Point/Counterpoint. Low-dose radiation as a treatment for COVID-19 pneumonia: A threat or real opportunity?

The ongoing impact of COVID-19 on the clinical education of Australian medical radiation science students

INTRODUCTION

The COVID-19 pandemic has had a significant and ongoing impact on health care, particularly for medical radiation science (MRS) professionals. There exist many studies that describe the negative effects of clinical placement restrictions and access to universities on the well-being of all health professional students during the pandemic. There also exists evidence of changes to MRS student teaching and impacts to students and academic clinical educators; however, there exists a paucity of research that investigates how changes have affected the performance of students within the clinical environment and entering the workforce. This study surveyed workplace MRS clinical educators within Australia to gather their perspectives regarding the impact of COVID-19 on student clinical education.

METHODS

A descriptive study comprising an online structured survey of 44 questions was provided to Medical Imaging and Radiation Therapy Clinical Educators across Australia.

RESULTS

A total of 55 survey responses were received. Of note, respondents described heavy reductions to student intake capacity, losses of clinical placement time, a noted theory-practice gap and possibility of sites 'failing to fail' students. Negative impacts to all domains of MRPBA professional capabilities, as well as a perceived unpreparedness to meet the MRPBA capabilities were described. There was general agreement that graduating students will require supportive periods upon entry into the profession.

CONCLUSION

This study highlights the considerable impact of changes to the education and training of MRS students in response to COVID-19. The results pose a real concern for a generation of MRS students affected by the COVID-19 pandemic.

Time Reveals the Truth! What Treatments for COVID-19 Were Quickly Abandoned, and Which Methods, Contrary to Popular Belief, Are Still Flourishing?

During the early days of the COVID-19 pandemic, low dose radiation therapy (LDRT) was proposed as a potentially effective treatment method. To minimize potential toxicity, the initial treatment approach involved a few mGy of adapting radiation followed by a single 250 mGy whole lung challenging dose. However, antiviral drugs were also introduced as a promising treatment option, which were thought to have the potential to revolutionize the management of the crisis. Despite early warnings, many physicians did not fully consider the key point that, in contrast with LDRT, antiviral drug treatments can result in strong selective pressure on the virus. This can lead to the emergence of new SARS-CoV-2 variants, a phenomenon that can have serious global consequences. After more than two years, the truth has been revealed the WHO Guideline Development Group has advised against the use of remdesivir, a widely used antiviral medication, for COVID-19. Meanwhile, a growing body of evidence suggests that LDRT can be a promising, low-risk approach for avoiding or delaying invasive respiratory support in COVID-19 patients. Although there is substantial supporting documentation, more high-quality, controlled, and randomized double-blind clinical trials are needed to further investigate the efficacy and potential therapeutic mechanisms of LDRT for COVID-19.

The Paradox of COVID-19 in Sub-Saharan Africa: Why it is More Unethical Not to Investigate Low Dose Radiotherapy for COVID-19

An accumulating body of evidence shows that various ethnicities are differentially affected by SARS-COV-2 infection. Moreover, some evidence shows that due to the vaccine inequity and millions of people living with HIV, a major catastrophe could occur in African countries that possibly affects the whole world. Given the possibility that Neanderthal genes confer a slight increase in susceptibility, this difference, at least to some extent, might possibly decrease the risk of the emergence of new SARS-CoV-2 variants among black people in Africa. Recent studies show less death and fewer cases among the ethnic group classified as “Black Africans”. Although Neanderthal DNA might explain some differences in morbidity and mortality of COVID-19, a multitude of confounders complicate things to where drawing definite conclusions is hard or even impossible. Using selective-pressure-free treatments (e.g. low dose radiotherapy) for COVID-19 pneumonia would be of crucial importance everywhere, but particularly in sub-Saharan Africa, where “long COVID” in millions of people with HIV paves the road for the more frequent emergence of new variants.

COVID-19 Update: The Golden Time Window for Pharmacological Treatments and Low Dose Radiation Therapy

At the beginning of the COVID-19 emergence, many scientists believed that, thanks to the proofreading enzyme of SARS-CoV-2, the virus would not have many mutations. Our team introduced the concept of radiation at extremely low doses in an attempt to establish selected pressure-free treatment approaches for COVID-19. The capacity of low-dose radiation to modulate excessive inflammatory responses, optimize the immune system, prevent the occurrence of dangerous cytokine storm, regulate lymphocyte counts, and control bacterial co-infections as well as different modalities were proposed as a treatment program for patients with severe COVID-19-associated pneumonia. There is now substantial evidence which indicates that it would be unwise not to further investigate low-dose radiation therapy (LDRT) as an effective remedy against COVID-19-associated pneumonia.

Revisiting the Paradox of Smoking: Radioactivity in Tobacco Smoke or Suppressing the SARS-CoV-2 Receptor, Angiotensin-Converting Enzyme 2, via Aryl-Hydrocarbon Receptor Signal?

