Sequential implementation of DSC-MR perfusion and dynamic [18F]FET PET allows efficient differentiation of glioma progression from treatment-related changes

Abstract

Purpose Perfusion-weighted MRI (PWI) and O-(2-[18F]fluoroethyl-)-l-tyrosine ([18F]FET) PET are both applied to discriminate tumor progression (TP) from treatment-related changes (TRC) in patients with suspected recurrent glioma. While the combination of both methods has been reported to improve the diagnostic accuracy, the performance of a sequential implementation has not been further investigated. Therefore, we retrospectively analyzed the diagnostic value of consecutive PWI and [18F]FET PET. Methods We evaluated 104 patients with WHO grade II–IV glioma and suspected TP on conventional MRI using PWI and dynamic [18F]FET PET. Leakage corrected maximum relative cerebral blood volumes (rCBVmax) were obtained from dynamic susceptibility contrast PWI. Furthermore, we calculated static (i.e., maximum tumor to brain ratios; TBRmax) and dynamic [18F]FET PET parameters (i.e., Slope). Definitive diagnoses were based on histopathology (n = 42) or clinico-radiological follow-up (n = 62). The diagnostic performance of PWI and [18F]FET PET parameters to differentiate TP from TRC was evaluated by analyzing receiver operating characteristic and area under the curve (AUC). Results Across all patients, the differentiation of TP from TRC using rCBVmax or [18F]FET PET parameters was moderate (AUC = 0.69–0.75; p < 0.01). A rCBVmax cutoff > 2.85 had a positive predictive value for TP of 100%, enabling a correct TP diagnosis in 44 patients. In the remaining 60 patients, combined static and dynamic [18F]FET PET parameters (TBRmax, Slope) correctly discriminated TP and TRC in a significant 78% of patients, increasing the overall accuracy to 87%. A subgroup analysis of isocitrate dehydrogenase (IDH) mutant tumors indicated a superior performance of PWI to [18F]FET PET (AUC = 0.8/< 0.62, p < 0.01/≥ 0.3). Conclusion While marked hyperperfusion on PWI indicated TP, [18F]FET PET proved beneficial to discriminate TP from TRC when PWI remained inconclusive. Thus, our results highlight the clinical value of sequential use of PWI and [18F]FET PET, allowing an economical use of diagnostic methods. The impact of an IDH mutation needs further investigation.

Two Decades of Brain Tumour Imaging with O-(2-[18F]fluoroethyl)-L-tyrosine PET: The Forschungszentrum Jülich Experience

“…However, FET PET and advanced MR methods should not be regarded as competing, but complementary. The complementary or additive nature of both approaches is currently the subject of numerous studies with promising results [ 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”

Relevance of Dynamic 18F-DOPA PET Radiomics for Differentiation of High-Grade Glioma Progression from Treatment-Related Changes

“…The latter has been defined as our reference since the addition of clinical features to this model did not show any significant diagnostic performance improvements (AUC of 0.79 for the combination of TBR mean and clinical features, Table 2 ). In the context of differential diagnosis of glioma progression and TRC, dynamic parameters of amino-acid PET radiotracers, exclusively extracted from tumor VOIs, did not improve on the diagnostic performances of static parameters reported in the literature [ 3 , 32 , 33 , 34 , 35 , 36 ]. To date, few studies have investigated the value of amino-acid PET radiomic features in the context of glioma progression [ 8 , 9 , 10 ].…”

The diagnostic accuracy of O-(2-18F-fluoroethyl)-L-tyrosine parameters for the differentiation of brain tumour progression from treatment-related changes

“…For the 18 F-FET static parameters in the differentiation of true progression and treatment-related changes, the TBR max was found in 17 studies [8,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], and the TBR mean was found in 12 studies [8,[13][14][15][16][17][18][19]21,24,25,28] (Fig. 2).…”

“…For the 18 F-FET dynamic parameter, five studies [14,16,24,26,28] used the slope dynamic parameter, five studies [16,18,21,23,28] used TTP and four studies [8,13,18,21] used kinetic patterns (Supplementary Figure S3, Supplemental digital content 1, http://links.lww.com/ NMC/A212). The pooled sensitivity of slope, TTP and kinetic pattern were 70% (95% CI, 64-76%), 73% (95% CI, 67-78%) and 81% (95% CI, 75-86%), respectively.…”