Detection of cardiac neuroendocrine tumour metastases by somatostatin receptor PET/CT: a systematic review and meta-analysis

Abstract

Background: Cardiac neuroendocrine tumour metastases (CNTM) are rare, but advancements in molecular imaging including somatostatin receptor PET/CT (SSTR-PET/CT) could lead to a more frequent identification. The aim of this article is to perform a systematic review and meta-analysis on the detection of CNTM by SSTR-PET/CT.

Methods: A comprehensive literature search of studies on CNTM detected by SSTR-PET/CT was carried out. Three different bibliographic databases were screened (Cochrane library, PubMed/MEDLINE, EMBASE) until 20 August 2024. Two review authors independently selected the eligible original articles and performed the quality assessment and the data extraction. Main findings of eligible studies were summarized and a proportion meta-analysis on the prevalence of patients with CNTM among those with neuroendocrine neoplasm (NEN) performing SSTR-PET/CT was carried out using a random-effects model.

Results: Ten articles reporting data on 163 patients with CNTM were included in the systematic review. SSTR was able to detect CNTM earlier compared to other radiological imaging techniques. Most patients with CNTM had other metastatic sites and CNTM were often asymptomatic. The meta-analysis of seven articles demonstrated a pooled prevalence of 1.5% (95% confidence interval: 1.0-1.9%) of patients with CNTM (n = 119) among those performing SSTR-PET/CT for NEN (n = 9,300). Moderate statistical heterogeneity was found (I ² test: 62%).

Conclusion: Evidence-based data demonstrate that SSTR-PET/CT enables early and better detection of CNTM compared to other radiological imaging methods. CNTM are encountered with a pooled prevalence of 1.5% of NEN patients performing SSTR-PET/CT. Prospective and multicentric studies are warranted to better clarify the impact of CNTM detection by SSTR-PET/CT on overall survival and clinical decision-making in NEN patients.

Keywords: cardiac metastases; hybrid imaging; meta-analysis PET/CT; neuroendocrine neoplasm; neuroendocrine tumours; nuclear medicine; positron emission tomography; somatostatin.

Figure 1

Examples of CNTM detected by SSTR-PET/CT in two NEN patients. Case 1: Myocardial metastasis of left ventricular latero-basal wall (arrows) detected by SSTR-PET/CT (A: anterior MIP) in a 74-year-old patient with G2 pancreatic NEN. The CNTM appeared at cardiac magnetic resonance (CMR) as a 22-mm nodule with intermediate intensity on T1-weighted images (B, short axis), with peripheral contrast-enhancement on phase sensitive inversion recovery sequence (C, short axis). Fused SSTR-PET/CMR image is also showed (D, short axis). Case 2: 76-year-old patient with inter-atrial myocardial lesion (arrows) of metastatic G1 small intestinal NEN detected by SSTR-PET/CT (E: anterior MIP). Echocardiography (4-chamber view) showed hypoechoic mass on the right side of interatrial septum (F). The CNTM showed a slight peripheral enhancement on delayed post-contrast inversion recovery CMR sequences (G, short axis). Fused SSTR-PET/CMR image is also showed (H, axial slice).

Figure 2

Flow chart of the search for eligible studies on the role SSTR-PET/CT for CNTM detection.

Figure 3

Overall quality assessment of the studies included in the systematic review according to the QUADAS-2 tool.

Figure 4

Plots of individual studies and pooled prevalence of patients with CNTM among those with NEN performing SSTR-PET/CT, including 95% confidence intervals (95% CI). The size of the squares indicates the weight of each study. A random-effect model was used for the statistical analysis.