“Our meta-analysis of 5-year data from published randomized trials of partial breast irradiation (PBI, alone or within a risk-adapted approach) vs. whole breast irradiation (WBI) for invasive breast cancer treated with lumpectomy, found no difference in breast cancer mortality (n=4489,difference 0.000%(95%CI -0.7 to +0.7),p=0.972). PBI was better than WBI for non-breast cancer mortality (n=4231,difference 1.1% (95%CI -2.1% to -0.2%),p=0.023), and total mortality (difference 1.3% (95%CI -2.5% – 0.0%),p=0.05), leading to a 25% relative risk reduction.”
In the figure below, PBI means Partial Breast Irradiation i.e., radiation only to the area near the tumour rather than the whole breast (Whole Breast Irradiation WBI).
The red diamond shows the overall effect from several trials with over 4000 patients. If the diamond sits on the vertical line, it means there is no effect – and if it is on the left it means that treatment is better for the patient.
So PBI (using TARGIT IORT as a single shot radiation at the time of lumpectomy for breast cancer, for example) reduces mortality, possibly by avoiding irradiation of vital organs, while maintaining cancer control.
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Full paper can be accessed at: