A New Labeling Method of ^99m Tc-PSMA-HBED-CC

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Chemistry
• Oncology Imaging

Background:

• Gallium-68 PSMA-HBED-CC (68Ga-PSMA-11) is an FDA-approved PSMA-targeted PET imaging drug for prostate cancer.
• Accessibility limitations of PET/CT, PET/MR, and 68Ga availability hinder widespread use of 68Ga-PSMA-HBED-CC.
• Development of an alternative imaging agent is crucial for broader clinical application.

Purpose of the Study:

• To develop an in-house preparation method for 99mTc-PSMA-HBED-CC as a ubiquitous and affordable alternative.
• To optimize radiolabeling conditions for high radiochemical yield and purity.
• To evaluate the stability of the developed 99mTc-PSMA-HBED-CC.

Main Methods:

• Radiolabeling of PSMA-HBED-CC with 99mTc-pertechnetate using SnCl2·2H2O as a reducing agent.
• Optimization of labeling parameters including reagent amounts, temperature, and incubation time.
• Quality control using instant thin-layer chromatography to assess radiochemical purity and stability.

Main Results:

• Successful radiolabeling of 99mTc-PSMA-HBED-CC achieved with optimal conditions: 10 µg PSMA-HBED-CC, 3 µg SnCl2·2H2O, and 370 MBq 99mTc-pertechnetate at 100°C for 15 minutes.
• High radiochemical yield (71.49 ± 2.42%), radiochemical purity (98.29 ± 2.65%), and specific activity (37.84 ± 1.47 GBq/µmol) were obtained.
• The 99mTc-PSMA-HBED-CC conjugate demonstrated stability, maintaining >95% radiochemical purity for up to 4 hours at room temperature.

Conclusions:

• A novel and efficient labeling method for 99mTc-PSMA-HBED-CC has been successfully developed.
• The quality control parameters of the 99mTc-PSMA-HBED-CC meet European Pharmacopoeia standards.
• This method provides a promising, accessible, and cost-effective alternative for PSMA-targeted PET imaging in prostate cancer patients.