By Maria Bishop
Special to DG News
BOSTON, MA -- October 26, 2000 -- High-dose-rate brachytherapy (HDR-BT) is an effective palliative therapy for central lung tumours-and afterloading of the bronchus with two applications appears to be more effective and convenient for patients than is the standard four-application dose.
In brachytherapy (a form of implant radiation), radioactive material is sealed in needles, seeds, wires or catheters, and placed directly into or near the tumor.
German researchers at the 42nd Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Boston, Massachusetts, described a trial of 142 patients who had advanced tumours with inoperable central-lung masses and endoluminal tumour growth.
Trial participants were randomized to receive either four applications of 3.8 Gy weekly (group 1) or two applications of 7.4 Gy, separated by a three-week interval (group 2). The implants were placed at 10-cm depth from the source axis.
The research team was led by Barbara Pollinger, MD, department of radiation oncology, Ludwig-Maximilians University, Munich, Germany. Following treatment, several parameters were examined -- local control, survival and side effects.
Local control was found to be significantly superior for group 2, a mean of 17 weeks, compared to Group 1, which maintained local control for a mean of eight weeks.
Mean survival in group 2 was 33 weeks, while in group 1 it was 25 weeks. Median survival in both groups, however, was 20 weeks.
Side effects were also examined, and group 2 did show evidence of greater incident: Fatal hemoptysis (the expectoration of blood) in group 2 was 12 percent, as compared to 17 percent in group 1.
Overall, however, radiation therapy can produce palliation in the majority of lung-cancer patients, and HDR-BT, noted the researchers, is extremely successful in this regard.
Dr. Pollinger concluded: "High-dose-rate
brachytherapy is an effective local treatment for central-lung tumours.
Furthermore," she added, "[the two-application afterloading] is more convenient
for the patients."