Radioguided sentinel node detection in breast cancer patients:: comparison of 99mTc phytate and 99mTc rhenium colloid efficacy

Background Radioguided sentinel node biopsy (SNB) of breast cancer patients has become a standard method for detecting early stage breast cancer. However, no standard radiopharmaceutical exists. Methods Tc-99m rhenium colloid or Tc-99m phytate SNB was used to aid detection in breast cancer patients. For each radiopharmaceutical, 100 patients were examined. The following points were compared: (1) scintigraphic detection rate of axillary sentinel nodes (detectability and number when detectable) and internal mammary sentinel nodes; (2) the number of nodes detected scintigraphically and the number detected during surgery; (3) sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for axillary sentinel nodes. Results Axillary sentinel nodes of patients were biopsied using either Tc-99m rhenium or Tc-99m phytate. The number of axillary nodes surgically removed from patients given Tc-99m rhenium was 2.28 +/- 1.08 (mean +/- SD), and the number of axillary nodes surgically removed from patients given Tc-99m phytate was 1.68 +/- 0.82. Some patients given Tc-99m rhenium showed a spill-over of radioactivity from sentinel nodes. Concordance of scintigraphically detected nodes and surgical removed nodes was superior for Tc-99m phytate compared to that with Tc-99m rhenium, with a statistically significant difference. The sensitivity and negative predictive value was superior with Tc-99m phytate compared to that with Tc-99m rhenium, even though no statistical difference was detectable. However, visualization of internal mammary nodes was superior with Tc-99m rhenium. Conclusion In breast cancer patients, Tc-99m phytate is a better choice for the detection of axillary SNB than Tc-99m rhenium colloid. However, Tc-99m rhenium colloid is a better choice for the detection of internal mammary nodes. Nucl (C) 2004 Lippincott Williams Wilkins.