The use of (99m}Tc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Abstract

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]O[3], and Group II patients (n=30) received 99mTc-labeled phytate colloid. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. 18 hours after {99m}Tc-Al[2]O[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II SLNs were detected in 27 patients. 18 hours after injection of the phytate colloid the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. The new radiopharmaceutical based on the {99m}Tc-Al[2]O[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. The sensitivity and specificity of {99m}Tc-Al[2]O[3] were 100% for both SPECT and intraoperative gamma probe identification.