FDG Uptake in WT1 Peptide Vaccination Adjuvant-induced Granuloma: A 93-month Follow-up.
Yuka Onishi, Tomoya Kotani, Taisei Kanayama et al.
✦ AI-curated · Sources linked
Case in brief
A woman in her 20s with alveolar rhabdomyosarcoma received WT1 peptide vaccination as part of an investigational immunotherapy. Serial PET/CT scans revealed intense FDG uptake at the injection site, accompanied by progressive skin thickening and calcification. Notably, FDG uptake increased even after vaccination stopped, peaking at 49 months before gradually declining, indicating chronic inflammation and granuloma formation.
What made this case unusual
The prolonged FDG uptake and granuloma formation due to the oil-based adjuvant Montanide, contrasting with the transient inflammation typically seen with conventional vaccines.
Diagnostic / clinical pearl
Clinicians should recognize that prolonged FDG uptake following WT1 peptide vaccination may indicate chronic inflammation rather than cutaneous metastasis.
Why it matters
Understanding this characteristic response is crucial for accurate diagnosis and management in patients receiving similar immunotherapies.