Sentinel node mapping for early breast cancer patients using 99mTc-phytate: Single center experience on 165 patients

Introduction: Several radiotracers are being used for sentinel node mapping in patients with breast cancer. In the current study, we reported our experience with 99m-Tc Phytate for sentinel node mapping in Mashhad University of Medical Sciences. Methods: All breast cancer patients who underwent sentinel node mapping using 99m-Tc Phytate were included. All patients received intradermal peri-areolar injection of 0.5 mCi/0.1cc 99m-Tc Phytate. Lymphoscintiraphy was performed for 145 patients 5-10 minutes post-injection. The sentinel nodes were found during surgery using a hand-held gamma probe as well as blue dye technique. Results: In total 165 patients were evaluated. Lymphoscintigraphy showed axillary sentinel nodes in 135 out of 145 patients (93%) following imaging. At least one sentinel node could be detected in all these 135 patients during surgery. In the remaining 10 patients with sentinel node non-visualization, 5 had sentinel node harvesting failure during surgery. Median number of sentinel nodes on the lymphoscintigraphy images was 1. Sentinel node detection rate was 95% (157/165). In the 8 patients with sentinel node harvesting failure, 7 had pathologically involved axilla. Median number of harvested sentinel nodes was 1. Mean sentinel node to background count ratio was 10±2. Conclusions: 99m-Tc Phytate is an effective and highly successful radiotracer for sentinel node mapping. Sentinel node can be visualized in a short time after 99m-Tc Phytate injection on the lymphoscintigraphy images. The sentinel to background count during surgery is high which results in more convenient sentinel node harvesting and high detection rate.

Sentinel node mapping for early breast cancer patients using 99mTc-phytate: Single center experience on 165 patients Keywords:

Tc-99m Phytate , Lymphoscintigraphy , Breast cancer , Sentinel node , Detection rate