Investigating Patient-Specific Absorbed Dose Assessment for Copper-64 Pet/Ct Publisher



Kadhim AA ; Sheikhzadeh P ; Abbasi M ; Afshar S ; Vahidfar N ; Asidkar S ; Karimipourfard M ; Valibeiglou Z ; Ay MR
Source: Frontiers in Biomedical Technologies Published:2025

Abstract

Purpose: There is a growing interest in the clinical application of new PET radiopharmaceuticals. This study focuses on using 64Cu-DOTA-Trastuzumab for Positron Emission Tomography–Computed Tomography (PET/CT) imaging in gastric cancer patients. It aims to enhance the understanding of its bio-kinetic distribution and absorbed dose for safe and practical application in nuclear medicine. Materials and Methods: The study was conducted at the Agricultural, Medical, and Industrial Research School (AMIRS), where 64Cu was produced and purified. The radiopharmaceutical 64Cu-DOTA-Trastuzumab was prepared, and three patients with confirmed Human Epidermal growth factor Receptor 2 (HER2)-positive gastric cancer underwent PET/CT scans at 1, 12 and 48 hours post-injection. Images were gained using a Discovery IQ PET/CT system and analyzed for an SUV. Bio-distribution was modeled using a two-exponential function, and absorbed doses were calculated using IDAC-Dose 2.1 software. CT doses were also evaluated. Results: The study found that post-injection imaging at 12 hours or more provided superior image quality. The liver exhibited the highest cumulative activity, followed by the spleen and other organs. The effective dose estimates for 64Cu-DOTA-Trastuzumab were within acceptable limits. CT dose calculations revealed that sensitive organs received higher doses. Conclusion: This study successfully assessed the bio-kinetic distribution and absorbed dose of 64Cu-DOTA-Trastuzumab in gastric cancer patients, demonstrating its safety and potential for clinical use. The optimal timing for PET/CT imaging and dosimetry data can inform clinical decision-making. Further research is warranted to explore the therapeutic potential of 64Cu-DOTA-Trastuzumab and to establish clinical guidelines for its use. Copyright © 2026 Tehran University of Medical Sciences. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International license (https://creativecommons.org/licenses/by-nc/4.0/). Noncommercial uses of the work are permitted, provided the original work is properly cited.