Imaging Prostate Cancer
Posted: Nov 01, 2018
POSTED: March 21, 2018
Dr. James Eastham, Chief of Memorial Sloan Kettering’s Urology Service, is a surgeon who specializes in nerve-sparing radical prostatectomy and salvage radical prostatectomy.
Prostatepedia spoke with him recently about surgical options when cancer comes back after initial treatment.
Dr. Eastham: A salvage procedure just means something failed beforehand: a salvage radical prostatectomy is surgery done on a prostate that has been treated with something else. That something else can be radiation. It can be prior high-intensity focused ultrasound, meaning the patient had a heat application to the prostate to try to treat prostate cancer. The something else can be cryotherapy that was unsuccessful. But basically, salvage surgery means surgery after a failed non prostate-removing technique.
Dr. Eastham: Most of the salvage surgeries that are done are still done for patients who fail radiation therapy.
A patient underwent radiation therapy for prostate cancer. They’re followed, and then their PSA blood test starts to go up. Typically, as part of the evaluation for a rising PSA after failed radiation therapy, the patient will undergo imaging studies.
There are different imaging studies that we can do to check if there is any evidence of cancer beyond the prostate. If all of those studies are negative, then the patient will typically have a biopsy of his prostate. If that biopsy shows persistent prostate cancer, the patient is at least a candidate for additional local therapy, meaning therapy directed at the prostate. All of these therapies are called salvage. Surgery to remove the prostate is a salvage prostatectomy. Some patients may have cryotherapy. That’s salvage cryotherapy. Patients can have radiation after failed radiation. That would be salvage radiation therapy. There are a variety of options.
Dr. Eastham: The patient should have a cancer that was potentially curable with local therapy at the time of the original diagnosis. The cancer at the time of treatment failure must still be potentially curable with local therapy.
There are some patients who, at the time of their original diagnosis of prostate cancer, had a big, bulky cancer that was treated with radiation therapy and subsequently failed this treatment. These patients really aren’t appropriate for salvage radical prostatectomy because they were never surgically curable.
To be a good candidate for salvage local therapy, including salvage prostatectomy, the patient would have to have been diagnosed with clinically localized, non-metastatic cancer, have undergone a treatment that didn’t work, and after initial treatment failure, still have a clinically localized, non-metastatic cancer amenable to local therapy.
Dr. Eastham: Most of the follow up is still done with PSA, so routine imaging is typically not done after prostate cancer treatment. Most of the treatments are still based on waiting for a PSA to rise. A rising PSA typically leads to other testing. This other testing has become more sensitive in picking up patients with low-volume metastatic disease. That is where the imaging matters.
If someone already has metastasis, as shown by whatever imaging study, it’s unlikely that salvage radical prostatectomy is going to provide them with any particular benefit because this is a big surgery and has potential risks. That is where the imaging comes into consideration. Imaging looks for metastatic disease and basically excludes patients who won’t benefit.
Dr. Eastham: Absolutely. Any prior treatment to the prostate results in the development of scar tissue.
After radiation therapy, high-intensity focused ultrasound (HIFU), or cryotherapy, scar tissue develops. The prostate fuses to organs from which it would typically be easily separated.
The primary concern is the rectum; injury to the rectum is a potentially devastating complication of salvage radical prostatectomy. All of the tissues tend to not heal as well because the scar tissue has an impaired blood supply. There is slower healing. The anastomosis, where we sew the bladder and the urinary tube back together, also tends to heal more slowly. This can lead to a higher risk of urinary leakage, or anastomotic leak. There are higher risks of strictures, or bladder neck contractures, which is scar tissue that develops where the bladder and urinary tube are sewn back together. When that happens, the man just basically can’t urinate. There is much higher risk of incontinence.
Again, the radiation therapy results in scar tissue, so things just don’t heal as well as they should. On top of that, it’s very difficult, even in those men who still have erectile function after radiation therapy, to preserve erectile function in men undergoing some type of salvage surgery. It’s just a far more difficult operation for the surgeon. But from the patient’s perspective, there is a much higher risk involved in terms of side effects and negative consequences.
Dr. Eastham: Yes. This is not something that is typically undertaken by someone who doesn’t have much experience in terms of doing traditional radical prostatectomy. The surgeon needs a bit of experience and has hopefully been trained in dealing with post-radiation tissue changes.
Dr. Eastham: The issue is always: how curable is his cancer. The tendency after radiation therapy is to watch patients’ PSAs rise for much longer than is clinically beneficial. The traditional definition of failure is the lowest PSA the man achieves plus two; this is called the Phoenix definition. Waiting for the PSA to rise two whole points just gives the cancer a chance to grow. But the earlier one treats prostate cancer, the better.
Waiting until the PSA is nadir plus two is too long for the patient to still be an optimal candidate for salvage treatment. The earlier the better. A man with a rising PSA after radiation, even if his PSA hasn’t yet reached nadir plus two, should be considered for imaging studies and potentially a biopsy.
Members can read all of this month’s conversations in their March issue of Prostatepedia.