Accuracy of multi-detector CT scan in pre-operative staging of renal cell carcinoma: Comparison of radiological and histopathological findings.

ABSTRACT

Objective: To evaluate the accuracy of pre-operative multi-detector CT scan (MDCT) compared to histopathology findings in tumor staging of renal cell carcinoma. Methods: Retrospective review of 29 renal cell carcinomas at Siriraj Hospital from 2004-2007. Two blinded radiologists evaluated the pre-operative MDCT images independently. Imaging findings were compared with surgical specimens and pathological findings. Results: A total of 29 renal cell carcinomas were proven on histopathology. The respective accuracy for overall staging of reader 1 and 2 were 0.75 and 0.65. The reader 1 and 2 reached a sensitivity of 75% and 87%, a specificity of 70% and 50% for perinephric involvement, and a sensitivity of 100% and 100%, a specificity of 63% and 54% for renal pelvis involvement. The kappa interobserver agreements for perinephric involvement and renal pelvis involvement were 0.67 and 0.83, respectively. Conclusion: False positive finding of perinephric involvement causes overstaging of Robson stage I disease or in T1-T2 disease of TNM classification. Perinephric stranding may not be reliable or specific findings, and a result of perinephric involvement in CT scan is still limited. MDCT is accurate in the pre-operative evaluation of renal cell carcinoma in Robson stage II-IV disease.