Dosimetric Techniques in 90Y-Microsphere Therapy of Liver Cancer: The MIRD Equations for Dose Calculations

Therapy with 90Y-microspheres is emerging as a main-stream treatment modality in the management of patients with primary and metastatic liver cancer (1,2). The tech-nique involves the administration of 90Y-microspheres into the hepatic artery, which is accessed via the transfemoral route or through a hepatic arterial infusion port or pump. The technique was first introduced by Ariel, who also re-ported the first series of successful treatment in patients with metastatic colorectal cancer (3,4). The patients were treated with intraarterial chemotherapy and 3.7–5.5 GBq (100–150 mCi) of 90Y-resin microspheres. The estimated radiation dose to the liver from 3.7 GBq (100 mCi) of 90Y-microspheres was 120–180 Gy using the MIRD approach. It took a few decades since Ariel’s early experience, in the 1960s, to refine the manufacturing technology and ad