Quality control of 99mTc-labeled dextran for lymphoscintigraphy

Area of Science:

• Nuclear medicine
• Radiopharmaceutical chemistry
• Biomedical imaging

Background:

• Technetium-99m-labeled dextran (99mTc-dextran) is a potential agent for lymphoscintigraphy.
• Previous studies reported controversial quality-control results, hindering its clinical application.

Purpose of the Study:

• To determine the optimal stannous ion concentration and pH for maximal 99mTc-dextran labeling.
• To validate the labeling efficiency and purity of the optimized radiopharmaceutical.

Main Methods:

• Optimization of stannous ion concentration and pH.
• Paper and thin-layer chromatography for assessing labeling efficiency.
• Anthrone test and colorimetric analysis for verifying dextran localization and purity.

Main Results:

• Maximal labeling efficiency exceeding 98.4% was achieved under optimized conditions.
• Chromatographic and colorimetric analyses confirmed the successful and specific labeling of dextran.
• Dextran was localized precisely with peak radioactivity, indicating high purity.

Conclusions:

• The study successfully established optimal conditions for preparing high-purity 99mTc-dextran.
• These findings resolve previous quality-control issues and support the use of 99mTc-dextran in lymphoscintigraphy.