Comparison of 68Ga-DOTA-FAPI and 18FDG PET/CT Imaging Modalities in the Detection of Liver Metastases in Patients with Gastrointestinal System Cancer

Abstract

PurposeWe aimed to compare the diagnostic performance of PET/CT imaging performed with 68Ga-DOTA-FAPI and 18FDG in detection of liver metastases in patients with gastrointestinal system (GIS) cancer.MethodsA total of 31 patients who underwent 68Ga-DOTA-FAPI and 18F-FDG PET/CT examinations and diagnosed with GIS cancer (15 colorectal, 9 pancreas, 4 stomach and 3 other cancers) were included in the study. The presence of liver metastasis was decided based on histopathologic diagnosis, PET/CT, other radiologic examinations or tumor biomarker findings, and both PET/CT imaging findings were compared on the patient and lesion basis. ResultsOf the 31 patients, 28 were found as true positive with 68Ga-DOTA-FAPI-PET/CT and 17 with 18FDG-PET/CT. Of the 98 metastatic liver lesions determined according to our diagnostic criteria, 92 were found as true positive lesions with 68Ga-DOTA-FAPI-PET/CT and 65 with 18FDG-PET/CT. There was a statistically significant difference between both imaging modalities in the patient and lesion based comparisons (p<0.05).When semiquantitative values (SUVmax, mlr) obtained from the lesions were compared between the two imaging methods, mlr values showed statistically significant difference in all tumor subgroups (p<0.05).ConclusionIt was concluded that 68Ga-DOTA-FAPI-PET/CT was superior over 18FDG-PET/CT in detection of liver metastases of GIS cancers and it can be a complementary method especially in negative cases with 18FDG-PET/CT.

Comparison of 18F-FDG and 68Ga-FAPI PET/CT in Gastric Kaposi Sarcoma

“…Also, recent published articles reported that 68 Ga-FAPI PET/CT may be a more accurate choice in the detection of primary and metastatic lesions, especially in gastrointestinal and some other cancer types 4–6 . As shown in our case, 18 F-FDG seems to be a more useful and reliable agent in the diagnosis and staging of KS when compared with 68 Ga-FAPI-4 in determining the extent of the disease and the localization of metastatic lesions 7–9 . Also, 18 F-FDG PET/CT scanning demonstrated higher radiotracer accumulation in hepatic metastases.…”

Comparison of the Detection Performance Between FAP and FDG PET/CT in Various Cancers

“…To compare the differences in clinical values between FAP and FDG tracers in cancer patients, we reviewed relevant studies and integrated 30 studies and found that the FAP tracer mainly focused on 68 Ga-FAPI-04 and 68 Ga-DOTA-FAPI-04 22,25,27–30,32–43,45,47,48,50 . The current meta-analysis noted that the FAP tracers were a better detection than FDG in various cancer, and its uptake was highest for primary tumors than for LN or distant metastasis.…”

The application of FAPI-targeted theranostics in pancreatic cancer: a narrative review

“…Şahin et al [49] 68 Ga DOTA-FAPI Imaging PET/CT Retrospective study Human 9 Zhao et al [50] 68 Ga DOTA-FAPI-04 Imaging PET/CT Retrospective study Human 6 Shou et al [51] 68 Ga FAPI-04 Imaging PET/MRI Case report Human 1 Lindner et al [41] Ferdinandus et al [52] 90 Y FAPI-46 Treating PET/CT Retrospective study Human 3 Assadi et al [53] 177 Lu FAPI-46 Treating PET/CT SPECT Retrospective study Human 2 pNET Cheng et al [54] 68 Ga FAPI-04 Imaging PET/CT Case report Human 1 Kömek et al [55] 68 Ga FAPI-04 Imaging PET/CT Case report Human 1 CT = computed tomography, FAPI = fibroblast activation protein inhibitor, MRI = magnetic resonance imaging, PET = positron emission computed tomography, pNET = pancreatic neuroendocrine tumor, SPECT = single-photon emission computed tomography.…”

“…Because of high bowel activity and high FDG uptake, especially in liver and gastrointestinal tract, some bowel metastases cannot be discovered on 18 F-FDG PET/CT. [49] Some studies propose that pancreatic cancer metastases are similarly desmoplastic compared with primary tumors. [60][61][62] The metastatic lesions also display FAP + CAFs that may originate from local PSCs or transfer along with the metastasizing tumor cells, thus targeting 68 Ga-FAPI.…”

“…Because of high bowel activity and high FDG uptake, especially in liver and gastrointestinal tract, some bowel metastases cannot be discovered on 18 F-FDG PET/CT. [49]…”