Abstract
We report a case of a 64-year-old male with metastatic non-small-cell lung carcinoma who was undergoing neoadjuvant chemoimmunotherapy with cisplatin, pemetrexed, and nivolumab. Restaging 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) demonstrated segmental, linear 18F-FDG uptake along the abdominal aortic wall with corresponding crescentic soft-tissue thickening. Differential diagnoses included intramural hematoma, focal aortitis, atherosclerotic plaque, and tumor thrombus. CT angiography revealed a mildly enhancing periaortic soft-tissue rim involving a 5 cm infrarenal aortic segment, consistent with isolated periaortitis, likely induced by immunotherapy. Steroid therapy was initiated. Follow-up 18F-FDG PET/CT showed complete metabolic resolution, supporting an immune-related etiology. 18F-FDG PET/CT played a crucial role in early recognition of this immune-related adverse event by sensitively detecting vascular inflammation and guiding further evaluation with CT angiography. Early PET-based detection enabled timely initiation of steroid therapy, preventing potential vascular complications.
Keywords:
18F-FDG PET/CT, immune checkpoint inhibitors, periaortitis, immune-related adverse events, anti-programmed-death-receptor-1 (PD-1) antibody
Ethics
Informed consent: The consent was obtained for image use.
Authorship Contributions
Surgical and Medical Practices: S.U., S.P.N., Concept: S.U., N.A., Design: S.U., A.J., K.A.R., A.A.B., N.A., S.P.N., Data Collection or Processing: S.U., A.J., K.A.R., N.A., Analysis or Interpretation: S.U., K.A.R., S.P.N., Literature Search: S.U., Writing: S.U., S.P.N.
Conflict of Interest: No conflicts of interest were declared by the authors.
Financial Disclosure: The authors declare that this study has received no financial support.
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