Non-invasive monitoring of anticancer effects of cisplatin on lung cancer in an orthotopic SCID mouse model using [¹⁸F] FDG PET-CT.

Positron emission tomography-computed tomography (PET-CT) with [18F] fluorodeoxyglucose (FDG) has recently been applied for evaluating tumor response to anticancer therapy. The aim of the present study was to evaluate the utility of FDG PET-CT in monitoring non-invasively and repeatedly the inhibitory effect of cisplatin (CDDP) on an orthotopic lung cancer model. Validation of in vivo FDG uptake in human lung cancer Ma44-3 cell line in an orthotopic SCID mouse model was carried out. Next, we assessed the use of FDG PET-CT to monitor the response of orthotopic lung cancer to the anticancer effect of CDDP. SCID mice were divided into the CDDP group (7 mg/kg single dose intraperitoneally) and the control group. Tumor volume and maximal standardized uptake value (SUV max) were calculated for all mice. All mice were sacrificed for histopathologic analysis. Validation of FDG PET-CT showed that tumor volume and SUV max were significantly correlated with postmortem tumor length measured in specimens (P=0.023) and (P=0.012), respectively, and there was a significant correlation between SUV max and tumor volume (P=0.048). Response monitoring showed that significant growth inhibition by CDDP in the form of SUV max of the CDDP group was significantly lower than that of the control group on day 8 (P=0.02) and on day 13 (P=0.003). Tumor volume of the CDDP group was significantly lower than that of the control group on day 13 (P=0.03). The present study supports using FDG PET-CT in monitoring tumor progression and therapeutic response of lung cancer in an orthotopic model non‑invasively and repeatedly.