Work

A Biological-Driven Approach to Explore Dose-Escalated Ultra-Hypofractionation in Breast Cancer Radiotherapy

Year: 2025

Type: article

Abstract: To explore a more personalized approach to radiation therapy for adjuvant whole-breast irradiation in triple-negative breast cancer (TNBC), we analyzed the cell lines BT549 and MDA-MB-231 as in vitro models for radiobiological characterization. The local disease-free survival (LSR) values were determined for both cell lines' median, maximum, and minimum α and β parameters to achieve an LSR probability of close to 100% in a five-fraction schedule. Based on these findings, fifteen treatment plans were created for BC to simulate the proposed dose schedule. For the MDA-MB-231 cell line, the α/β ratios were 3.79 Gy (minimum), 15 Gy (maximum), and 7 Gy (median). For the BT-549 cell line, the α/β ratios were 5.95 Gy (minimum), 22.93 Gy (maximum), and 16.51 Gy (median). To achieve an LSR probability of close to 100%, the required doses per fraction were 5.2 Gy, 5.3 Gy, and 7.3 Gy for MDA-MB-231 and 8 Gy, 9.1 Gy, and 9.9 Gy for BT-549. We selected the highest dose per fraction, 9.9 Gy × 5, to simulate the worst-case scenario. To achieve 100% cell death effectiveness in TNBC, it is likely that higher radiation doses are required-doses that are not feasible within the setting of adjuvant whole-breast irradiation. Our model, which relies on the intrinsic biological features of the tumor, paves the way to reach more tailored RT plans and to improve the classic LQ model.

Source: Biomedicines

DOI: 10.3390/biomedicines13092154