MRI and prostate cancer screening
The month of November is dedicated to men's health and in particular thanks to the Movember movement which does a great job of raising awareness about the various diseases that can affect men and in particular male cancers such as the prostate or testicles.
Men are the first victims of cancer and more particularly in France with the highest rate in Europe (source : Institut National du Cancer - Le cancer de la prostate). Among these cancers, prostate cancer is the most common and the one that kills the most. There are 1.3 million new cases for the year 2018 worldwide (source : World Cancer Research Fund - Prostate cancer statistics). These high numbers are also the result of increasingly effective screening campaigns.
There is currently a panel of exams possible to perform this screening, all these exams are complementary, each providing different information. The digital rectal exam allows the doctor to check the volume, consistency, and texture of the prostate surface. This examination often takes place after a PSA (prostate specific antigen) biological assay which allows the level of PSA to be measured via a blood test. Unfortunately, these two tests remain insufficiently reliable and it is even observed that in 70% of cases a high PSA level was not linked to prostate cancer. For this reason, imaging plays an important role in the screening strategy, with MRI, often combined with ultrasound.
MRI imaging role in prostate cancer screening
In many studies it appears that MRI imaging has a big role to play in this screening for prostate cancer. Initially dedicated to the extension assessment of this cancer, prostate MRI allows its detection by combining morphological and functional imaging and allows a tumor map. The information provided, such as the estimation of the prostate and tumor volume, the location and the aggressiveness of the suspect focus, make it possible to adapt the therapeutic management strategy, biopsy and monitoring of new targeted therapies and the detection of recurrences after curative treatment.
The functional and multiparametric prostate MRI technique combines morphological (T2) and functional perfusion and diffusion sequences. This technique makes it possible to obtain a map of prostate cancer. Information on tumor detection, location, volume estimation, and tumor aggressiveness are obtained. However, there is some difficulty in identifying small-volume tumors (<1cm3) with a Gleason score less than or equal to 6, prostate MRI is therefore more efficient for the detection of "significant" lesions.
Another important aspect of an MRI scan of the prostate as part of cancer screening is the reporting. This must be detailed with the description of each suspect areas (or targets) identified and analyzed objectively and subjectively (PI-RADS score), with a suspicion scale ranging from 1 to 5 (1 normal, 2 probably normal , 3 equivocal or doubtful, 4 probably suspect).
MRI also plays an important role in treatment planning, particularly through tumor mapping. This allows better treatment planning, whether before surgery with the precise location of the lesions, before possible radiotherapy with the identification of extensions or even in the progression of the disease. MRI allows better identification of patients with progression risk thanks to its locoregional assessment.
In most cases patients with high PSA levels are offered a prostate biopsy performed transrectally and under ultrasound guidance. This examination is not without risk and can cause complications, exposing to an over-diagnosis of indolent cancers and an under-diagnosis of aggressive cancers, for these reasons it is usually performed after a prostate MRI.
Currently many studies are being carried out with the aim of improving detection rate of prostate cancer. Research is currently focused on the combination between nuclear medicine (PET) and MRI, making it possible to detect 25% more cancers and to better manage the pathological stage, and therefore the treatment of patient. This promising technique is based on the combination of two modalities and on the addition of PET exams with the injection of fluciclovine F-18. Research shows that advanced molecular imaging such as performed with Axumin PET is a useful addition to standard imaging to guide treatment decisions in patients who may benefit from radiation therapy after prostatectomy. According to the study (source : AuntMinnie.com - PET with Axumin boosts prostate cancer outcomes), the 3-year survival rate increases to 75.5% for patients who benefited from this new technique against 63% for conventional imaging alone, the gap is even greater at 4 years with 75, 5% against 51.2%.
Myrian XP-Prostate, dedicated to prostate MRIs
Intrasense has developed a tool specifically dedicated to MRI prostate examinations. The application's clinical workflow is adapted to medical requirements, providing a clear and precise diagnosis. Myrian interface offers the right tools at the right time in order to refocus the radiologist's work on his medical decision-making. XP-Prostate offers all the information necessary to score lesions and grade tumor involvement through the study of ADC diffusion maps and sequences with dynamic injection. The clinical application also allows a locoregional assessment through a simple and intuitive display of anatomical sequences. Myrian XP-Prostate allows you to achieve an estimated prostate volume intuitively and very quickly. All these tools are used to create a report containing the main scoring sources.