Rofo 2010; 182 - WI_PO62
DOI: 10.1055/s-0030-1253066

Is there a role for dose painting within the prostate in the primal therapy of patients with localized prostate cancer using choline PET/CT, dynamic MRI and CAD or choline MRS?

M Schmuecking 1, S Perner 2, C Boltze 3, H Geyer 4, H Salz 5, F Finsterbusch 6, S Reske 6, TG Wendt 5, KH Kloetzer 7, C Marx 1, NM Blumstein 8
  • 1Greiz County Hospital, Center for Radiology, Greiz
  • 2University of Ulm, Dept. of Pathology, Ulm
  • 3University Teaching Hospital Gera, Dept. of Pathology, Gera
  • 4Greiz County Hospital, Dept. of Urology, Greiz
  • 5FSU Jena, Dept. of Radiation Oncology, Jena
  • 6University of Ulm, Dept. of Nuclear Medicine, Ulm
  • 7University Teaching Hospital Gera, Dept. of Radiation Oncology, Gera
  • 8Inselspital, Bern University Hospital, Dept. of Radiation Oncology, Bern

Ziele: To evaluate the role of molecular/functional imaging for the delineation of intraprostatic subvolumes for radiation therapy (IMRT, dose painting) 26 patients received a 11C choline PET/CT study and 67 patients a MR study consisting of DCE-MRI and MRS. Methode: Inclusion criteria: pathological prostate-specific antigen values (PSA) and/or previously negative transrectal ultrasound guided biopsy. Acquisition of choline PET/CT images after intravenous injection of 1112±131 MBq 11C choline. Image fusion of colored parametric maps derived from DCE-MRI and MRS (single voxel spectroscopy, SVS; chemical shift imaging, CSI) with T2 images for morphological localization. Correlation of the detected cancer lesions with histology and cytokeratin positive areas in biopsy and/or prostatectomy specimens. Ergebnis: Choline PET/CT: Sensitivity (sens.) 81%, specificity (spec.) 87%. In 1/26 (4%) patients SUVmax was detected outside the prostate cancer lesions. Using the threshold SUV of 2.65 of the receiver-operating-characteristic (ROC) curve, 6/26 (23%) patients showed a lower 11C choline uptake in up to 58–72% of the segments with cancer compared to the SUVmax of the segments with benign histopathologic lesions. DCE-MRI: Sens. 82%, spec. 89%. SVS: Sens. 55%, spec. 62%. CSI: Sens. 68%, spec. 67%. Cut-off level for PET/CT: lesions smaller 4mm and low density of cancer cells, cut-off level for DCE-MRI: lesions smaller 3mm and less than 30% cancer cells, for SVS: lesions smaller 8mm and less than 50% cancer cells), for CSI: lesions smaller 4mm and less than 40% cancer cells). In 10 patients the cancer volume as detected by MR or PET/CT was smaller than in the prostatectomy specimens, though shrinkage of the histological cancer lesion might occur due to formaline fixation. Schlussfolgerung: Till now it is questionable, if the parametric maps of DCE-MRI and MRS as well as the choline PET/CT images can be used for the delineation of intraprostatic subvolumes for radiation treatment planning (IMRT, dose painting).

Korrespondierender Autor: Schmuecking M

Greiz County Hospital, Center for Radiology, Wichmannstr. 12, 07973 Greiz

E-Mail: michael.schmuecking@gmx.net

prostate cancer - IMRT - dose painting - choline PET/CT - DCE-MRI - MRS