Impact of noninvasive imaging on increased incidental detection of renal cell carcinoma.

Objective: To determine the impact of non-invasive imaging, specifically ultrasound imaging and computed tomography, on the incidental detection of renal cell carcinoma during two consecutive time periods, one prior and one subsequent to the acquisition of imaging equipment.

Methods: All located patient charts (83% of 207) of renal cell carcinoma cases (n = 172) were reviewed, and categorized by presentation method as 'incidental' or 'nonincidental' cases, based on defined criteria. Clinical information was recorded, cases were staged, and survival estimates were calculated.

Results: More than a third of the 172 cases were categorized as incidentally detected, most of which (82.5%) were detected during the latter time period. Either ultrasound or CT imaging was credited with detecting over 80% of the incidentally detected tumors.

Conclusion: Ultrasound and CT imaging have contributed to the incidental detection of renal cell carcinomas during the two time periods. Stage significantly predicted survival (p<0.001) in a Cox proportional hazard model that also controlled for presentation, sex, and age.