Complementary prognostic value of hotspot-to-centroid distance (NHOCpeak) to SUVpeak in high-grade glioma
摘要
The normalized distance from the metabolic hotspot to the tumor centroid (NHOC) in Positron Emission Tomography (PET) scans is an imaging biomarker previously shown to have prognostic value in non-small cell lung cancer (NSCLC) and breast cancer (BC). The primary objective of this study was to assess whether this metric could also possess prognostic value in high-grade glioma patients.
MethodsWe retrospectively collected 18F-FCHOL diagnostic PET studies from 61 patients with confirmed high-grade glioma. We delineated the metabolically active tumor regions and calculated the geometrical tumor centroid. SUVpeak was obtained and its distance to the geometrical centroid calculated and normalized by the mean spherical radius—a linear measure of tumor size. We used this metric (NHOCpeak) and SUVpeak to perform survival analysis using the Kaplan–Meier method and multivariable Cox regression analysis.
ResultsNHOCpeak (log-rank test, p = 0.02) and SUVpeak (log-rank test, p < 0.001) were uncorrelated (Spearman’s ρ = 0.094) and separated patients in groups with different median survivals (10.1 and 7.7 months respectively). Taking NHOCpeak and SUVpeak as independent variables for the location and activity in the hotspot, we separated the patient cohort into 4 groups (high/low NHOCpeak and high/low SUVpeak). Patients with low SUVpeak and low NHOCpeak—the most beneficial group—had the longest survival, with a median benefit of 16.4 months (log-rank test, p = 0.017) compared to the second-best (high NHOCpeak/low SUVpeak). Patients with low NHOCpeak and low SUVpeak had a median survival gain of 21.9 months (log-rank test, p < 0.001) with respect to the group with the worst outcome (high SUVpeak/high NHOCpeak).
ConclusionsThe metric NHOCpeak, calculated as the relative distance between the hotspot of activity and the tumor centroid normalized by tumor size, provides complementary spatial information to SUVpeak, and their combination may improve prognostic stratification in high-grade glioma imaged with 18F-FCHOL.