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Updated: Jan 14, 2026
A Practical Guide for the Production and PET/CT Imaging of 68Ga-DOTATATE for Neuroendocrine Tumors in Daily Clinical Practice
Published on: April 17, 2019
Per-Lesion Assessment of Individual MRI Sequences and 68 Ga-DOTATATE PET in Neuroendocrine Liver Metastases
Objectives:
To explore magnetic resonance imaging (MRI) and gallium-68 ( 68 Ga)-DOTATATE positron emission tomography (PET) performance in the assessment of neuroendocrine liver metastases (NELMs) on a per-lesion basis, with particular attention to the contribution of individual MRI sequences and assessment of other factors that might influence their detection.
Materials And Methods:
This observational retrospective study included patients with histologically confirmed neuroendocrine tumors who underwent both contrast-enhanced MRI and 68 Ga-DOTATATE PET within 12 weeks between August 2017 and December 2023. Three readers in consensus assessed individual MRI sequences [diffusion-weighted imaging (DWI), dynamic contrast-enhanced imaging (DCE), and hepatobiliary phase (HBP) imaging when available], entire MRI data set, and PET in random order. The reference standard was histopathology or follow-up imaging. Diagnostic performance metrics were calculated using generalized estimating equations with Bonferroni correction. Correlations were assessed using Pearson correlation coefficients.
Results:
A total of 1249 lesions, comprising 1050 metastases, were analyzed in 60 patients (mean age: 64.9±11.5 years; 56.7% male). Compared with PET, MRI demonstrated superior sensitivity (93% vs. 59%, P <0.001) and accuracy (93% vs. 63%, P <0.001), with DWI and HBP providing the highest sensitivity (89% and 92%). Size-stratified analysis showed that MRI outperformed PET, particularly for metastases <5 mm (81.6% vs. 19.7%) and 5 to 10 mm (96.1% vs. 61.8%) ( P <0.001). Arterial enhancement and portal venous washout were present in 67.8% and 23.7% of metastases, respectively, with only portal venous washout showing size dependence (11.9% in <5 mm to 55.6% in >20 mm lesions, P <0.01). PET-negative metastases were smaller than PET-positives (5.0 vs. 8.0 mm, P =0.001), with lesion size correlating with maximum standardized uptake values and normalized uptake ratios ( r =0.54 to 0.59, P <0.001).
Conclusions:
MRI outperformed 68 Ga-DOTATATE PET in detecting NELMs, with DWI and HBP providing particularly high sensitivity for small metastases.
Insights
Magnetic resonance imaging (MRI) significantly outperforms gallium-68 (68Ga)-DOTATATE positron emission tomography (PET) in detecting neuroendocrine liver metastases (NELMs). Specific MRI sequences like diffusion-weighted imaging (DWI) and hepatobiliary phase (HBP) show high sensitivity, especially for small lesions.
Area of Science:
- Radiology
- Oncology
- Nuclear Medicine
Background:
- Neuroendocrine liver metastases (NELMs) pose diagnostic challenges.
- Accurate detection is crucial for effective patient management and treatment planning.
Purpose of the Study:
- To compare the diagnostic performance of MRI and 68Ga-DOTATATE PET for NELMs.
- To evaluate the contribution of individual MRI sequences (DWI, DCE, HBP) in detecting NELMs.
- To identify factors influencing lesion detection.
Main Methods:
- Retrospective observational study of patients with confirmed neuroendocrine tumors.
- Analysis of contrast-enhanced MRI and 68Ga-DOTATATE PET scans performed within 12 weeks.
- Consensus assessment by three readers of MRI sequences, full MRI, and PET data.
- Histopathology or follow-up imaging served as the reference standard.
Main Results:
- MRI demonstrated superior sensitivity (93%) and accuracy (93%) compared to PET (59% and 63%, respectively).
- Diffusion-weighted imaging (DWI) and hepatobiliary phase (HBP) imaging showed the highest sensitivity (89% and 92%).
- MRI outperformed PET in detecting smaller metastases (<5 mm and 5-10 mm).
Conclusions:
- MRI is more effective than 68Ga-DOTATATE PET for detecting NELMs.
- DWI and HBP sequences are particularly valuable for identifying small NELMs.
- MRI's superior performance aids in more comprehensive assessment of liver metastases.
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