for treating more than 10,000 rheumatoid arthritis patients annually in Europe. Several recent clinical trials have reported that LDRT can effectively reduce the severity of coronavirus disease (COVID-19) and other cases of viral pneumonia. However, the therapeutic mechanism of LDRT remains unelucidated. Therefore, in the current study, we aimed to investigate the molecular mechanism underlying immunological alterations in influenza pneumonia after LDRT. Mice were irradiated to the whole lung 1 day post-infection. The changes in levels of inflammatory mediators (cytokines and chemokines) and immune cell populations in the bronchoalveolar lavage (BALF), lungs, and serum were examined. LDRT-treated mice displayed markedly increased survival rates and reduced lung edema and airway and vascular inflammation in the lung; however, the viral titers in the lungs were unaffected. Levels of primary inflammatory cytokines were reduced after LDRT, and transforming growth factor-ß (TGF-ß) levels increased significantly on day 1 following LDRT. Levels of chemokines increased from day 3 following LDRT. Additionally, M2 macrophage polarization or recruitment was increased following LDRT. We found that LDRT-induced TGF-ß reduced the levels of cytokines and polarized M2 cells and blocked immune cell infiltration, including neutrophils, in BALF. LDRT-induced early TGF-ß production was shown to be a key regulator involved in broad-spectrum anti-inflammatory activity in virus-infected lungs. Therefore, LDRT or TGF-ß may be an alternative therapy for viral pneumonia.

COVID-19 and low-dose radiation therapy.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of the coronavirus disease 2019 (COVID-19), has caused more than 179 million infections and 3.8 million deaths worldwide. Global health authorities working on the COVID-19 outbreak continue to explore methods to reduce the rate of its transmission to healthy individuals. Treatment protocols thus far have focused on social distancing and masking, treatment with antivirals early in infection, and steroids to reduce the inflammatory response. An alternative approach is therapy with low dose radiation (LDR), which has several advantages compared to the current drugs and medicines. To date more than 10 case reports and pilot clinical trial preliminary outcome are available from different countries. These reports cover a wide range of patient conditions and LDR treatment strategies. Although one report showed the failure to observe the improvement of COVID-19 patients after LDR therapy, the majority showed some clinical improvement, and demonstrated the safety of LDR for COVID-19 patients, particularly with 0.5 â€‹Gy. This review aims to summarize the potential rationales and mechanisms of LDR therapy for COVID-19 patients, and its current clinical status and potential use.

Application of chest low-dose CT screening of Corona Virus Disease 2019 with a third-generation dual-source scanner.

Objective: To investigate the application value of third-generation dual-source CT(3-G DSCT) low-dose scan mode combined with iterative reconstruction technology in the screening of COVID-19 and to evaluate the radiation dose. Method(s): One hundred and twenty patients suspected of COVID-19 from December 2019 to February 2020 were retrospectively analysed and randomly divided into two groups (test group and conventional group, 60 patients in each). The parameters for test group included 3-G DSCT, Turbo Flash scan mode, CARE kV, with reference 90 kV, pitch 2.0, and ADMIRE algorithm, while those parameters for conventional group included the 128-slice CT, conventional spiral scan mode, 120 kV, pitch 1.2, and FBP algorithm. The CT values of aorta, spinal posterior muscle, and subcutaneous fat, the aortic noise, signal-to-noise ratio (SNR), and contrast noise ratio (CNR) were compared to evaluate the image quality between two groups. Two experienced doctors scored the image quality using a double-blind method, and compared the CT dose index volume (CTDIvol), dose-length product (DLP), and effective dose (E) of the two groups. Result(s): The CT value of the aorta and spinal posterior muscle and the aortic SNR in the test group were (45.38+/-4.77), (53.41+/-8.44) HU, and 2.82+/-0.59, and significantly higher than those in the conventional group [(39.68+/-6.26), (42.66+/-6.32) HU, 2.58+/-0.61, t=5.608, 7.897, 2.162, P<0.05]. The aortic noise, CNR and subjective scores between the two groups had no significant difference( P>0.05). The CTDIvol, DLP, and E in the test group were (3.09+/-1.02) mGy, (107.57+/-32.81) mGy*cm, (1.51+/-0.46) mSv, significantly lower than those in the conventional group [(7.00+/-1.80) mGy, (261.65+/-73.93) mGy*cm, (3.66+/-1.03) mSv;t=-14.680, -14.756, -14.756, P<0.05]. Conclusion(s): In the screening of COVID-19, using low-dose scanning mode of 3-G DSCT combined with iterative reconstruction technology would provide diagnostic quality images and meanwhile effectively reduce the radiation dose and improve the SNR of the image.Copyright © 2020 by the Chinese Medical Association.

