Role of 18F-FDG PET/CT in assessment of HCC patients after therapeutic interventions compared to DW MRI

Abstract

Background Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths worldwide in both men and women. Early-stage HCCs are treated either by curative surgical resection and/or by locoregional interventions, such as radiofrequency ablation or trans-arterial chemoembolization. Functional imaging as diffusion-weighted magnetic resonance imaging (DW MRI) and metabolic imaging with 18F-positron emission tomography/computed tomography (18F-FDG PET/CT) has been used for assessment of treatment response. This retrospective study was conducted on 29 patients known to have HCC with locoregional therapeutic interventions and referred for radiological follow-up searching for residual/recurrence neoplasia or metastatic deposits. The study aimed to assess the benefits of using the metabolic parameters of 18F-FDG PET/CT in the follow-up of HCC patients after therapeutic interventions in comparison with DW MRI. Results Regarding qualitative assessment of residual active viable HCC by PET/CT and DW MRI, the sensitivity, specificity, PPV, NPP and accuracy were 77.3%, 91.7%, 94.4%, 68.8%, 82.4% and 95.5%, 75%, 87.5%, 90%, 88.2%, respectively. The optimal cutoff point of the SUVmax to differentiate viable from non-viable HCC was 3.4 (AUC = 0.898), with sensitivity, specificity, PPV and NPV of 77.27%, 100.0%, 100.0% and 66.7%, respectively. The optimal ADC cutoff value for discrimination between viable and non-viable HCC was 1247 mm2/s (AUC = 0.976) with sensitivity, specificity, PPV and NPV of 90.48%, 100.0%, 100.0% and 83.3%, respectively. New hepatic lesions were found in 38.2% of patients by DW MRI, while detected only in 26.5% of patients by PET/CT. The PET/CT revealed extrahepatic metastasis in 44.1% of patients, while detected only in 8.8% of patients by DW MRI. Conclusions DWI was more sensitive than PET/CT for detecting tumor residual and hepatic recurrence compared to PET/CT which was much better in detecting distant metastases.

The value of PET/CT combined with complementary MRI in the follow-up of hepatocellular carcinoma after transarterial chemoembolization.

“…In the current study, the accuracy, sensitivity and specificity of the MRI were calculated being 97.5%, 95.8% and 100% respectively with positive predictive and negative predictive values of 100% and 94.1% respectively. Similarly, Nashi et al, (14) found that MRI assessment of HCC patients after therapeutic interventions had a sensitivity of 90.48%, specificity of 100.0%, PPV of 100.0%, and NPV of 83.3%. Also, Lu and Pan (15) found a high pooled sensitivity (84%) and specificity (94%) for non-contrast MRI in HCC detection; while Jalli et al (16) established that MRI had a sensitivity of 83.33%, specificity of 100.0%, accuracy 94.79%, PPV of 100.0%, and NPV of 92.96% for detection of HCC.…”

“…Similar values were calculated for PET/CT revealing accuracy, sensitivity and specificity of 72.5%, 62.5% and 87.5% respectively with positive predictive and negative predictive values of 88.2% and 60.9% respectively. Correspondingly, the study performed by Nashi et al, (14) showed that PET/CT had a sensitivity of 74.60%, specificity of 57.54%, PPV of 87.5%, NPV of 90.0% as well as accuracy of 88.2% respectively in the assessment of HCC patients after therapeutic interventions. On the other hand, Abdelrahman et al, (7) established that the sensitivity, specificity, and accuracy of FDG PET/CT for the detection of residual viable tumoral tissue after TACE were 81.5%, 75%, and 80% respectively, whereas Kim et al, (13) reported sensitivity of 87.5%, specificity of 71.4% and accuracy of 80% respectively.…”

“…The optimal ADC value obtained in our study was 1.35 × 10−3 mm2/s having accuracy, sensitivity and specificity of the DWI and ADC 97.5%, 95.8% and 100% respectively with positive predictive and negative predictive values of 100% and 94.1% respectively. Nashi et al, (14) obtained an ADC value of 1.25 × 10−3 mm2/s having a sensitivity of 90.48%, specificity of 100.0%, PPV of 100.0% and NPV of 83.3%. However, Jalli et al, (16) found that DWI had of 83.33%, specificity of 100.0%, accuracy of 94.79%, PPV of 100.0%, and NPV of 92.96%.…”

Recent nanotheranostic approaches in cancer research

“…Furthermore, the amalgamation of both PET and CT shows effective functionality and provides detailed facts based on molecularity. F18 (fluorodeoxyglucose) as a contrast agent have shown effective properties in detecting thyroid cancer but CT imaging alone is not that efficient which showed only 80% effectiveness compared to PET and CT together with 84% effectiveness in diagnosing the cancer [ 46 ].…”

“…To detect HCC, therapeutic intervention is performed followed by the application of radiofrequency with 18F-FDG to assess the therapy through PET/CT and determine the benefits of using metabolic parameters. A comparison between diffused MRI and PET/CT was conducted to observe the outcomes, which revealed that diffusion weighted-MRI was more effective than PET/CT in diagnosing tumor cells [ 46 ].…”