The Conditioning Regimen Performing an allogeneic transplant allows us to give big doses of anticancer therapy. Because the upper dose of many drugs is limited by toxicity to the bone marrow, by replacing your bone marrow after you have received the drug, five to 10 times as much drug can be given. What limits giving 100 times the dose is toxicity to other organs, such as the heart, liver, and lungs. The type of preparative regimen depends on the type of cancer.
Some cancers respond very well to radiation.
Radiation treatment is like getting an X-ray but the amount of radiation given is obviously much greater. The lungs are more sensitive to radiation than the rest of the body so they are shielded for one dose. Most people tolerate the radiation treatment well although it may cause nausea and mouth ulcers, but these usually occur several days after the treatment is completed. Radiation treatment is always given with at least one chemotherapy drug. Although radiation is effective against many diseases its use is associated with more lung toxicity and non-radiation conditioning regimens are preferred for many diseases.