Could ultra-low dose radiotherapy treat COVID-19-related pneumonia?

By Angela Betsaida B. Laguipo, BSNFeb 2 2021

More than one year into the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome 2 (SARS-CoV-2) pathogen, there is still no targeted, safe and effective treatment for the illness. To date, the virus has spread to 192 countries, infecting over 102.67 million people.

Since the emergence of COVID-19, researchers have focused their efforts on finding a treatment to prevent the fatal outcomes of severe infection, particularly among high-risk groups like older adults, immunocompromised individuals, and those with comorbidities.

Study: COVID-19 pneumonia treated with ultra-low doses of radiotherapy (ULTRA-COVID study): a single institution report of two cases. Image Credit: Mark_Kostich / Shutterstock

In a new study, published in the journal Strahlentherapie und Onkologie, researchers at the Department of Radiation Oncology, La Milagrosa Hospital, GenesisCare, Madrid, Spain, showed the potential benefit of treating COVID-19 pneumonia with ultra-low doses of radiotherapy, called ULTRA-COVID.

ULTRA-COVID

Since the pandemic first emerged in December 2019 in Wuhan City, China, scientists have been racing to find an effective and safe treatment for people who are severely ill. However, more than a year into the pandemic, there is still no targeted treatment available.

Though many COVID-19 patients are asymptomatic or have a mild illness, complications may arise. These include acute respiratory distress syndrome (ARDS), pneumonia, and respiratory failure, which can lead to fatal outcomes in patients. Often, these cases require admission to the intensive care unit and invasive mechanical ventilator (IMV) support.

In worse COVID-19 cases, scientists believe that the cause is the body’s host response against the virus, which is mediated by a cytokine storm, leading to a macrophage-mediated inflammatory mechanism and ARDS in the form of bilateral pneumonitis.

To prevent the progression of COVID-19 to this critical stage, the research team suggests that the cytokine storm can be safely treated with a course of ultra-low-dose radiotherapy (ultra-LDRT), which can mitigate symptoms of respiratory distress to reduce disease progression and death.

The team believes that Ultra-Low Doses of Therapy with Radiation Applied to COVID-19 (ULTRA-COVID) could play an imperative role in reducing the pulmonary inflammatory response, counteracting the cytokine storm, and preventing the progression into the critical state, which may require ventilation.

The study

To arrive at the study findings, the researchers designed a study of Ultra-Low Doses of Therapy with Radiation Applied to COVID-19 (ULTRA-COVID) for patients who have pneumonia and who are not candidates for invasive mechanical ventilation. Also, these patients did not improve with medical therapy.

At first, four patients were eligible for the treatment. However, one declined to participate while another one died before the treatment. Two patients underwent the procedure.

The patients had a baseline thoracic computerized tomography (CT) scan, which was used to evaluate lung improvement using the Total Severity Score (TSS). Further, the patients received ultra-LDRT using 6MV photon beams.

After the treatment, the radiological response was evaluated using TSS change on CT imaging, which was assessed at 7 days and 4 weeks after being treated. The team categorized the radiological improvement as mild, moderate, or high, based on the TSS scores.

The study findings showed that respiratory status improved rapidly in both patients. The first patient manifested improvement in his oxygen saturation (Sp02) and Pa02/Fi02, which is the ratio of arterial oxygen partial pressure (PaO2 in mmHg) to fractional inspired oxygen, two days after being treated. The patient was discharged on the eighth day after ULTRA-COVID with 95 percent SpO2 values on air. The patient remained stable two months later.

The second patient, however, had a slower recovery, attaining less need of oxygen support at two, five, and seven days after treatment. The patient also dropped oxygen support two months after treatment and was discharged 14 days after ultra-LRDT.

Hence, the two patients were discharged from the hospital about two weeks after the radiation treatment. The researchers concluded that the preliminary clinical and radiological results suggest a potential benefit of COVID-19 pneumonia treatment with ULTRA-COVID. They added that the procedure had a positive impact on the disease’s progression and patient recovery.

The researchers believe the therapy can help treat people with severe COVID-19, which has now claimed more than 2.22 million lives globally.