In fact, the reason why 80 to 90 percent of those brain cancer surgeries ultimately fail is because of those small little extra margins that were left positive, those small little leftover tumors that were left there.
Na verdade, de 80 a 90% dessas cirurgias  de câncer cerebral acabam falhando devido àquelas pequenas margens extras que restaram positivas, aqueles pequenos tumores  que foram deixados lá.