Response by authors re: Differentiation of oncocytoma and renal cell carcinoma in small renal masses (<4 cm): the role of 4-phase computerized tomography

Throughout medicine, there is a recurrent paradigm of development of noninvasive/less invasive testing used to identify patients who may then be able to forgo relatively more invasive diagnostic testing and treatment. In the realm of cardiology, reconstructed advanced imaging has been extensively investigated as a substitute for cardiac catheterization [1]. In the realm of urology, we have long pursued use of PSA testing to identify men at risk for the prostate cancer and have used this to aid in the selection of patients to undergo prostate biopsy. More recently, further refinements in overall care to those patients diagnosed with prostate cancer, in response to potentially excessive diagnosis and treatment related morbidity, have been introduced with the development of active surveillance protocols to aid in the identification of patients with prostate cancer that may potentially be spared treatment-associated morbidity [2]. In the case of renal tumors, to date, only limited advancements have taken place in terms of preoperative characterization of renal masses. Due to lack of such advancements, notably in the case of small renal masses, we as urologists, in the majority of cases, essentially resort to excisional biopsy of these poorly characterized lesions, for lack of better preoperative characterization. Though partial nephrectomy has certainly undergone a number of refinements and technical advances, this procedure, even in centers of excellence, has well defined risk for morbidity [3]. The effects and nature of renal ischemia are also currently under investigation at a large number of institutions due to concerns over what long-term impact this may have for the patient [4, 5].