Despite current controversies, some reports show a paradoxical mitigating effect associated with smoking in individuals with symptomatic COVID-19 compared to the general population. To explain the potential mechanisms behind the lower number of hospitalized COVID-19 patients, it has been hypothesized that cigarette smoking may reduce the odds of cytokine storm and related severe inflammatory responses through cholinergic-mediated anti-inflammatory mechanisms. Japanese scientists have recently identified a potential mechanism behind the lower numbers of COVID-19 cases amongst smokers compared to non-smokers. However, we believe that this mitigative effect may be due to the relatively high concentration of deposited energy of alpha particles emitted from naturally occurring radionuclides such as Po-210 in cigarette tobacco. Regarding COVID-19, other researchers and our team have previously addressed the anti-inflammatory and immune-modulating effects of low doses of ionizing radiation. MC-simulation using the Geant4 Monte Carlo toolkit shows that the radiation dose absorbed in a spherical cell with a radius of .9 μm for a single 5.5 MeV alpha particle is about 5.1 Gy. This energy deposition may trigger both anti-inflammatory and anti-thrombotic effects which paradoxically lower the risk of hospitalization due to COVID-19 in smokers.

COVID-19: The Disease, the Immunological Challenges, the Treatment with Pharmaceuticals and Low-Dose Ionizing Radiation

The year 2020 will be carved in the history books-with the proliferation of COVID-19 over the globe and with frontline health workers and basic scientists worldwide diligently fighting to alleviate life-threatening symptoms and curb the spread of the disease. Behind the shocking prevalence of death are countless families who lost loved ones. To these families and to humanity as a whole, the tallies are not irrelevant digits, but a motivation to develop effective strategies to save lives. However, at the onset of the pandemic, not many therapeutic choices were available besides supportive oxygen, anti-inflammatory dexamethasone, and antiviral remdesivir. Low-dose radiation (LDR), at a much lower dosage than applied in cancer treatment, re-emerged after a 75-year silence in its use in unresolved pneumonia, as a scientific interest with surprising effects in soothing the cytokine storm and other symptoms in severe COVID-19 patients. Here, we review the epidemiology, symptoms, immunological alterations, mutations, pharmaceuticals, and vaccine development of COVID-19, summarizing the history of X-ray irradiation in non-COVID diseases (especially pneumonia) and the currently registered clinical trials that apply LDR in treating COVID-19 patients. We discuss concerns, advantages, and disadvantages of LDR treatment and potential avenues that may provide empirical evidence supporting its potential use in defending against the pandemic.

Low Doses of Radiation Increase the Immunosuppressive Profile of Lung Macrophages During Viral Infection and Pneumonia

Purpose

Severe pneumonia and acute respiratory distress syndrome (ARDS) have been described in patients with severe coronavirus disease 2019 (COVID-19). Recently, early clinical data reported the feasibility of low doses of radiation therapy (RT) in the treatment of ARDS in patients with severe COVID-19. However, the involved mechanisms remained unknown.

Methods and Materials

Here, we used airways-instilled lipopolysaccharide (LPS) and influenza virus (H1N1) as murine models of pneumonia, and toll-like receptor (TLR)-3 stimulation in human lung macrophages.

Results

Low doses of RT (0.5-1 Gray) decreased LPS-induced pneumonia, and increased the percentage of nerve- and airway-associated macrophages producing interleukin (IL) 10. During H1N1 viral infection, we observed decreased lung tissue damage and immune cell infiltration in irradiated animals. Low doses of RT increased IL-10 production by infiltrating immune cells into the lung. Irradiation of TLR-3 ligand-stimulated human lung macrophages ex vivo increased IL-10 secretion and decreased interferon γ production in the culture supernatant. The percentage of human lung macrophages producing IL-6 was also decreased.

Conclusions

Our data highlight a mechanism by which low doses of RT regulate lung inflammation and skew lung macrophages toward an anti-inflammatory profile. These data provide a preclinical mechanistic support to clinical trials evaluating low doses of RT, such as COVID-19-induced ARDS.

Why Do Some Reports Claim that the Number of COVID-19 Hospitalized Smokers is Smaller than Expected?

Researchers believe that smoking might increase the severity of infections caused by SARS-CoV-2 by altering the viability and integrity of the BBB, while promoting the expression of ACE2 in endothelial cells, glia, and neurons. Moreover, as smoking increases the blood circulatory level of VWF and decreases the levels of thrombomodulin, it can lead to dysregulated blood homeostasis and hence, increased risk of thrombosis which significantly increases the risk of stroke and cardiovascular disorders. However, despite current controversies and remarkable study limitations, a recent systematic review and meta-analysis claims that the findings of 18 recent COVID-19 clinical and epidemiological studies show that smokers were statistically less likely to be hospitalized. The authors state that their observations might be due to the effects of nicotine. We believe that the lower number of hospitalized smokers than expected, if confirmed by further studies, can be due to the higher concentration of deposited energy of alpha particles emitted from radionuclides such as Po-210 in cigarette tobacco. The anti-inflammatory effects of localized radiation energy deposition of alpha particles as well as the effect of low doses of radiation on reducing the risk of thrombosis, are possibly involved in the lower number of hospitalized smokers than expected.

Cancerona: Challenges of Cancer Management in Times of COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) has infected millions of people worldwide and emerged to be the biggest global health threat claiming hundreds of thousands of lives at exponential rates. The severity of the disease increases with old age and presence of underlying health conditions, such as cancer. Managing cancer patients under these circumstances is rather challenging, given their compromised immunity and the overwhelmed health care services by COVID-19 community transmission. Thus, it is prudent to establish common guidelines for the monitoring and treatment of cancer patients. In this review, we comprehensively investigate the various aspects of cancer care during the COVID-19 pandemic, discuss challenges faced while treating cancer patients, and propose potential approaches to manage COVID-19 among this vulnerable population. We also discuss molecular aberrations and genetic changes associated with cancer and their role in affecting the virus' infectivity and severity. Lastly, we shed light on therapeutic approaches that can encompass both diseases without compromising one over the other.