Elaine Yuen Phin Lee1, Harinder Gill, Yong Wang, Yok-Lam Kwong, Pek-Lan Khong. 1. aDepartment of Diagnostic Radiology, Queen Mary Hospital, Li Ka Shing Faculty of Medicine bDepartment of Medicine, Queen Mary Hospital, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong cDepartment of Radiology, Zhongshan Hospital, Xiamen University, Fujian, China.
Abstract
OBJECTIVE: To evaluate the diagnostic accuracy of PET/computed tomography (CT) in detecting marrow infiltration in indolent non-Hodgkin lymphoma (NHL) with histopathological correlation. METHODS: All treatment-naive newly diagnosed indolent NHL with staging PET/CT were retrospectively evaluated for marrow infiltration and categorized on the basis of the PET/CT uptake pattern: normal (PET/CT negative), focal/diffuse (PET/CT positive). Bone marrow biopsy (BMB) was considered the standard, except in focal PET/CT uptake, which was confirmed to be positive or negative by serial PET/CT. The BMB pattern was assessed as diffuse and nondiffuse and the degree of lymphoid infiltration was documented. RESULTS: Forty-six patients (mean age 59 ± 15 years) were evaluated. In the PET/CT-positive group of 22 cases (diffuse = 15, focal = 7), BMB was positive in 21 cases. In 80% of diffuse PET/CT uptake cases, a diffuse BMB infiltrative pattern was observed. However, in cases with focal PET/CT uptake, no predominant histological pattern was observed. No correlation was found between semiquantitative uptake and degree of lymphoid infiltration on BMB (r = 0.2, P = 0.434). In the PET/CT-negative group of 24 cases, 20 cases were BMB negative and four cases were positive. The overall diagnostic accuracy of PET/CT in determining marrow infiltration was 89% (sensitivity 84%, specificity 95%, positive predictive value 95% and negative predictive value 83%). CONCLUSION: PET/CT showed high specificity and positive predictive value with moderate accuracy in detecting marrow disease in indolent NHL. The metabolic uptake lacked a significant correlation with the degree of lymphoid infiltration, but a potential relationship may exist between the pattern of metabolic uptake and the BMB infiltrative pattern.
OBJECTIVE: To evaluate the diagnostic accuracy of PET/computed tomography (CT) in detecting marrow infiltration in indolent non-Hodgkin lymphoma (NHL) with histopathological correlation. METHODS: All treatment-naive newly diagnosed indolent NHL with staging PET/CT were retrospectively evaluated for marrow infiltration and categorized on the basis of the PET/CT uptake pattern: normal (PET/CT negative), focal/diffuse (PET/CT positive). Bone marrow biopsy (BMB) was considered the standard, except in focal PET/CT uptake, which was confirmed to be positive or negative by serial PET/CT. The BMB pattern was assessed as diffuse and nondiffuse and the degree of lymphoid infiltration was documented. RESULTS: Forty-six patients (mean age 59 ± 15 years) were evaluated. In the PET/CT-positive group of 22 cases (diffuse = 15, focal = 7), BMB was positive in 21 cases. In 80% of diffuse PET/CT uptake cases, a diffuse BMB infiltrative pattern was observed. However, in cases with focal PET/CT uptake, no predominant histological pattern was observed. No correlation was found between semiquantitative uptake and degree of lymphoid infiltration on BMB (r = 0.2, P = 0.434). In the PET/CT-negative group of 24 cases, 20 cases were BMB negative and four cases were positive. The overall diagnostic accuracy of PET/CT in determining marrow infiltration was 89% (sensitivity 84%, specificity 95%, positive predictive value 95% and negative predictive value 83%). CONCLUSION: PET/CT showed high specificity and positive predictive value with moderate accuracy in detecting marrow disease in indolent NHL. The metabolic uptake lacked a significant correlation with the degree of lymphoid infiltration, but a potential relationship may exist between the pattern of metabolic uptake and the BMB infiltrative pattern.