Time, distance, shielding and ALARA; drawing similarities between measures for radiation protection and Coronavirus disease pandemic response.

ABSTRACT

The practice of radiation oncology requires stringent adherence to specific steps and principles designed to minimize exposure of an individual to unnecessary doses of radiation. The basic principles of such measures to reduce the risk of exposure and limit the doses of irradiation follow the "as low as reasonably achievable " or ALARA principle by using the concepts of time, distance and shielding. Potential exposures in radiation oncology are controlled through combination of optimal design and installation of radiation delivery equipment with well-defined standard operating procedures (SOPs). In the modern era of viral pandemics, similar principles can also be applied toward prevention of viral transmission and protection of populations at risk. In the ongoing COVID-19 pandemic, the probability of an individual getting infected is dependent on the viral load that an individual is exposed to in public spaces over a period of time. All prevention and control measures are based on preventing any such exposure to the virus, that can be achieved through limiting space for movement of the virus, using barriers and increasing distance to vulnerable surfaces, and limiting the duration of exposure. Apart from adhering to the laid-down provisions of a lock-down, preventive measures recommended for the general public include maintaining hand-hygiene, social distancing, and using facemasks to break the chain of transmission. Appropriate triage and customization of treatment protocols can help curtail hospital visits and time-spent by cancer patients during pandemic times, thereby reducing their risk of exposure as well as allowing efficient utilization of resources. The outbreak of the contagious COVID-19 pandemic threatens to disrupt healthcare systems globally with its unprecedented challenges. However, despite all the difficulties and hardships, it has also enabled new ways of learning and communication, which are likely to persist even in the post-COVID world.