Phytate technetium-99m versus dextran 500 technetium-99m in the sentinel lymph node biopsy

Abstract

Purpose: To study which of the two most used radiopharmaceutical drugs for the sentinel lymph node (SLN) biopsy procedure (dextran 500 Tc-99m and phytate Tc-99m) best defines the SLN and migrates less to other lymph nodes.Material and Methods: Thirty-two rats, separated into two groups, underwent lymphoscintigraphy examination with either dextran or phytate followed by sentinel (popliteal), lumbar, and inguinal lymph node biopsy. Radiation was detected with a gamma probe.Results: the statistical study indicated count rates significantly higher in the SLN than in the other basins for both the dextran (P < 0.01) and phytate groups (P < 0.001). There was no statistically significant difference concerning SLN absorption in either group (P=0.2981). in the dextran group, migration occurred to 1.5 lymphatic basins with counting higher than 10% of that found in the SLN versus 0.8 in the phytate group (P=0.0023). Migration was thus higher in the dextran group (P=0.0207).Conclusion: There was no statistically significant difference between dextran and phytate in the SLN identification, but the phytate migrated to fewer lymphatic basins beyond the SLN and with less intensity.