#If anyone wanted to consider Doffy's internal injuries sustained at Dressrosa further

[caelestisdemon]

Symptoms of surviving Law’s Gamma knife to the chest/abdomen may include the following:

Fatigue

Hair loss 

Skin changes

Throat problems, such as trouble swallowing

Cough

Shortness of breath

Diarrhea

Nausea and vomiting

Urinary and bladder problems

And that’s just describing potential symptoms of a regular radiotherapy treatment and not that of a fatal dose of radiation given by an enemy with intent to kill.

For Doflamingo, his organs were practically reduced to goo, with only his strings holding them remotely together. The marines themselves I imagine did not prove very helpful in fixing his many issues. Not only that, before he was finally knocked unconscious where his strings would no longer be able to help him, but enduring an intensive battle against Luffy no doubt greatened his internal injuries further to the point where regardless of what happens, anything short of immortality will be unable to save his life.

Beyond the symptoms listed I imagine these organs had taken the brunt of the damage: The heart, the lungs, and his stomach.

His heart no longer beats an even rhythm, his great lungs now struggle to deliver him ample oxygen, and his stomach now afflicted with Gamma knife-spawned ulcers, infrequently spews blood whenever those rupture.

All in all, Doflamingo would realistically be getting a fate that Law would probably deem worthy. The inevitability of dying alone from wounds no one would ever dare treat even if they could without the OP Op fruit, the very thing Doffy would now rely on to live.