EANM dosimetry committee recommendations for dosimetry of 177Lu-labelled somatostatin-receptor- and PSMA-targeting ligands

Katarina Sjögreen Gleisner,Nicolas Chouin,Frederik A Verburg,Caroline Stokke,Marta Cremonesi,Peter Bernhardt,Francesco Cicone,Uta Eberlein,Mark Konijnenberg,Pablo Minguez Gabina,Jonathan Gear,Silvano Gnesin

doi:10.1007/s00259-022-05727-7

Abstract

The purpose of the EANM Dosimetry Committee is to provide recommendations and guidance to scientists and clinicians on patient-specific dosimetry. Radiopharmaceuticals labelled with lutetium-177 (177Lu) are increasingly used for therapeutic applications, in particular for the treatment of metastatic neuroendocrine tumours using ligands for somatostatin receptors and prostate adenocarcinoma with small-molecule PSMA-targeting ligands. This paper provides an overview of reported dosimetry data for these therapies and summarises current knowledge about radiation-induced side effects on normal tissues and dose-effect relationships for tumours. Dosimetry methods and data are summarised for kidneys, bone marrow, salivary glands, lacrimal glands, pituitary glands, tumours, and the skin in case of radiopharmaceutical extravasation. Where applicable, taking into account the present status of the field and recent evidence in the literature, guidance is provided. The purpose of these recommendations is to encourage the practice of patient-specific dosimetry in therapy with 177Lu-labelled compounds. The proposed methods should be within the scope of centres offering therapy with 177Lu-labelled ligands for somatostatin receptors or small-molecule PSMA.

Highlights

Background informationLutetium‐177The radionuclide lutetium-177 (177Lu) is a rare earth metal that undergoes β− decay to stable hafnium-177 with a halflife of 6.647 days [1]
When high activities are administered through a punctured vein, potential extravasation of 177Lu may lead to high absorbed doses and injury of surrounding tissue, such as skin desquamation and necrosis [143]
The absorbed dose to the site of injection would be very high if clearance had not occurred

Summary

Introduction

The radionuclide lutetium-177 (177Lu) is a rare earth metal that undergoes β− decay to stable hafnium-177 with a halflife of 6.647 days [1]. On decay 177Lu, emits electrons, including β− particles and internal conversion electrons with a mean kinetic energy of 147 keV per decay and maximum electron energy of 497 keV. These energies correspond to ranges (continuous slowing down approximation) in unit-density soft tissue of 0.28 and 1.8 mm, respectively [2]. In the former route, the long-lived isomer 177mLu is produced (half-life 160.44 days), forming a low-amount radionuclide impurity mainly of importance for waste management [3, 4]

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