AUTHOR=Lin Xinfeng , Li Yingjie , Wang Shuailiang , Zhang Yan , Chen Xuetao , Wei Maomao , Zhu Hua , Wu Aiwen , Yang Zhi , Wang Xuejuan 

TITLE=Diagnostic value of [68Ga]Ga-FAPI-04 in patients with colorectal cancer in comparison with [18F]F-FDG PET/CT

JOURNAL=Frontiers in Oncology

VOLUME=12

YEAR=2023

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.1087792

DOI=10.3389/fonc.2022.1087792

ISSN=2234-943X

ABSTRACT=<sec><title>Purpose</title><p>This study aimed to compare the diagnostic performance of [<sup>68</sup>Ga]Ga-FAPI-04 PET/CT and [<sup>18</sup>F]F-FDG PET/CT in primary and metastatic colorectal cancer (CRC) lesions.</p></sec><sec><title>Methods</title><p>This single-center preliminary clinical study (NCT04750772) was conducted at the Peking University Cancer Hospital &amp; Institute and included 61 participants with CRC who underwent sequential evaluation through PET/CT with [<sup>18</sup>F]F-FDG and [<sup>68</sup>Ga]Ga-FAPI-04. Their PET/CT images were analysed to quantify the uptake of the two tracers in the form of maximum standardised uptake (SUV<sub>max</sub>) values and target-to-background ratio (TBR), which were then compared using Wilcoxon’s signed-rank test. The final changes in the tumour–node–metastasis (TNM) stage of all participants were recorded.</p></sec><sec><title>Results</title><p>Of all the participants, 21 were treatment naïve and 40 had been previously treated. In primary CRC lesions, the average TBRs of [<sup>68</sup>Ga]Ga-FAPI-04 and [<sup>18</sup>F]F-FDG were 13.3 ± 8.9 and 8.2 ± 6.5, respectively. The SUV<sub>max</sub> of [<sup>68</sup>Ga]Ga-FAPI-04 in signet-ring/mucinous carcinomas (11.4 ± 4.9) was higher than that of [<sup>18</sup>F]F-FDG (7.9 ± 3.6) (<italic>P</italic> = 0.03). Both median SUV<sub>max</sub> in peritoneal metastases and TBR in liver metastases of [<sup>68</sup>Ga]Ga-FAPI-04 were higher than those of [<sup>18</sup>F]F-FDG (5.2 vs. 3.8, <italic>P</italic> &lt; 0.001; 3.7 vs. 1.9, <italic>P</italic> &lt; 0.001, respectively). Compared with [<sup>18</sup>F]F-FDG PET/CT, clinical TNM staging based on [<sup>68</sup>Ga]Ga-FAPI-04 PET/CT led to upstaging and downstaging in 10 (16.4%) and 5 participants (8.2%), respectively. Therefore, the treatment options were changed in 13 participants (21.3%), including 9 with additional chemo/radiotherapy and/or surgery and others with avoidance or narrowed scope of surgery.</p></sec><sec><title>Conclusion</title><p>[<sup>68</sup>Ga]Ga-FAPI-04 showed potential as a novel PET/CT tracer to detect lymph nodes and distant metastases, which improved CRC staging, thus prompting the optimisation or adjustment of treatment decisions.</p></sec>