Imaging Prostate Cancer
Posted: Nov 01, 2018
POSTED: October 27, 2017
Dr. Charles “Snuffy” Myers offers his comments on our November issue on focal therapy for prostate cancer:
Last month we reviewed the impact of new tools like imaging on treatment choices for newly diagnosed men. We discussed how improved imaging impacts planning of both radiation therapy and surgery, as well as the role imaging plays in active surveillance in terms of patient selection and monitoring. .
This issue is a logical extension of those conversations as we look at focal therapy treatment options based on those imaging tools. The renaissance of focal therapy is due to MRI, which has the ability to visualize cancer within the prostate gland with much greater precision than older techniques.
Focal treatment makes sense when the cancer is of limited extent, usually limited to a single major lesion on one side of the prostate. If the cancer is truly limited to only part of the gland, it may not be necessary to destroy the whole prostate. The hope is that focal therapy will have less impact on sexual function and urination than radical prostatectomy or radiation therapy to the whole gland. A frequently used analogy is a lumpectomy versus mastectomy for breast cancer.
As you read the interviews, there are a number of issues to keep in mind. With radical prostatectomy and radiation therapy, we know in detail the odds of long-term cancer control. This information is lacking for the various forms of focal therapy. One reason that cancer control might be less complete after focal therapy is that focal therapies largely depend on the ability of the MRI to identify patients with cancer limited to one area of the prostate gland. But, as we learned last month, the MRI is not a perfect tool and can miss small, aggressive cancers. Also, first-rate MRI facilities with well-trained radiologists are limited in number.
As a medical oncologist, I have recently had to deal with a particularly difficult situation. With the arrival of new, highly sensitive imaging for metastatic disease, such as the C-11 Acetate, fluciclovine F 18, and PSMA PET/CT scans, I am seeing a growing number of patients who have had radiation therapy and the only detectable recurrent cancer is in the prostate gland. Focal therapy in this setting is difficult because of radiation damage to surrounding normal tissue as well as dense scar formation within the gland. Several interviews touch on treatment options for this situation, but those options are far from ideal. It is unclear what the right path is for these men.