Abstract #0787

Diffusion-Weighted MRI to Detect Pelvic Lymph Node Metastases in Patients with Bladder or Prostate Cancer: Comparison with Histopathology as Gold Standard

Maria Triantafyllou¹, Tobias Binser², Frederic Birkhaeuser³, Urs E. Studer³, Achim Fleischmann⁴, Michael Von Gunten⁵, Johannes M. Froehlich⁶, Peter Vermathen², Harriet C. Thoeny⁷

¹Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital Bern, Bern, Switzerland; ²Department of Clinical Research, Inselspital, Bern, Switzerland; ³Department of Urology, Inselspital, Bern, Switzerland; ⁴Department of Pathology, Inselpital, Bern, Switzerland; ⁵Department of pathology, Inselspital, Bern, Switzerland; ⁶Guerbet, Switzerland; ⁷Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern, Switzerland

The hypothesis that a decreased ADC value in lymph nodes of patients suffering from prostate or bladder cancer might indicate metastatic involvement was studied in a prospective controlled clinical study including forty patients. Hyperintense structures on b 1000 images were correlated with the morphological images to check whether these were lymph nodes. In case of an ADC value beyond 90 x 10-5 mm/sec these were classified as metastatic, while lymph nodes between 90 and 100 were ambigous. Overall a sensitivity of 80%, a specificity of 79%, a positive-predictive value of 57% and a negative predictive value of 92% resulted.