ATLANTAThe first patients have completed treatment using the
MammoSite Radiation Therapy System (RTS) in a multisite,
investigational clinical trial currently underway.
MammoSite RTS, developed by Proxima Therapeutics, Inc., is an
intracavitary balloon device designed to provide accelerated
site-specific radiation therapy in patients with early-stage breast
cancer treated by lumpectomy, the company said in a news release.
MammoSite therapy is simpler to deliver than brachyther-apy, the
company said, and may avoid the side effects associated with external
beam radiation therapy.
accelerated treatment time [twice daily for 5 days] may make breast-conserving
treatment an option for many more women, said Robert R. Kuske,
MD, radiation oncologist, Ochsner Clinic, New Orleans, and principal
investigator of the study. Traditional whole breast external
beam radiation takes up to 6 or 7 weeks. Many elderly patients and
those who work full time or live a great distance from the treatment
center now opt for mastectomy to avoid the lengthy therapy.
The MammoSite device consists of an applicator with a balloon-tipped
end (see Figures). During surgery or shortly afterward, the balloon
is inserted into the surgical cavity and inflated with sterile fluid.
The end of the catheter is attached to a high-dose-rate afterloader,
which houses the radioactive source, a tiny radioactive bead attached
to a wire. The bead exits from the afterloader and slides up the
catheter into the center of the inflated balloon, stopping at
multiple positions to deliver various levels of radiation to the
tumor cavity and surrounding areas.
The balloon is deflated after the final treatment session, and the
MammoSite RTS catheter is removed.
The clinical trial, with enrollment of 50 patients, will be completed
in early 2001, at which time the company expects to apply for FDA