In this kind of prostate cancer treatment, “bigger is better” and “less is more” both apply.
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With stereotactic body radiation therapy (SBRT) the bigger the doses of radiation you get, the better the outcome. And the less time you spend getting treatment, the more success you’ll have.
SBRT is a newer kind of prostate cancer treatment that beams large doses of radiation to the prostate. Greater intensity is targeted to high-risk areas, rather than evenly to the entire prostate.
SBRT has higher tumor control, lower toxicity
SBRT delivers greater doses to the outer edges of the prostate, where the cancer is most likely to be. This allows lower doses to nearby normal tissue.
Early outcomes for this treatment are excellent, comparing favorably with traditional radiation, says oncologist Kevin Stephans, MD.
“Biological data supports bigger, more intense doses of radiation for prostate cancer,” he says.
Increased, targeted radiation reduces time commitment
Traditional radiation treatment for intermediate to advanced prostate cancer is rigorous, requiring 39 to 45 treatment sessions, done every day for several weeks.
SBRT requires just five 45-minute sessions. The actual treatment is only three to four minutes. SBRT provides more beam angles and they’re calibrated at different radiation doses.
The precision of SBRT allows for greater customization of where radiation dose falls.
Experiencing the SBRT process
Before the SBRT is performed, you get a CAT scan to define the target treatment area. Markers are placed to track the movement of the prostate during treatment.
During the scan, the at-risk tissue is identified along with the rectum, bladder, urethra and other normal surrounding tissue. The radiation target area is calculated and you’re ready for the SBRT.
You’re placed on the SBRT machine’s robotic table top so that your prostate is positioned within millimeters of the target area. Movement during treatment is tracked continuously to allow the radiation to be refocused if needed.
You’re awake during the procedure. There is no pain. To say that recovery time is quick is an understatement, says Dr. Stephans.
“You walk out feeling the same way you did walking in,” he says.
The only post-procedure problem reported is patients having to urinate more frequently, but this subsides after a week or so.
The overall five-year survival rate after SBRT depends on the risk factor of the cancer — but the numbers so far suggest results on par or perhaps even better than traditional external beam radiation.