Gallium-68 Neomannosylated Human Serum Albumin-Based PET/CT Lymphoscintigraphy for Sentinel Lymph Node Mapping in Non-small Cell Lung Cancer

Abstract

To develop imaging of lymphatics with resolution greater than that of lymphoscintigraphy using technetium-99 m neomannosyl human serum albumin (Tc-99m-MSA), we developed a Gallium-68 (Ga-68) MSA for positron emission tomography (PET). This study is the first clinical trial to evaluate the feasibility of sentinel node detection using this novel Ga-68 tracer for the management of non-small cell lung cancer. We enrolled 34 patients (20 men, 14 women; mean age, 64.3 +/- A 10.4 years) who were candidates for lobectomy with mediastinal lymph node dissection for clinical stage I non-small cell lung cancer. Ga-68-MSA was administered in one injection into the peritumoral region, and lymphoscintigraphy was performed by PET/CT just before surgery. All harvested lymph nodes were cut into 2 mm slices and were ultimately diagnosed using formalin-fixed and paraffin-embedded sections with hematoxylin and eosin staining. The sentinel nodes were well visualized by PET/CT imaging from 15 to 120 min, and especially within 60 min, after injection. In all patients (100 %), sentinel nodes could be identified on PET/CT. The number of sentinel nodes identified was 1.9 +/- A 0.9 (range 1-5) per patient. The maximum standardized uptake values were 2882.2 +/- A 2124.3 in the tumor and 82.5 +/- A 159.0 in the sentinel nodes. Eight of 34 patients (23.5 %) had metastases in 13 sentinel nodes. No false-negative sentinel nodes were detected in any of the eight patients with N1 or N2 disease (0 %). Ga-68-MSA appears to be a promising tracer for sentinel node identification in non-small cell lung cancer.