Prospective Evaluation of 18F-Fluorodeoxyglucose Positron Emission Tomography-Computerized Tomography to Assess Inguinal Lymph Node Status in Invasive Squamous Cell Carcinoma of the Penis

PurposeWe prospectively evaluated 18F-fluorodeoxyglucose positron emission tomography-computerized tomography to assess inguinal lymph node status, the main prognostic factor in invasive squamous cell carcinoma of the penis.Materials and MethodsFrom March 2005 to January 2010, 30 patients with invasive squamous cell carcinoma of the penis from the department of urology at our institution were prospectively included in this study. Lymph node status was assessed preoperatively by positron emission tomography-computerized tomography to detect subclinical metastasis in 22 patients with initially cN0 disease and quantify inguinal lymph node invasion in 8 with cN+.ResultsIn the 22 cN0 cases (total of 44 inguinal lymph node basins analyzed) positron emission tomography-computerized tomography had 75% sensitivity and 87.5% specificity. Positive and negative predictive values were 37.5% and 97.2%, respectively. In the 8 cN+ cases (total of 16 inguinal lymph node basins analyzed) this type of imaging had 100% sensitivity, specificity and positive predictive value. In 3 cases staged clinically as cN1 positron emission tomography-computerized tomography revealed several metabolically active lesions on the same side, which was confirmed by histological examination, up-staging these cases to pN2.Conclusions18F-fluorodeoxyglucose positron emission tomography-computerized tomography is a useful staging examination for invasive penile cancer. It confirms inguinal lymph node invasion and can detect subclinical inguinal lymph node invasion.