Recently, I have been hearing more and more about the possibility of detecting prostate cancer without having to do a biopsy. Biopsies are done after the urologist detects an abnormality on the rectal exam or blood PSA test. The rectal exam and PSA test are only screening tools. They don't tell us if the patient has cancer or not. Biopsies are performed by taking 10 to 12 "cores" with a needle gun through the rectum with an ultrasound probe. Yes, not too fun. So what is this new way of detecting cancer?
MRI and MRI spectroscopy
Magnetic Resonance Imaging, or MRI, can depict prostate anatomy with excellent contrast resolution and can uncover cancer in areas not routinely sampled on biopsy and not palpable on rectal examination. In addition, MRI allows assessment of local extent (read: extracapsular extension and seminal vesicle invasion), which can help with staging the cancer. The addition of spectroscopy to MRI can improve prostate cancer detection- combining the detail of MRI and the ability to "sniff" the biological aggressiveness of cancer with MR spectroscopy.
Would I operate based on the data from this new technology, without biopsies? The test is very sensitive and specific, but I still would not because you would try to avoid an unecessary operation at all costs. What if there was no cancer? However, there are situations where this test would be useful.
For example, if the patient has had prior biopsies done for an elevated PSA and they were negative. Unfortunately, the PSA keeps going up. The MRI might help the urologist FOCUS his area of biopsies.
Another case: a low but rising PSA. Many biopsies are uneccesary. The MRI could spare the patient the trauma of biopsies if the risk of cancer is low.
Also, the growing popularity of "watchful waiting" where the disease is monitored in low-risk patients- the MRI could give us a better idea than just depending on PSA. A picture of the disease could be compared yearly, giving us a precise view of the progress of disease.
