Figure 5.
FDG and [68Ga]Ga-FAPI-04 PET/CT in a 33-year-old man with histopathologically proven mucinous adenocarcinoma of appendix post cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, and platin-based adjuvant chemotherapy. FDG PET/CT (A) did not reveal significant abnormal tracer uptake. However, FAPI PET/CT (B) performed two days later revealed multiple tracer avid paracolic gutter, omental, peritoneal, and liver metastases (green arrows). Palliative chemotherapy with capecitabine and oxaliplatin was started. Subsequent response assessment was performed after 3 cycles of this second-line chemotherapy. FDG PET/CT (C) underestimated disease burden when compared with FAPI PET/CT (D), which showed few new peritoneal deposits (red arrows) in addition to pre-existing lesions (green arrows), suggestive of disease progression. This impacted management as the patient was started on third-line agents, irinotecan and panitumumab.