Correlation between NEN bone metastasis performance and tumor proliferation: 112 cases of [68Ga]Ga-DOTA-TATE results analysis

Abstract

Purpose: To analyze neuroendocrine neoplasm (NEN) bone metastasis (BM) and Gallium-68 (68Ga)-DOTA-TATE performance and to explore their correlation with the immunohistochemical proliferation index (Ki-67). Procedures: A total of 112 patients with BMs were screened from 1082 NEN patients who underwent [68Ga]Ga-DOTA-TATE imaging. All patients had pathological results, and BMs were affirmed by clinical/imaging follow-up of and/or histopathology. The maximum standard uptake value (SUVmax) ratio of BM to normal bone determined for each patient was used in the final analysis. Results: The incidence rate of BMs in NENs was 10.35%. BMs occurred in the spine (75%), pelvis (72.3%), ribs (58%), clavicles and scapulae (41.1%), limbs (37.5%) and skull (28.6%). Most cases were associated with liver metastases (70.5%) and lymph node metastases (65.2%) simultaneously. The SUVmax ratio of G3b (median ratio=3.77, Ki-67>55%) was significantly lower than that of G1 (11.43, Ki-67≤2%) and G2a (11.15, 3%≤Ki-67≤10%) separately P<0.05), while no differences were found for the G2b (8.5, 11%≤Ki-67≤55%) and G3a (6.64, Ki-67>55%) groups. In the total patients there was a significant negative correlation between the SUVmax ratio of BMs to normal bone and Ki-67 (r=-0.267, P<0.01). According to the changes in bone density on computed tomography (CT) scans, the cases were divided into four groups: osteogenesis, osteolysis, no change and a mixed group (median Ki-67: 6.5%, 15%, 12%, and 22.5%). The Ki-67 values were significantly different between the osteogenesis group and the other groups (P<0.05). Conclusion: BM is present in 10.35 % of NEN patients, and most have simultaneous liver and/or lymph node metastases. The occurrence of osteogenesis indicates relativity good differentiation and there is a negative correlation between SUVmax ratio of BMs and NEN proliferation.