Application of low dose radiation therapy in the treatment of COVID-19 pneumonia.

With the global pandemic of COVID-19, cytokine storms in critical patients with pneumonia is really a problem and need to be solved immediately.Low dose radiation therapy (LDRT) has been temporarily used to treat pneumonia.In the past decades, researchers were dedicated to clarify the biological mechanism of LDRT.LDRT plays a unique role in the suppression of inflammation, preliminary outcomes have been acquired in critical patients with COVID-19 pneumonia, and radiotherapy community is paying attention to this treatment strategy.This review summarizes the application of LDRT in pneumonia, its biological mechanism, the result of LDRT in COVID-19 pneumonia, the existing problems and prospective in clinic.Copyright © 2021 Chinese Medical Association

Treatment of COVID-19 pneumonia with low-dose radiotherapy plus standard of care versus standard of care alone in frail patients : The SEOR-GICOR IPACOVID comparative cohort trial.

PURPOSE: To assess the efficacy of lung low-dose radiotherapy (LD-RT) in the treatment of patients with COVID-19 pneumonia. MATERIALS AND METHODS: Ambispective study with two cohorts to compare treatment with standard of care (SoC) plus a single dose of 0.5 Gy to the whole thorax (experimental prospective cohort) with SoC alone (control retrospective cohort) for patients with COVID-19 pneumonia not candidates for admission to the intensive care unit (ICU) for mechanical ventilation. RESULTS: Fifty patients treated with LD-RT were compared with 50 matched controls. Mean age was 85 years in both groups. An increase in arterial oxygen partial pressure (PaO2)/fraction of inspired oxygen (PAFI) in the experimental LD-RT-treated group compared to the control group could not be found at 48 h after LD-RT, which was the primary endpoint of the study. However, PAFI values significantly improved after 1 month (473 vs. 302 mm Hg; p < 0.0001). Pulse oxymetric saturation/fraction of inspired oxygen (SAFI) values were also significantly higher in LD-RT-treated patients than in control patients at 1 week (405 vs. 334 mm Hg; p = 0.0157) and 1 month after LD-RT (462 vs. 326 mm Hg; p < 0.0001). All other timepoint measurements of the respiratory parameters were similar across groups. Patients in the experimental group were discharged from the hospital significantly earlier (23 vs. 31 days; p = 0.047). Fifteen and 26 patients died due to COVID-19 pneumonia in the experimental and control cohorts, respectively (30% vs. 48%; p = 0.1). LD-RT was associated with a decreased odds ratio (OR) for 1­month COVID-19 mortality (OR = 0.302 [0.106-0.859]; p = 0.025) when adjusted for potentially confounding factors. Overall survival was significantly prolonged in the LD-RT group compared to the control group (log-rank p = 0.027). No adverse events related to radiation treatment were observed. CONCLUSION: Treatment of frail patients with COVID-19 pneumonia with SoC plus single-dose LD-RT of 0.5 Gy improved respiratory parameters, reduced the period of hospitalization, decreased the rate of 1­month mortality, and prolonged actuarial overall survival compared to SoC alone.

Interim Analysis of Impact of Adding Low Dose Pulmonary Radiotherapy to Moderate COVID-19 Pneumonia Patients: IMpaCt-RT Study.

