Surgery vs. Seeds vs. IMRT

BY MARK SCHOLZ, MD

 

Many men with Intermediate-Risk prostate cancer consider treatment with radiation or surgery. Treatment selection is influenced by age and preexisting status, especially as regards baseline sexual and urinary function. These days “surgery” usually means robotic surgery rather than the older, “open” procedure. Brachytherapy (radioactive seeds), and intensity modulated radiation (IMRT) are the most widely used types of radiation.

 

Cure Rates

All treatment options result in similar cure rates assuming the best physicians and technology are used. If any single treatment can be considered to have a slight advantage, it is brachytherapy. Seed implants deliver a somewhat higher dose of radiation, possibly with slightly better accuracy. All types of radiation have a slight cure-rate advantage over surgery because radiation treats a small margin around the gland. Surgery, especially when extra-capsular disease is present, may leave cancer behind, an unfortuante situation called “a positive margin.”

 

Quality of Life

Since cure rates are equivalent, the main criteria for selecting treatment are side effects. Table 1 lists the risks faced by a 65-year-old with good erectile function and without preexisting prostate problems. Risks are adjusted up or down based on a man’s age and his sexual and urinary function prior to treatment.
 

Table 1 Long Term Side Effects

Impotence Incontinence Climacturia* Urethritis Stricture** Proctitis Surgery 50% 8% 15% - 5% - Seeds 30% 1% - 10% 2% 1% IMRT 30% 1% - 4% 2% 2% *Climacturia is the ejaculation of urine rather than sperm **Stricture is a urethral scar

Short Term Side Effects
Some of the long-term effects noted in Table 1 also occur short term. All men are impotent after surgery though 50% eventually recover some functionality. Urinary symptoms, termed “urethritis,” occur in two-thirds of men who undergo brachytherapy, usually lasting a couple months. Proctitis symptoms lasting one to two months occur in about half of the men who are treated with IMRT.

Treatment for Long Term Side Effects

Shrinkage and shortening of the penis due to surgery may be partially averted with early use of Viagra, Cialis or Levitra, and when necessary, the injection of prostaglandins. For treating impotence or incontinence, patient satisfaction is about 85% with a surgically implanted penile prosthesis and 60% with a surgically implanted artificial urinary sphincter. Chronic urethritis, a non-healing radiation burn of the urinary passage, manifests as pain, frequent urination, and a compelling urge to urinate right now. Proctitis side effects can be described similarly, but affecting the rectum. Palliative treatments for chronic urethritis and proctitis are only partially effective.

 

Further Aspects of Surgery and Radiation

 

Surgery: The surgical skill of urologists varies and is measured by how frequently cancer is left behind after the surgery, termed a positive margin. The best surgeons average a 10% rate. Studies show that many urologists, even at reputable centers, leave cancer behind up to 50% of the time. Prostate removal gives information about the size and grade of the cancer, helping to improve the accuracy of projections about future relapse. Surgery also simplifies PSA monitoring, since unlike radiation, there is no residual prostate gland producing PSA.

Seeds: Brachytherapy with permanent seeds is an outpatient procedure. Temporary, high-dose-rate (HDR) brachytherapy requires an overnight stay in the hospital. Men with preexisting urinary problems or glands over 60cc are more prone to develop urethritis from brachytherapy. A benign PSA rise after the implant, termed a “PSA Bump,” occurs in 30% of men and can engender considerable anxiety.

IMRT treatment requires two months to deliver. Radiation beaming through surrounding organs may increase the risk of bladder and rectal tumors, though the risk is clearly less than one percent. The biggest risk besides impotence is proctitis. In the future, the injection of hydrogel between the prostate and the rectal wall may eliminate this risk (Hydrogel is pending FDA approval).

Cyberknife and Proton Therapy: Cyberknife is like IMRT but treatment is over one to two weeks rather than two months. Proton therapy is also similar to IMRT except it fires heavier subatomic particles (proton vs. photon). Proctitis rates are reported to be slightly higher with either of these two modalities.

Combination Radiation with Seeds and IMRT: Men with High-Risk disease and even some with Intermediate-Risk are treated with a combination of Seeds and IMRT. The side effects of Seed/IMRT combinations are similar to those of seeds alone.

The Outdated Sequencing Argument
As stated at the outset, cure rates are high with both radiation and surgery. Arguments touting surgery as the “Gold Standard” were true ten years ago when suboptimal radiation resulted in lower cure rates. Regrettably, to this day, many surgeons are still claiming that sequencing surgery before radiation is advantageous. This outdated thinking prioritizes planning for relapse, forgetting about the need to focus on quality of life. The goal is to be cured with the first treatment and be spared the side effects of additional rounds of therapy.

Taking Time to Decide
Prostate cancer is slow moving condition. There is no need rush to a decision. Radiation or surgery cures men with Intermediate-Riskprostate cancer 70-90% of the time. Even if a relapse occurs, salvage therapy usually gives a normal life expectancy. Additional options, besides surgery and radiation, can also be considered for men in the Intermediate-Risk category including active surveillance, focal therapy and intermittent hormone blockade. However, these treatments are outside the medical mainstream and beyond the scope of this short blog.