Evaluation of External Radiation Exposure in Patients Treated With 177Lu-Psma and Radiation Safety Assessment of the Patient Caregivers Publisher Pubmed



P Sheikhzadeh PEYMAN ; S Farzanehfar SAEED ; M Abbasi MEHRSHAD ; Z Bayat ZEINAB ; M Abdolmaleki MOHAMMADREZA ; F Koosha FERESHTEH ; N Kasraie NIMA
Source: Radiation Protection Dosimetry Published:2025

Abstract

This study evaluates dose rates at various distances and time intervals after 177Lu-PSMA treatment and assesses caregivers' effective doses. Dose rates were measured in 47 patients at 0.5 and 1 m up to 168 h post-injection. Initial dose rates were 34.6 ± 9 μSv (0.5 m) and 24.6 ± 5 μSv (1 m) at 5 min, peaking at 48.5 ± 15 and 31.6 ± 8 μSv at 1 h, then declining significantly over time. Caregivers' effective doses ranged from 20 to 1170 μSv, remaining below international safety limits. This study demonstrates that patient dose rates at a distance of 1-m decline to below 30 μSv/h within 2-3 h post-injection and fall further to under 20 μSv/h after 6 h. Patients may be considered radiologically safe approximately four days post-procedure, depending on individual factors. While 177Lu-PSMA is a safe and effective PRRT modality, strict safety measures are essential to minimize exposure risks. © 2025 Elsevier B.V., All rights reserved.