Background: Treatment for coronavirus disease 2019 (COVID-19) pneumonia remains largely supportive till date and multiple clinical trials took place within the short span of time to evaluate the role of investigational therapies. The anti-inflammatory effect of low dose whole lung radiation in treating pneumonia has been documented earlier. This clinical trial analyzed the effect of low dose radiation therapy (LDRT) in a moderately affected COVID-19 pneumonia patient cohort and has evaluated its effect in stopping the conversion of moderate disease into severe disease. Methods: Patients with moderate COVID-19 pneumonia as characterized by the Ministry of Health and Family Welfare (MOHFW), Government of India, were randomized (1:1) to low dose whole lung radiation versus no radiation. All treatment of patients was concurrently being given as per institutional protocol. Patients were followed up with clinical and laboratory parameters monitored on Days 1, 3, 7, and 14. Computed tomography scan (CT scan) of thorax was performed on Days 1 and 7. Patients were evaluated for conversion of moderate into severe disease as per National Early Warning Score-2 (NEWS-2 score) as the primary end point. The secondary endpoints included changes in ratio between peripheral capillary oxygen saturation and fraction of inspired oxygen (SpO2/FiO2), biochemical markers, 25-point CT severity score, and radiation induced acute pulmonary toxicities. Findings: At the interim analysis, there were seven patients in the radiation arm and six in the control. A whole lung LDRT improved the outcome of SpO2/FiO2 at Day 3; however it did not convert into a statistically significant improvement for the NEWS-2 score. The serum levels of LDH, CRP, Ferritin and D-dimer were significantly reduced on 14 days in the LDRT arm in comparison to the baseline value but were not significant between the two groups. Interpretation: LDRT seems to have the potential to prevent moderate COVID-19 pneumonia from a deteriorating to severe category. However, further randomized clinical trial with an adequate number of such patients is warranted to establish the definitive role of LDRT in the management of COVID-19 pneumonia. Funding: An intramural research project bearing code: I-27/621, was sanctioned from the All India Institute of Medical Sciences, Patna, India. Clinical Trial Registration: Clinical Trials Registry-India (CTRI/2021/06/033912, 25th May 2021) ctri.nic.in/Clinicaltrials/login.php.

SARS-CoV-2 Serum Viral Load and Prognostic Markers Proposal for COVID-19 Pneumonia in Low-Dose Radiation Therapy Treated Patients.

Several studies have shown that the plasma RNA of SARS-CoV-2 seems to be associated with a worse prognosis of COVID-19. In the present study, we investigated plasma RNA in COVID-19 patients treated with low-dose radiotherapy to determine its prognostic value. Data were collected from the IPACOVID prospective clinical trial (NCT04380818). The study included 46 patients with COVID-19 pneumonia treated with a whole-lung dose of 0.5 Gy. Clinical follow-up, as well as laboratory variables, and SARS-CoV-2 serum viral load, were analyzed before LDRT, at 24 h, and one week after treatment. The mean age of the patients was 85 years, and none received any of the SARS-CoV-2 vaccine doses. The mortality ratio during the course of treatment was 33%. RT-qPCR showed amplification in 23 patients. Higher mortality rate was associated with detectable viremia. Additionally, C-reactive protein, lactate dehydrogenase, and aspartate aminotransferase were significant risk factors associated with COVID-19 mortality. Our present findings show that detectable SARS-CoV-2 plasma viremia 24 h before LDRT is significantly associated with increased mortality rates post-treatment, thus downsizing the treatment success.

Effect of Low-Dose Radiotherapy on the Circulating Levels of Paraoxonase-1-Related Variables and Markers of Inflammation in Patients with COVID-19 Pneumonia.

