This is the finding from researchers in Germany who say their technique of irradiating blood contaminated with tumour cells leaves the blood free of viable cancer cells and safe to put back into patients. Traditionally, intra-operative blood salvage has been contraindicated in cancer patients because of a potential risk of sending viable cancer cells into the blood stream, said Dr. Ernil Hansen, associate professor of anesthesiology at the University of Regensburg in Regensburg, Germany. Blood in general is already irradiated at levels of 30 Gy before it is reused, he said. The trick with cancer patients is to irradiate it at much higher levels.
Various data show different types of cancer cells have different radio-sensitivities.
A level of 50 Gy covers all bases, and then some. The process does not leave any radioactive products, red blood cells remain unimpaired and vital, and platelets and granulocytes are not affected, he said. Blood from cancer patients is normally thrown out because cancer cells in the blood are capable of proliferation. This has been confirmed in mouse studies, he said. To get around the potential risk of transfused blood spreading cancer to other sites, patients normally receive banked blood.