Quantification of In-Pentetreotide Single Photon Emission Computed Tomography Images in Gastrointestinal Neuroendocrine Tumors and Possibility of Grade Prediction.

PURPOSE

Neuroendocrine tumors (NETs) can be classified into three grades based on the malignancy index identified via histological and pathological diagnosis, and In-pentetreotide single photon emission computed tomography (SPECT) is effective for diagnosis. Therefore, this study aimed to distinguish between NET grade 1 (G1) and NET grade 2 (G2) based on the change in standardized uptake value (SUV) 4 and 24 h after injection in pancreatic and gastrointestinal NETs.

METHODS

Twenty-two patients underwent In-pentetreotide SPECT and were definitively diagnosed with pancreatic or gastrointestinal NETs. The volume of interest were set in the tumor areas 4 and 24 h after injection, and SUV and SUV were calculated. The ⊿tumor SUV (24 h-4 h) was calculated for each G1 and G2 by subtracting the SUV 4 h from SUV 24 h.

RESULTS

The ⊿tumor SUV (24 h-4 h) was 19.35 ± 23.26 in G1 and - 13.30 ± 20.26 in G2, and the ⊿tumor SUV (24 h-4 h) was 7.64 ± 15.58 in G1 and - 8.89 ± 15.45 in G2. The ⊿tumor SUV (24 h-4 h) and ⊿tumor SUV (24 h-4 h) were higher in G1 compared to G2 ( < 0.05).

CONCLUSION

The ⊿tumor SUV (24 h-4 h) in patients with pancreatic/gastrointestinal NET on In-pentetreotide SPECT images were higher in G1 compared to G2. The ⊿tumor SUV (24 h-4 h) for pancreatic and gastrointestinal NETs may predict the malignancy grade, as determined by histological and pathological diagnosis.