The role of magnetic resonance imaging in the local staging of penile cancer.

OBJECTIVES: To assess the accuracy of magnetic resonance imaging (MRI) as a local staging technique in penile cancer and its role in selecting patients for conservative surgical management.

METHODS: Fifty-five men diagnosed with invasive penile carcinoma on biopsy were locally staged with the use of MRI. Prostaglandin E1 (alprostadil) was injected into the corpora to induce an artificial erection. Radiologic staging was compared against final histopathologic stage of the tumour. Sensitivity, specificity, and kappa agreement values were calculated for each tumour stage. Additionally, corpora cavernosa involvement was reviewed in 20 consecutive cases and suitability for conservative surgery assessed.

RESULTS: A good correlation between radiologic and histologic staging was achieved with an overall kappa value of 0.75 (p<0.001). Stage-specific sensitivities and specificities were calculated: T1 (85%; 83%), T2 (75%; 89%), and T3 (88%; 98%). MRI accurately predicted corpora cavernosa invasion in all cases of pathologically proven disease. These patients were selected to undergo partial penectomy. There were no complications using this imaging technique.

CONCLUSIONS: This study demonstrates that penile MRI is highly accurate in the local staging of penile cancer. Associated improvements in surgical planning allow the provision of conservative surgical treatments over more radical procedures.