AUTHOR=Richardson Carrie , Javadi Mehrbod S. , Shah Ami A. , Connolly Caoilfhionn , Solnes Lilja B. , Wigley Fredrick M. , Hummers Laura K. , Christopher-Stine Lisa 

TITLE=18F-NaF PET/CT identifies muscular and subcutaneous calcifications in both dermatomyositis- and systemic sclerosis-related calcinosis

JOURNAL=Frontiers in Nuclear Medicine

VOLUME=Volume 5 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/nuclear-medicine/articles/10.3389/fnume.2025.1593825

DOI=10.3389/fnume.2025.1593825

ISSN=2673-8880

ABSTRACT=BackgroundCalcinosis is a morbid complication of dermatomyositis (DM) and systemic sclerosis (SSc) with no effective pharmacologic treatment or validated whole-body assessment modality. 18F-NaF PET/CT may help to quantify and characterize calcinosis.MethodsIn this pilot study, we enrolled three adults with DM and three with SSc, all with new calcinosis deposits. Each underwent 18F-NaF PET/CT and clinical examination with semi-quantitative scoring of calcinosis. We described the 18F-NaF PET/CT findings and compared these to CT imaging alone as well as to clinical examination.ResultsCalcinosis was noted on 18F-NaF PET/CT in the subcutaneous tissue in all patients and the muscle in three patients, including two with SSc. The average semi-quantitative score was 23.5 by 18F-NaF PET/CT and 20 by clinical exam. Wilcoxon signed rank test indicated greater scores by 18F-NaF PET/CT than by clinical exam (p = 0.0264). 18F-NaF uptake varied among calcinosis deposits and occurred without corresponding calcifications on CT.Conclusions18F-NaF PET/CT appears to be a sensitive method of detecting and characterizing calcinosis that provides both quantitative and qualitative data beyond what can be obtained by physical examination or CT alone. 18F-NaF uptake occurs in muscle in both SSc and DM, suggesting the possibility that myositis may be driving calcinosis in a subset of patients with SSc.