Calculation of absorbed dose due to the ⁹⁰ Y-DOTATOC peptide receptor radionuclide ther apy by MCNP5/X

Abstract

© 2018; Vinca Inst Nuclear Sci. All rights reserved. Strong beta emitters, like 90 Y, 177 Lu labelled peptide, are used for treatment of neuroendocrine tumours where there is a good expression of somatostatin receptors. In this work, MCNP5/X computer software and ORNL human phantoms were used lo calculate absorbed dose due to 90 Y labelled DOTATOC in the peptide receptor radionuclide therapy. Tumour was considered as a sources of beta radiation and represented as a sphere with diameter of 1-4 cm and 5 cm in liver, pancreas, and lungs. Results are expressed as absorbed dose per unit of cumulated activity, S -value in units mGy(MBq.s) -1 . The far largest dose is in tumour itself, then in organ which contains the tumour. Doses in other organs, where the metastasis are the most frequent, due lo the bremsslrahlung radiation, are much smaller and could be neglected. The largest dose, 8.66.10 -3 mGy.(MBq.s) -1 was obtained lor tumour with size of 3 cm.