Diagnosis of pseudoprogression in patients with glioblastoma using O-(2-[18F]fluoroethyl)-l-tyrosine PET

Abstract

(18)F-FET PET may facilitate the diagnosis of PsP following radiochemotherapy of glioblastoma.

Late Pseudoprogression in Glioblastoma: Diagnostic Value of Dynamic O-(2-[18F]fluoroethyl)-L-Tyrosine PET

“…In our cohort of patients with glioblastoma, diagnostic accuracy for identifying true progression was highest at a threshold of 1.9 for TBR mean and TBR max . This cutoff value is close to the previously reported cutoff for TBR max (2.3) for distinguishing glioblastoma patients with early PsP from true early progressive disease (9). Similarly, the presence of curve patterns type II and III were predictive for true progression.…”

“…Therefore, 18 F-FET PET appears to be a promising diagnostic tool to investigate for PsP and it may be particularly helpful in making the difficult diagnosis of late PsP. We have already demonstrated the applicability of 18 F-FET PET for diagnosing early PsP in a recent case series (9). To furthermore assess whether 18 F-FET PET is capable of drawing a distinction between true progression and late PsP/radionecrosis-which is even more infrequent, and thus difficult to diagnose-we retrospectively examined the predictive value of 18 F-FET PET for detecting late PsP in 26 patients with glioblastoma.…”

“…18 F-FET) allows imaging of amino acid transport in brain tumors and has shown promise in distinguishing early PsP from truly progressive tumor (9). Comparing with the most known tracer, 18 F-FDG 18F-FET is considered particularly suitable for glioma research because of its low background activity (10).…”

Pseudoprogression, radionecrosis, inflammation or true tumor progression? challenges associated with glioblastoma response assessment in an evolving therapeutic landscape

“…A recent systematic review finds amino acid tracers (MET, FET, and FDOPA) to have higher diagnostic accuracy than conventional and advanced MRI in the differentiation of glioma recurrence from treatment-induced changes, and superior to MRI in the assessment of treatment response [48]. For instance, 18 F-FET has been shown to have greater than 90% sensitivity and specificity in the diagnosis of pseudoprogression [49]; and 18 F-FDOPA has been shown to have a nearly 90% sensitivity and 72% specificity for the diagnosis of glioblastoma recurrence [50]. Similar to amino acid PET, SPECT imaging using a variety of radiolabeled 201 Tl, 99m Tc, or 123 I compounds has shown promise [51][52][53].…”

Therapeutic options in recurrent glioblastoma—An update

“…FET-PET) may help to identify pseudoprogression versus early progression after radiochemotherapy, too [19].…”