For Release: October 5, 1998
Contact:
Michael J. Bernstein
(703) 648-8910
e-mail: [email protected]
RTOG Embarks on Three Ground-Breaking Studies
The Radiation Therapy Oncology Group (RTOG) has just begun work on three potentially ground-breaking studies of cancer of the brain, prostate and lung.
RTOG is a federally funded cancer clinical trials cooperative group, which carries out multi-disciplinary research nationwide. It is a major clinical research component of the American College of Radiology.
In one study, the first multi-institutional evaluation of the use of radioactive seed implants for cancer that is confined to the prostate gland will be carried out. To date a number of single-institution studies have been conducted, showing the technique to be effective in controlling the disease.
This new RTOG study will look closely at potential side effects as well as the effectiveness of the seed therapy, according to Colleen Lawton, M.D., study chair. Dr. Lawton is a radiation oncologist at the Medical College of Wisconsin, Milwaukee.
Earlier studies have claimed fewer side effects with seed implants than with other prostate cancer treatments.
A second clinical trial will study the safety and effectiveness of using 3-D conformal radiation therapy to attack a certain type of brain cancer (glioblastoma multiforme) with higher doses of radiation.
Typically, glioblastomas recur in the site in the brain that had been treated with radiation, says Jeff Michalski, M.D., study chair and a radiation oncologist at Mallinckrodt Institute of Radiology, St. Louis, MO. The problem, he explains, is that by increasing the radiation dose to prevent recurrence, damage can be done to the normal brain.
With the new 3-D method, the radiation beam can be shaped rather precisely to the site of the tumor, thereby allowing a higher dose to be used, but sparing healthy brain tissue, Dr. Michalski says. A main objective of the clinical trials, he adds, is to learn what the maximum safe, effective dose might be.
Also of importance, the study will collect dose information in a central database so that other researchers can determine the maximum dose in the future. Previously, Dr. Michalski says, data on this type of dose was inexact.
Finally, an RTOG randomized clinical trial has just begun to evaluate whether a radio-protective agent (amifostine) can effectively reduce some side effects in certain lung cancer patients treated with combined radiation therapy and chemotherapy. The clinical trial involves patients with inoperable, non-small cell lung cancer.
Patients with this disease, when treated with radiation and chemotherapy, can develop significant inflammation of the esophagus, according to study chair Benjamin Movsas, M.D., Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia PA. "Typically, one-fourth to one-third of these patients develop significant problems swallowing, such that they may need I.V. fluids or, possibly, hospitalization."
These side effects can also lead to an interruption in treatment that could negate the advantages of this intensive therapy, Dr. Movsas said. In the past, the radio-protective agent to be used in the RTOG study has been shown to reduce mucositis caused by similar intensive therapy used to treat head and neck cancer, he added.
"While we strive to develop more intense therapies that are more effective," Dr. Movsas says, "we also need to pay closer attention to side effects and quality of life issues."
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