PET/CT Shows High Specificity in Pediatric Melanoma Imaging

A single-center retrospective study published in Children found that 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) demonstrated 90.3% diagnostic accuracy for detecting clinically active disease in children and adolescents with malignant melanoma.

Researchers Emine Goknur Isik and Rejin Kebudi evaluated the diagnostic performance of PET/CT for initial staging and restaging of pediatric melanoma, a rare malignancy accounting for approximately 1% to 3% of childhood cancers.

PET/CT Performance in Pediatric Melanoma Staging and Restaging

The analysis included 20 patients aged 4 to 18 years with histopathologically confirmed melanoma who underwent 31 PET/CT examinations between 2010 and 2025. Seventeen examinations were performed for initial staging and 14 for restaging. Mean follow-up was approximately 98 months.

PET/CT findings were negative in 22 examinations (71.0%) and positive in nine (29.0%). Diagnostic sensitivity reached 80.0% (95% CI, 49.0% to 94.3%), while specificity was 95.2% (95% CI, 77.3% to 99.2%).

The positive predictive value was 88.9%, and the negative predictive value was 90.9%. Overall diagnostic accuracy was 90.3% (95% CI, 75.1% to 96.7%). Agreement between imaging findings and clinical outcomes was substantial (Cohen κ = 0.77).

Twelve patients (60%) had exclusively true-negative examinations and remained disease-free during follow-up. Among nine PET-negative restaging examinations, one was subsequently classified as false-negative.

The investigators acknowledged that the small cohort, retrospective design, and single-center setting limit interpretation.

"In this exploratory retrospective study, 18F-FDG PET/CT demonstrated promising diagnostic performance for staging and restaging of pediatric malignant melanoma, with high specificity and negative predictive value," the authors concluded.

Source

Isik EG, Kebudi R. Children (Basel). 2026;13(10):1428. Doi:10.3390/children13101428