Investigating Patient-Specific Absorbed Dose Assessment for Copper-64 PET/CT

Ali Abdulhasan  Kadhim; Peyman  Sheikhzadeh; Mehrshad  Abbasi; Saeed  Afshar; Nasim  Vahidfar; Shirin  Asidkar; Mehrnoosh  Karimipourfard; Zahra  Valibeiglou; Mohammad Reza  Ay

doi:10.18502/fbt.v13i1.20755

Ali Abdulhasan Kadhim Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Peyman Sheikhzadeh Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Mehrshad Abbasi Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Saeed Afshar Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Nasim Vahidfar Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Shirin Asidkar Nursing Care Research Center, Iran University of Medical Sciences, Tehran, Iran
Mehrnoosh Karimipourfard Department of Ray-Medical Engineering, Shiraz University, Shiraz, Iran
Zahra Valibeiglou Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
Mohammad Reza Ay Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/fbt.v13i1.20755

Keywords: 64Cu-DOTA-Trastuzumab; Internal Dosimetry; Positron Emission Tomography Computed Tomography; Absorbed Dose.

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.