A critical evaluation of methods for preparing pentavalent 99Tcm-DMSA

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Chemistry
• Oncology Imaging

Background:

• Pentavalent 99Tcm-dimercaptosuccinic acid (99Tcm-(V)DMSA) is valuable for diagnosing medullary thyroid carcinoma, osteosarcoma, amyloidosis, and soft tissue tumors.
• Commercial kits for 99Tcm-(V)DMSA are not widely available, necessitating reliable preparation methods.

Purpose of the Study:

• To evaluate and compare published methods for preparing 99Tcm-(V)DMSA from commercial 99Tcm-(III)DMSA kits.
• To assess methods based on radiochemical purity and synthetic ease.

Main Methods:

• Evaluation of three preparation methods: Birmingham, Cambridge, and Canterbury.
• Radiochemical purity determined by thin-layer chromatography (silica gel) using a specific solvent system.
• Quantification and analysis using gamma camera imaging and standard software.

Main Results:

• All investigated methods, with experience, achieved radiochemical purities exceeding 90%.
• The Birmingham method demonstrated superior reliability and simplicity in synthesis compared to Cambridge and Canterbury methods.
• Thin-layer chromatography proved effective for quantifying 99Tcm-(V)DMSA activity.

Conclusions:

• The Birmingham method is recommended for its practicality and reliability in synthesizing 99Tcm-(V)DMSA.
• Optimized preparation methods are essential for the clinical availability of 99Tcm-(V)DMSA for diagnostic imaging.
• Further research into radiopharmaceutical preparation can enhance diagnostic capabilities in oncology and other fields.