Baseline Computed Tomography or Positron Emission Tomography in Patients with Locally Advanced High-Risk Breast Cancer Facilitates Highly Customized Radiation Therapy in Anatomical Areas beyond the Scope of Surgery

The aim of the study was to compare the standard baseline imaging, with extended radiological staging. To assess our hypothesis, we performed a prospective, single-centre study which included 132 participants recruited between October 2015 and March 2020. Descriptive statistics, the Friedman and chi-squared tests were performed and p < 0.05 was considered significant. Patients were grouped into two cohorts, CT scan cohort (n=87) and PET-CT cohort (n=43). In the first group the originally determined disease stage changed in 36.8 % of cases, in second group in 51.2 %. The consistency between assessment of axillary lymph nodes by imaging (cN) and the postoperative pathology report (pN) was evaluated. In most cases, clinical and pathological evaluation of involved nodes was consistent, for CT scan the result was χ2(1) = 18.98; p < 0.001, for PET-CT the result was χ2(1) = 6.41; p = 0.03. Highly customized radiation therapy defined as dose boost within the involved lymph nodes, not covered by surgeon, was applied in nine patients.