Brain Metastases of Non-Small Cell Lung Cancer: Magnetic Resonance Spectroscopy for Clinical Outcome Assessment in Patients with Stereotactic Radiotherapy

Abstract

Congli Jia,1 Zhengquan Li,2 Dong Guo,1 Zhen Zhang,3 Jingming Yu,4 Guangdong Jiang,1 Xiaobo Xing,3 Shengjun Ji,5 Feng Jin3 1Weifang Medical University, Weifang, People’s Republic of China; 2Department of Laboratory Pathology, People’s Liberation Army 80th Group Military Hospital, Weifang, People’s Republic of China; 3Department of Radiotherapy & Oncology, Qingdao Center Hospital, Qingdao, People’s Republic of China; 4Department of Radiotherapy & Oncology, Shandong Hospital, Jinan, People’s Republic of China; 5Department of Radiotherapy & Oncology, Nanjing Medical University Affiliated Suzhou Hospital, Suzhou, People’s Republic of ChinaCorrespondence: Shengjun JiDepartment of Radiotherapy & Oncology, Nanjing Medical University Affiliated Suzhou Hospital, No. 16 Baita Road, Suzhou 215001, People’s Republic of ChinaEmail [email protected] JinDepartment of Radiotherapy & Oncology, Qingdao Center Hospital, No. 127 Siliu Road, Qingdao 266042, People’s Republic of ChinaEmail [email protected]: Brain metastases (BM) are severe incidents among patients with non-small cell lung cancer (NSCLC) and have been associated with significant morbidity and decreased survival; thus, new methods are required to improve clinical management. Magnetic resonance spectroscopy (MRS) allows noninvasive measurements of biochemical information from tumor tissue, providing clinically useful imaging biomarkers. The primary aim of this study was to explore the application of MRS in the assessment of tumor prognosis after stereotactic radiotherapy in NSCLC patients with BM.Patients and Methods: MRS was performed on NSCLC patients attending Qingdao Center Hospital with suspected BM, and 68 patients were included in the survival analysis. The qualitative and quantitative parameters of MRS metabolites, such as choline (Cho), creatine (Cr), and N-acetyl-aspartate (NAA), were recorded. To select a cutoff for MRS metabolite parameters in the tumor and to distinguish patients who had recurrence, we performed an ROC curve analysis. Univariate and multivariate Cox regression analyses were used to assess the association between MRS metabolite parameters and clinical cancer prognosis.Results: The average age was 56 years. A total of 68 NSCLC patients underwent metabolic evaluation with single voxel proton MRS and were selected for retrospective analysis. According to the area under the curve (AUC) to predict recurrence, the MRS metabolite parameters were determined as Cho (AUC=0.550), Cr (AUC=0.415), NAA (AUC=0.524), NAA/Cr (AUC=0.600), Cho/Cr (AUC=0.723), and Cho/NAA (AUC=0.543). Cho and Cr predicted poor survival while Cho/Cr and NAA/Cr predicted improved survival (P< 0.05). In the multivariate model with adjustment to establish the potential role of MRS metabolite parameters, Cho/Cr showed a significant association with OS (P=0.009) and PFS (P=0.006) after stereotactic radiotherapy.Conclusion: The positive results of this study indicate the predictive value of metabolic characteristics of BM detected with MRS for the outcome after stereotactic radiotherapy.Keywords: brain metastases, magnetic resonance spectroscopy, stereotactic radiotherapy

Keywords

• brain metastases
• magnetic resonance spectroscopy
• stereotactic radiotherapy.