The aim of our study was to investigate the changes produced by low-dose radiotherapy (LDRT) in the circulating levels of the antioxidant enzyme paraoxonase-1 (PON1) and inflammatory markers in patients with COVID-19 pneumonia treated with LDRT and their interactions with clinical and radiological changes. Data were collected from the IPACOVID prospective clinical trial (NCT04380818). The study included 30 patients treated with a whole-lung dose of 0.5 Gy. Clinical follow-up, as well as PON1-related variables, cytokines, and radiological parameters were analyzed before LDRT, at 24 h, and 1 week after treatment. Twenty-five patients (83.3%) survived 1 week after LDRT. Respiratory function and radiological images improved in survivors. Twenty-four hours after LDRT, PON1 concentration significantly decreased, while transforming growth factor beta 1 (TGF-ß1) increased with respect to baseline. One week after LDRT, patients had increased PON1 activities and lower PON1 and TGF-ß1 concentrations compared with 24 h after LDRT, PON1 specific activity increased, lactate dehydrogenase (LDH), and C-reactive protein (CRP) decreased, and CD4+ and CD8+ cells increased after one week. Our results highlight the benefit of LDRT in patients with COVID-19 pneumonia and it might be mediated, at least in part, by an increase in serum PON1 activity at one week and an increase in TGF-ß1 concentrations at 24 h.

Low-Dose Radiation Therapy for COVID-19: A Systematic Review

Simple SummaryThere are limited available data indicating that in oxygen-dependent elderly patients with COVID-19-associated pneumonia, low-dose whole-lung radiation doses, ranging from 0.5 to 1.5 Gy, can lead to accelerated recovery and progress in clinical status, encephalopathy, and radiographic consolidation without any detectable acute toxicity. Therefore, low-dose radiation therapy (LDRT), using conventional cancer radiation therapy machines, could be introduced as a safe treatment with promising efficacy that fully warrants further large-scale studies. Current findings indicate that LDRT could increase the survival of elderly patients and of patients with genetic risk factors, who are at greater risk of mortality due to COVID-19, even if more preclinical work and clinical trials are needed before any clear conclusion can be made.The ongoing COVID-19 pandemic is of great concern for the whole world, and finding an effective treatment for the disease caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is, therefore, a global race. In particular, treatment options for elderly patients and patients with genetic risk factors with COVID-19-associated pneumonia are limited, and many patients die. Low-dose radiotherapy (LDRT) of lungs was used to treat pneumonia many decades ago. Since the first report on the potential efficacy of LDRT for COVID-19-associated pneumonia was published on 1 April, 2020, tens of papers have addressed the importance of this treatment. Moreover, the findings of less than 10 clinical trials conducted to date are now available. We performed a detailed search of PubMed/MEDLINE, Web of Science, Google Scholar, and Scopus and selected the nine most relevant articles. A review of these articles was conducted. The available data indicate that in oxygen-dependent elderly patients with COVID-19-associated pneumonia, whole-lung radiation at doses of 0.5–1.5 Gy can lead to accelerated recovery and progress in clinical status, encephalopathy, and radiographic consolidation without any detectable acute toxicity. Although data collected so far show that LDRT could be introduced as a treatment with promising efficacy, due to limitations such as lack of randomization in most studies, we need further large-scale randomized studies, especially for elderly patients who are at greater risk of mortality due to COVID-19. However, more preclinical work and clinical trials are needed before any clear conclusion can be made.

Low dose radiation therapy attenuates ACE2 depression and inflammatory cytokines induction by COVID-19 viral spike protein in human bronchial epithelial cells.

