Utility of flouro-deoxy-glucose positron emission tomography/computed tomography in the diagnostic and staging evaluation of patients with primary CNS lymphoma

Abstract

Aim: To prospectively assess the clinical utility of pretreatment flouro-deoxy-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in patients with primary central nervous system (CNS) lymphoma (PCNSL). Materials & methods: Patients with suspected/proven PCNSL underwent baseline whole-body 18F-FDG-PET/CT. Maximum standardized uptake value and tumor/normal tissue ratios were compared between CNS lymphoma and other histological diagnoses. Results: The mean maximum standardized uptake value (27.5 vs 18.2; p = 0.001) and mean tumor/normal tissue ratio (2.34 vs 1.53; p < 0.001) of CNS lymphoma was significantly higher than other histologic diagnoses. Five of 50 (10%) patients with biopsy-proven CNS lymphomas had pathologically increased FDG-uptake at extraneuraxial sites uncovering systemic lymphoma. Conclusion: Pretreatment whole-body 18F-FDG-PET/CT provides valuable complementary information in the diagnostic and staging evaluation of patients with PCNSL to guide therapeutic decision-making.

Positron emission tomography and magnetic resonance imaging in primary central nervous system lymphoma—a narrative review

“…However, some lesions visualized on MRI had no correlate on FDG PET ( 31 , 107 , 110 – 112 ) due to, e.g., small lesion size (usually <1 cm) and their pattern on MRI, such as disseminated presentation. Furthermore, leptomeningeal disease and eye involvement, diagnosed on CSF flow cytometry and vitreous aspirate, are usually not detectable on PET ( 31 ), due to small volume of FDG-avid disease or prominent FDG uptake in adjacent physiologic structures. This is also true for lesions in proximity to basal ganglia, which exhibit high physiologic FDG uptake.…”

“…The utility of whole-body FDG PET/CT for the staging and detection of lymphoma outside the brain has been corroborated in several studies. Indeed, FDG PET/CT has shown that about 4–10% of patients with suspected lymphoma confined to the brain have systemic involvement ( 31 , 117 ).…”

“…In another study with 101 patients (including 25 patients with lymphoma), an SUV max cut-off of 15.5 had 84% sensitivity and 80% specificity for diagnosing lymphomas ( 122 ). Finally, in a prospective study in 49 patients ( 31 ), 26 (53%) patients were found to have DLBCL-type CNS lymphoma, and the remaining 23 (47%) had other diagnoses such as HGG (n=17), infectious/inflammatory pathology (n=4), or brain metastases (n=2). CNS lymphoma was unifocal in 50% and multifocal in the other 50%.…”

“…Performance of a body fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has been recommended by several centers inside and outside the US, including our group ( 19 , 28 – 31 ); however, in the past, it was not included in guidelines by the International Primary CNS Lymphoma Collaborative Group (IPCG). For systemic staging, a whole-body FDG PET may be preferential to and obviate whole-body CT scan and testicular sonography.…”

Primary central nervous system lymphoma: advances in MRI and PET imaging

“…There is increasing evidence to suggest that FDG-PET imaging may be more sensitive than a conventional CT of the chest, abdomen, and pelvis as well as bone marrow biopsies for detecting systemic disease in PCNSL ( 69 ). Recent prospective studies suggest a significantly higher FDG-uptake in CNS lymphomas (n=45) compared to other histologic diagnoses (n=23) ( 70 ). Similarly, other authors have suggested that metabolic PET imaging with agents such as FDG and 11 C-methionin shows promise as a predictive biomarker and early detection of recurrences ( 71 , 72 ).…”