原文Damage dealt to Doctor Doom is tracked even if he has indestructible. For example, if Doctor Doom is dealt what would be lethal damage and then he loses indestructible (probably because you lose control of all your artifact creatures and Plans), he'll be destroyed the next time state-based actions are performed.
原文The check for whether a creature dealt damage by a source with deathtouch is destroyed happens only the first time that state-based actions are performed after that damage-dealing event. For example, if Doctor Doom is dealt 1 damage by a creature with deathtouch while he has indestructible, he won't die if he loses indestructible later in the turn.