Gallium-68 neomannosylated human serum albumin-based PET/CT lymphoscintigraphy for sentinel lymph node mapping in non-small cell lung cancer.

PURPOSE

To develop imaging of lymphatics with resolution greater than that of lymphoscintigraphy using technetium-99 m neomannosyl human serum albumin ((99m)Tc-MSA), we developed a Gallium-68 ((68)Ga) MSA for positron emission tomography (PET). This study is the first clinical trial to evaluate the feasibility of sentinel node detection using this novel (68)Ga tracer for the management of non-small cell lung cancer.

METHODS

We enrolled 34 patients (20 men, 14 women; mean age, 64.3 ± 10.4 years) who were candidates for lobectomy with mediastinal lymph node dissection for clinical stage I non-small cell lung cancer. (68)Ga-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.

RESULTS

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 ± 0.9 (range 1-5) per patient. The maximum standardized uptake values were 2882.2 ± 2124.3 in the tumor and 82.5 ± 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 %).

CONCLUSIONS

(68)Ga-MSA appears to be a promising tracer for sentinel node identification in non-small cell lung cancer.