Diagnosing prostate cancer with pinpoint accuracy
If there is suspicion of prostate cancer due to increased PSA values, a conspicuous ultrasound and/or palpation, only tissue removal from the prostate can provide clarity. To this day, the prostate biopsy is the only way to detect a prostate carcinoma unambiguously and to determine its spread and malignancy,"explains Dr. Pedram Derakhshani, urologist at the West German Prostate Center in Cologne. The so-called punch biopsy is the standard procedure. Under ultrasound control, at least 12 tissue samples are systematically taken from all areas of the prostate gland and examined histologically for malignant cells. The disadvantage: Smaller or atypically located carcinomas sometimes fall through the tissue sampling grid. The result is a further increase in PSA values, which leads to a new biopsy.
3-Tesla MRT: Quantum leap in the diagnosis of prostate cancer
A quantum leap in the diagnosis of prostate carcinoma is brought about by the so-called MRI-supported biopsy. For this purpose, the Cologne urologists in cooperation with the radiology department of KLINIK am RING use what is currently the most modern imaging method and combine it with punch biopsy. While most of the facilities have magnetic resonance tomographs with a field strength of 1.5 Tesla, the clinic in Cologne can offer one of the most modern, high-resolution MRIs, the 3-Tesla-MRI. This enables us to detect prostate carcinomas with a significantly higher sensitivity and specificity than is possible with the standard transrectal ultrasound (TRUS),"said Derakhshani. According to the urologist,"For patients whose PSA levels continue to rise despite a negative biopsy and for whom the suspicion of cancer persists, MRI-assisted biopsy is a meaningful and important extension of the diagnostic spectrum.
Prior to the actual biopsy, the patient's prostate is first examined in an MRI. In this process, a kind of "map" is created in which areas suspected of being tumor are marked, on which the urologists orientate themselves precisely when removing tissue. The actual biopsy then takes place in a second step under the control of a high-resolution transrectal ultrasound. By combining both diagnostic methods, we increase the hit rate and thus save the patient from further biopsies,"said Derakhshani. As recent studies have shown, the detection rate of prostate carcinoma in a biopsy supported by a 3 Tesla-MRI is 41 percent after tissue removal, which is significantly higher than 10 to 20 percent in a biopsy under sole transrectal ultrasound.
A further advantage: The exact determination of both the localisation and the extent of the individual tumour centres in the prostate allows the treatment to be very targeted. Especially for modern therapies such as brachytherapy, in which the entire prostate is not removed but irradiated with pinpoint accuracy, the MRI-supported biopsy provides valuable information,"said Derakhshani.