Comparison as a lymphoscintigraphic agent between 99Tcm dextran and 99Tcm antimony sulphide colloid

Area of Science:

• Nuclear medicine
• Radiopharmacology
• Lymphatic system imaging

Background:

• Accurate lymph node imaging is crucial for diagnosing and staging various diseases.
• Traditional agents like technetium-99m antimony sulphide colloid (99TcmSb2S3) have limitations.
• Novel agents are being investigated to improve lymph node imaging efficacy.

Purpose of the Study:

• To evaluate the suitability of technetium-99m dextran (99TcmDx) as a lymph node imaging agent.
• To compare the performance of 99TcmDx with 99Tcm antimony sulphide colloid (99TcmSb2S3) in preclinical models.
• To assess absorption, lymph node sequestration, and image quality of both agents.

Main Methods:

• Comparative study in rabbits and dogs.
• Interstitial injection of 99TcmDx and 99TcmSb2S3.
• Quantification of absorption, lymph node uptake, and total body distribution.
• Evaluation of popliteal lymph node sequestration and image quality.

Main Results:

• 99TcmDx demonstrated faster and greater total body uptake than 99TcmSb2S3 in rabbits.
• Despite rapid uptake rates, 99TcmDx showed significantly lower popliteal lymph node sequestration than 99TcmSb2S3.
• Disparities in lymph node uptake and image quality between the agents were observed in both species.

Conclusions:

• 99TcmDx's non-colloidal nature and instability contribute to reduced lymph node sequestration.
• 99TcmDx is unsuitable for imaging pathological lymph node features.
• The rapid absorption and distribution of 99TcmDx may be beneficial for studying lymphatic kinetics.