ESTRO Multidisciplinary Management of Breast Cancer 2017

Can Boost remove the need for clear margins?

• Lupe et al, 2011. 2264 women treated with BCS and WBRT and boost. 1980 had clear margins, 222 close and 62 positive margins. 5.2 year follow up. 92% of close or positive cases had boost. • When close/positive margin cases were matched to negative margin controls for other risk factors such as age, grade, subtype, the difference in 5- year LR remained significant (4.25% vs. 0.7%, p < 0.001).

P<0.001

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• Housami meta-analysis found that correction for boost rates did not reduce the impact of a positive versus a negative margin

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LR rate

negative close positve