Major changes in the incidence, diagnosis, and treatment of prostate cancer and benign prostate disease highlight an urgent need for an up-to-date center for the early detection and proper therapy of prostate tumors. The median age of occurrence of prostate cancer, formerly a problem of older men, is now 45 years. This means that men in their thirties are susceptible to developing prostate cancer. Many men are overwhelmed with the variety of medical tests and their safety. Physicians are troubled by varying PSA levels. Biopsies have a 6% incidence of significant side effects, and the results are frequently difficult to interpret even by experienced pathologists. MRI studies are currently sensitive but not specific for screening. PSA and its variants are notoriously unreliable with accuracy approximately 47%. The Mayo Clinic in 2004 reported that high-grade cancers often have low PSA. Additionally, 5% to 10% of cancers are located anteriorly, an area not included in the standard sextant biopsy protocol.
Cancer of the prostate is almost universal in older men. Two types of tumors occur. The most common form (94%) is extremely slow growing and can be treated conservatively. The remainder are rapidly invasive, requiring aggressive medical or surgical therapy. The sonogram test showing blood flow has climbed to the pinnacle of diagnostic accuracy. Imaging of the power Doppler sonography type (PDS) has been used worldwide to evaluate tumor blood flow and aggressiveness. Slow-growing or nonaggressive prostate cancers have no blood flows. Fast-growing tumors have high blood flows. 3T-MRI is the state of the art in evaluating tumor spread outside the prostate to the bones and lymph nodes.
NEW PARADIGM
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3D power Doppler sonography images show tumor penetrating prostate capsule (arrows). |
A state-of-the-art diagnostic and treatment center for prostate cancer would combine the use of high-resolution 3D power Doppler sonography (3D-PDS) with 3T-MRI (ultrahigh strength) scanning that together diagnose, stage, and grade prostate cancer. I predict that this combination will replace the PSA and digital rectal examination in the next 5 years. The negative predictive value of these examinations is 99%. This means that a negative examination indicates a 1% chance of having aggressive cancer.
The primary market for such a center would be radiologists (when a CT scan shows a prostate problem), urologists, gerontologists, oncologists, and radiation therapy planners. Additionally, marketing efforts would be directed toward a secondary market of internists, family practitioners, general surgeons, and complementary medicine. A tertiary market for the center would be patients who are concerned about the recent conflicting news reports on diagnosis and ongoing dissatisfaction with conventional treatment options. Our center, the Biofoundation for Angiogenesis Research, New York City, started with one patient per week in 1995 and now sees 15 patients per week. We market to patients and internists who treat prostate cancer with hormone therapy.
Many patients, amounting to 10% in my practice, now refuse to have PSA testing, due to equivocal results. Increasingly, patients choose graphic imaging results over confusing biopsy reports and oscillating PSA readings. Healthworld Communications Group, New York, cites a 22% increase in usage of MRI in 2004 over the previous year and notes the projected high growth areas are in prostate, breast, and vascular imaging.
IMAGING FOR DIAGNOSIS
3D-PDS is safer, quicker, cheaper, and less invasive than the other imaging modalities used in the diagnosis of prostate cancer and is the most accurate of all diagnostic tools for prostate imaging. However, the steep learning curve for 3D-PDS likely will slow the transition to its use. 3D imaging completely shifts the way sonography is performed by the technician and necessitates new reading skills by the physician, frequently a urologist. The 3D-PDS technique requires taking about 1,000 pictures in three planes and reconstructing the images on a workstation. The study can be performed in 10 minutes for high patient throughput. This technique is considered the best way to look for high-grade cancers prior to biopsy. 1 It also is an excellent way to detect spread of cancer outside the capsule, changing the tumor from operable to inoperable. 2
To assess spread outside the prostate, 3T-MRI screening may be done in 15 minutes, also yielding high throughput. The use of 3T-MRI permits spectroscopy and advanced imaging protocols to be performed as additional procedures.
Trends in treatment show that watchful waiting is preferred, and this modality gives a 99% predictive negative value: if no cancer is shown, the chance of significant tumor is 1%. Beyond diagnosis, both modalities will also play a role in various treatment strategies: Organ sparing intervention is possible using 3D ultrasound guidance for localized tumors, and 3T MRI will discover widespread disease, making radiation planning more specific.
Patients are opting for more control in medical decisions and this test gives them “patient power.” The outpatient setting provides a patient-friendly site for these services. A center for prostate imaging features a better yet alternative approach to prostate cancer diagnosis and management.
Robert L. Bard, MD, is assistant professor of radiology at New York Medical College. He has developed an optico-mechanical device for prescreening images to increase throughput.
References:
- Halpern EJ, Cochlin DL, Goldberg BB, eds. Imaging of the Prostate. London: Martin Dunitz, Ltd; 2002.
- Bard RL. 3D sonography of tumor invasion of the prostatic capsule. Presented at: 104th American Roentgen Ray Society Meeting; May 6, 2004; Miami Beach, Fla. Abstract 256.
