Evaluating Treatment Response of Radioembolization in Intermediate-Stage Hepatocellular Carcinoma Patients Using 18F-Fluoroethylcholine PET/CT.
UNLABELLED
The aim of this study was to evaluate (18)F-fluoroethylcholine PET/CT as a metabolic imaging technique for the assessment of treatment response to (90)Y radioembolization in patients with locally advanced hepatocellular carcinoma (HCC).


METHODS
Thirty-four HCC patients undergoing 78 (18)F-fluoroethylcholine PET/CT scans were identified for this study. Patients with initial or follow-up metastastic disease (n = 9) were excluded at the time point of the metastatic occurrence as well as patients with negative α-fetoprotein (AFP; n = 1), resulting in 24 patients and 57 scans that were eligible. All patients were scheduled for radioembolization and underwent 1 pretherapeutic and at least 1 posttherapeutic (18)F-fluoroethylcholine PET/CT scan. Volume-of-interest analysis and volume-of-interest subtractions were performed. Maximum, mean, and peak standardized uptake value (SUV) analysis was performed, and the total intrahepatic (18)F-fluoroethylcholine positive tumor volume (FEC-PTV) and tumor-to-background ratio were assessed. Statistical analysis was performed using a decreasing AFP of at least 20% as a standard of reference for therapy response including receiver-operating-characteristic analyses as well as descriptive and correlation analyses and multiple logistic regression.


RESULTS
Fourteen follow-up examinations were categorized as responder and 19 follow-up examinations as nonresponder. Absolute AFP values did not correlate with SUV parameters (P = 0.055). In receiver-operating-characteristic analyses, the initial mean SUV, Δmaximum SUV, and Δtumor-to-background ratio demonstrated the highest area under the curve, 0.84 (P = 0.009), 0.83 (P = 0.011), and 0.83 (P = 0.012), respectively, resulting in a positive prediction of 82%, 83%, and 91% at the respective cutoff points. When multiple logistic regression analysis was applied, this resulted in an area under the curve of 0.90 (P = 0.001), with a positive prediction of 94% and a sensitivity of 94%. The FEC-PTV did not reach significance in the presented dataset.


CONCLUSION
(18)F-fluoroethylcholine PET/CT demonstrates a high potential for follow-up assessment in the context of radioembolization in patients with locally advanced, but nonmetastatic, HCC and initially elevated AFP, possibly enabling early therapy monitoring independent of morphology.
['Hartenbach|Markus|M|', 'Weber|Stefan|S|', 'Albert|Nathalie L|NL|', 'Hartenbach|Sabrina|S|', 'Hirtl|Albert|A|', 'Zacherl|Mathias J|MJ|', 'Paprottka|Philipp M|PM|', 'Tiling|Reinhold|R|', 'Bartenstein|Peter|P|', 'Hacker|Marcus|M|', 'Haug|Alexander R|AR|']
D006528:Carcinoma, Hepatocellular D002794:Choline D004621:Embolization, Therapeutic D006801:Humans D008113:Liver Neoplasms D049268:Positron-Emission Tomography D011237:Predictive Value of Tests D012372:ROC Curve D019275:Radiopharmaceuticals D012189:Retrospective Studies D016896:Treatment Outcome D000509:alpha-Fetoproteins
radioembolization hepatocellular carcinoma PET PET/CT therapy FEC GI oncology radionuclide