title: FLAIR signal increase of the fluid within the resection cavity after glioma surgery: generally valid as early recurrence marker?
abstract: OBJECTIVE Recent studies have indicated that a signal intensity increase of the fluid within the resection cavity on FLAIR images may predict tumor recurrence after glioma surgery. The aim of this study was to assess the increase in FLAIR signal intensity in a large patient cohort and in subgroups to assess its prognostic value for early tumor recurrence in glioma patients. METHODS A total of 212 patients (213 cases) who had undergone surgery for an intracranial glioma (WHO Grade IV [n = 103], WHO Grade III [n = 57], and WHO Grade II [n = 53]) were included in this retrospective study. FLAIR signal within the resection cavity at the time of tumor recurrence/last contact and on the previous MRI study was assessed qualitatively and quantitatively. Appearance of FLAIR signal increase was studied over time using Kaplan-Meier estimates in subgroups. RESULTS Patients with WHO Grade II glioma and connection of the resection cavity to CSF who did not undergo radiotherapy did not regularly develop this sign and were excluded from further analysis. For the remaining 87 cases, FLAIR signal intensity increase was observed in 27 cases. Recurrent disease was found in 26 of these 27 cases, resulting in a specificity of 80.0%, a sensitivity of 31.7%, and positive and negative predictive values of 96.3% and 6.7%, respectively. In 4 cases this sign had been observed prior (range 2.8-8.5 months) to tumor recurrence defined by standard criteria. Quantitative analysis underlined the results of qualitative analysis, but it did not add a diagnostic value. CONCLUSIONS Signal intensity increase of the fluid within the resection cavity on FLAIR images is a rare but highly specific and early sign for tumor recurrence/tumor progression in completely and incompletely resected high-grade glioma without connection of the resection cavity to CSF and with radiotherapy.
authors: Departments of 1 Neuroradiology.
authors: Stefanie
authors: S
authors: Bette
authors: Neurosurgery, and.
authors: Jens
authors: J
authors: Gempt
authors: Departments of 1 Neuroradiology.
authors: Thomas
authors: T
authors: Huber
authors: Neuropathology, Klinikum rechts der Isar, Technische Universität München, Germany.
authors: Claire
authors: C
authors: Delbridge
authors: Neurosurgery, and.
authors: Bernhard
authors: B
authors: Meyer
authors: Departments of 1 Neuroradiology.
authors: Claus
authors: C
authors: Zimmer
authors: Departments of 1 Neuroradiology.
authors: Jan S
authors: JS
authors: Kirschke
authors: Departments of 1 Neuroradiology.
authors: Tobias
authors: T
authors: Boeckh-Behrens
mesh_terms: D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D002555:Cerebrospinal Fluid / Q000000981:diagnostic imaging; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D059906:Neuroimaging; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors
keywords: FET = O-(2-[18F]fluoroethyl)-l-tyrosine; FLAIR; IQR = interquartile range; MPRage = magnetization prepared rapid gradient echo; NPV = negative predictive value; PPV = positive predictive value; RANO = response assessment in neurooncology; ROI = region of interest; glioma; oncology; resection cavity; signal increase; tumor recurrence