Primena različitih perfuzionih tehnika magnetne rezonance mozga u cilju diferenciranja postterapijskih sekvela i tumorskih promena kod osoba sa glioblastomom

Abstract

Iako je postoperativna primena radioterapije i hemioterapije produžila preživljavanja pacijenata obolelih od glioblastoma multiforme (GBM), ona je uslovila i dijagnostičke teškoće u diferenciranju recidiva GBM tumora od terapijskih sekvela. Kako konvencionalni magnetno rezonantni prikaz (magnetic resonance imaging, MRI) endokranijuma onemogućava diferenciranje ova dva entiteta, koja zahtevaju različite terapijske pristupe, primena naprednih MRI tehnika je neophodna. Cilj ove studije je bio da se proceni vrednost parametara naprednih MRI tehnika statističkom analizom i primenom veštačkih neuronskih mreža (artificial neuronal network, ANN) u diferencijaciji GBM rekurentnog tumora od terapijskih sekvela. Metode: Studija je primenjena kod 56 pacijenata sa patohistološki verifikovanim GBM koji su imali kliničko i/ili radiološko pogoršanje nalaza nakon sprovedene posthirurške radioterapije i hemioterapije temozolomidom. Kod svih pacijenata je primenjen konvencionalni MR pregled endokranijuma sa primenom naprednih MRI tehnika: difuzijskih prikaza (diffusion-weighted imaging, DWI), prikaza susceptibilnosti (susceptibility-weighted imaging, SWI), protonske magnetno rezonanantne spektroskopije (proton magnetic resonance spectroscopy, 1H-MRS), a kod 31 pacijenata su primenjene i napredne tehnike perfuzijskih prikaza (perfusion-weighted imaging, PWI) – tehnika obeležavanja arterijskih spinova (arterial spin labeling, ASL) i dinamske susceptibilnosti kontrasta (dynamic susceptibility contrast, DSC). Analizirane su: vrednosti normalizovanog minimalnog i srednjeg prividnog difuzijskog kojeficijenta (apparent-diffusion coefficient, ADC), broj krvnih sudova prikazanih na SWI, holin (choline, Cho)/kreatin (creatine, Cr) odnos, vrednosti normalizovanog cerebralnog krvnog protoka (cerebral blood flow, CBF) i cerebralnog krvnog volumena (cerebral blood volume, CBV). Na osnovu neuroradiološke MR analize pacijenti su klasifikovani u grupu GBM rekurencije ili terapijskih sekvela. Radiološka dijagnoza je potvrđena kliničko-radiološkim praćenjem u trajanju od najmanje tri meseca od inicijalnog kliničkog ili radiološkog pogoršanja stanja pacijenta. Although, surgical resection followed by radiotherapy and different modalities of chemotherapy have increased the overall survival of patients with glioblastoma multiforme (GBM), they have hampered neuroradiological diagnostic in differentiation between GBM recurrence and treatment effects. Since brain conventional magnetic resonance imaging (MRI) can not achieve clear differentiation between these two entities, which require a different treatment approach, the application of advanced MRI techniques is necessary. The aim of this study was to evaluate the values of parameters of advanced MRI techniques by statistical analysis and the use of artificial neuronal network (ANN) in the differentiation of GBM recurrent tumors from treatment effects. Methodes: The study was applied in 56 patients with pathohistologically verified GBM who had a clinical and/or radiological deterioration after postsurgical radiotherapy and chemotherapy with temozolomide. In all patients, a conventional MRI of the brain was applied with advanced MRI techniques: diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI) and proton magnetic resonance spectroscopy (1H-MRS), and in 31 patients were also applied advanced perfusion-weighted imaging (PWI) techniques - arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) techniques. The values of: the normalized minimal and mean apparent diffusion coefficient (ADC), the number of blood vessels on SWI, the choline (Cho)/creatine (Cr) ratio, the values of normalized cerebral blood flow (CBF) and cerebral blood volume (CBV) were analyzed. Based on neuroradiologic MRI analyzes, patients were classified into GBM recurrence or treatment effects. Radiological diagnosis was confirmed by clinical-radiological monitoring lasting at least three months from the initial clinical or radiological deterioration of the patient's condition.