Letter to the Editor: Evaluation of renal lesions using contrast-enhanced ultrasound

by Daniel Herrera and Luis Serrano (danielherrera50@hotmail.com)

Evaluation of renal lesions using contrast-enhanced ultrasound (CEUS); a 10-year retrospective European single-centre analysis

Dear Editor,

We read with great interest the article from Doctors Johannes Reübenthaler, Negráo de Figueiredo, Mueller-Peltzer and D.A. Clevert’s “Evaluation of Renal Lesions Using Contrast-Enhanced Ultrasound (CEUS); a 10-Year Retrospective European Single-Centre Analysis [1].  We would like to thank and congratulate their work on the significant effort in conducting a study to understand and complete while utilizing a big population. Moreover, apart from being a large study, it incorporates the application of a technique which possesses the ultimate outcome of providing for the well-being and best diagnosis of the patient.

It is for this reason that we would like to clear up any doubts that arise in an attempt to compliment such a great study.   In the article, reference is made to taking a cohort of 981 patients with cystic or solid injuries, of which were applied Contrast-Enhanced Ultrasound (CEUS), taking a subcohort of 255 patients who had a histopathological study after a surgical removal. Thus, patients of the subcohort, would already have been labeled as serious or with somewhat of a doubt of a malignancy as a result of performing a histopathological study as a compliment, thus creating a selection bias and leaving doubt if there was any other complementary image study which could guide the presumed diagnosis.  Likewise, we would like to know if the outcome of the 726 remaining patients, of whom did not have a histopathological study, could be confirmed with some type of follow up, hence establishing that they actually did not have a malignant lesion.   This would create an adequate relationship with CEUS. As this study now permits and opens up great options in the use of the imaging technique for managing a patient with possible renal malignancy, according to different patterns of enhancement, it would be important to know if the lesions discarded as benign, based in the classification of Bosniak, really are in fact benign, considering that this classification in the beginning is made for kidney cysts in tomography and its refinement for the diagnosis must be based in complementary techniques [2].

Our intention with these questions is to reduce the maximum amount of doubts which can arise around such a sizable study which unto itself is a pioneer in the use of new imaging techniques and which brings the best quality to our patients.