Information for Patients
Advanced Prostate Imaging
The Advanced Prostate Imaging Team
(From left to right) Kathy Pitts, Leon Parris, Daryl Turlington, Dr. Mary Turner, Dr. Jinxing Yu, Dr. Charles Cockrell, Jean Snow, Michael Coleman, Dr. Robert Halvorsen and Brad Metcalf.
To set an appointment for an MR of the prostate, call 804-237-6645 or for an MR guided prostate biopsy, call 804-828-4467.
VCU Medical Center is the only site in Virginia using all advanced MR imaging techniques for prostate cancer, and is one of only a few sites in the country performing MR Guided Prostate Biopsy. The radiologists, scientists, physicists and technologists at VCU Medical Center’s Department of Radiology work together to bring cutting-edge technology and science into clinical practice for the benefit of patients with prostate cancer. By providing the most advanced, accurate and comprehensive MR imaging techniques now available to prostate cancer diagnosis and treatment, these highly-trained experts provide the most precise information and guidance for the urologists and radiation oncologists.
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Each year, more than 217,000 American men are diagnosed with prostate cancer, making it the second most common cancer among men. Prostate cancer is also the second leading cause of cancer death in American men (more than 32, 000 per year).
Treatment of Prostate Cancer
Treatment of prostate cancer is determined primarily by whether the disease is localized, locally advanced or metastatic. Generally speaking, localized cancer is treated by surgery, radiation or watchful waiting. Locally advanced cancer is treated mainly by radiation. Hormone therapy is used in patients with metastatic prostate cancer. Therefore, knowing the stage of the prostate cancer is crucial for the treating clinician to choose an appropriate therapy.
For patients with a history of prior radical prostatectomy or radiation therapy, increase of the level of prostate-specific antigen (PSA, a blood protein secreted by prostate cancer) raises the possibility of recurrent tumor at the surgical bed or in the treated prostate. It is very important to know the location of the recurrence because these days, the radiation oncologist is able to treat the recurrence by delivering a high dose of radiation to the specific target (recurrence) without radiating adjacent normal tissue.
Screening of Prostate Cancer and Diagnosing Recurrence
Prostate cancer screening usually begins with a periodic evaluation of a patient’s blood sample for PSA. A primary care physician or urologist may also begin with a digital rectal exam (DRE). In case of elevated PSA or a palpable prostate nodule, the urologist will perform an ultrasound guided biopsy of the peripheral zones of the prostate, taking a total of six to 12 biopsy samples. Then, the pathologist will evaluate these samples under the microscope and decide whether the histological features of the prostate specimens meet the criteria of diagnosing prostate cancer. If so, the cancer severity is graded using the Gleason Score (most ranging from six to 10). The higher the Gleason score, the more aggressive the tumor is likely to act and the worse the patient’s prognosis. Unfortunately, errors in the predicted biopsy Gleason score are common and most often result in under-grading of the actual tumor.
There is no reliable clinical method that can be used to diagnose tumor recurrence during the follow-up of prostate cancer patients who have been treated with radical prostatectomy or radiation therapy. The interval increase of blood serum PSA likely indicates recurrent disease, but it does not tell us the location of the recurrence. The likelihood of proving local recurrence by transrectal ultrasonagraphy-guided biopsy is relatively low (positive rate between 38 to 54%).
At VCU Medical Center, magnetic resonance imaging (MRI), supplemented by MR spectroscopic imaging (MRSI) has been used in staging of prostate cancer and diagnosing tumor recurrence for many years. Excellent demonstration of zonal anatomy and pathological processes of prostate is possible with MR imaging (Fig. 1). Greater specificity and characterization of the pathological processes of prostate is possible using MR spectroscopy (Fig. 2), which helps distinguish adenocarcinoma from other disease processes such as infection, inflammation or post-treatment changes.
Figure 1: Prostate cancer (arrow) in right mid gland of peripheral zone (P) on T2 weighted imaging.
