NEW ORLEANS (WVUE) - COVID-19 remains a potent virus that has proven it can sicken and kill, and because of that, clinical trials using radiation are underway.
Dr. Kyle Happel is a pulmonologist and critical care medicine physician at LSU Health New Orleans. He sees the impact of the virus up close.
“We’re seeing very serious cases of coronavirus. We’ve seen many people who have had to be placed on a ventilator for days, if not weeks. Many of those patients do survive and they do recover; some of those patients, unfortunately, do not,” said Happel.
Nearly 900 miles away, a clinical trial is underway at the Miami Cancer Institute.
Dr. Minesh Mehta is the co-principal investigator on the study. He is also Deputy Director of the Miami Cancer Institute and Chief of Radiation Oncology at Baptist Health.
“We are actually very excited to test the concept of low-dose radiotherapy in COVID-19 patients who have developed COVID-19 related pneumonia,” said Mehta.
The virus can spawn a storm of inflammation in the body.
“The lung is a primary source of viral infection. You obviously acquire coronavirus by inhaling it and it’s also a target organ of the infection. It causes, in many cases, a severe pneumonia that can lead to respiratory failure,” said Happel.
Mehta is studying whether a single treatment of low-dose radiation could reduce inflammation in people with the virus.
“The mechanism of action, or at least the suspected mechanism of action, is that low-dose radiation acts in an anti-inflammatory manner because this pneumonic process is fueled and driven by inflammation,” Mehta stated.
But how does low-dose radiation compare to what cancer patients receive?
Mehta responded, “Six thousand or 7,000 centigray of radiation is a common total dose that a cancer patient would receive. In this trial, we are using much, much, much lower doses than cancer patients get because they get only one treatment, unlike cancer patients where they get multiple treatments, these patients get only one.”
He says centigray (cGy) is the unit used to measure the radiation dose.
Mehta explained how radiation is used to focus on a large area of the body.
“It actually targets both lungs and not both lungs, it actually targets the thorax, the chest, so the entirety of the chest is targeted, which includes both lungs and the center of the chest, which contains the heart as well as a lot of big blood vessels,” he said.
Happel, a lung expert, discussed the virus, the challenges it presents, and the idea of trying radiation on coronavirus patients as he sat inside a simulated operating room in LSU Health New Orleans’ Isidore Cohn Jr., M.D. Student Learning Center.
“I think it’s a neat idea in the sense that it does not rely on a specific anti-viral effect and we’ve had our fair share of challenges trying to develop specific anti-viral medications, so lung radiation would work differently. It works on the host and it works on the host by decreasing the inflammatory response to the coronavirus pneumonia,” said Happel.
The hyper-inflammation associated with the virus in many patients has commanded a lot of attention from healthcare professionals.
“The lung is an organ that makes inflammatory molecules called cytokines and these cytokines are believed to play a very important role in the host response against the coronavirus, but if the cytokine release is excessive, it can cause a condition known as a cytokine storm, and the idea behind the radiation therapy to the lung is to decrease the cytokine storm in the lung during coronavirus pneumonia,” said Happel.
Mehta said the only clinical trial of its type in Florida is using an incremental approach.
“In the first phase of the trial, we hope to enroll 40 patients on what we call the treatment arm. The treatment arm is the radiation arm, but we also have the control arm where people get standard of care, in other words, they get every therapy that you would give to these patients except for radiation,” Mehta stated.
A plethora of scientific articles on other research involving radiation and COVID-19 is emerging, suggesting it’s an area with growing interest.
“We do have some preliminary data from a group out of Emory [University] that does suggest that the treatment of coronavirus patients with low-dose, whole lung radiation decreases the amount of time that those people are symptomatic, and so I think it’s encouraging,” said Happel.
Those researchers concluded: “In a pilot trial of 5 oxygen-dependent elderly patients with COVID-19 pneumonia, low-dose whole-lung radiation led to rapid improvements in clinical status, encephalopathy, and radiographic consolidation without acute toxicity. Low-dose whole-lung radiation appears to be safe, shows early promise of efficacy, and warrants further study.”
Happel and Mehta were asked about the risks involved with radiation therapy.
“I think we know that from certainly higher doses of radiation as delivered for say lung cancer, there is a condition known as radiation pneumonitis, which is inflammation in the lung in response to the radiation therapy itself,” said Happel.
“Like every other therapy in the field of medicine, this therapy too can carry some risks. We think the risks are relatively low,” Mehta said.
Mehta says the clinical trial he is involved in is proceeding carefully.
“Is it possible that the use of this treatment actually accelerates viral replication because we are repressing the immune system?” asked Mehta in talking about two areas of concern.
He says a pause is intentionally put into the study.
“To say, after the first ten patients, we would be looking to make sure that we were not seeing unusually worse outcomes in the first patients, a quarter of patients, and we don’t see that and we’re doing that again at every few patients that we enroll in the study,” Mehta stated.
Low-dose radiation has been used to treat other medical conditions as well.
“Low-dose radiation to the lung is an interesting concept. It’s not a new concept. They’ve been doing radiation to the lung since the 1900s. In fact, before we had effective antibiotic therapy for pneumonia, physicians were using radiation to attempt to treat pneumonias,” said Happel.
Mehta says that increases optimism it will help patients with coronavirus.
“So, given that history and given the knowledge that there are other immune-mediated conditions where radiation has shown benefit, that provides us some optimism that we will see a positive result in this trial,” said Mehta.
The research prompts questions on who might be a good candidate for the low-dose radiation.
“It’s hard to know exactly who would be the best candidate for that therapy, but again, we would want to see those people who are doing low-dose lung radiation doing so in the context of a clinical trial,” said Happel.
At the Miami Cancer Institute, such an investigation is underway.
“The hope and expectation is that low-dose radiation will stop the rapid inflammatory changes that are occurring and will allow the body to reverse those changes and heal itself,” said Mehta.
He says the clinical trial is taking place at just under a dozen medical facilities around the country.
While the focus on new therapies and vaccines is important Happel and Mehta urge the public to adhere to precautions to reduce the chances of contracting the virus in the first place.
“But until we get there, I think that we continue on the medical side to really ask people to continue to adhere to their social distancing practices, wearing a mask, just realize that this is a very tough disease,” said Happel.
“But the reminder, be cautious, try not to get infected in the first place so we don’t have to go down this path,” said Mehta.
Anyone interested in the Florida clinical trial should contact the Miami Cancer Institute.
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