TECHNICAL ASPECTS OF DOSIMETRY OF YTRIUM-90 IN TRANS-ARTERIAL TREAMENT OF LIVER CANCER AT CHORAY HOSPITAL

Abstract

SIRT (Selective Internal Radiation Therapy)for liver cancer therapy is a method in which a dose of radiation was delivered millions of microspheres SIR-Spheres Ytrium-90 directly to liver tumors via hepatic artery.In this treatment, millions of tiny radioactive beads are injected directly into the arteries that supply blood to the tumour. These beads will stay in the blood vessels around the tumours. This allows a very strong radiation to reach the tumours directly. There is a very little effect on healthy parts of the liver or other tissues in the area such as intestines or skin.The treatment dose was limited less than the Maximum Treatment Activity (MTA) in order that the absorbed doses were not greater than the tolerances of normal liver (30Gy), of lungs (12Gy) and of bone marrow (1.5Gy)[1]. Clinical experiences gave the result: when combining with chemotherapy, radioactive microspheres can reduce the size of tumours better than using chemotherapy only. It can help to improve the quality of life and prolong the life of patients. For a large number of patients, this treatment can also help to shrink tumours which can be removed later by surgery.