Study Identifies Dose Escalation Radiation Treatment Technique for Community Doctors
PHILADELPHIA (November 2, 2001) -- Research shows that higher radiation doses improve prostate cancer cure rates. Radiation oncologists practicing in the community setting have been cautious to utilize such doses due to the increased risk of treatment toxicity especially in the absence of advanced localizing technology. Now, a new study demonstrates a treatment technique allowing dose escalation using readily available technologies in the community setting.
These findings will be presented by Derek B. Chism, M.D. of Fox Chase Cancer Center, Philadelphia, Pa., on November 7th from 12:00 to 1:00 p.m. PT during a poster presentation at the American Society for Therapeutic Radiology and Oncology Annual Meeting in San Francisco, California.
The purpose of this study is to describe the frequency and magnitude of gastrointestinal (GI) and genitourinary (GU) side effects in prostate cancer patients treated with radiation to high dose levels using a four-field treatment technique. The technique is designed to deliver sufficient dose safely and to be easily implemented in community practice.
The study includes 156 patients with aggressive cancer (Gleason < or = 7), a high PSA or a bulky tumor who were treated between January 1992 and February 1999. All patients received high dose radiation using the four-field technique to treat the prostate, seminal vesicles, and peri-prostatic lymph nodes.
Twenty-four (24) patients were treated at the initiation of the dose escalation program without a rectal block. These patients are included in the study for the purposes of comparison, and this treatment is not recommended.
Median follow-up was 28 months overall (range 2-106 months), 26 months for patients treated with rectal blocking and 86 months for patients treated without rectal blocking.
GI Complications Twenty-six (26) months after treatment, nine (9) of the 132 patients treated with a rectal block developed rectal bleeding with one who progressed to serious. One patient experienced frequent bowel movements. For comparison, of the 24 patients treated without rectal blocking, eight (8) developed serious rectal bleeding.
GU Complications Mild GU complications occurred in 12 percent of the patients 36 months after treatment. Of these, 10 patients experienced urinary frequency, two (2) experienced hematuria (blood in urine), and two developed cystitis (bladder infection). Two percent of all patients experienced serious GU complications at 12 and 36 months following treatment. Rectal blocking was not associated with GU complications.
"This treatment technique can be used to deliver high doses of radiation to the prostate with a reasonable amount of side-effects," said Chism. "Because of the simple nature the treatment design, this four field treatment program could be safely implemented in the community radiation oncology setting.
"We are not suggesting that this treatment take the place of technological developments, but rather that the safe implementation of high dose treatment strategies not be delayed in the community."
Of the 132 patients treated with rectal blocking, 94 percent are disease-free at only 28 months. "The disease control rates represent our findings to date and should be viewed with caution," Chism warned. "More follow up time is needed to get an accurate rate of disease control."
Other authors on the study include A. L. Hanlon and G. E. Hanks of Fox Chase Cancer Center.
Fox Chase Cancer Center, one of the nation's first comprehensive cancer centers designated by the National Cancer Institute in 1974, conducts basic and clinical research; programs of prevention, detection and treatment of cancer; and community outreach. For more information about Fox Chase activities, visit the Center's web site at www.fccc.edu.
Fox Chase Cancer Center, part of Temple University Health System, is one of the leading cancer research and treatment centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase also was among the first institutions to receive the National Cancer Institute’s prestigious comprehensive cancer center designation in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are routinely recognized in national rankings, and the Center’s nursing program has achieved Magnet status for excellence three consecutive times. Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research and oversees programs in cancer prevention, detection, survivorship, and community outreach. For more information, call 1-888-FOX-CHASE (1-888-369-2427).