Tumorsize dependent detection rate of endorectal MRI of prostate cancer--a histopathologic correlation with whole-mount sections in 70 patients with prostate cancer.

摘要

PURPOSE: To evaluate the value of T2w endorectal MRI (eMRI) for correct detection of tumor foci within the prostate regarding tumor size. MATERIALS AND METHODS: 70 patients with histologically proven prostate cancer were examined with T2w eMRI before radical prostatectomy at a 1.5T scanner. For evaluation of eMRI, two radiologists evaluated each tumor focus within the gland. After radical prostatectomy, the prostates were prepared as whole-mount sections, according to transversal T2w eMRI. For each slice, tumor surroundings were marked and compared with eMRI. Based on whole-mount section, 315 slices were evaluated and 533 tumor lesions were documented. RESULTS: Based on the T2w eMRI, 213 tumor lesions were described. In 137/213, histology could prove these lesions. EMRI was able to visualize 0/56 lesions with a maximum size of <0.3 cm (detection rate 0%), between 0.3 and 0.5 cm 4/116 (3%), between 1 and 0.5 cm 22/169 (13%), between 2 and 1cm 61/136 (45%) and for >2 cm 50/56 (89%). False positive eMRI findings were: <0.3 cm n=0, 0.5-0.3 cm n=12, 0.5-1cm n=34, 1-2 cm n=28 and >2 cm n=2. CONCLUSION: T2w eMRI cannot exclude prostate cancer with lesions smaller 10mm and 0.4 cm(3) respectively. The detection rate for lesions more than 20mm (1.6 cm(3)) is to be considered as high.