18F-FDG PET/CT versus anatomic imaging for evaluating disease extent and clinical trial eligibility in Erdheim-Chester disease: results from 50 patients in a registry study
Julian Kirchner, Vaios Hatzoglou, Justin B. Buthorn, Dana Bossert, Allison Sigler, Anne S. Reiner, Gary A. Ulaner, Eli L. Diamond
Abstract
Abstract Objectives The aim of this study was to [1] characterize distribution of Erdheim-Chester Disease (ECD) by 18 F-FDG PET/CT and [2] determine the utility of metabolic ( 18 F-FDG PET/CT) imaging versus anatomic imaging (CT or MRI) in evaluating ECD patients for clinical trial eligibility. Methods 18 F-FDG PET/CT and corresponding CT or MRI studies for ECD patients enrolled in a prospective registry study were reviewed. Sites of disease were classified as [1] detectable by 18 F-FDG PET only, CT/MRI only, or both and as [2] measurable by modified PERCIST (mPERCIST) only, RECIST only, or both. Descriptive analysis was performed and paired t test for between-group comparisons. Results Fifty patients were included (mean age 51.5 years; range 18–70 years). Three hundred thirty-three disease sites were detected among all imaging modalities, 188 (56%) by both 18 F-FDG PET and CT/MRI, 67 (20%) by 18 F-FDG PET only, 75 (23%) by MRI brain only, and 3 (1%) by CT only. Of 178 disease sites measurable by mPERCIST or RECIST, 40 (22%) were measurable by both criteria, 136 (76%) by mPERCIST only, and 2 (1%) by RECIST only. On the patient level, 17 (34%) had mPERCIST and RECIST measurable disease, 30 (60%) had mPERCIST measurable disease only, and 0 had RECIST measurable disease only ( p < 0.0001). Conclusion Compared with anatomic imaging, 18 F-FDG PET/CT augments evaluation of disease extent in ECD and increases identification of disease sites measurable by formal response criteria and therefore eligibility for clinical trials. Complementary organ-specific anatomic imaging offers the capacity to characterize sites of disease in greater anatomic detail. Trial registration ClinicalTrials.gov Identifier: NCT03329274