3D-Conformal Cuts Complications
of Radiation Therapy for Early Stage Prostate Cancer Patients
With proper equipment and strict quality control, can be done at community hospitals,study says
Boston, MA /PSA Rising, NYC/ October 25, 2000 -- Radiation oncologists can increase the dose of radiation and still lower
the rate of complications if they use 3D conformal radiation therapy (3D-CRT) when treating patients with
early stage prostate cancer, a new study presented shows.
Earlier studies have indicated that increased doses would increase cure
rates, says Jeff Michalski, M.D., at Washington University School of
Medicine, St. Louis, MO. But, he says, "we were concerned that as the dose was
increased, complication rates would also increase - maybe not right after
treatment, but several months and several years later."
This study found that 396 patients, even three years after treatment, had
the same or fewer complications than those who were treated with standard
external beam radiation therapy, Dr. Michalski says. He presented results in Boston October 25 at the annual American Society for Therapeutic
Radiology and Oncology annual meeting.
One way of measuring radiation doses is by the Gy, or "Gray" (name of the man who invented this measure). Standard radiation doses for prostate cancer range between 66.6 Gy and 70 Gy, says Dr.
Michalski. One hundred eleven patients received 68.4 Gy, 274 patients
received 73.8 Gy.
Only one patient treated to 68.4 Gy suffered a grade-three complication (a
complication that requires hospitalization, surgery or medical
intervention for six months or longer). "That compares to the 18 we would
have expected to see with standard external beam radiation therapy," says
Three patients treated to 73.8 Gy suffered a grade-three complication
compared to an expected 42, Dr. Michalski adds.
The results haven't been fully analyzed for patients treated to 79.2 Gy.
It looks like there is no increase in complication rates in this group
either, says Dr. Michalski.
In addition, this study found that 3D-CRT can be done, and done well, in
the community hospitals/centers not just at academic hospitals/facilities,
notes Dr. Michalski. This study was conducted as a Radiation Therapy
Oncology Group (RTOG) clinical trial at 40 institutions across the U.S.
RTOG outlined very specific quality controls that needed to be met at the
institutions, he says. Those quality controls are essential in treating
with 3D-CRT Dr. Michalski says.
Dr. Michalski presented the data at the American Society for Therapeutic
Radiology and Oncology annual meeting, October 25 in Boston, MA.
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This page last modified
26 October 2000