TY - JOUR T1 - (4<em>S</em>)-4-(3-<sup>18</sup>F-Fluoropropyl)-<span class="sc">l</span>-Glutamate for Imaging of x<sub>C</sub><sup>¯</sup> Transporter Activity in Hepatocellular Carcinoma Using PET: Preclinical and Exploratory Clinical Studies JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 117 LP - 123 DO - 10.2967/jnumed.112.108704 VL - 54 IS - 1 AU - Sora Baek AU - Andre Mueller AU - Young-Suk Lim AU - Han Chu Lee AU - Young-Joo Lee AU - Gyungyub Gong AU - Jae Seung Kim AU - Jin-Sook Ryu AU - Seung Jun Oh AU - Seung Jin Lee AU - Claudia Bacher-Stier AU - Lüder Fels AU - Norman Koglin AU - Christoph A. Schatz AU - Ludger M. Dinkelborg AU - Dae Hyuk Moon Y1 - 2013/01/01 UR - http://jnm.snmjournals.org/content/54/1/117.abstract N2 - (4S)-4-(3-18F-fluoropropyl)-l-glutamate (18F-FSPG, or BAY 94-9392) is a new tracer to assess system xC¯ transporter activity with PET. The aim of this study was to explore the tumor detection rate of 18F-FSPG, compared with that of 18F-FDG, in patients with hepatocellular carcinoma (HCC). Methods: Preclinically, in vivo HCC models of orthotopically implanted Huh7 and MH3924a cancer cells were studied with 18F-FSPG in Naval Medical Research Institute nude mice (n = 3) and August-Copenhagen Irish rats (n = 4), respectively. Clinically, 5 patients with HCC who had hyper- or isometabolic lesions on 18F-FDG PET were enrolled for evaluation of the tracer. Dynamic whole-body PET images with 18F-FSPG were acquired for up to 120 min after injection of approximately 300 MBq of 18F-FSPG. Immunohistochemical expression levels of the xCT subunit of the system xC¯ and CD44 of HCC were studied in 4 patients with HCC. Results: Strong tumor uptake and low background from nontarget tissue allowed excellent tumor visualization in animal models with orthotopically implanted liver tumors. 18F-FSPG PET procedures were well tolerated in all patients. 18F-FSPG PET and 18F-FDG detected lesions in 5 of 5 and 3 of 5 patients, respectively. The maximal standardized uptake values (SUV) were comparable (18F-FSPG, 4.7 ± 3.2; 18F-FDG, 6.1 ± 2.9). The ratios of maximal SUV of the tumor to mean SUV of normal liver were also comparable (18F-FSPG, 3.6 ± 2.2; 18F-FDG, 2.7 ± 1.3), but the mean SUV of normal liver of 18F-FSPG was significantly lower than that of 18F-FDG (P &lt; 0.05). Two patients with HCC who showed both xCT and CD44 expression had moderate or intense accumulation of 18F-FSPG, but the remaining 2 patients with negative CD44 expression showed mild uptake. Conclusion: 18F-FSPG was successfully translated from preclinical evaluation into patients with HCC. 18F-FSPG may be a promising tumor PET agent with a high cancer detection rate in patients with HCC. ER -