Huh J, Park J, Kim KW, Kim HJ, Lee JS, Lee JH, Jeong YK, Shinagare AB, Ramaiya NH. Optimal Phase of Dynamic Computed Tomography for Reliable Size Measurement of Metastatic Neuroendocrine Tumors of the Liver: Comparison between Pre- and Post-Contrast Phases.
Korean J Radiol 2018;
19:1066-1076. [PMID:
30386138 PMCID:
PMC6201971 DOI:
10.3348/kjr.2018.19.6.1066]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 04/22/2018] [Indexed: 11/16/2022] Open
Abstract
Objective
The reliability of size measurements of liver metastases from neuroendocrine tumors (NETs) on contrast-enhanced computed tomography (CT) phases made by different readers may be hampered due to transient, variable rim enhancement in arterial phase (AP) or portal venous phase (PVP) images. We aimed to assess the reliability of tumor size measurements in pre- and post-contrast scans.
Materials and Methods
The study coordinator selected target lesions according to Response Evaluation Criteria in Solid Tumors 1.1 guidelines in 44 consecutive patients with pathologically confirmed NET liver metastases. Two blinded readers measured the longest diameters of target lesions on pre-contrast, AP, and PVP images twice with a 4-week interval. Inter- and intra-observer agreements were evaluated using Bland-Altman plots and 95% limit of agreement (LOA) calculations.
Results
Of the 79 target lesions (approximate mean size of 3 cm), 45 showed rim enhancement. Inter-observer agreement assessed based on LOA was highest in pre-contrast CT images (−6.1–5.7 mm), followed by PVP (−7.9–7.1 mm) and AP (−8.5–7.4 mm) images. Intra-observer agreement showed the same trend: −2.8–2.9 mm and −2.9–2.9 mm for readers 1 and 2, respectively, on pre-contrast CT, −2.8–2.9 mm and −3.0–3.2 mm, respectively, on PVP, and −3.2–4.2 mm and −3.4–3.2 mm, respectively, on AP images. Mean tumor diameters differed significantly among the phases in the following increasing order: pre-contrast CT, PVP, and AP images.
Conclusion
There was better inter- and intra-observer agreement in size measurements of NET liver metastases on precontrast scans than on AP and PVP scans. Pre-contrast CT may be the optimal for measuring NET liver metastases if its accuracy is proven.
Collapse