Senthilnathan S, Memon K, Lewandowski RJ, Kulik L, Mulcahy MF, Riaz A, Miller FH, Yaghmai V, Nikolaidis P, Wang E, Baker T, Abecassis M, Benson AB, Omary RA, Salem R. Extrahepatic metastases occur in a minority of hepatocellular carcinoma patients treated with locoregional therapies: analyzing patterns of progression in 285 patients. Hepatology. 2012 May; 55(5):1432-42.