Background: Neoadjuvant chemotherapy (NAC) is increasingly utilised in breast cancer management to enable tumour downstaging, facilitate breast conservation, and provide prognostic information through pathological complete response (pCR). Accurate imaging assessment of treatment response is essential to guide surgical decision-making. Contrast-enhanced MRI (CE-MRI) is widely regarded as the reference standard; however, its use is limited by cost, availability, prolonged acquisition time, and patient contraindications. Contrast-enhanced spectral mammography (CESM) has emerged as a potential pragmatic alternative. Aim: To evaluate the accuracy of CESM in assessing response to NAC by correlating radiological findings with final pathological outcomes. Methods: A retrospective single-centre study is being conducted at Royal Perth Hospital. Women with breast cancer treated with NAC between January 2021 and December 2023 who underwent CESM before and during or after treatment are being identified through multidisciplinary meeting records and radiology databases. Radiological response on CESM will be categorised based on residual enhancement and compared with surgical histopathology to assess concordance and prediction of pCR. Data are de-identified and stored in accordance with institutional governance requirements. Conclusion: This study will provide local data on the utility of CESM in evaluating response to NAC. Findings may support CESM as a practical and accessible alternative to CE-MRI in selected patients and help inform future imaging pathways. References: Tang S et al. Br J Radiol. 2020;93:20200301. Savaridas SL et al. Br J Radiol. 2023;96:20220921.