Abstract
A 57-year-old man diagnosed with a metastatic bladder tumor was initiated on pembrolizumab treatment. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging performed to evaluate treatment response showed numerical-dimensional and metabolic increase in the metastatic lesions. In the 18F-FDG PET/CT imaging performed 8 weeks later due to suspicion of pseudoprogression, a significant regression of the lesions was observed, and the patient was diagnosed with pseudoprogression. Pseudoprogression should be kept in mind when 18F-FDG PET/CT is performed after the use of immunotherapy, and evaluation with follow-up PET/CT is recommended to confirm that the patient has hyperprogression or pseudoprogression.
Keywords:
Immunotherapy, pseudoprogression, bladder cancer, pembrolizumab, PET/CT
Ethics
Informed Consent: Informed consent was obtained from the patient.
Authorship Contributions
Concept: H.K., C.G., Design: H.K., C.G., İ.H.D., Data Collection or Processing: F.K., V.Ş., İ.H.D., Literature Search: F.K., C.G., V.Ş., Writing: F.K., C.G.
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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