18F-FDG PET/CT AS AN ASSESSMENT TOOL OF HEPATOCELLULAR CARCINOMA SECONDARY TO NON-ALCOHOLIC FATTY LIVER DISEASE DEVELOPMENT IN EXPERIMENTAL MODEL.

BACKGROUND: Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression. OBJECTIVE: To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD. METHODS: Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed. RESULTS: The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC. CONCLUSION: 18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.

PET/CT com 18F-FDG como ferramenta de avaliação do desenvolvimento de carcinoma hepatocelular secundário a doença hepática gordurosa não alcoólica em modelo experimental / 18f-fdg pet/ct as an assessment tool of hepatocellular carcinoma secondary to non-alcoholic fatty liver disease development in experimental model

ABSTRACT BACKGROUND: Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression. OBJECTIVE: To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD. METHODS: Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed. RESULTS: The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC. CONCLUSION: 18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.

RESUMO BACKGROUND: O carcinoma hepatocelular (CHC) pode ser a última fase da doença hepática gordurosa não alcoólica (DHGNA). Modelos experimentais são cruciais para elucidação da patogênese do CHC secundário a DHGNA. A tomografia por emissão de pósitrons/tomografia computadorizada (PET/TC) com 2-desoxi-2-(18F)fluoro-D-glicose (18F-FDG) desempenha um importante papel na avaliação do desenvolvimento e progressão do CHC. OBJETIVO: Padronizar a metodologia de imagem por PET/TC com 18F-FDG como uma ferramenta de avaliação do modelo experimental de CHC secundário a DHGNA. MÉTODOS: Dez ratos Sprague-Dawley machos foram alimentados com dieta hiperlipídica deficiente em colina associada a dietilnitrosamina (DEN) na água de beber por 16 semanas e depois receberam 1 mL de solução salina (0,9%) por gavagem diariamente por três semanas. Nas 16ª e 19ª semanas, foi realizada a ultrassonografia abdominal. As imagens do PET/TC com 18F-FDG foram obtidas antes do início do experimento (semana 0) e no final (semana 19). Análises histológica e imunohistoquímica também foram realizadas. RESULTADOS: Os resultados da ultrassonografia demonstraram um grupo homogêneo na 16ª semana com uma média de 4,6±2,74 nódulos por animal. Na 19ª semana, os achados do PET/CT demonstraram uma média de 8,5±3,7 nódulos por animal. Os valores médios de SUVmed e SUVmáx foram 2,186±0,1698 e 3,8±1,74, respectivamente. A média do número de nódulos na análise histológica foi de 5,5±1,5. De todos os nódulos, 4,6% foram classificados como bem diferenciados e 81,8% foram classificados como CHC pouco diferenciado. CONCLUSÃO: O PET/TC com 18F-FDG foi capaz de avaliar o desenvolvimento do CHC secundário a DHGNA de forma não invasiva. A partir da padronização do PET/CT neste modelo, faz-se possível a utilização desta ferramenta em futuros estudos para monitorar, in vivo e de forma não invasiva, a progressão do CHC.

Inhibitory effects of fluorinated pyrimidines, 5'-DFUR, UFT and T-506, in a model of hepatic metastasis of mouse colon 26 adenocarcinoma-assessment of inhibitory activity and adverse reactions at the maximum tolerated dose.

The effects of fluorinated pyrimidines, 5'-DFUR, UFT and T-506, on a mouse model of hepatic metastasis were assessed in regard to inhibitory activity and adverse reactions at the maximum tolerated dose. The model was prepared by injecting the mouse colonic cancer cell line, colon 26, into the portal vein of CDF1 mice. At the treatment regimens employed for 5'-DFUR (1.0 mmol/kg/day, p.o., daily from days 1 to 7), UFT (0.1 mmol/kg/day, p.o., daily from days 1 to 7), and T-506 (0.074 mmol/kg/day, i.v., days 1, 4, 7, and 10), complete inhibition of hepatic metastasis was obtained in six out of seven mice (85.7%) with 5'-DFUR, and in five out of six mice (83.3%) with T-506. Significant inhibition of hepatic metastasis was not achieved with UFT (3/7, 42.9%). 5'-DFUR and T-506 showed the highest rate of inhibition of hepatic metastasis, suggesting that these drugs would be effective for the prophylactic treatment of metastatic disease. 5'-DFUR and UFT exhibited mild adverse reactions such as loss of body weight.