Differentiation of HIV-associated lymphoma from HIV-associated reactive adenopathy using quantitative FDG PET and symmetry

Abstract

Purpose To determine the diagnostic accuracy of a semiautomated 18F-FDG PET/CT measurement of total lesion glycolysis (TLG), maximum and peak standardized uptake value at lean body mass (SUL-Max and SUL-Peak), qualitative estimates of left/right nodal symmetry and FDG uptake for differentiating lymphoma from reactive adenopathy in HIV-infected patients. Methods We retrospectively analyzed 41 whole-body 18F-FDG PET/CT studies performed in HIV-infected patients for clinical reasons. The study received institutional review board approval. Of the 41 patients, 19 had biopsy-proven untreated lymphoma, and 22 with reactive adenopathy without malignancy on follow-up were used as controls. Nodal and extranodal visual qualitative metabolic scores, SUL-Max, SUL-Peak, CT nodal size, and PERCIST 1.0 threshold-based TLG and metabolic tumor volume (MTV) were determined. The qualitative intensity of nodal involvement and symmetry of uptake were compared using receiver operator curve (ROC) analysis. HIV plasma viral RNA measurements were also obtained. Results All of the quantitative PET metrics performed well in differentiating lymphoma from reactive adenopathy and performed better than qualitative visual intensity scores. The areas under the ROC curves (AUC) were significantly higher for TLG=0.96, single SUL-Peak=0.96, single SUL-Max=0.97, and MTV=0.96, compared to 0.67 for CT nodal size (p<0.001). These PET metrics performed best in separating the two populations in aviremic patients, with AUCs of 1 (AUC 0.91 for CT nodal size). TLG, MTV, SUL-Peak and SUL-Max were more reliable markers among viremic individuals, with AUCs between 0.84 and 0.93, compared to other metrics. PET metrics were significantly correlated with plasma viral load in HIV-reactive adenopathy controls. Asymmetrical FDG uptake had an accuracy of 90.4 % for differentiating lymphoma from reactive adenopathy in HIV-infected patients. Conclusion Quantitative PET metabolic metrics as well as the qualitative assessment of symmetry of nodal uptake appear to be valuable tools for differentiating lymphoma from reactive adenopathy in HIV-infected patients using FDG PET. These parameters appear more robust in aviremic patients.

CT-based texture analysis potentially provides prognostic information complementary to interim fdg-pet for patients with hodgkin’s and aggressive non-hodgkin’s lymphomas

“…As iPET has low or variable reported positive predictive value in DLBCL, this would be useful to investigate in future studies. Quantification of changes in tumour FDG using % reduction in SUV max values or other functional markers such as total lesion glycolysis and metabolic tumour volume may be necessary to optimize the prognostic performance of iPET, particularly in DLBCL [33–35], and may help reduce false-positive findings relative to visual assessment alone. This was not assessed in our study, as uptake times for all scans were not strictly controlled.…”

CT Texture Analysis of Cervical Lymph Nodes on Contrast-Enhanced [18F] FDG-PET/CT Images to Differentiate Nodal Metastases from Reactive Lymphadenopathy in HIV-Positive Patients with Head and Neck Squamous Cell Carcinoma

“…16,18,34 In past years, other quantitative approaches, including metabolic tumor volume and total lesion glycolysis for [ 18 F] FDG-PET evaluations, have been investigated for differentiation of HIV-associated lymphoma from HIV-associated reactive adenopathy. 35,36 CT texture features can also be obtained from the same [ 18 F] FDG-PET/CT study. The combination model based on these quantitative PET metabolic metrics, CT texture parameters, and clinical parameters may need to be further evaluated in a future study for patients with head and neck squamous cell carcinoma.…”

Differentiation of HIV-associated lymphoma from HIV-reactive adenopathy using quantitative FDG-PET and symmetry

“…& Liu found that a coexistent FDG avid nasopharyngeal lesion and generalized lymphadenopathy on PET/CT imaging is indicative of a malignant lymphoma rather than benign lymphoproliferative disease or nasopharyngeal carcinoma [10]. However, Mhlanga et al [1] found no significant difference in the nasopharyngeal region mean SUL-Max scores between patients with HIV-associated lymphoma and those with HIV-reactive adenopathy.…”

“…In this issue of the European Journal of Nuclear Medicine and Molecular Imaging, Mhlanga et al [1] address the important challenge of differentiating between HIV-reactive lymphadenopathy and HIV-associated lymphoma using FDG PET/CT. What is more interesting about this study is the fact they rigorously assessed the quantitative PET metabolic metrics to distinguish these entities.…”

“…Current knowledge about HIV-associated lymphomas can be summarized as follows: (1) they are closely linked to oncogenic herpesviruses, namely Epstein-Barr virus and Kaposi sarcoma-associated herpesvirus; (2) they are predominantly aggressive B-cell malignancies (widely disseminated with frequent involvement of extranodal sites); (3) most are Burkitt lymphoma and diffuse large B-cell lymphoma; (4) Hodgkin lymphoma which is a non-AIDS-defining malignancy has been shown to be increased in incidence in the setting of HIV infection [1,3].…”