From the Departments of Nuclear Medicine.
Dermatology.
Clin Nucl Med. 2019 Oct;44(10):806-807. doi: 10.1097/RLU.0000000000002707.
A 49-year-old patient with metastatic melanoma was treated with nivolumab (Opdivo). An early F-FDG PET/CT after 2 cycles showed a progressive metabolic disease. A 4-month optimal follow-up F-FDG PET/CT showed a complete metabolic response. The treatment was stopped after 22 cycles because of immunotherapy-related pneumonitis. After discontinuation of treatment, PET/CT examinations demonstrated a metabolic complete remission during 2 years. The metabolic pattern on early PET was suggestive of pseudoprogression, which is a rare phenomenon reflecting an activation of inflammatory cells within the tumor microenvironment causing lesions to increase in size and to accumulate FDG until a sufficient immune response is developed.
一位 49 岁患有转移性黑色素瘤的患者接受了纳武利尤单抗（Opdivo）治疗。 2 个周期后的早期 F-FDG PET/CT 显示疾病呈进行性代谢。 4 个月的最佳随访 F-FDG PET/CT 显示完全代谢缓解。由于免疫治疗相关的肺炎，在 22 个周期后停止了治疗。治疗停止后，2 年内 PET/CT 检查显示代谢完全缓解。早期 PET 的代谢模式提示假性进展，这是一种罕见的现象，反映了肿瘤微环境中炎症细胞的激活，导致病变增大并积聚 FDG，直到产生足够的免疫反应。