Figure 2: MR spectroscopy imaging. On left, MRSI demonstrates elevated choline peak (A) and decreased citrate peak (B), consistent with prostate cancer. On right, MRSI shows citrate peak (B) is higher than choline peak (A), consistent normal tissue.
New Advanced MR Techniques
More advanced MR techniques are now available and are being used routinely at VCU Medical Center to stage and better detect prostate cancer. MR diffusion (Fig. 3) and contrast-enhanced imaging, or perfusion, (Fig. 4) are new MR imaging techniques that are noninvasive and offer enhanced capabilities in prostate imaging. These techniques are sensitive and helpful in all prostate cancer patients, including those who have had prior prostatectomy or radiation therapy. MR-guided prostate biopsy (Fig. 5) allows precise placement of the biopsy needle under direct vision and allows tissue sampling with fewer passes of the biopsy needle. MR- guided biopsy of prostate cancer has been proven to be an accurate tool in confirming the diagnosis of prostate cancer, particularly useful for patients with prior failed transrectal US- guided biopsy (positive yield up to 60%).
Figure 3: Diffusion-weighted MR imaging of prostate demonstrates low signal focus (+) in the right mid gland of peripheral zone (P), consistent with prostate cancer.
Figure 4: Dynamic contrast enhanced imaging (DCE) of prostate demonstrates enhancement with rapid wash-out (+) in the right mid gland. Biopsy confirmed adenocarcinoma in the right mid gland with Gleason score 7.
a b
Figure 5: Dynamic contrast enhanced imaging (DCE) of prostate and MR guided prostate biopsy. a, DCE demonstrates enhancement with rapid wash-out (+) in the right transitional zone consistent with prostate cancer. b, MR guided prostate biopsy was performed and Gleason score 7 adenocarcinoma was found in the right transitional zone.
VCU Medical Center is the only site in Virginia using all of these techniques.
Specialized abdominal radiologists at VCU Medical Center, trained in MR imaging of the prostate gland, are using these new advanced techniques routinely to assess patients with suspected prostate cancer, and to evaluate patients who have been previously treated with surgery or radiation for recurrent disease. They work closely with the radiation oncologists and urologists to provide the latest, most advanced diagnostic tools for prostate imaging.
Indications for Prostate MR at VCU Medical Center
Advanced MR prostate imaging, based on anatomic, metabolic and physiologic properties of prostate cancer, provide the best characterization of prostate cancer in individual patients. The list of indications for prostate MRI at VCU Medical Center is:
- Staging – Accurate staging of prostate cancer is important for choosing an appropriate therapy. MR imaging has been shown to be accurate in staging of prostate cancer and in detecting tumor spread outside the prostate gland.
- Improving biopsy yield – Recently, prostate MRI has been increasingly used in pre-biopsy patients. The information from the prostate MR will help urologists to perform a more targeted biopsy, resulting in a higher positive biopsy yield.
- Providing a roadmap – Minimally invasive and robotic surgeons are increasingly turning to preoperative MR imaging which would help provide a roadmap of the location of the tumor as well as the relationship between the tumor and the surrounding important structures. The roadmap will guide the urologist in resection of cancer while preserving essential delicate arteries and nerves that help maintain urinary continence and sexual function.
- Improving diagnosis – There are a growing number of patients with negative biopsies and elevated or rising PSAs, in whom prostate MRI is used to target regions for subsequent ultrasound-guided biopsy by urologists.
- Detecting recurrent cancer after radiation therapy or after radical prostatectomy – Advanced MR imaging using multiple parameters has been proven to be useful in the detection and localization of recurrent cancer. It is crucial for the treating radiation oncologists to know the exact size and location of the recurrence before starting new treatment.
- Monitoring “watchful waiting” patients – Most prostate cancers usually grow very slowly. Patients who have low Gleason scores, other medical complications or low grade tumors may wish to postpone treatment due to the side effects. MR imaging is an excellent noninvasive tool in monitoring the growth of the tumor over time.
For Referring Physicians
To schedule an appointment for a Prostate MRI, please call 804-237-6645 or for an MR Guided Prostate Biopsy, call 804-828-4467.
For more clinical information regarding these techniques, click here.