[Conventional transrectal ultrasound guided biopsy. Current role, indications, techniques and limitations]

The objective of this work is to evaluate the current role of conventional transrectal ultrasound guided biopsy of the prostate in the diagnosis of cancer. With this aim we review its indications, the various techniques, associated complications and limitations of this test.

We performed a bibliographic review through NCBI-PUBMED. We also evaluated the information and recommendations of the available clinical guidelines with their respective evidence levels. Lastly, some of the appraisals included are based on our group's personal experience that has performed more than 7000 prostate biopsies with various protocols and methodologies over two decades of health care practice.

Conventional prostatic biopsies lack precision; they are not close to reality in terms of tumor amount, localization and grading. The number and localization of the cores to be taken is not clear; there are too many biopsy schemes, making it less reliable and reproducible than expected. Although it is a good tool, there is an obvious risk of over diagnosis of clinically non-significant tumors. The lack of standardization of the various biopsy schemes has clear prognostic and decision-making implications. Another limitation is the scarce number of results attributable to biopsies targeted at ultrasound visible lesions. Obviously, the complications, discomfort, and distress generated by conventional biopsy and repeated biopsy programs are some of their limitations and the reasons for patient rejection. We are in a crossroad where multiple groups try to demonstrate the sensitivity and reproducibility of targeting the biopsy, by means of various techniques, to the lesions found in multiparametric MRI.

Ultrasound guided prostatic biopsy is the main diagnostic method for prostate cancer yet. The information it gives is greatly relevant for staging, prognostic evaluation and therapeutic decision-making. Nevertheless, its limitations are evident: low sensitivity, overdiagnosis, complicacions, patient's distress, etc. There are two lines of development to improve its efficiency. The one aiming to reduce the number of biopsies and cores by selectively targeting the findings of the MRI and the one that continues systematizing schemes with increasing number of cores to achieve the optimal sampling. Technical advances, such as image fusion, will maybe allow us in the future to translate the MRI findings into verified and reproducible clinical results. We must standardize the conventional techniques of prostate biopsy in our centers, using protocols and making them safe for patients. We must review our results to ensure reasonable detection rates, as well as our indications, considering patient's age, comorbidities and expectations about therapy. We must include, as far as possible, other tools, such as multiparametric MRI to enable biopsy rationalization and improve their efficacy.