Background and Purpose: Distinguishing treatment-induced imaging changes from progressive disease has important implications for avoiding inappropriate discontinuation of a treatment. Our goal in this study is to evaluate the utility of dynamic contrast-enhanced (DCE) perfusion MRI as a biomarker for the early detection of progression. We hypothesize that DCE-MRI may have the potential as an early predictor for the progression of disease in GBM patients when compared to the current standard of conventional MRI. Methods: We identified 26 patients from 2011 to 2023 with newly diagnosed primary glioblastoma by histopathology and gross or subtotal resection of the tumor. Then, we classified them into two groups: patients with progression of disease (POD) confirmed by pathology or change in chemotherapy and patients with stable disease without evidence of progression or need for therapy change. Finally, at least three DCE-MRI scans were performed prior to POD for the progression cohort, and three consecutive DCE-MRI scans were performed for those with stable disease. The volume of interest (VOI) was delineated by a neuroradiologist to measure the maximum values for Ktrans and plasma volume (Vp). A Friedman test was conducted to evaluate the statistical significance of the parameter changes between scans. Results: The mean interval between subsequent scans was 57.94 days, with POD-1 representing the first scan prior to POD and POD-3 representing the third scan. The normalized maximum Vp values for POD-3, POD-2, and POD-1 are 1.40, 1.86, and 3.24, respectively (FS = 18.00, p = 0.0001). It demonstrates that Vp max values are progressively increasing in the three scans prior to POD when measured by routine MRI scans. The normalized maximum Ktrans values for POD-1, POD-2, and POD-3 are 0.51, 0.09, and 0.51, respectively (FS = 1.13, p < 0.57). Conclusions: Our analysis of the longitudinal scans leading up to POD significantly correlated with increasing plasma volume (Vp). A longitudinal study for tumor perfusion change demonstrated that DCE perfusion could be utilized as an early predictor of tumor progression.

BACKGROUND AND PURPOSE: The aim of this study was to determine the diagnostic value of fractional plasma volume derived from dynamic contrast-enhanced perfusion MR imaging versus ADC, obtained from DWI in differentiating between grade 2 (low-grade) and grade 3 (high-grade) intracranial ependymomas. MATERIALS AND METHODS: A hospital database was created for the period from January 2013 through June 2022, including patients with histologically-proved ependymoma diagnosis with available dynamic contrast-enhanced MR imaging. Both dynamic contrast-enhanced perfusion and DWI were performed on each patient using 1.5T and 3T scanners. Fractional plasma volume maps and ADC maps were calculated. ROIs were defined by a senior neuroradiologist manually by including the enhancing tumor on every section and conforming a VOI to obtain the maximum value of fractional plasma volume (Vp_max) and the minimum value of ADC (ADC_min). A Mann-Whitney U test at a significance level of corrected P = .01 was used to evaluate the differences. Additionally, receiver operating characteristic curve analysis was applied to assess the sensitivity and specificity of Vp_max and ADC_min values. RESULTS: A total of 20 patients with ependymomas (10 grade 2 tumors and 10 grade 3 tumors) were included. Vp_max values for grade 3 ependymomas were significantly higher (P < .002) than those for grade 2. ADC_min values were overall lower in high-grade lesions. However, no statistically significant differences were found (P = .12114). CONCLUSIONS: As a dynamic contrast-enhanced perfusion MR imaging metric, fractional plasma volume can be used as an indicator to differentiate grade 2 and grade 3 ependymomas. Dynamic contrast-enhanced perfusion MR imaging plays an important role with high diagnostic value in differentiating low- and high-grade ependymoma.

BACKGROUND AND PURPOSE: Epidural spinal cord compression (ESCC) is an important cause of disability among cancer patients. Early detection is crucial for optimizing clinical outcomes. MRI is the preferred imaging modality for ruling out ESCC and frequently requested in radiology departments, particularly in the emergent setting. However, data on the efficacy and diagnostic yield of total spine MRI for diagnosis of ESCC in oncology patients remain limited. This study evaluates the frequency of positive findings and associated risk factors in a tertiary cancer center. MATERIALS AND METHODS: This retrospective study included patients who underwent total spine MRI for assessment of ESCC over a 3-year period. A standardized non-contrast MRI protocol was utilized. Clinical and imaging data, including patient demographics (sex, age), tumor pathology, tumor-node-metastasis (TNM) stage, ESCC grade, symptoms, prior treatments (radiotherapy, surgery, chemotherapy), and ordering physician/department, were retrospectively reviewed. Patients were categorized into 2 groups based on presence or absence of cord compression (ESCC 2 or 3). Associations between ESCC and other variables were assessed via Wilcoxon rank sum test, Pearson’s chi-squared test, and Fisher’s exact test. Statistical significance was defined as p < 0.05. RESULTS: Among 289 patients (median age 66 years, 148 females) and 300 total spine MRI examinations, ESCC was detected in 18 cases (6.0%). Significant associations with ESCC included advanced TNM stage (p = 0.03) and prior treatments, such as radiation to the site of compression (p = 0.002), decompression surgery (p = 0.01), and recent systemic chemotherapy (p < 0.001). Bone metastases to the spine on body CT exams performed within 2 weeks prior to MRI also correlated with ESCC (p < 0.001). Notably, no ESCC cases occurred in patients without spine bone metastases on recent body CT, or in those with less than stage IV disease. Patient symptoms did not correlate with ESCC presence (p = 0.3). CONCLUSIONS: This study suggests that the diagnostic yield of total spine MRI for ESCC in oncology patients is relatively low and may be improved by refining selection criteria. Patients with advanced-stage disease, prior spinal interventions, and bone metastases on recent body CT may be at higher risk. ABBREVIATIONS: Epidural spinal cord compression (ESCC), tumor-node-metastasis (TNM)