Diagnostic accuracy of visual analysis versus dual time-point imaging with 18F-FDG PET/CT for the characterization of indeterminate pulmonary nodules with low uptake

F Grisanti; J Zulueta; J J Rosales; M I Morales; L Sancho; M D Lozano; M Mesa-Guzmán; M J García-Velloso

doi:10.1016/j.remn.2020.03.019

Diagnostic accuracy of visual analysis versus dual time-point imaging with ¹⁸F-FDG PET/CT for the characterization of indeterminate pulmonary nodules with low uptake

Rev Esp Med Nucl Imagen Mol (Engl Ed). 2021 May-Jun;40(3):155-160. doi: 10.1016/j.remn.2020.03.019. Epub 2021 Mar 27.

[Article in English, Spanish]

Authors

F Grisanti¹, J Zulueta², J J Rosales³, M I Morales³, L Sancho⁴, M D Lozano⁵, M Mesa-Guzmán⁶, M J García-Velloso³

Affiliations

¹ Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España. Electronic address: fabianagrisanti@gmail.com.
² Departamento de Neumología, Clínica Universidad de Navarra, Pamplona, España.
³ Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
⁴ Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Madrid, España.
⁵ Departamento de Patología, Clínica Universidad de Navarra, Pamplona, España.
⁶ Departamento de Cirugía Torácica, Clínica Universidad de Navarra, Pamplona, España.

PMID: 33781718
DOI: 10.1016/j.remn.2020.03.019

Abstract

Objective: To determine the accuracy of visual analysis and the retention index (RI) with dual-time point ¹⁸F-FDG PET/CT for the characterization of indeterminate pulmonary nodules (IPN) with low FDG uptake.

Materials and methods: A retrospective analysis was performed on 43 patients (28 men, 64 ± 11 years old, range 36-83 years) referred for IPN characterization with ¹⁸F-FDG-PET/CT and maximum standard uptake value ≤ 2.5 at 60 minutes post-injection (SUV_max1). Nodules were analyzed by size, visual score for FDG uptake on standard (OSEM 2,8) and high definition (HD) reconstructions, SUV_max1, SUV_max at 180 minutes post-injection (SUV_max2), and RI was calculated. The definitive diagnosis was based on histopathological confirmation (n = 28) or ≥ 2 years of follow-up.

Results: Twenty-four (56%) nodules were malignant. RI ≥ 10% on standard reconstruction detected 18 nodules that would have been considered negative using the standard SUV_max ≥ 2.5 criterion for malignancy. RI ≥ 10% had a sensitivity, specificity, PPV, NPV and accuracy of 75, 73.7, 78.3, 70, and 74.4%, respectively, while for FDG uptake > liver on HD these were 79.1, 63.2, 73.1, 70.6, and 72.1%, respectively. SUV_max1 ≥ 2, SUV_max2 > 2.5 and FDG uptake > liver on standard reconstruction had a PPV of 100%. FDG uptake > mediastinum on HD had a NPV of 100%.

Conclusions: RI ≥ 10% was the most accurate criterion for malignancy, followed by FDG uptake > liver on HD reconstruction. On standard reconstruction, SUV_max1 ≥2 was highly predictive of malignancy, as well as SUV_max2 > 2.5 and FDG uptake > liver. FDG uptake < mediastinum on HD was highly predictive of benign nodules.

Keywords: Adenocarcinoma de pulmón; Adenocarcinoma of lung; Cáncer de pulmón; Diagnostic accuracy; Dual-time-point imaging; Lung cancer; Nódulo pulmonar solitario; PET/CT; PET/TC; Precisión diagnóstica; Protocolo de imagen tardía; Solitary pulmonary nodule.