Prostate biopsy by magnetic resonance fusion with ultrasound

Evolution of prostate cancer diagnosis

Prostate cancer is perhaps one of the most complicated diseases affecting men today, not only because of physical and mental exhaustion, like any other type of neoplasm, but also because of the complexity of its diagnosis and the risk of death. Despite being one of the most studied types of cancer, sometimes the clinic is not evident until it has already been extended, so that the prognosis almost always ends up being bad if it is not dealt with in time.

In spite of being a disease with an important genetic component, where the relatives of patients with prostate cancer must be under control after crossing the barrier of 40 years, any person -especially those with diets full of fat- can suffer from this pathology.

General anatomy of the prostate 01

The important thing is to act on prevention, and avoid prolonging the damage. For this, as well as to achieve a valid and accurate diagnosis, many methods have been used that have evolved over the years.

Decades ago, simple and rudimentary techniques such as a rectal exam were used to guide towards the possibility of prostatic hyperplasia (the precursor of prostate cancer) but medical science has advanced and new methods have appeared. Current diagnostic techniques include:

Prostate Specific Antigen (PSA)

Under normal conditions, prostate antigen is a molecule that can be produced in the prostate; however, when a pathological state exists, levels are usually elevated. The most important example is benign prostatic hyperplasia, which, as we said, is the prelude to prostate cancer.

Even so, when the cancer is present, very high levels of this antigen are usually observed, so it would be very suggestive of the diagnosis, although it is not definitive at all, or in other words, false positives may occur.

PCA 3

PCA 3, Prostate Cancer Gene 3, is a gene specific to prostate cancer that can be tested in the urine. Unlike PSA, this is a much more specific marker because it is only expressed in patients with prostate cancer.

However, it is usually necessary to perform other complementary studies, such as the PSA itself or the confirmation biopsy, to add weight to the diagnosis, since it is also not a completely definitive study.

Transrectal ultrasound

An ultrasound probe is inserted into the rectum to directly look at the prostate and check for findings suggestive of prostate cancer. Even so, as in the case of the previous ones, this is not a definitive study and is carried out especially in conjunction with the prostate biopsy.

Biopsy

This is undoubtedly the best exam, although it is the most invasive. The biopsy can guide us to the definitive diagnosis prior to a surgical intervention. It consists of the removal of a small portion of the prostate with a needle for examination.

The biggest problem is the way in which the biopsy is taken, which does not always reach the regions where the cancer is present, so it can give false negatives, so it is necessary to take up to 15 tissue samples to increase the probability of diagnosis.

Prostate biopsy in the operating room

Transrectal Ultrasound with Ultrasound-directed Biopsy

When biopsies are directed at internal organs, it is normal that ultrasound is used as a guideline. It would be difficult, for example, to do a biopsy on a specific segment of the lung based only on X-rays or the clinical experience of the doctor.

Even so, although we ensure that the biopsy reaches the prostate through the sound waves that bounce off it, it is difficult for us to take a sample of the specific lesion, especially if its diameter is very small as it is at an early stage of the disease.

This has been the preferred method in recent years, in combination with non-invasive methods (PSA and PCA3). It has been recognized internationally as a fundamental pillar of the certainty diagnosis, although as we mentioned, it still has its disadvantages.

Of course, transrectal ultrasound can be used alone to orient the possible diagnosis, however, due to the same low specificity it has, it is always performed in combination with the biopsy.

The procedure consists of placement and insertion of the probe through the rectum for direct recognition of the prostate. Once positioned, the needle is inserted (recognizable by ultrasound) with direct orientation to the particular site where we want to take the sample. A relatively short procedure that can be performed on an outpatient basis and takes no more than 20 minutes, although it depends directly on the clinician’s expertise.

The Novel Prostate Fusion Biopsy: Embracing the Future

As technology advances, so do studies. New methods have been perfected for the various diseases, although one of the most useful diagnostic tools, speaking of medicine in general, has always been Nuclear Magnetic Resonance (NMR or MRI).

MRI and transrectal ultrasound have recently been linked to biopsy to create a new type of diagnostic method with a very high sensitivity and specificity, that is, a high probability of making the most accurate diagnosis.

This consists of performing an initial MRI in search of possible lesions found in the prostate. Unlike in the ultrasound, in this study it can be directly identified (in the image) where the altered sectors of the prostate are.

This technique is also known as prostate mapping, and the most commonly used is based on the BIOPSEE system, which fuses both MRI and ultrasound images to record the position of possible neoplastic alterations through the perineum.

For urologists who have many years of experience, and have been treating prostate problems since the 1990s, it is certainly incredible (and exciting) that we can have a direct view of the affected areas to perform the prostate biopsy via transperineal. There are many direct advantages to using the BIOPSEE System:

Less chance of infection: By not passing through the rectal mucosa, which is filled with the same microorganisms that emerge in the stool, the risk of infection decreases to 0.01%.
High detection rate: the high capacity to fix potentially neoplastic images gives a probability close to 100% in our experience, and more than 90% in the medium and long term scientific studies published internationally. Even those tumors existing in the anterior region of the prostate that cannot be detected by the transrectal ultrasound, on the other hand, with the BIOPSEE system have a good detection percentage.

Greater precision in the determination of the grade and volume of the tumor (better stratification of the risk and greater precision in the choice of therapies).
Higher rates of detection of clinically significant tumors that require active treatment.
Potential reductions in the diagnosis of indolent disease, which reduces overdiagnosis and overtreatment.
Reduction in the number of patients submitted to biopsy.

Speed translates into life expectancy: the faster the diagnosis is made, and the staging of the cancer (a necessary classification for management), the better the treatment used. Each patient needs a diagnosis according to the progress of the cancer and the sooner the better. In addition, the results can be obtained much faster, even the next day.
Thought for the patient: the transrectal ultrasound - no doubt - is a very uncomfortable procedure that deserves a lot of will and serenity. However, fusion biopsy is transperineal, so there is no need to place probes in the rectum.
Repetition rate: A major defect of other types of biopsy is that, as they were not direct and well oriented, it was usually necessary to repeat it several times until the diagnosis was reached (both positive and negative). With this method, fewer directed biopsies per patient are required to make effective diagnoses and minimize biopsy-related morbidity. The high efficiency of the BIOPSEE system is an increase in safety and also in the long term, a great economic saving.

There is a lot of difference between the conventional systems and the newest ones. At Andromedi we have been implementing this technique for months and it is certainly something revolutionary. It is our commitment to always adopt the changes and technological developments in our practice in Seville, especially when it is designed for the patient. If there is the possibility of performing the biopsy by fusion, this will always be our recommendation.