To explore the value of ¹⁸F-FDG PET/CT in detecting Richter syndrome (RS) in chronic lymphocytic leukemia (CLL) patients.

From August 2010 to November 2019, 101 histologically confirmed CLL patients (62 males, 39 females; age (58.0±12.7) years) who underwent PET/CT in Nanjing Drum Tower Hospital and the First Affiliated Hospital of Nanjing Medical University were retrospectively included. ROI was drawn and PET/CT images were semi-quantitatively examined by estimating SUV_max. Mann-Whitney U test was used to compare the SUV_max of RS and non-RS patients. ROC curve analysis was utilized to analyze the optimal cut-off value of SUV_max in detecting RS.

RS was histologically confirmed in 27 CLL patients. The SUV_max of RS patients was 13.7(11.0, 20.1), which was significantly higher than that of non-RS patients (4.1(3.1, 5.8); z=-6.48, P<0.001). ROC curve analysis identified the optimal cut-off value of SUV_max was 10.0 and the AUC was 0.923, with accuracy of 94.1%(95/101), sensitivity of 85.2%(23/27), specificity of 97.3%(72/74), positive predictive value of 92.0%(23/25) and negative predictive value of 94.7%(72/76).

As the semi-quantitative index measured by ¹⁸F-FDG PET/CT, SUV_max can help to diagnose RS and provide important information for clinical use.

Leukemia, lymphocytic, chronic, B-cell; Syndrome; Positron-emission tomography; Tomography, X-ray computed; Fluorodeoxyglucose F18