Technology insight: radioguided sentinel lymph node dissection in the staging of prostate cancer.

Pelvic lymph node dissection is the only reliable method of staging for clinically localized prostate cancer. Despite the obvious prognostic advantages conferred by accurate staging, pelvic lymph node dissection is associated with significant morbidity and prolonged operative time. A substantial decrease in the sensitivity to lymph node metastasis occurs by simple reduction of the dissection area to the obturator fossa. Radioguided sentinel lymph node dissection provides accurate staging despite use of a minimal-area dissection template. Results from studies in prostate cancer indicate that this method has a high sensitivity for very early detection of lymphatic spread. A substantial number of the detected metastases are of a small size, solitary and widely distributed throughout the pelvic lymph nodes. These features make metastases undetectable by preoperative imaging modalities, and by the current, standard method of lymph node dissection limited to the obturator fossa.