Prediction Role of Baseline Digital Substraction Angiography in GEP Neuroendocrine Liver Metastases Treated with TAE/ TACE

Abstract Aim Transarterial embolization (TAE) or transarterial chemoembolization (TACE) is an important treatment approach for unresectable liver metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs). The prediction tool for therapeutic evaluation is still unclear. This study was performed to assess the prediction role of baseline digital substraction angiography (DSA) in synchronous liver metastatic GEP-NETs treated with TAE/ TACE. Methods Twenty-two patients with synchronous unresectable liver metastatic GEP-NETs (G1/2) and treated with TAE/ TACE were retrospectively enrolled. Clinical characteristics, baseline DSA and computed tomography (CT) information were collected. Results Totally, the overall response rate of TAE/ TACE on liver metastasis was 45.5%. The average baseline CT ratio (the density of the target lesion / the density of abdominal aorta during arterial phase) between responsive group and nonresponsive group were not statistically different (0.30±0.06 versus 0.36±0.11, P=0.149). Whereas, the average baseline DSA ratio (the density of target lesion / the density of liver background on DSA imaging before TAE/ TACE) of responsive group was significantly lower compared with that of nonresponsive group (0.57±0.13 versus 0.70±0.15, P=0.037). Patients with a DSA ratio ≤0.64 were more responsive to TAE/ TACE than those with a DSA ratio ༞0.64 (58.3% versus 30%). Univariate and multivariate analysis indicated that patients with lower hepatic tumor burden had longer PFS. Conclusions Baseline DSA ratio is a simple and potentially useful method to predict therapeutic effect of TAE/ TACE in liver metastases from GEP-NETs. And patients with lower hepatic tumor burden might indicate better prognosis. Prospective large-scale study is warranted.