This proposal is targeted at all patients with prostate cancer who are candidates for either curative surgery or curative radiotherapy in whom lymph node staging is indicated. Recently, it has been shown, that in patients with PSA <10 ng/ml and Gleason score < 7 the risk of lymph node metastases is low. Therefore, unnecessary PLND and non-invasive imaging can be avoided safely in this group. PLND is nowadays performed only in patients with intermediate or high risk for nodal metastases. Thus the subgroup of patients targeted in this study consists of patients with prostate cancer with a PSA >10 ng/ml and Gleason score > 6.

• If the high sensitivity (90%) and negative predictive value (96%) of MRL can be validated in the 8 participating centres, in patients with a negative MRL invasive PLND may be avoided.
• In patients with a positive MRL with enlarged nodes (larger than 8 mm) histological diagnosis may be obtained by imaged guided biopsy, and thus also in these patients avoid PLND. A limitation of image guide biopsy, however, is the 30% false negative rate. [Barentsz, Oyen, Wolf]
• In patients with positive small nodes (smaller than 8 mm) the urologist may, focussed by the MRL findings of a positive node outside his “surgical field-of-view”, extend his dissection, and thus improve his accuracy.
• Based on the expected higher sensitivity of MRL this technique will completely replace CT-scanning.