Imaging - March - April 2023
This issue focuses on two major advances in imaging that should both have major impacts on the care men with prostate cancer receive.
The first is that it is now clear that MRI is superior to transrectal ultrasound as a method to make the initial diagnosis of prostate cancer. Actually, the superiority of MRI has been apparent for some years. One major advantage of MRI is that it is superior to transrectal ultrasound in visualizing the cancer.
In fact, ultrasound is so inadequate in seeing the cancer that the subsequent biopsy is essentially done blind with the cancer only detected if by chance the biopsy needle hits the cancer. As a result, it has been common practice to do multiple blind biopsies on both sides of the gland.
In contrast, MRI tells the physician the precise location of the cancer and as a result, the biopsy is targeted rather than blind. As an added advantage, MRI is most likely to miss small, indolently growing cancers that do not require treatment.
While transrectal ultrasound may not be able to reliably visualize the cancer, it can be useful in guiding the biopsy of a cancer detected by MRI. With this approach, the MRI image showing the cancer location is fused with the ultrasound image that visualizes the prostate gland and surrounding structures. The urologist can then use this fused image to accurately biopsy the cancer while minimizing the risk of damage to normal tissue.
The second major advance is the development of the PSMA-PET scan. The PSMA-PET scan represents a dramatic advance in visualizing prostate cancer that has spread outside the gland to lymph nodes, bone or other organs. It has proven its utility in newly diagnosed patients in detecting cancer outside the gland in patients who might otherwise be candidates for radical prostatectomy.
It is also of use in determining the extent of the cancer in those with more advanced disease. Finally, it is the most sensitive approach to finding the location of cancer recurrent after surgery or radiation. In addition, the PSMA antibody used to carry the isotope needed to image the cancer can be used to deliver radiation of sufficient intensity to treat the cancer.
The combined impact of these two imaging advances is potentially large. If these are not yet available your area, it is worthwhile to travel to gain access.
Charles E. Myers, Jr. MD
Interviews:
Michael Hofman, MD
Imaging and Treatment
Declan Murphy, MD
Imaging and Theranostics
Ali Arafa, MD
PSMA-PET Change Treatment?