Abstract #1847

Diagnostic Accuracy of Diffusion-Weighted MRI in Comparison to Histopathology for Detection of Lymph Node Metastases in Normal Sized Pelvic Lymph-Nodes in Patients with Bladder or Prostate Cancer

Johannes M. Froehlich¹, Maria Triantafyllou¹, Giuseppe Petralia¹, Daniel GQ Chong¹, Peter Vermathen¹, Frederic D. Birkhaeuser², Achim Fleischmann³, Urs E. Studer², Harriet C. Thoeny¹

¹Department of Radiology, University Hospital, Bern, Switzerland; ²Department of Urology, University Hospital, Bern, Switzerland; ³Institute of Pathology, University, Bern, Switzerland

Diffusion-weighted MRI(DW-MRI) may help to increase the diagnostic confidence of lymph node staging in patients with bladder or prostate cancer. In an ongoing prospective clinical trial 87 patients, all with normal sized lymph nodes prior to inclusion, underwent DW-MRI followed by surgical treatment with radical lymphadenectomy. A first prospective reading yielded a sensitivity of 56%, specificity of 64.5%, PPV of 39%, NPV of 78.4% and diagnostic accuracy of 62.1%, respectively. Three independent readers blinded for all clinical information performed a second reading with even slightly improved results. In comparison to morphological imaging DW-MRI improves the diagnostic confidence.