PT  - JOURNAL ARTICLE
AU  - Amanda J. Boyle
AU  - Junchao Tong
AU  - Sami S. Zoghbi
AU  - Victor W. Pike
AU  - Robert B. Innis
AU  - Neil Vasdev
TI  - Repurposing <sup>11</sup>C-PS13 for PET Imaging of Cyclooxygenase-1 in Ovarian Cancer Xenograft Mouse Models
AID  - 10.2967/jnumed.120.249367
DP  - 2021 May 10
TA  - Journal of Nuclear Medicine
PG  - 665--668
VI  - 62
IP  - 5
4099  - http://jnm.snmjournals.org/content/62/5/665.short
4100  - http://jnm.snmjournals.org/content/62/5/665.full
SO  - J Nucl Med2021 May 10; 62
AB  - Cyclooxygenase-1 (COX-1), a biomarker for neuroinflammation, is implicated in the progression and prognosis of ovarian cancer (OvCa). This study considered the repurposing of 11C-labeled 1,5-bis(4-methoxyphenyl)-3-(2,2,2-trifluoroethoxy)-1H-1,2,4-triazole (11C-PS13), a COX-1 PET neuroimaging radiopharmaceutical, in OvCa xenograft mouse models. Methods: 11C-PS13 was evaluated in ICRscid mice with subcutaneous or intraperitoneal human OVCAR-3 OvCa xenografts by dynamic PET/MRI, ex vivo biodistribution, and radiometabolite analysis of plasma and tumor. Results: OVCAR-3 xenografts were well visualized with 11C-PS13 in xenograft mouse models. Time–activity curves revealed a steady accumulation of tumor radioactivity that plateaued from 40 to 60 min and was significantly reduced by pretreatment with ketoprofen (3.56 ± 0.81 and 1.30 ± 0.18 percentage injected dose/g without and with pretreatment, respectively, P = 0.01). Radiometabolite analysis showed that intact 11C-PS13 accounted for more than 80% of radioactivity in the tumor, with less than 20% in plasma, at 40 min after injection. Conclusion: 11C-PS13 shows promise for PET imaging of COX-1 in OvCa, and rapid translation for clinical cancer research should be considered.