Purpose: The main objective of the study is to evaluate the accuracy of PET/MRI (Positron Emission Tomography / Magnetic Resonance Imaging) in estimating residual tumor in patients with invasive breast carcinoma undergoing neoadjuvant chemotherapy.
Materials and Methods: This prospective and multicenter study included 42 patients diagnosed with invasive breast carcinoma who underwent neoadjuvant chemotherapy before surgical treatment. PET/MRI scans were conducted both before and after neoadjuvant treatment. The imaging protocols included both whole-body scans and dedicated breast studies. The PET/MRI equipment used was a Siemens Biograph mMR system. All PET/MRI scans were interpreted by a radiologist specialized in breast imaging, a radiologist experienced in whole-body MRI (Magnetic Resonance Imaging) and a nuclear physician with expertise in interpreting PET images. The imaging exam findings were correlated with the anatomopathological findings of the surgical specimens. Statistical analysis assessed the accuracy of this new method in estimating residual tumors in these patients.
Results: The overall accuracy of the PET/MRI method was 78.5% in predicting residual tumor in patients with invasive breast carcinoma undergoing neoadjuvant chemotherapy. PET/MRI scans demonstrated a sensitivity of 85.3% (95% CI: 68.9-95.0) and a specificity of 50% (95% CI: 15.7-84.3) in predicting residual tumor in these patients. The positive predictive value was 87.9% (95% CI: 67.8-96.6), and the negative predictive value was 44.4% (95% CI: 13.7-78.8).
Conclusion: PET/MRI exam showed high sensitivity and accuracy in the evaluation of residual tumor in breast cancer patients following neoadjuvant treatment. This method has the potential to benefit patients, especially those undergoing both PET/CT and MRI. However, further research with a larger patient population is needed to fully elucidate its contribution in clinical practice, enhancing diagnostic and treatment planning options.
Clinical Relevance Statement: The application of PET/MRI for evaluating breast cancer patients receiving neoadjuvant chemotherapy has been relatively underexplored. The study’s findings indicate its potential to become a novel tool for this purpose, emphasizing the clinical significance of our research.
