The diffusion-weighted imaging perfusion fraction f is a potential marker of sorafenib treatment in advanced hepatocellular carcinoma: a pilot study

Objective To determine the total Apparent Diffusion Coefficient (ADC), the pure Diffusion coefficient (D) and the perfusion fraction (f) in advanced hepatocellular carcinoma (HCC) under sorafenib treatment. Materials and methods Two target tumors were prospectively analyzed in 12 patients at baseline, 2-weeks and 2-months treatment using b values of 0, 200, 400, 800 s/mm. Repeatability error was estimated on a healthy volunteer. Results Lesion sizes, ADC and D values did not significantly change during treatment (overall mean values, respectively, 47.8 +/- 31.0 mm, 1.34 +/- 0.14x10(-3) mm(2)/s and 1.18 +/- 0.22x10(-3) mm(2)/s). However, f values significantly increased in seven responder patients (+38.39% at 2-weeks, +50.94% at 2-months, P=0.005) while they decreased in five non responder patients (-41.93% at 2-weeks, P=0.006). Furthermore, f was inversely correlated with alpha FP levels (P=0.032) and responder patients had a higher mean overall survival (OS) than non responder patients (12.29 +/- 4.46 vs. 7.80 +/- 4.97 months). The % variation of f relative to baseline at 2-months was correlated with OS (P=0.038) and symptomatic time to progression (P=0.022). Conclusion Contrary to ADC and D, the perfusion fraction f is a valuable marker of sorafenib treatment in advanced HCC.