Characterizing Normal Upper Extremity Lymphatic Flow with ^99mTc In-House Dextran: A Retrospective Study

Area of Science:

• Nuclear Medicine
• Radiopharmacy
• Anatomy

Background:

• Lymphoscintigraphy is crucial for evaluating lymphatic system disorders.
• Radiocolloid particle size influences distribution and imaging timing.
• Normal upper extremity lymphatic drainage patterns require detailed characterization.

Purpose of the Study:

• To characterize normal lymphatic drainage patterns of the upper extremity.
• To establish imaging timelines for technetium-99m in-house Dextran lymphoscintigraphy.
• To assess sentinel lymph node visualization and clearance kinetics.

Main Methods:

• Retrospective analysis of 84 upper extremity lymphoscintigraphies (2008-2021).
• Intradermal injection of 99mTc in-house Dextran into both hands.
• Whole-body imaging at intervals up to 60 minutes and delayed imaging.

Main Results:

• 92% lymphatic tract visualization within 45 minutes.
• Axillary lymph node detection increased from 46% at ≤15 min to 86% at 46-60 min.
• Epitrochlear/brachial node visualization was rare (4%); hepatic, renal, and bladder activity common.

Conclusions:

• This study provides a detailed map of normal upper extremity lymphatic drainage using 99mTc in-house Dextran.
• Established timelines aid in interpreting lymphoscintigraphy for conditions like lymphedema.
• Findings support the clinical utility of 99mTc in-house Dextran for lymphatic imaging.