Dynamic MRI and CAD vs. MRS vs. Choline PET/CT for Lesion Characterization in Prostate Cancer

Ziele: Imaging prostate cancer with 11C-choline PET/CT a threshold SUV of 2.65 yielded an area under the receiver-operating-charcteristic (ROC) curve of 0.89 +/- 0.01 for correctly locating prostate cancer with a maximal accuracy of 84%, a sensitivity of 81% and a specificity of 87%. To evaluate the role of pre-interventional fused high resolution T2-weighted images with parametrically analyzed dynamic contrast enhanced T1-weighted MR images (DCE-MRI) and 1H MR spectroscopy (MRS) for a precise biopsy for the detection of prostate cancer and for the delineation of intraprostatic subvolumes for IMRT, findings in 67 patients are analyzed prospectively. Methode: Inclusion criteria: pathological PSA and/or previously negative TRUS-biopsy. Mean age 68a, mean PSA 11.5ng/ml. Standardized biopsy of the prostate divided into 20 regions. Image fusion of colored parametric maps derived from DCE-MRI and MRS (SVS, CSI) with T2 images for morphological localization using a workstation of CAD-Sciences, Siemens or the radiation treatment planning system. Correlation of these intraprostatic subvolumes with histology and cytokeratin (CK34ßE1.2) positive areas in prostatectomy species. Statistics: Friedman test and Wilcoxon test. Ergebnis: MR volume of prostate cancer: mean 6.4ml, median 3.8ml. Dynamic MRI: Sensitivity 82%, specificity 89%, accuracy 88%, PPV 61%, NPV 96%. MRS (SVS): sensitivity 55%, specificity 62%. False positive findings due to prostatitis, adenomatous hyperplasia, False negative findings due to low signal (PIN, cut-off level for dynamic MRI: lesions smaller 3mm and less than 30% cancer cells, for MRS (SVS): lesions smaller 8mm and less than 50% cancer cells). Schlussfolgerung: DCE-MRI has the same potential for correctly locating prostate cancer as compared to C11-choline PET/CT and is superior to MRS (SVS). Future data derived from the same study population (paired data) will show if DCE-MRI has still the same potential as compared to 11C-choline PET/CT. DCE-MRI and MRS are helpful for a precise biopsy of the prostate. The ESTRO Guidelines 2006 for radiation treatment planning of the prostate have to be revised, if the standardized biopsy will be replaced by a lesion orientated biopsy.

Korrespondierender Autor: Schmuecking M

Kreiskrankenhaus Greiz, Radiologisches Zentrum, Wichmannstr. 12, 07973 Greiz

E-Mail: [e-mail]

CAD - MRI - MRS - choline signal - PET/CT