Proton therapy in Asia Pacific: current resources, international disparities and steps forward.

The burden of cancer in Asia Pacific, a region home to over four billion people, is growing. Because of sheer demographics alone, the Asia Pacific region arguably has the highest number of patients who can benefit from protons over conventional x-rays. However, only 39 out of 113 proton facilities globally are in Asia Pacific, and 11 of them are in low- and middle-income countries where 95% of the regional population reside. We draw attention to present resource distribution of proton therapy in Asia Pacific, highlight disparities in access, and suggest steps forward.