Prospective evaluation of hybrid 18F-fluorodeoxyglucose positron emission tomography/computed tomography in staging clinically node-negative patients with penile carcinoma.

OBJECTIVE

To prospectively evaluate the performance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) to detect occult metastasis in patients with clinically node-negative (cN0) penile carcinoma, as there is little information on the use of (18)F-FDG-PET/CT in penile carcinoma.

PATIENTS AND METHODS

In 24 patients, scheduled to undergo dynamic sentinel-node biopsy, hybrid PET/CT was used before surgery to assess the nodal status of the cN0-groins. Six of the 24 patients were unilaterally cN0. Thus, 42 cN0-groins were evaluated for occult metastasis using PET/CT. All scans were assessed by two experienced nuclear physicians. The histopathological tumour status of the removed sentinel node was used as the standard of care to evaluate the PET/CT-results.

RESULTS

Histopathology was tumour-positive in five of the 42 (12%) evaluated cN0-groins, two of which contained only micrometastases (<2 mm). One of the five tumour-positive cN0-groins was correctly predicted on the PET/CT-images. All false-negative PET/CT scans contained metastasis of <or=10 mm. Of the remaining 37 tumour-negative groins, 34 were correctly predicted with PET/CT (specificity 92%).

CONCLUSION

The role of PET/CT in evaluating the groins of patients with cN0 penile cancer appears to be limited, due to its low sensitivity. In this series, only one of the five tumour-positive groins was identified. Surgical staging methods remain necessary at present.