Low Dose Radiotherapy (LDRT) helps relieve respiratory distress in COVID-19 patients who suffer a dip in blood oxygenation levels. Oxygen demand in COVID-19 patients came down by at least 66.6% within 48 hours of receiving LDRT, as per the final results of a phase II study taken up by a city hospital.
The final results of a Phase II study LDRT as a treatment for COVID-19 conducted by Tiruchi-based HarshaMitra Super Speciality Cancer Centre and Research Institute has been published in the Journal of Radiotherapy and Oncology.
The institute began studying the usage of LDRT in 2021. There was rapid relief from respiratory distress and a potential reduction in mortality rate, the researchers found.
A total of 61 patients were recruited for the Phase II study from November 2020 to May 2021. The initiative was taken up following a pilot study conducted by All India Institute of Medical Sciences, New Delhi showing 90% efficacy in a sample of 10 patients with LDRT.
The doctors at Harshamitra also conducted a pilot study, after which Phase I was conducted by a team of 13 doctors and researchers. According to the researchers, 25 patients had rapid improvement in oxygenation status within 48 hours of receiving a single dose of radiation treatment. The recovery rate was 88 % they claimed.
Explaining the procedure, G. Govindaraj, surgical oncologist and principal investigator of the study said that LDRT works as an anti-inflammatory response. Radiotherapy helps soothe the inflammation caused by COVID-19, he explained. For all the recruited cases, standard government protocol for treatment was followed, and one single dose of LDRT was given.
However, the treatment has to be given at an appropriate time- which is when the lungs are affected, lest it would not be effective. "There needs to be inflammation for the anti-inflammatory effect to work. We identify this by monitoring the patient's blood oxygenation levels. If the patient requires oxygenation, they can be given radiotherapy," he said.
Mr. Govindaraj clarified that 0.5 gray of radiation is used in LDRT, while for cancer patients, at least 50-60 gray is used. Because of this, the radiation is not harmful, he said. "There are numerous studies which have studied the effects and have proved that the effect is negligible. We have quoted them in our papers," he said.
However, a few practical concerns were flagged by the oncologists' community. Speaking to The Hindu , a senior radiation oncologist in Tiruchi said that all hospitals will not have access to the equipment required for radiotherapy. Further, all equipment including the machine need to be sterilised after treating a COVID-19 patient before it is used again. "At a cancer-treating facility, at least 70-100 patients are given radiotherapy in a day. We will be compromising on their needs if we provide it to COVID-19 patients," the doctor said.
