November 12, 2021 Author : João Magalhães Pina Prostate cancer is the most common malignant tumor in men over 50 years of age and is the second leading cause of death due to cancer in this age group. The definitive diagnosis of prostate cancer involves pathology evaluation of a tissue sample from this organ, which is obtained by biopsy. Ultrasound and prostate biopsy Most often, prostate biopsy is performed transrectally and guided by ultrasound. Ultrasound is an imaging technique that allows a good visualization of the prostate in real time, but, in most cases, it does not allow the distinction of the cancer area . The ultrasound-guided biopsy is thus aimed at the prostate (the samples are distributed throughout the organ) and not at a particular suspicious lesion. That is why it is referred to as a “blind” biopsy . Although several samples are obtained, so that they are representative of the entire organ, the fact that it is a "blind" biopsy is related with a higher rate of under-detection of the disease due to false negative results, that is, the samples obtained may not include cancer tissue. MRI and prostate biopsy Magnetic resonance imaging revolutionized imaging techniques uses in prostate cancer diagnosis. Magnetic resonance imaging allows to assess the structure of the organ in more detail; It can detect areas strongly suggestive of cancer. Furthermore, MRI only identifies more aggressive cancers, which is not a limitation, but a significant advantage. Indolent cancers without aggressiveness or potential for progression cannot be visualized on MRI images and therefore overdiagnosis and overtreatment are avoided. Magnetic resonance images a llow directing the biopsy to suspicious areas . Thus, compared to ultrasound, magnetic resonance greatly increases the probability of detecting and diagnosis aggressive prostate cancer, that is, with the potential to evolve, metastasize and be a cause of death. Fusion guided prostate biopsy Due to technical and logistical reasons it is not feasible to perform a biopsy inside an MRI machine. Therefore, magnetic resonance images cannot be obtained in real time, that is, simultaneously with the biopsy. However, technology evolution has made it possible to merge magnetic resonance images with ultrasound images obtained in real time . Thus, imaging fusion biopsies were developed: Using MRI and ultrasound imaging to t ake advantage of the two imaging techniques : the sensitivity and specificity of MRI and the real-time imaging of ultrasound. While navigating with the ultrasound probe, the doctor is viewing the MRI images at the same time. It then directs the biopsy needle to the suspicious areas, with greater precision . Fusion guided prostate biopsy can be performed in two ways: Transrectal , that is, through the rectum; Transperineal , that is, through the perineum which is the area located between the scrotal sac and the anus. The use of the transperineal route significantly reduces the rate of infection associated with classic transrectal biopsies. This approach is now internationally recommended as preferred. Fusion guided prostate biopsy can be performed either under local anesthesia or under sedation , which reduces the patient anxiety and improves his adherence to the procedure. According to the guidelines of the European Association of Urology , fusion guided prostate biopsy is indicated whenever there are changes in the magnetic resonance that justify it (PIRADS lesions ≥ 3), preferably using the transperineal approach. Meet the urology clinical team from Hospital da Luz network and book your consultation The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
