Utility of fluorine18 fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography in metabolic characterization of solid renal mass lesion and localization of extra renal lesions in the body - A prospective study from the tertiary care center in South India

• Published in: Indian journal of nuclear medicine 2022-10, Vol.37 (4), p.329-336
• Main Authors: Sri Charan, Kommu, Kalawat, Tekchand, Priya, Rallapeta, Nallabothula, Anil, Manthri, Ranadheer, Reddy, Singareddy, Narendra, Hulikal, Rukmangadha, Nandyala, Kale, Pavan, Ajit, Nimmagadda
• Format: Article
• Language: English
• Subjects: Computed tomography; Dextrose; Emission analysis; Etiology; Glucose; Lesions; Metabolism; Metastasis; Original; Parameter identification; PET imaging; Positron emission; Tomography
• ISSN: 0972-3919; 0974-0244
• DOI: 10.4103/ijnm.ijnm_41_22

Purpose of the Study: Renal mass lesions in majority of the cases are due to malignant etiology and about one-third of them are reported with metastatic lesions at the time of presentation. Thus proper investigational workup is needed for staging and thereby treatment planning. The current fluorine18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F18-FDG PET/CT) study was designed to characterize renal mass lesions metabolically and identifying other metabolically active lesions in the body suggesting metastatic disease. Materials and Methods: A total of 24 patients (males - 18 and females - 6) with a mean age of 53.8 ± 12.3 years were recruited in this study for dual time-point PET/CT scan. All patients with renal mass lesions underwent contrast-enhanced CT prior to PET/CT. Metabolic parameters such as maximum standardized uptake value (max.SUV) with a cut off ≥2.5 and retention index (RI) of ≥10% were used to label the lesion as malignant and remaining less than cutoff as benign. The final diagnosis of lesion on imaging was confirmed with a histopathological examination (HPE). Results: Using max.SUV cut off value, 17/24 renal mass lesions were characterized as malignant and remaining 7/24 renal lesions of benign etiology. PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 80%, 75%, 94.1%, 42.8%, and 79.1%, respectively, by considering HPE as a gold standard. Nine patients were diagnosed with distant site involvement suggestive of metastases. Conclusion: F18-FDG PET/CT can efficiently characterize solid renal mass lesion as benign and malignant using metabolic parameters such as max.SUV and RI. In addition, whole-body survey identified distant site involvement in 25% of the patients, thus contributing change in management.