過誤症

there's a condition called acute lymphoblastic leukaemia (ALL) which mainly affects children aged 2-5 years, where the cells that normally turn into white blood cells and fight off infection go wrong and don't function correctly and start invading other organs. the mortality rate without intervention for ALL is 100%. the management of this condition is actually quite fascinating. basically you blast them with chemicals to destroy the bad cells and hope they don't come back. and you keep at it, injecting toxic chemicals into their body - and it really is torture for the kids - regularly in calculated intervals for up to 3 years to prevent the disease from coming back. and in 95% of children it works, and they are effectively cured. but some of them don't respond well, or have a relapse of ALL. For these children the prognosis is not so good. when this happens, there's an alternative treatment to conventional chemotherapy that is sometimes offered. a risky and not at all guaranteed to succeed last ditch effort to save their life. how to save someone whose renegade, mutinous cancerous cells have overrun - what to do when their very blood is the thing that's killing them - the way to essentially salvage the person is by performing an operation called total body irradiation and bone marrow transplantation in which the recipient undergoes intense chemotherapy plus radiotherapy to kill off all the bad cells - at such high doses that not only the cancer cells die but their native healthy bone marrow dies as well - all of it - and then they receive new, undiseased marrow from a donor into their body. the new marrow then produces new, cancer free blood cells, which then flows through their veins, but the thing is they have to use a crazy amount of radiation in order to be sure they kill off all of the old cells, because if even a little bit remains after they've had the transplant, their risk of relapse and the disease returning again increases drastically. One more thing, is that for bone marrow transplant to occur, you need someone - usually a sibling - who is HLA identical, as in, someone with the same blood, right down to the last molecule, but who doesn't have the disease, to choose to go through a very unpleasant and by all accounts painful procedure to donate their bone marrow. You see, it can't be just anyone, it must be someone who on a fundamental level is identical to you, only without the cancer - otherwise the body just won't accept it. It takes very rare, special blood to save someone.