Evaluation of neovascularization with spectral computed tomography in a rabbit VX2 liver model: a comparison with real-time contrast-enhanced ultrasound and molecular biological findings

Quantitative dual-energy computed tomography texture analysis predicts the response of primary small hepatocellular carcinoma to radiofrequency ablation

BACKGROUND

Radiofrequency ablation (RFA) is one of the effective therapeutic modalities in patients with hepatocellular carcinoma (HCC). However, there is no proper method to evaluate the HCC response to RFA. This study aimed to establish and validate a clinical prediction model based on dual-energy computed tomography (DECT) quantitative-imaging parameters, clinical variables, and CT texture parameters.

METHODS

We enrolled 63 patients with small HCC. Two to four weeks after RFA, we performed DECT scanning to obtain DECT-quantitative parameters and to record the patients' clinical baseline variables. DECT images were manually segmented, and 56 CT texture features were extracted. We used LASSO algorithm for feature selection and data dimensionality reduction; logistic regression analysis was used to build a clinical model with clinical variables and DECT-quantitative parameters; we then added texture features to build a clinical-texture model based on clinical model.

RESULTS

A total of six optimal CT texture analysis (CTTA) features were selected, which were statistically different between patients with or without tumor progression (P < 0.05). When clinical variables and DECT-quantitative parameters were included, the clinical models showed that albumin-bilirubin grade (ALBI) [odds ratio (OR) = 2.77, 95% confidence interval (CI): 1.35-6.65, P = 0.010], λ_{AP (40-100 keV)} (OR = 3.21, 95% CI: 3.16-5.65, P = 0.045) and IC_AP (OR = 1.25, 95% CI: 1.01-1.62, P = 0.028) were associated with tumor progression, while the clinical-texture models showed that ALBI (OR = 2.40, 95% CI: 1.19-5.68, P = 0.024), λ_{AP (40-100 keV)} (OR = 1.43, 95% CI: 1.10-2.07, P = 0.019), and CTTA-score (OR = 2.98, 95% CI: 1.68-6.66, P = 0.001) were independent risk factors for tumor progression. The clinical model, clinical-texture model, and CTTA-score all performed well in predicting tumor progression within 12 months after RFA (AUC = 0.917, 0.962, and 0.906, respectively), and the C-indexes of the clinical and clinical-texture models were 0.917 and 0.957, respectively.

CONCLUSIONS

DECT-quantitative parameters, CTTA, and clinical variables were helpful in predicting HCC progression after RFA. The constructed clinical prediction model can provide early warning of potential tumor progression risk for patients after RFA.

Preoperative normalized iodine concentration derived from spectral CT is correlated with early recurrence of hepatocellular carcinoma after curative resection

OBJECTIVES

To investigate whether normalized iodine concentration (NIC) correlates with tumor microvessel density and early recurrence in patients with HCC.

MATERIALS AND METHODS

We included 71 patients with surgically resected single HCC in this prospective study who underwent preoperative spectral CT between November 2014 and June 2016. Two observers independently measured the NIC in the arterial phase (AP) and portal venous phase (PVP). The relationship between NIC and microvessel density was evaluated. Univariate and multivariate logistic regression was performed to evaluate independent predictors of early recurrence.

RESULTS

Early recurrence occurred in 28 of 71 patients (39.4%) during the 2-year follow-up. NIC-AP positively correlated with microvessel density for the two observers (r = 0.593 and 0.527). Based on multivariate analysis, independent risk factors for early HCC recurrence were tumor size (odds ratio, 1.200; p = 0.043) and NIC-AP (odds ratio, 2.522; p = 0.005). For the two observers, areas under the receiver operating characteristic curve for predicting early HCC recurrence were 0.719 and 0.677. Early recurrence rates were significantly higher among patients with NIC-AP values higher than the optimal cutoff than among those with values below the cutoff.

CONCLUSION

Normalized iodine concentration in the arterial phase from spectral CT reflects tumor-derived angiogenesis and is a potential predictive biomarker for early recurrence of hepatocellular carcinoma.

