Treating Prostate Cancer with IGRT
Image-Guided Radiation Therapy Is The Latest In High-Tech Treatment
Image-Guided Radiation Therapy, or IGRT, is the cutting edge in high-dose radiation for prostate cancer treatment, perhaps the biggest breakthrough in a generation.
For many prostate cancer patients, IGRT promises a cure rate equal to surgery, but without many of the potential side effects – mainly, incontinence and impotency.
While many physicians, primarily surgeons, argue that surgery remains the ‘gold standard’ treatment for men under 60 years of age, that perception may be changing due to the benefits of IGRT.
IGRT Targets Tumors
Introduced a few years ago, IGRT is an advanced technology designed to improve the precision and effectiveness of cancer treatments by giving doctors the ability to target and track tumors more accurately.
An automated system for IGRT, the On-Board Imager, enables clinicians to obtain high-resolution three-dimensional images to pinpoint tumor sites, adjust patient positioning when necessary, and complete a treatment all within the standard treatment time slot.
Before IGRT, radiation oncologists have had to deal with daily variations in patient positioning, including internal organ movement by treating a margin of healthy tissue around the tumor.
IGRT Adapts to Patient Motion
IGRT enables doctors to locate the tumor before each dose is administered by locking on to four gold “markers” inserted into the prostate while the patient is in the treatment position.
Even if the prostate moves -- say, from gas bubbles -- the IGRT adjusts daily to any new position. The dosage can even be regulated within the radiation beam to avoid sensitive areas, like the urethra, which is central to a man’s urinary system.
In fact, the usual “spillage” of radiation outside the prostate, compared to earlier external beam and brachytherapy (“seeding”) delivery systems, has been minimized from several centimeters down to a one or two millimeters, according to Dr. Bruce Green, head of the Bethesda Comprehensive Care Center in Boynton Beach, Florida. “IGRT minimizes the volume of healthy tissue exposed to radiation during treatment,” he told Suite101, in an interview April 29th, 2008.
In short, compared to older external beam radiation techniques, IGRT saves the bladder, protects the urethra, largely avoids sensitive sexual apparatus from getting singed and scarred by radiation.
Equal Cure Rate With Surgery?
According to Dr. Green and most physicians today, surgery and high-dose radiation are virtually equal in cure rates for localized, early-stage prostate cancer. But there's one caveat for high-dose radiation like IGRT: many cautionary physicians say the science cannot confirm a cure rate after 10-12 years.
No one knows the ultimate outcome because high-dose, targeted radiation hasn’t been around that long; high-dose brachytherapy seeding, for example, was the cutting-edge in the mid-1990s. Physicians simply don’t have the data that extends 20 and 30 years, into their comfort zone, like surgery data. So naturally, they tend to be cautious with younger PC patients (age 40s and 50s), whose cancer is more aggressive and needs to be dealt with in a serious manner.
Dr. Green has no doubt in the long-term effectiveness of IGRT. “Intuitively we believe that high-dose, targeted radiation like IGRT will be as good if not better than surgery, and without the side effects,” he said.
Other articles on prostate cancer by Steve Vogel
Prostate Cancer: Are You At Risk?
Prostate Cancer: Treatment Options?
