The value of ¹⁸F-FDG PET/CT in transcatheter hepatic arterial chemoembolization therapy of primary hepatocellular carcinoma with high FDG uptake

Objective: To evaluate the therapeutic response of transcatheter hepatic arterial chemo-embolization (TACE) for primary HCC using ¹⁸F-FDG PET/CT. Methods: Twenty-four HCC patients (21 males, 3 females; age range: 40 to 75 years, mean age: 58.1 years) with high uptake of ¹⁸F-FDG on pretreatment PET/CT and with follow-up ¹⁸F-FDG PET/CT 1-2 months post TACE were retrospectively analyzed. A lesion was regarded as positive for HCC if it had higher FDG uptake than the surrounding liver parenchyma. All patients were followed for 3 months by clinical symptoms, AFP and ¹⁸F-FDG PET/CT. χ² test was used to analyze the difference between the diagnostic value of ¹⁸F-FDG PET/CT and AFP. Results: On follow-up ¹⁸F-FDG PET/CT, 9 patients had lower ¹⁸F-FDG uptake than the surrounding liver parenchyma, indicating no residual tumor; while 11 patients with residual tumor showed higher uptake of FDG than the liver background though the uptake was lower than that of baseline PET/CT. Two patients with isometabolic FDG uptake were confirmed of having residual tumor during follow-up. One case showed increased ¹⁸F-FDG uptake more than that of baseline, indicating disease progression. One case was false positive for residual tumor due to over attenuation correction in the presence of lipiodol. The sensitivity and accuracy for the detection of residual tumor by ¹⁸F-FDG PET/CT and AFP were 100% (14/14) vs 71.4% (10/14), and 95.8% (23/24) vs 70.8%(17/24) (χ²=6.56 and 4.18, both P<0.05), respectively. Conclusion: ¹⁸F-FDG PET/CT is useful to evaluate the efficacy of TACE for ¹⁸F-FDG-avid HCC and it may provide important information for further treatment planning. (authors)