Renal Masses Detected on FDG PET/CT in Patients With Lymphoma: Imaging Features Differentiating Primary Renal Cell Carcinomas From Renal Lymphomatous Involvement

Abstract

OBJECTIVE The purpose of this study is to analyze the 18F-FDG PET/CT features of solid renal masses detected in patients with lymphoma and to evaluate the ability of PET/CT to differentiate renal cell carcinoma (RCC) from renal lymphomatous involvement. MATERIALS AND METHODS Thirty-six patients with solid renal masses on PET/CT performed for staging or follow-up of lymphoma were evaluated retrospectively. The features recorded for each renal mass included the following standardized uptake values (SUVs) on PET/CT: the maximum SUV (SUVmax), the mean SUV (SUVmean), the ratio of the SUVmax of the tumor to that of the normal kidney cortex, the ratio of the SUVmean of the tumor to that of the normal kidney cortex, the ratio of the SUVmax of the tumor to that of the normal liver, and the ratio of the SUVmean of the tumor to that of the normal liver. Renal mass size and margins (well defined vs infiltrative) and the presence of calcifications were evaluated on CT. Renal biopsy results were used as the reference standard. Relationships between imaging parameters and histopathologic findings were assessed. RESULTS Of the 36 renal masses evaluated, 22 (61.1%) were RCCs and 14 (38.9%) were renal lymphomas. All SUV metrics were higher for renal lymphomas than for RCCs (p< 0.0001, for all). All renal lymphomas had an SUVmax higher than 5.98 g/mL (median, 10.99 g/mL), whereas all RCCs had an SUVmax lower than 5.26 g/mL (median, 2.91 g/mL). No statistically significant differences in mass size or margins were found between RCCs and renal lymphoma. CONCLUSION PET/CT features may be useful for differentiating RCCs from renal involvement in patients with lymphoma with solid renal masses.

Radiomics based on 18F‐FDG PET/CT could differentiate breast carcinoma from breast lymphoma using machine‐learning approach: A preliminary study

“…11 Texture analysis of computed tomography (CT) and magnetic resonance imaging (MRI) showed promising discriminative ability in various lesions, including breast lesions, lung lesions, and so on. [12][13][14] Texture analysis on 18 F-FDG positron emission tomography (PET)/CT images also showed great diagnostic utility among lung lesions, 15 renal lesions 16 and bone and soft-tissue lesions. 11 While the possibility using radiomic features to differentiate between carcinoma and lymphoma in the breast has not been investigated yet.…”

Three-Dimensional Texture Analysis Based on PET/CT Images to Distinguish Hepatocellular Carcinoma and Hepatic Lymphoma

“…PET/CT can reveal the metabolic characters of organs, and as tumor cells have enhanced glycolysis, they have higher 18F-FDG uptake compared with normal tissue. Previous studies have indicated that the SUV metrics of lymphoma was higher than that of carcinoma in PET/CT images when differentiating renal carcinoma and lymphoma with renal involvement (14, 15). However, a study claimed that the SUV max was not conclusive when distinguishing between primary nasopharyngeal lymphoma and nasopharyngeal carcinoma (16).…”

Primary renal lymphoma: CT findings of a rare case

“…21,22 However, PET/CT may be useful in distinguishing between lymphoma and RCC since the former is intensely FDG-avid while the latter may not show as much FDG uptake. 23 Traditionally, PRL has been associated with a poor prognosis. 16,[24][25][26] However, early diagnosis and proper management results in a favorable outcome.…”