Consensus statement on tumour bed localization for radiation after oncoplastic breast surgery
Background: Oncoplastic surgery (OPS) is becoming the new standard of care for breast-conserving surgery. OPS has led to some challenges with adjuvant radiation, particularly when accurate tumour bed (TB) delineation is needed for focused radiation (i.e. accelerated partial breast radiation or boost radiation). Currently, there on no guidelines on tumour bed localization for adjuvant targeted radiation after OPS.
Methods: A modified-Delphi method was used to establish consensus amongst a panel of 20 experts in surgical and radiation oncology at the Canadian Locally Advanced Breast Cancer National Consensus (LABCNC) Group and in subsequent online surveys.
Results: The main recommendations are as follows: 1) Surgical clips are necessary and should, at a minimum, be placed along the four side walls of the cavity plus one to four clips at the posterior margin if necessary; 2) Operative reports should include pertinent information to help guide the radiation oncologists; 3) Breast surgeons and radiation oncologists should have a basic understanding of OPS techniques and work on “speaking a common language”; and 4) Careful consideration is needed when determining the value of targeted radiation, like boost, in higher level OPS procedures with extensive tissue rearrangement.
Conclusion: The panel developed a total of six recommendations on TB delineation for more focused radiation therapy after OPS, with over 80% agreement on each statement. These are summarized along with the corresponding evidence and/or expert opinion.