Purpose: Low-dose radiation therapy (LDRT) is an evidence-based anti-inflammatory treatment. In anti-COVID-19, our study suggests that low to moderate dose radiation of < 1.5 Gy can inhibit the induction of inflammatory cytokine and attenuate the ACE2 depression induced by spike protein in human bronchial epithelial cells in COVID-19 infection. Our study provided further mechanistic evidence to support LDRT as a cost-effective treatment for COVID-19 to relieve the severe inflammatory reaction and lung injury. Methods and materials: A cellular model was created by treating human bronchial epithelial cells (BEP2D) with SARS-CoV-2 spike protein. We used the qRT-PCR and ELISA analysis to identify the production of inflammatory cytokines. The BEP2D control cells and the spike-treated cells were irradiated using a single low to moderate dose radiation of 0.5 Gy, 1 Gy, and 1.5 Gy. The inflammatory cytokines and ACE2 expression were detected at different time points. Results: The soluble SARS-CoV-2 spike protein stimulated the formation of inflammatory cytokines IL-6 and TNF-α while reducing the ACE2 protein expression in human bronchial epithelial cells. A single low to moderate dose exposure of 0.5 Gy, 1 Gy, and 1.5 Gy could attenuate the IL-6 and TNF-α induction and rescue the depression of ACE2 by spike protein. Moreover, the spike protein increased the proteolytic degradation of ACE2 protein by promoting NEDD4-mediated ubiquitination of ACE2. Conclusions: The low-dose radiation can attenuate ACE2 depression and inflammatory response produced in the targeted human bronchial epithelial cells by spike protein. This coordinating effect of LDRT may relieve the severe inflammatory reaction and lung injury in COVID-19 patients.

Low-dose radiation effects

The Earth was highly radioactive four billion years ago when life emerged. Even today, all humans are bombarded by 20,000 radiation strikes each second. Although high radiation doses are hazardous, organisms have evolved not only to tolerate lower-dose radiation but also to benefit by it (hormesis). Hormesis is prevailing in all species in various respects. An example is that hibakusha (Japanese A-bomb survivors) have longer lifespans and have lower risk of cancer, on average. Many microbes thrive in deep subsurface regions by consuming radiation as a source of nutrition. Low-dose radiation (LDR) is effective at treating severely affected COVID-19 patients, but the invalid linear no-threshold model (LNT) hinders the full beneficial use of LDR.

The Role of Ionizing Radiation for Diagnosis and Treatment against COVID-19: Evidence and Considerations.

The Coronavirus disease 2019 (COVID-19) pandemic continues to spread worldwide with over 260 million people infected and more than 5 million deaths, numbers that are escalating on a daily basis. Frontline health workers and scientists diligently fight to alleviate life-threatening symptoms and control the spread of the disease. There is an urgent need for better triage of patients, especially in third world countries, in order to decrease the pressure induced on healthcare facilities. In the struggle to treat life-threatening COVID-19 pneumonia, scientists have debated the clinical use of ionizing radiation (IR). The historical literature dating back to the 1940s contains many reports of successful treatment of pneumonia with IR. In this work, we critically review the literature for the use of IR for both diagnostic and treatment purposes. We identify details including the computed tomography (CT) scanning considerations, the radiobiological basis of IR anti-inflammatory effects, the supportive evidence for low dose radiation therapy (LDRT), and the risks of radiation-induced cancer and cardiac disease associated with LDRT. In this paper, we address concerns regarding the effective management of COVID-19 patients and potential avenues that could provide empirical evidence for the fight against the disease.

Estimating cancer risks due to whole lungs low dose radiotherapy with different techniques for treating COVID-19 pneumonia.

BACKGROUND: Low dose radiotherapy (LDRT) of whole lungs with photon beams is a novel method for treating COVID-19 pneumonia. This study aimed to estimate cancer risks induced by lung LDRT for different radiotherapy delivery techniques. METHOD: Four different radiotherapy techniques, including 3D-conformal with anterior and posterior fields (3D-CRT AP-PA), 3D-conformal with 8 coplanar fields (3D-CRT 8 fields), eight fields intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy using 2 full arcs (VMAT) were planned on the CT images of 32 COVID-19 patients with the prescribed dose of 1 Gy to the lungs. Organ average and maximum doses, and PTV dose distribution indexes were compared between different techniques. The radiation-induced cancer incidence and cancer-specific mortality, and cardiac heart disease risks were estimated for the assessed techniques. RESULTS: In IMRT and VMAT techniques, heart (mean and max), breast (mean, and max), and stomach (mean) doses and also maximum dose in the body were significantly lower than the 3D-CRT techniques. The calculated conformity indexes were similar in all the techniques. However, the homogeneity indexes were lower (i.e., better) in intensity-modulated techniques (P < 0.03) with no significant differences between IMRT and VMAT plans. Lung cancer incident risks for all the delivery techniques were similar (P > 0.4). Cancer incidence and mortality risks for organs located closer to lungs like breast and stomach were higher in 3D-CRT techniques than IMRT or VMAT techniques (excess solid tumor cancer incidence risks for a 30 years man: 1.94 ± 0.22% Vs. 1.68 ± 0.17%; and women: 6.66 ± 0.81% Vs. 4.60 ± 0.43%: cancer mortality risks for 30 years men: 1.63 ± 0.19% Vs. 1.45 ± 0.15%; and women: 3.63 ± 0.44% Vs. 2.94 ± 0.23%). CONCLUSION: All the radiotherapy techniques had low cancer risks. However, the overall estimated risks induced by IMRT and VMAT radiotherapy techniques were lower than the 3D-CRT techniques and can be used clinically in younger patients or patients having greater concerns about radiation induced cancers.

Whole-lung low-dose radiation therapy (LD-RT) for non-intubated oxygen-dependent patients with COVID-19-related pneumonia receiving dexamethasone and/or remdesevir.

BACKGROUND: Low-dose radiotherapy (LD-RT) has produced anti-inflammatory effects in both animal models and early human trials of COVID-19-related pneumonia. The role of whole-lung LD-RT within existing treatment paradigms merits further study. METHODS: A phase II prospective trial studied the addition of LD-RT to standard drug treatments. Hospitalized and oxygen-dependent patients receiving dexamethasone and/or remdesevir were treated with 1.5 Gy whole-lung LD-RT and compared to a blindly-matched contemporaneous control cohort. RESULTS: Of 40 patients evaluated, 20 received drug therapy combined with whole-lung LD-RT and 20 without LD-RT. Intubation rates were 14% with LD-RT compared to 32% without (p = 0.09). Intubation-free survival was 77% vs. 68% (p = 0.17). Biomarkers of inflammation (C-reactive protein, p = 0.02) and cardiac injury (creatine kinase, p < 0.01) declined following LD-RT compared to controls. Mean time febrile was 1.4 vs 3.3 days, respectively (p = 0.14). Significant differences in clinical recovery (7.5 vs. 7 days, p = 0.37) and radiographic improvement (p = 0.72) were not detected. On subset analysis, CRP decline following LD-RT was predictive of recovery without intubation compared to controls (0% vs. 31%, p = 0.04), freedom from prolonged hospitalizations (21+ days) (0% vs. 31%, p = 0.04), and decline in oxygenation burden (56% reduction, p = 0.06). CRP decline following 1st drug therapy was not similarly predictive of outcome in controls (p = 0.36). CONCLUSIONS: Adding LD-RT to standard drug treatments reduced biomarkers of inflammation and cardiac injury in COVID-19 patients and may have reduced intubation. Durable CRP decline following LD-RT predicted especially favorable recovery, freedom from intubation, reduction in prolonged hospitalization, and reduced oxygenation burden. A confirmatory randomized trial is now ongoing. CLINICAL TRIAL REGISTRATION: NCT04366791.

Low dose lung radiotherapy for COVID-19 pneumonia: A potential treatment.

The covid-19 pandemic has been affecting many countries across the world and lost precious lives. Most patients suffer from respiratory disease which progresses to the severe acute respiratory syndrome, termed as SARS-CoV-2 pneumonia. A systemic inflammatory response occurs in SARS-CoV-2 pneumonia severely ill patients, The inflammation process if uncontrolled has a detrimental effect, and the release of cytokines play an important role leading to lung fibrosis. Radiation therapy used in low doses has an anti-inflammatory and immunomodulatory effect. Its low cost, wider availability, and decreased risk of acute side effects can reduce the burden on the health care system.

