Role of salvage lymph node dissection in prostate cancer

Purpose of review Oligometastatic prostate cancer (PCA) has increasingly been detected in the era of modern imaging studies such as choline-specific and prostate-specific membrane antigen (PSMA)-positron emission tomography and X-ray computed tomography (PET/CT). Recent evidence suggests that durable control is attainable with local treatment modalities such as salvage metastasectomy or stereotactic radiation therapy targeting oligometastases, either with or without the use of systemic therapy. The purpose of this article is to critically review the current findings on the indication, extent, and oncologic outcome of salvage lymphadenectomy (SLAD). Recent findings Oligometastatic PCA is defined by three or less to five metastatic lesions, no rapid spread to more sites, and feasibility of targeted treatment of all metastatic lesions with surgery or radiation therapy. 68Ga-PSMAPET/CT or 18C-choline PET/CT represents the imaging study of choice to identify patients with potential lymph node metastases, and both studies should be performed at prostate-specific antigen serum levels around 1 ng/ml in order to achieve optimal results. If available, 68Ga-PSMA-PET/CT should be preferred because of higher sensitivity, specificity, and accuracy. With regard to pelvic SLAD, only data of retrospective studies with a total of more than 400 patients and an evidence level III-IV are available. SLAD should always be performed in terms of an extended lymph node dissection. Five-year biochemicalfree survival ranges between 19 and 25%, 5-year cancer-specific survival varies between 75 and 90%. The median time to systemic treatment is in the range of 20-30 months. Patients with retroperitoneal metastases have a poorer prognosis with less than 10% responding. Summary SLAD in oligometastatic PCA represents an individual approach with the major goal to prolong progression-free survival and time until systemic therapy is started. It is currently unclear whether SLAD will have an impact on long-term survival. Prospective randomized trials targeting this issue are on their way.