To summarize and analyse the short-term efficacy and safety of transarterial embolization (TAE) on low-to-intermediate grade neuroendocrine neoplasm liver metastasis (NENLM) with hypovascular pattern.

From January 2016 to December 2019, at the First Affiliated Hospital of Sun Yat-sen University, among the patients with different primary site of low-to-intermediate grade NENLM after the treatment of TAE, 42 cases were selected whose preoperative imaging findings for lack of blood supply. All cases had completed postoperative imaging evaluation. Respectively according to RECIST 1.1 and mRECIST criteria to evaluate the curative effect, the objective response rate (ORR) and disease control rates (DCR) were calculated within 1-3 months after the operation. Recorded the postoperative adverse events according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

TAE has a significant debulking effect on low-to-intermediate grade NENLM with hypovascular pattern, which was evaluated according to RECIST 1.1, ORR was 66.7%, DCR was 92.9%. And according to mRECIST criteria, ORR was 85.7%, DCR was 92.9%, and CR rate was 16.7%. The major complications were fever (88.1%), hepatic pain (78.6%) and transient liver dysfunction [elevated liver enzymes (40.5%), elevated bilirubin (19.1%)], which can be alleviated after symptomatic treatment. There is no serious postoperative complications.

Although some low-to-intermediate grade NENLM is characterized by lack of blood supply in imaging, its ORR is still significant after TAE. TAE is safe and effective in reducing burden in NENLM with hypovascular pattern.