KEY POINTS

• Normalized iodine concentration in the arterial phase positively correlated with microvessel density of hepatocellular carcinoma. • In the patients with hepatocellular carcinoma, tumor size and normalized iodine concentration in the arterial phase were independent risk factors for early hepatocellular carcinoma recurrence. • Early hepatocellular carcinoma recurrence rates were significantly higher when normalized iodine concentration in the arterial phase values was above the optimal cutoff.

High-Performance Poly(lactic-co-glycolic acid)-Magnetic Microspheres Prepared by Rotating Membrane Emulsification for Transcatheter Arterial Embolization and Magnetic Ablation in VX2 Liver Tumors

Interventional embolization is a popular minimally invasive vascular therapeutic technique and has been widely applied for hepatocellular carcinoma (HCC) therapy. However, harmful effects caused by transcatheter arterial chemoembolization (TACE) and radioembolization, such as the toxicity of chemotherapy or excessive radiation damage, are serious disadvantages and significantly reduce the therapeutic efficacy. Here, a synergistic therapeutic strategy combined transcatheter arterial embolization and magnetic ablation (TAEMA) by using poly(lactic-co-glycolic acid) (PLGA)-magnetic microspheres (MMs) has been successfully applied to orthotopic VX₂ liver tumors of rabbits. These MMs fabricated by novel rotating membrane emulsification system with well-controlled sizes (100-1000 μm) exhibited extremely low hemolysis ratio and excellent biocompatibility with HepG2 cells and L02 cells. Moreover, experimental results demonstrated that, while exposed to alternating magnetic field (AMF) after TAE, the tumor edge could be heated up by more than 15 °C both in vivo and in vitro, whereas only a negligible increase of temperature was observed in the normal hepatic parenchyma (NHP) nearby. Sufficient temperature increase induces apoptosis of tumor cells. This can further inhibit the tumor angiogenesis and results in necrosis compared to the rabbits only treated with TAE. In stark contrast, tumors rapidly grow and subtotal metastasis occurs in the lungs or kidneys, causing severe complications for rabbits only irradiated under AMF. Importantly, the results from the biochemical examination and the gene expression of relative HCC markers further confirmed that the treatment protocol using PLGA-MMs could achieve good biosafety and excellent therapeutic efficacy, which are promising for liver cancer therapy.

Spectral computed tomography in advanced gastric cancer: Can iodine concentration non-invasively assess angiogenesis?

AIM

To investigate the correlation of iodine concentration (IC) generated by spectral computed tomography (CT) with micro-vessel density (MVD) and vascular endothelial growth factor (VEGF) expression in patients with advanced gastric carcinoma (GC).

METHODS

Thirty-four advanced GC patients underwent abdominal enhanced CT in the gemstone spectral imaging mode. The IC of the primary lesion in the arterial phase (AP) and venous phase (VP) were measured, and were then normalized against that in the aorta to provide the normalized IC (nIC). MVD and VEGF were detected by immunohistochemical assays, using CD34 and VEGF-A antibodies, respectively. Correlations of nIC with MVD, VEGF, and clinical-pathological features were analyzed.

RESULTS

Both nICs correlated linearly with MVD and were higher in the primary lesion site than in the normal control site, but were not correlated with VEGF expression. After stratification by clinical-pathological subtypes, nIC-AP showed a statistically significant correlation with MVD, particularly in the group with tumors at stage T4, without nodular involvement, of a mixed Lauren type, where the tumor was located at the antrum site, and occurred in female individuals. nIC-VP showed a positive correlation with MVD in the group with the tumor at stage T4 and above, had nodular involvement, was poorly differentiated, was located at the pylorus site, of a mixed and diffused Lauren subtype, and occurred in male individuals. nIC-AP and nIC-VP showed significant differences in terms of histological differentiation and Lauren subtype.

CONCLUSION

The IC detected by spectral CT correlated with the MVD. nIC-AP and nIC-VP can reflect angiogenesis in different pathological subgroups of advanced GC.