Breast cancer specialists are divided over the pros and cons of intraoperative radiation therapy, or IORT, a single-dose of radiation that is given at the same time a patient has lumpectomy surgery to get a tumor removed. As The Wall Street Journal reports, a large, randomized controlled trial published in the medical journal The Lancet found that IORT has fewer side effects and could prevent cancer from returning as well as traditional treatment. Normally, patients undergo radiation sessions 5 days a week for up to 7 weeks as part conventional therapy. However, women included in the study also face double the risk of their cancer coming back compared with traditional radiation, the WSJ article notes, 3.3% over 5 years for IORT versus 1.3% over 5 years for the control group. Plus, the women in the trial were not followed long enough to make sure the results were accurate, according to IORT critics. The median follow-up for the study was only 29 months, not 5 years.
And because doctors don’t always have all the information about a tumor at the time of a lumpectomy, about 20% of participants in the trial who had IORT were later found to be at higher risk of breast cancer and received conventional radiation as well, the WSJ reports. However, those women were still included in the IORT group for the study, which could have skewed the findings. “A lot of us are scratching our heads as to why (IORT) would be appropriate,” David Wazer, chair of radiation oncology at Brown and Tufts medical schools, told the newspaper.
Still, IORT proponents are defending the technique, pointing to its potential benefits in women with breast cancer. The study was supposed to give the therapy to women with early-stage cancers and add conventional radiation later if the patient was deemed high risk, researchers told the WSJ. The women who had IORT had fewer severe skin problems, and there was no significant difference in the risk of death in either group. “We’ve analyzed this four different ways, and every way we get the same answer: There isn’t much difference in efficacy, but it is significantly less toxic, and significantly more convenient,” said Jayant Vaidya, a professor of surgery and oncology at University College London, and lead investigator in the trial, as quoted by the WSJ.
More data could settle some of the debates surrounding the radiation techniques. A trial in Italy is evaluating another form of IORT and a large randomized trial in the U.S. is comparing partial breast radiation using a balloon catheter with conventional radiation. However, results from the latter study won’t be available for several years, the WSJ notes, leaving question marks in the minds of those evaluating the two therapies.
REFERENCE: Fierce Medical Devices; 25 AUG 2015; Emily Wasserman