NEW YORK, Jun 08 (Reuters Health) - A new type of radiation treatment--known
as targeted radiation therapy--appears to be more effective than traditional
radiation for the treatment of prostate cancer, researchers report.
In fact, high doses of the targeted radiation may be as effective as more
invasive procedures, such as surgery to remove the prostate gland, according to
a report in the June issue of the International Journal of Radiation Oncology,
Biology and Physics. However, the investigators did not directly compare surgery
and the targeted radiation, so more research is needed to determine if this is
true.
A study by the same team of researchers, reported in the January issue of
the journal, found that the technique has fewer side effects than traditional
radiation treatment.
"The investments that we've made in high-tech radiation therapy are paying
dividends," said Dr. Jeff M. Michalski, of Washington University School of
Medicine in St. Louis, Missouri, who was involved in both studies. "We're seeing
real clinical benefits," he told Reuters Health in an interview.
Conventional radiation therapy for prostate cancer aims x-rays at not only
the prostate, but also the bladder, rectum and other healthy tissue. Side
effects of the treatment may include frequent or painful urination, diarrhea,
and blood in urine and stool. In contrast, the type of radiation used in the
studies, 3-D conformal radiation therapy, spares surrounding tissue by targeting
the prostate gland more accurately.
In a study that compared the two types of therapy, 131 men with prostate
cancer underwent conventional radiation and 146 received 3-D conformal
radiation. Higher doses of 3-D radiation could be used since it was more
precisely targeted at the prostate.
"The men who received the conformational radiation therapy did have better
relapse-free survival than patients who received just the standard radiation
therapy," Michalski said. From 91% to 96% of the men in the 3-D radiation group
were still disease-free 5 years after treatment, compared with 53% to 58% of
conventionally treated men, the authors report.
And the targeted radiation achieved these benefits without causing as many
side effects as conventional radiation. Both groups experienced similar levels
of some side effects, like frequent urination, but other side effects, such as
rectal bleeding, loose stools and diarrhea were less common in men treated with
targeted radiation.
According to Michalski, the targeted technique allows doctors to use a
higher dose of radiation to attack the cancer without causing as much damage to
surrounding tissue.
"We're hitting it more often, we're hitting it better," he said. "At the
same time, (we're) sparing the bladder and the rectum."
Right now, only about 25% to 30% of radiation oncologists--physicians who
use radiation to treat cancer--have access to the technology, according to
Michalski, but he said that this type of radiation is becoming much more common.
Now that it has proven effective in treating prostate cancer, researchers are
starting to study its use as a therapy for other types of cancer, such as lung
cancer, brain tumors and cancer of the head and neck, he said.
