JACKSONVILLE, Fla. − A five day course of radiotherapy to treat breast cancer may, in some cases, expose as much lung and heart tissue to potentially toxic radiation as does the standard six weeks of treatment, say researchers at Mayo Clinic Jacksonville.
That because the short treatment, known as partial breast irradiation, focus radiation to a small sector of the breast through multiple beams, these beams can pass through the breast to the heart and lungs that lie behind, researchers found. Radiating the entire breast over weeks, as is standard practice, can expose much of the heart and lungs to long periods of lower dose radiation, they say.
These findings, presented at the annual meeting of the American Society for Therapeutic Radiation and Oncology (ASTRO), suggest that both methods carry risks and benefits that may be equivalent, says the studys lead investigator, Laura Vallow, M.D.
This tells us that the standard course of therapy isnt that bad in terms of its exposure to normal tissue, but also that, sometimes, partial breast irradiation may not spare as much normal tissue as we hope, Vallow says.
Oncologists are currently testing the two modes of radiotherapy − whole breast irradiation (WBI) and 3-D conformal partial breast irradiation (PBI) − in a large federally-supported clinical trial that is enrolling thousands of women across the country who have been diagnosed with early stage breast cancer and have undergone lumpectomy.
The hope is that a short course of radiotherapy will be as effective as the much longer course, and that this could lead to increased use of breast conservation over mastectomy, Vallow says. Many women may be opting for a mastectomy instead of a lumpectomy in order to avoid weeks and weeks of radiation treatment, she says. If the results of both methods are equivalent, then perhaps some of these women will choose less drastic surgery.
In two studies being
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