Clinical trial using Atovaquone to increase radio effectiveness  https://clinicaltrials.gov/ct2/show/NCT02628080  
Atovaquone is a anti malaria drug easily available across the world. Taken daily in doses from 250mg capule to 4x250mg capsule/day.

A trial to see if atovaquone can increase the level of oxygen in non small cell lung cancer (ATOM)  https://www.cancerresearchuk.org/about-cancer/find-a-clinical-trial/a-trial-to-see-if-atovaquone-can-increase-the-level-of-oxygen-in-non-small-cell-lung-cancer-atom