Sentinel lymph node biopsy in penile carcinoma

Sentinel lymph node (SLN) biopsy is a fairly new technique that is becoming the standard of care for regional lymph node staging of many solid tumors. This technique is based on the hypothesis of stepwise distribution of malignant cells in the lymphatic system. The absence of tumor cells in the first lymph node(s) in the lymphatic drainage of a tumor would indicate the absence of further spread in the regional lymph node basin(s). Therefore, this first lymph node is the guardian (sentinel) of the regional lymph node basin. To localize the sentinel node preoperatively, lymphoscintigraphy is usually performed after intradermal peritumoral injections of colloid particles labeled with technetium-99m. The tracer is transported through the lymphatic channels to the first draining nodes in the groins and is visible on the lymphoscintigram as hot spots. The main advantage of SLN biopsy in penile cancer is to decrease the treatment-related morbidity without compromising the survival benefit for the patient. Recent figures indicate a false-negative rate of 7%, with a complication rate of less than 5% for SLN biopsy. In conclusion, sentinel node biopsy of patients with penile cancer has evolved into a highly reliable procedure enabling the detection of lymph node invasion at the earliest possible time with minimal morbidity. With this technology at hand, which minimizes the treatment-related morbidity, there is hardly any place for standard lymphadenectomy in penile cancer patients.