Comparative evaluation of 18F-FDOPA, 13N-AMMONIA, 18F-FDG PET/CT and MRI in primary brain tumors - A pilot study

Abstract

Aim:To determine the diagnostic reliability of 18F-FDOPA, 13N-Ammonia and 18F-FDG PET/CT in primary brain tumors and comparison with magnetic resonance imaging (MRI).Materials and Methods:A total of 23 patients, 8 preoperative and 15 postoperative, undergoing evaluation for primary brain tumors were included in this study. Of them, 9/15 were operated for high grade gliomas (7/9 astrocytomas and 2/9 oligodendrogliomas) and 6/15 for low grade gliomas (5/6 astrocytomas and 1/6 oligodendroglioma). After PET study, 2 of 8 preoperative cases were histopathologically proven to be of benign etiology. 3 low grade and 2 high grade postoperative cases were disease free on 6 months follow-up. Tracer uptake was quantified by standardized uptake values (SUVmax) and the SUV max ratio of tumor to normal symmetrical area of contra lateral hemisphere (T/N). 18F-FDOPA uptake was also quantified by SUVmax ratio of tumor to striatum (T/S). Conventional MR studies were done in all patients.Results:Both high-grade and low-grade tumors were well visualized with 18F-FDOPA PET. Sensitivity of 18F-FDOPA PET was substantially higher (6/6 preoperative, 3/3 low grade postoperative, 7/7 high grade postoperative) than with 18F-FDG (3/6 preoperative, 1/3 low grade postoperative, 3/7 high grade postoperative) and 13N-Ammonia PET (2/6 preoperative, 1/3 low grade postoperative, 1/7 high grade postoperative). FDOPA was equally specific as FDG and Ammonia PET in operated cases but was falsely positive in two preoperative cases. Sensitivity of FDOPA (16/16) was more than MRI (13/16).Conclusion:18F-FDG uptake correlates with tumor grade. Though 18F-FDOPA PET cannot distinguish between tumor grade, it is more reliable than 18F-FDG and 13N-Ammonia PET for evaluating brain tumors. 18F-FDOPA PET may prove to be superior to MRI in evaluating recurrence and residual tumor tissue. 13N-Ammonia PET did not show any encouraging results.

Diagnostic accuracy of magnetic resonance imaging techniques for treatment response evaluation in patients with high-grade glioma, a systematic review and meta-analysis

“…Several of the included studies analysed multiple MRI modalities; therefore, a total of five anatomical MRI studies ( N = 166) [ 23 , 29 , 39 , 44 , 47 ], seven apparent diffusion coefficient (ADC) studies ( N = 204) [ 14 , 15 , 24 , 25 , 30 , 33 , 41 ], 18 dynamic susceptibility contrast (DSC) studies ( N = 708) [ 15 – 17 , 19 , 20 , 22 – 28 , 30 , 31 , 37 , 38 , 40 , 45 ], five studies on dynamic contrast enhanced (DCE) ( N = 207) [ 18 , 21 , 32 , 40 , 42 ], two arterial spin labelling (ASL) studies ( N = 102) [ 20 , 40 ], and nine magnetic resonance spectroscopy (MRS) studies ( N = 203) were included [ 22 , 24 , 34 – 36 , 40 , 43 , 46 , 48 ].…”

“…The anatomical MRI forest plot (five studies, 166 patients) shows a high variation in both sensitivity and specificity, with wide confidence intervals for three studies [ 23 , 29 , 44 ]. The wide confidence intervals of two references could be explained by the small sample size [ 23 , 29 ]. The moderate methodological quality might explain the wider confidence intervals in the other study [ 44 ].…”

“… - rCBV (0.71) 22 2 16 0 Hu et al [ 28 ] 11 Pros 47 91 WHO III: 3 WHO IV: 8 HGG with suspected recurrence after treatment undergoing re-resection Histology ( N = 11) 3 T. T1C fs 3D 2/0 (6.8/2.8/300); DSC 5/0 mm (2000/20). - rCBV without BLS/PLD (0.92-0.96) rCBV with BLS/PLD (1.02-1.03) 13 19 0 0 15 15 8 2 Jora et al [ 29 ] 7 Pros 43 ± 14.9* 61* WHO III + IV: 7 PHGG with suspected residual or recurrence after treatment Histology ( N = 7) 1.5 T. T1 tra, sag 3-5/- (400-550/14); T1C tra, cor, sag 3/- (400/15); T2 3/- (4000/126-130). - cMRI 3 1 2 1 Kim et al [ 30 ] 51 Retro 52 (35-72) 49 WHO IV: 51 GBM with new or enlarged enhan-cement after treatment undergoing re-resection Histology ( N = 51) 3 T. DWI - -/- (-/-) b 0, 10, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, 500, 700 and 900; DSC - -/-(1407/40).…”

Subependymal spread of glioblastoma multiforme in positron emission tomography/computed tomography

“…In a paper published recently aimed to compare the diagnostic reliability of ( 18 F)-L-dihydroxyphenylalanine ( 18 F FDOPA) versus magnetic resonance imaging (MRI) in primary brain tumors,[ 1 ] positron emission tomography/computed tomography (PET/CT) proved to be superior to MRI in evaluating recurrence and residual tumor tissue. [ 1 ] Here, we report a case of recurrent glioblastoma multiforme (GM) of the left frontal lobe. The patient was admitted to our center after a seizure episode in the right upper limb and a history of cognitive and memory impairment, apathy, and depression.…”

“…[ 18 F] FDOPA PET/CT has been proposed for the study of primary brain tumors and a higher diagnostic accuracy of this imaging modality as compared to contrast-enhanced MRI, has been reported. [ 1 ] Multifocal lesions with subependymal or subarachnoid spread is a quiet rare condition representing approximately 1.2% of recurrence in GM and approximately 15% of the intracranial dissemination of GM in adults. [ 3 ] If one considers that subependymal and periventricular enhancement in MRI could be related to several benign conditions (periventricular vascular structures, arteriovenous malformations, collateral venous drainage, etc.…”