Technologies for image-guided surgery for managing lymphatic metastases in prostate cancer.

One of the challenges for the surgical management of prostate cancer is the lymphatic spread of metastases. Lymph node metastases vary in size (micrometastases (<2 mm) or macrometastases (>2 mm)), and their interactions with the lymphatic environment differ (whether they are hypoxic or connected to blood flow). Thus, devising a universal imaging system and an image-guided surgical approach that supports the resection of all affected lymph nodes is difficult. Two complementary approaches to identifying affected lymph nodes have been described as alternatives to performing a traditional pelvic lymph node dissection: lymphatic mapping using radioguidance (the most widely applied modality), fluorescence guidance, integrated hybrid radioguidance and fluorescence guidance or magnetic guidance; and surgery guided by radiolabelled prostate-specific membrane antigen. Careful patient selection using preoperative imaging seems to be a crucial aspect in determining whether one of the individual image-guided surgery procedures alone would be optimal or whether a combination would be considered to be the most desirable course of action. The successful implementation and dissemination of both lymph-node-targeted and disease-targeted procedures are very much reliant on ongoing technical developments in the field and their standardization and interpretation. However, when these innovative surgical procedures are fully refined, evaluation of their influence on oncological outcome is imperative.