Intraoperative dosimetry of ⁹⁰Y in liver tissue

The use of an intraoperative radiation detection probe was assessed following the injection of ⁹⁰Y labelled radioactive microspheres into the normal liver of 10 sheep. The absorbed dose to the liver ranged from 10 to 50 Gy. There was a linear relationship between the probe recordings and the radiation dose as measured by scintillation counting of liver tissue. By using the probe during the procedures for internal radiation therapy the injected dose of radioactive microspheres can be manipulated to provide the maximum tolerable dose to normal tissue.