Tissue factor (TF) has emerged as a critical factor in oncogenic events, leading to the development of TF-targeted diagnostic and therapeutic approaches. A non-invasive imaging method to evaluate target molecule expression with high sensitivity and high quantitative ability is imperative for selecting the appropriate patients for TF-targeted therapy. To elucidate the potential of 111 In-labeled anti-TF antibody 1849 ( 111 In-1849) as an immuno-single photon emission computed tomography (SPECT) probe targeting TF, we evaluated TF-dependent in vitro binding as well as in vivo biodistribution and tumor accumulation of 111 In-1849 in pancreatic cancer cells/models with varying TF expression levels. TF expression levels in five human pancreatic cancer cell lines, BxPC-3, BxPC-3-TF-knockout (BxPC-3-TFKO), Capan-1, PSN-1 and SUIT-2, were examined by immunofluorescence. Binding of 111 In-1849 to each cell line was assessed. Biodistribution and imaging studies were also conducted in tumor-bearing mice.Furthermore, the relationship of TF expression with cell binding and tumor uptake was analyzed. In the immunofluorescence studies, BxPC-3 exhibited the highest TF expression, followed by Capan-1, PSN-1, SUIT-2 and BxPC-3-TFKO. Cell binding assays revealed that BxPC-3 cells had the highest 111 In-1849 binding, followed by PSN-1, Capan-1 and SUIT-2; no binding was detected in BxPC-3-TFKO cells. The BxPC-3 xenograft was clearly visualized on 111 In-1849 SPECT/CT, and the highest uptake was detected on day 4. The biodistribution of 111 In-1849 on day 4 revealed that tumor uptake ranged from 8.68 to 50.58% of the injected dose per gram of tissue; BxPC-3 had the highest uptake and SUIT-2 had the lowest. TF expression was significantly associated with cell binding (R 2 =0.79, P<0.05) and tumor uptake (R 2 =0.92, P<0.01). The association of 111 In-1849 uptake with TF expression suggests the potential application of non-invasive imaging with radiolabelled 1849 for selecting the appropriate patients who would likely respond to TF-targeted therapies in clinical practice.