Subclassification of advanced-stage hepatocellular carcinoma with macrovascular invasion: combined transarterial chemoembolization and radiotherapy as an alternative first-line treatment.

Background/Aim: The Barcelona Clinic Liver Cancer (BCLC) guidelines recommend systemic therapy as the only first-line treatment for patients with BCLC stage C hepatocellular carcinoma (HCC) despite its heterogeneity of disease extent. We aimed to identify patients who might benefit from combined transarterial chemoembolization (TACE) and radiation therapy (RT) by subclassifying BCLC stage C. Methods: A total of 1,419 treatment-naïve BCLC stage C patients with macrovascular invasion (MVI) who were treated with combined TACE and RT (n=1,115) or systemic treatment (n=304) were analyzed. The primary outcome was overall survival (OS). Factors associated with OS were identified and assigned points by the Cox model. The patients were subclassified into three groups based on these points. Results: The mean age was 55.4 years, and 87.8% were male. The median OS was 8.3 months. Multivariate analysis revealed a significant association of Child-Pugh B, infiltrative-type tumor or tumor size ≥10 cm, main or bilateral portal vein invasion, and extrahepatic metastasis with poor OS. The sub-classification was categorized into low (point ≤1), intermediate (point=2), and high (point ≥3) risks based on the sum of points (range, 0-4). The OS in the low, intermediate, and high-risk groups was 22.6, 8.2, and 3.8 months, respectively. In the low and intermediate-risk groups, patients treated with combined TACE and RT exhibited significantly longer OS (24.2 and 9.5 months, respectively) than those who received systemic treatment (6.4 and 5.1 months, respectively; P<0.0001). Conclusions: Combined TACE and RT may be considered as a first-line treatment option for HCC patients with MVI when classified into low- and intermediate-risk groups.

Accuracy of Dental Replica Models Using Photopolymer Materials in Additive Manufacturing: In Vitro Three-Dimensional Evaluation.

PURPOSE: To evaluate the accuracy (trueness and precision) of dental replica models produced by using photopolymer materials in additive manufacturing. MATERIALS AND METHODS: A complete arch model was scanned using an extraoral scanner (Identica Blue) and established as reference. For the control group, 10 stone models were acquired through the conventional method from the reference model. For the experimental groups, digital data were acquired using an intraoral scanner (CEREC Omnicam), and 10 stereolithographic apparatus (SLA) models and 10 PolyJet models were made. All models were scanned with an extraoral scanner. Three-dimensional analysis software was used to measure differences between the 3D scanned images in root mean square values. The ISO-5725-1 specification was followed to measure trueness and precision between two 3D scanned data. Trueness was calculated by overlapping scanned data with the reference model and precision by performing pairwise intragroup comparisons. Also the ratio of region out of tolerance (> ±50 µm) was measured. One-way ANOVA and Tukey's post hoc analysis were applied. RESULTS: There was no statistically significant difference in trueness between the stone and the SLA models (p > 0.05). Dental replica models using photopolymer materials showed statistically significantly better precision than that of the stone model (p < 0.05). Regarding tolerance, no statistically significant difference was observed between the stone and the SLA models (p > 0.05). CONCLUSIONS: Although the dental replica models using photopolymer materials did not show better trueness than the conventional stone models, there was no significant difference between the SLA and the stone models. Concerning precision, dental replica models using photopolymer materials presented better results than that of the conventional stone models. In sum, dental replica models using photopolymer materials showed sufficient accuracy for clinical use.

Accuracy (trueness and precision) of dental models fabricated using additive manufacturing methods.

OBJECTIVE: This study evaluated the accuracy (trueness and precision) of dental models fabricated using additive manufacturing (AM) methods such as PolyJet and fused deposition modeling (FDM). MATERIALS AND METHODS: 10 stone models were acquired for the control group by scanning a complete arch model. For the experimental groups, 10 PolyJet models and 10 FDM models were fabricated from digital impressions using an intraoral scanner. All 30 models were then scanned, and root mean square values were measured using three-dimensional (3D) analysis software. RESULTS: Trueness did not significantly differ between the stone and PolyJet models. The precision of the AM models was significantly higher than that of the stone models. The layer thicknesses of the FDM models were greater than those of the PolyJet models. CONCLUSION: The results of this study show that it might be possible for the dental models fabricated using additive manufacturing methods to be used in clinical settings.