TAT-10: Correspondence between alpha-particle emitter dosimetry and normal organ toxicity

Kanazawa, Japan (UroToday.com) Alpha particle doses are often very non-uniform within an organ so micro-dosimetry  with good resolution is necessary. This is not possible with human subjects so this study uses mice.

Healthy neu-N mice were injected intravenously with 15, 22, 30, and 44 KBq of Ac225-anti-PD-L1-BC. The mice were sacrificed when one of three conditions were met: >20% weight loss, evidence of pain or distress, the 100 day endpoint was reached.  The liver, spleen, kidneys, and thymus were removed and sectioned for imaging with an alpha camera [see next paper for a description of an alpha camera].

Liver and spleen received the highest doses: 738 and 615 mGy/kBq respectively. The kidneys received 138 mGy/kBq. The dose was uniform in the liver so macrodosimetry should give an accurate measure and the liver will determine the maximum tolerated dose. Activity was very non-uniform in the kidneys, spleen, and thymus. In the case of the kidneys, the non-uniformity may be attributed to a substantial contribution of the Bi213 which is preferentially absorbed in the renal cortex

Presented By: Anders Josefsson from Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD

Written By: William Carithers, Lawrence Berkeley National Laboratory

at the 10th International Symposium on Targeted Alpha Therapy (TAT-10)  May 31 - June 1, 2017 - Kanazawa, Japan.