Correlation of the apparent diffusion coefficient with the standardized uptake value in meningioma of the skull plane using [68]Ga-DOTATOC PET/MRI

PurposeTo evaluate a correlation between an MRI-specific marker for cellular density [apparent diffusion coefficient (ADC)] and the expression of Somatostatin Receptors (SSTR) in patients with meningioma of the skull plane and orbital space.Methods68Ga-DOTATOC PET/MR imaging was performed in 60 Patients with suspected or diagnosed meningiomas of the skull base and eye socket. Analysis of ADC values succeeded in 32 patients. ADC values (ADCmean and ADCmin) were analyzed using a polygonal region of interest. Tracer-uptake of target lesions was assessed according to corresponding maximal (SUVmax) and mean (SUVmean) values. Correlations between assessed parameters were evaluated using the Pearson correlation coefficient.ResultsOne out of 32 patients (3%) was diagnosed with lymphoma by histopathological examination and therefore excluded from further analysis. Median ADCmean amounted to 822 x 10-5 mm(2)/s-1 (95% CI: 570-1497) and median ADCmin was 493 x 10-5 mm2/s-1 (95% CI: 162-783). There were no significant correlations between SUVmax and ADCmin (r = 0.60; P = 0.76) or ADCmean (r = -0.52; P = 0.79), respectively. However, Pearson's test showed a weak, inverse but insignificant correlation between ADCmean and SUVmean (r = -0.33; P = 0.07).ConclusionThe presented data displays no relevant correlations between increased SSTR expression and cellularity in patients with meningioma of the skull base. SSTR-PET and DWI thus may offer complementary information on tumor characteristics of meningioma.