Perfusion-weighted Imaging: Use of a Novel Perfusion Scoring Criteria for Accurate Assessment of Tumor Recurrence versus Treatment Effects

Introduction: Perfusion-Weighted Imaging (PWI) is a useful tool for identifying high-grade gliomas, tumor recurrences, treatment effects, among others. However, clinical PWI interpretation is non-standardized, and no grading criteria is used for assessment, leading to interpretation discrepancies. This variance and its subsequent effect on predictive value has not been studied, nor has a perfusion scoring criteria been created. Our objective is to highlight the importance of having a dedicated PWI scoring rubric, given the complexity of interpretation relating to CNS tumors.

Methods: Patients treated at Emory University Healthcare hospitals between 2012 and 2022 who had prior irradiated resection sites and subsequent progression of disease determined by PWI were retrospectively studied from CTORE (CNS Tumor Outcomes Registry at Emory). PWI reads were categorized as high, intermediate, or low perfusion, which translated to predominant tumor, mix of tumor and treatment effects, and predominant treatment effects, respectively, by two radiologists, one with our novel perfusion scoring rubric (experimental group) and the other without (control group). The interpretation accuracy in predicting true tumor percentage, our primary outcome, was assessed through Chi-Squared Analysis and inter-rater reliability was assessed using Cohen’s Kappa.

Results: Our 55-patient cohort had a mean age of 53.5 ± 12.2 years. The percentage agreement between the two neuroradiologists was 57.4% (κ = 0.271). Upon Chi-Squared Analysis, we found an association with the experimental group reads (p-value: 0.014) but no association with the control group reads (p-value: 0.734) in predicting tumor recurrence versus treatment effects.

Conclusion : With our study, we showed that having an objective perfusion scoring rubric aids in improved PWI interpretation. Although PWI is a powerful tool for CNS lesion diagnosis, methodological radiology evaluation greatly improves the accurate assessment and characterization of tumor recurrence versus treatment effects by all neuroradiologists. Further work should focus on standardizing and validating scoring rubrics for DWI evaluation in tumor patients.