RT Journal Article SR Electronic T1 Proton beam therapy for cancer JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E664 OP E666 DO 10.1503/cmaj.190008 VO 191 IS 24 A1 Derek S. Tsang A1 Samir Patel YR 2019 UL http://www.cmaj.ca/content/191/24/E664.abstract AB