MR perfusion and diffusion imaging in the follow-up of recurrent glioblastoma treated with dendritic cell immunotherapy: a pilot study.

Department of Radiology, University Clinical Center Ljubljana, Zaloška 7, 1000, Ljubljana, Slovenia.
Neuroradiology (Impact Factor: 2.7). 11/2010; 53(10):721-31. DOI:10.1007/s00234-010-0802-6
Source: PubMed

ABSTRACT This study aims to determine the potential value of MR-PWI and MR-DWI to differentiate immune therapy-induced inflammatory response from recurrent glioblastoma tumour growth. Both can present as contrast-enhancing lesions on conventional magnetic resonance imaging (MRI).
Patients with recurrent glioblastoma who could obtain a total or near-total resection were treated with dendritic cell immune therapy according to the HGG-IMMUNO-2003 trial. A retrospective analysis of 32 follow-up MRI examinations (mean follow-up time 21 months) in eight patients was performed for this pilot study. For the statistical analysis, the 32 examinations were divided into three groups: 0-obtained in patients that remained stable during the follow-up period, 1a-obtained in progressive-tumour patients at time points before definite progression and 1b-obtained in patients at or after progression.
Maximum lesional rCBV ratios were highest in group 1b (Student t test, 9.25 ± 2.68; p < 0.001) and were higher in group 1a (4.87 ± 1.61, p < 0.001) compared to group 0 (1.22 ± 0.47). The minimum apparent diffusion coefficients (ADCs) in the contrast-enhancing regions were lower in group 1a (0.62 ± 0.06 × 10(-3) mm(2)/s) than in group 0 (1.03 ± 0.43 × 10(-3) mm(2)/s, p = 0.01) and higher in group 1b (0.76 ± 0.08) compared to 1a (p = 0.02). The minimum ADCs in the FLAIR-hyperintense region were lower in group 1a (0.62 ± 0.06, p = 0.02) compared to group 0 (0.76 ± 0.16) but not significantly different in group 1b (0.68 ± 0.07) from groups 0 and 1a (p = 0.33, p = 0.10). The mean ADCs of the FLAIR-hyperintense region and the mean ADCs of the contrast-enhancing lesion were not significantly different.
The maximum lesional rCBV ratios and minimum ADC values in the contrast-enhancing area are potential radiological markers to differentiate between immune therapy-induced inflammatory response and recurrent glioblastoma tumour growth in glioblastoma patients treated with immune therapy.

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    11/2011; , ISBN: 978-953-307-284-5
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    ABSTRACT: Perfusion and diffusion magnetic resonance imaging (pMRI, dMRI) are valuable diagnostic tools for assessing brain tumors in the clinical setting. The aim of this study was to determine the correlation of pMRI and dMRI with (11)C-methionine positron emission tomography (MET PET) in suspected low-grade gliomas (LGG) prior to surgery. Twenty-four adults with suspected LGG were enrolled in an observational study and examined by MET PET, pMRI and dMRI. Histological tumor diagnosis was confirmed in 23/24 patients (18 gliomas grade II, 5 gliomas grade III). The maximum relative cerebral blood volume (rCBVmax) and the minimum mean diffusivity (MDmin) were measured in tumor areas with highest MET uptake (hotspot) on PET by using automated co-registration of MRI and PET scans. A clearly defined hotspot on PET was present in all 23 tumors. Regions with rCBVmax corresponded with hotspot regions in all tumors, regions with MDmin corresponded with hotspot regions in 20/23 tumors. The correlation between rCBVmax (r = 0.19, P = 0.38) and MDmin (r = -0.41, P = 0.053) with MET uptake in the hotspot was not statistically significant. Taken into account the difficulties of measuring perfusion abnormalities in non-enhancing gliomas, this study demonstrates that co-registered MET PET and pMRI facilitates the identification of regions with rCBVmax. Furthermore, the lack of a clear positive correlation between tumor metabolism in terms of MET uptake and tumor vascularity measured as rCBVmax suggests that combined pMRI/PET provides complementary baseline imaging data in these tumors.
    Journal of Neuro-Oncology 06/2013; · 3.12 Impact Factor

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