Christiane Marx, Abstract Co-Author: Nothing to Disclose

Michael Schmuecking, Presenter: Nothing to Disclose

Hagen Geyer, Abstract Co-Author: Nothing to Disclose

Carsten Boltze, Abstract Co-Author: Nothing to Disclose

Priska Bank, Abstract Co-Author: Nothing to Disclose

Thomas G. Wendt MD, Abstract Co-Author: Nothing to Disclose

Local relapse after radiotherapy for prostate cancer mostly originates at the original tumor location. Dose escalation reduces local relapse rates. It may be of benefit to focus the highest dose to intraprostatic lesions. 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 55 patients are analyzed prospectively.

Inclusion criteria: pathological PSA and/or previously negative TRUS-biopsy. Mean age 69a, mean PSA 10.8ng/ml. Standardized biopsy of the prostate divided into 20 regions. Image fusion of colored parametric maps derived from DCE-MRI and MRS with T2 images for morphological localization using a workstation of CAD-Sciences or the radiation treatment planning system. Correlation of these intraprostatic subvolumes with histology and cytokeratin (CK34bE1.2) positive areas in prostatectomy species. Statistics: Friedman test and Wilcoxon test.

MR volume of prostate cancer: mean 6.4ml, median 3.8ml. Sensitivity 82%, specificity 89%, accuracy 88%, PPV 61%, NPV 96%. False positive findings due to prostatitis, adenomatous hyperplasia, False negative findings due to low signal (PIN, cut-off level: lesions smaller 3mm and less than 30% cancer cells).

fMRI is 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. Using DCE-MRI and MRS for radiation treatment planning the cut-off level for detecting cancer cells has to be taken into consideration. Technically, it is feasible to use DCE-MRI and MRS for target volume delineation of intraprostatic lesions for IMRT; however, a histological validation of the MR signal has to be evaluated in a sufficiently larger number of patients in order to know if the fMRI is suitable for IMRT (dose painting).

DCE-MRI and MRS may play a major role in target volume delineation of prostate cancer for IMRT.

Marx, C, Schmuecking, M, Geyer, H, Boltze, C, Bank, P, Wendt, T, What Is the Role of Functional MRI (fMRI) for a Precise Biopsy and for the Delineation of Intraprostatic Subvolumes for Intensity Modulated Radiation Therapy (IMRT)?.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5016077.html