Could pulmonary low-dose radiation therapy be an alternative treatment for patients with COVID-19 pneumonia? Preliminary results of a multicenter SEOR-GICOR nonrandomized prospective trial (IPACOVID trial).

PURPOSE: To evaluate the efficacy and safety of lung low-dose radiation therapy (LD-RT) for pneumonia in patients with coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: Inclusion criteria comprised patients with COVID-19-related moderate-severe pneumonia warranting hospitalization with supplemental O2 and not candidates for admission to the intensive care unit because of comorbidities or general status. All patients received single lung dose of 0.5 Gy. Respiratory and systemic inflammatory parameters were evaluated before irradiation, at 24 h and 1 week after LD-RT. Primary endpoint was increased in the ratio of arterial oxygen partial pressure (PaO2) or the pulse oximetry saturation (SpO2) to fractional inspired oxygen (FiO2) ratio of at least 20% at 24 h with respect to the preirradiation value. RESULTS: Between June and November 2020, 36 patients with COVID-19 pneumonia and a mean age of 84 years were enrolled. Seventeen were women and 19 were men and all of them had comorbidities. All patients had bilateral pulmonary infiltrates on chest X­ray. All patients received dexamethasone treatment. Mean SpO2 pretreatment value was 94.28% and the SpO2/FiO2 ratio varied from 255 mm Hg to 283 mm Hg at 24 h and to 381 mm Hg at 1 week, respectively. In those who survived (23/36, 64%), a significant improvement was observed in the percentage of lung involvement in the CT scan at 1 week after LD-RT. No adverse effects related to radiation treatment have been reported. CONCLUSIONS: LD-RT appears to be a feasible and safe option in a population with COVID-19 bilateral interstitial pneumonia in the presence of significant comorbidities.

Effectiveness of low-dose radiation therapy to improve mortality of COVID-19.

INTRODUCTION: Performing low-dose radiation therapy (LDRT) is a new approach to treat pneumonia resulting from COVID-19 disease. This paper aims to evaluate the effectiveness of LDRT in treating COVID-19 patients. METHODS: Medline was searched for "low-dose" and "radiation therapy" and "COVID-19" and "pneumonia" and "inflammation", to retrieve papers that published on low-dose radiation therapy to improve mortality of COVID-19 patients. Only clinical investigations that included original and case report papers were selected for this paper. RESULTS: The completed clinical trials that have performed LDRT to treat COVID-19 showed that the effectiveness of LDRT in treating COVID-19 was up to 90%. CONCLUSION: The vast majority of primary and secondary outcomes of clinical trial investigations regarding LDRT in treating COVID-19 found that LDRT can be considered a feasible treatment to improve mortality of COVID-19 patients.

Low-dose radiotherapy (LD-RT) for COVID-19-induced pneumopathy: a worth considering approach.

PURPOSE: It seems that 2020 would be always remembered by the name of novel coronavirus (designated as SARS-CoV-2), which exerted its deteriorating effects on the health care, economy, education, and political relationships. In August 2020 more than eight hundred thousand patients lost their lives due to acute respiratory syndrome. In the limited list of therapeutic approaches, the effectiveness of low-dose radiation therapy (LD-RT) for curing inflammatory-related diseases have sparkled a light that probably this approach would bring promising advantages for COVID-19 patients. LD-RT owns its reputation from its ability to modulate the host inflammatory responses by blocking the production of pro-inflammatory cytokines and hampering the activity of leukocytes. Moreover, the cost-effective and availability of this method allow it to be applied to a large number of patients, especially those who could not receive anti-IL-6 treatments in low-income countries. But enthusiasm for applying LD-RT for the treatment of COVID-19 patients has been muted yet. CONCLUSION: In this review, we take a look at LD-RT mechanisms of action in the treatment of nonmalignant diseases, and then through studying both the dark and bright sides of this approach, we provide a thorough discussion if LD-RT might be a promising therapeutic approach in COVID-19 patients.