Diagnostic yield of simultaneous dynamic contrast-enhanced magnetic resonance perfusion measurements and [18F]FET PET in patients with suspected recurrent anaplastic astrocytoma and glioblastoma

Abstract

Purpose Both amino acid positron emission tomography (PET) and magnetic resonance imaging (MRI) blood volume (BV) measurements are used in suspected recurrent high-grade gliomas. We compared the separate and combined diagnostic yield of simultaneously acquired dynamic contrast-enhanced (DCE) perfusion MRI and O-(2-[18F]-fluoroethyl)-L-tyrosine ([18F]FET) PET in patients with anaplastic astrocytoma and glioblastoma following standard therapy. Methods A total of 76 lesions in 60 hybrid [18F]FET PET/MRI scans with DCE MRI from patients with suspected recurrence of anaplastic astrocytoma and glioblastoma were included retrospectively. BV was measured from DCE MRI employing a 2-compartment exchange model (2CXM). Diagnostic performances of maximal tumour-to-background [18F]FET uptake (TBRmax), maximal BV (BVmax) and normalised BVmax (nBVmax) were determined by ROC analysis using 6-month histopathological (n = 28) or clinical/radiographical follow-up (n = 48) as reference. Sensitivity and specificity at optimal cut-offs were determined separately for enhancing and non-enhancing lesions. Results In progressive lesions, all BV and [18F]FET metrics were higher than in non-progressive lesions. ROC analyses showed higher overall ROC AUCs for TBRmax than both BVmax and nBVmax in both lesion-wise (all lesions, p = 0.04) and in patient-wise analysis (p < 0.01). Combining TBRmax with BV metrics did not increase ROC AUC. Lesion-wise positive fraction/sensitivity/specificity at optimal cut-offs were 55%/91%/84% for TBRmax, 45%/77%/84% for BVmax and 59%/84%/72% for nBVmax. Combining TBRmax and best-performing BV cut-offs yielded lesion-wise sensitivity/specificity of 75/97%. The fraction of progressive lesions was 11% in concordant negative lesions, 33% in lesions only BV positive, 64% in lesions only [18F]FET positive and 97% in concordant positive lesions. Conclusion The overall diagnostic accuracy of DCE BV imaging is good, but lower than that of [18F]FET PET. Adding DCE BV imaging did not improve the overall diagnostic accuracy of [18F]FET PET, but may improve specificity and allow better lesion-wise risk stratification than [18F]FET PET alone.

Hybrid18F-Fluoroethyltyrosine PET and MRI with Perfusion to Distinguish Disease Progression from Treatment-Related Change in Malignant Brain Tumors: The Quest to Beat the Toughest Cases

“…This report provides additional evidence supporting the complementary nature of 18 18 F-FET PET data were acquired in list mode from 0 to 40 min, concurrent with MRI acquisitions, allowing reconstruction as both single-frame late static images and a dynamic sequence for assessing regional radiopharmaceutical kinetics. 18 F-FET (503-810 MBq) was administered as a bolus followed by a saline flush. Relatively high 18 F-FET doses were used to enhance small-lesion (,10 mm) detection, with estimated critical organ doses remaining commensurate with standard clinical nuclear medicine procedures.…”

“…To help overcome MRI's limitations, international working groups recommend amino acid PET imaging for complementary assessment of malignant brain tumors given superior tumor-to-background contrast (12)(13)(14). 18 F-fluoroethyltyrosine ( 18 F-FET) is the most commonly used amino acid radiotracer, providing a high diagnostic value for differentiating POD from TRC (15)(16)(17)(18). PWI combined with 18 F-FET PET demonstrates increased sensitivity and specificity for delineating POD from TRC in malignant brain tumors, with hybrid 18 F-FET PET/MRI further increasing the accuracy (5,19,20).…”

“…PWI combined with 18 F-FET PET demonstrates increased sensitivity and specificity for delineating POD from TRC in malignant brain tumors, with hybrid 18 F-FET PET/MRI further increasing the accuracy (5,19,20). We report the clinical application of hybrid 18 F-FET PET/MRI to patients with malignant brain tumors at a U.S. institution to discern POD from TRC. This report provides additional evidence supporting the complementary nature of 18 18 F-FET PET data were acquired in list mode from 0 to 40 min, concurrent with MRI acquisitions, allowing reconstruction as both single-frame late static images and a dynamic sequence for assessing regional radiopharmaceutical kinetics.…”

“…We report the clinical application of hybrid 18 F-FET PET/MRI to patients with malignant brain tumors at a U.S. institution to discern POD from TRC. This report provides additional evidence supporting the complementary nature of 18 18 F-FET PET data were acquired in list mode from 0 to 40 min, concurrent with MRI acquisitions, allowing reconstruction as both single-frame late static images and a dynamic sequence for assessing regional radiopharmaceutical kinetics. 18 F-FET (503-810 MBq) was administered as a bolus followed by a saline flush.…”

“…18 F-FET (503-810 MBq) was administered as a bolus followed by a saline flush. Relatively high 18 F-FET doses were used to enhance small-lesion (,10 mm) detection, with estimated critical organ doses remaining commensurate with standard clinical nuclear medicine procedures. Image analysis and interpretation followed the Society of Nuclear Medicine and European Association of Nuclear Medicine procedural recommendations for 18 F-FET PET/MRI of brain tumors (14).…”