Breast IMRT reduces side effects
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Study findings deemed practice-changing at an international level by the investigators reporting them indicate that intensity-modulated radiotherapy (IMRT) yields better cosmesis-related outcomes than does standard two-dimensional (2D) radiotherapy in persons with early breast cancer.
"These results ... should encourage other [centers] still using 2D standard RT to implement breast IMRT," concluded Dr. Charlotte E. Coles of Addenbrooke's Hospital Oncology Centre in Cambridge, United Kingdom, and her fellow researchers in their study abstract, presented at the 2nd Forum of the European Society for Radiotherapy and Oncology (ESTRO), held in Geneva, Switzerland, April 19-23, 2013.
IMRT, a high-precision form of radiotherapy, can deliver an even dose of radiation, which falls within the range of 95% to 107% of the prescribed dose. As noted in an ESTRO statement, too low a dose raises the risk for tumor recurrence, and too high a dose can cause skin changes and other cosmetic problems that often occur after breast radiotherapy.
Coles's team analyzed the radiotherapy treatment plans of 1,145 persons with early breast cancer who had had breast-conserving surgery previously. The plans called for the majority of patients (815 [71%]) to receive an uneven radiation dose with standard 2D radiotherapy. These patients were then randomized to proceed with the 2D treatment or to receive IMRT. The remaining patients, whose plans would not produce an uneven dose of radiotherapy, proceeded to undergo 2D radiotherapy and were followed in the study.
The late normal tissue toxicity outcome was available for 645 members of the full group of patients (57%), and for 465 of the randomized patients (57%). Compared with those undergoing standard radiotherapy, fewer of the IMRT recipients developed skin telangiectasia and suboptimal overall cosmesis. No significant difference between groups was seen in photographically assessed breast shrinkage, breast edema, tumor bed induration, or pigmentation. ONA