RESUMO
INTRODUCTION: To explore the feasibility, safety, and efficiency of ethiodized oil tumor marking combined with irreversible electroporation (IRE) for small hepatocellular carcinomas (HCCs) that were invisible on unenhanced computed tomography (CT). METHODS: A retrospective analysis of the institutional database was performed from January 2018 to September 2018. Patients undergoing ethiodized oil tumor marking to improve target-HCC visualization in subsequent CT-guided IRE were retrieved. Target-HCC visualization after marking was assessed, and the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNR) were compared between pre-marking and post-marking CT images using the paired t-test. Standard IRE reports, adverse events, therapeutic endpoints, and survival were summarized and assessed. RESULTS: Nine patients with 11 target-HCCs (11.1-18.8 mm) were included. After marking, all target-HCCs demonstrated complete visualization in post-marking CT, which were invisible in pre-marking CT. Quantitatively, the SNR of the target-HCCs significantly increased after marking (11.07 ± 4.23 vs. 3.36 ± 1.79, p = 0.006), as did the CNR (4.32 ± 3.31 vs. 0.43 ± 0.28, p = 0.023). In sequential IRE procedures, the average current was 30.1 ± 5.3 A, and both the delta ampere and percentage were positive with the mean values of 5.8 ± 2.1 A and 23.8 ± 6.3%, respectively. All procedures were technically successful without any adverse events. In the follow-up, no residual unablated tumor (endpoint-1) was observed. The half-year, one-year, and two-year local tumor progression (endpoint-2) rate was 0%, 9.1%, and 27.3%. The two-year overall survival rate was 100%. CONCLUSIONS: Ethiodized oil tumor marking enables to demarcate small HCCs that were invisible on unenhanced CT. It potentially allows a safe and complete ablation in subsequent CT-guided IRE.
RESUMO
PURPOSE: To evaluate dual-energy CT (DE) and dedicated metal artifact reduction algorithms (iMAR) during CT-guided biopsy in comparison to single-energy CT (SE). METHODS: A trocar was placed in the liver of six pigs. CT acquisitions were performed with SE and dose equivalent DE at four dose levels(1.7-13.5mGy). Iterative reconstructions were performed with and without iMAR. ROIs were placed in four positions e.g. at the trocar tip(TROCAR) and liver parenchyma adjacent to the trocar tip(LIVER-1) by two independent observers for quantitative analysis using CT numbers, noise, SNR and CNR. Qualitative image analysis was performed regarding overall image quality and artifacts generated by iMAR. RESULTS: There were no significant differences in CT numbers between DE and SE at TROCAR and LIVER-1 irrespective of iMAR. iMAR significantly reduced metal artifacts at LIVER-1 for all exposure settings for DE and SE(p = 0.02-0.04), but not at TROCAR. SNR, CNR and noise were comparable for DE and SE. SNR was best for high dose levels of 6.7/13.5mGy. Mean difference in the Blant-Altman analysis was -8.43 to 0.36. Cohen's kappa for qualitative interreader-agreement was 0.901. CONCLUSIONS: iMAR independently reduced metal artifacts more effectively and efficiently than CT acquisition in DE at any dose setting and its application is feasible during CT-guided liver biopsy.
Assuntos
Algoritmos , Artefatos , Tomografia Computadorizada por Raios X/métodos , Animais , Processamento de Imagem Assistida por Computador , Biópsia Guiada por Imagem , Fígado/diagnóstico por imagem , Fígado/patologia , Metais/química , Doses de Radiação , Razão Sinal-Ruído , SuínosRESUMO
BACKGROUND: The aim of this study was to evaluate the effect of 2nd generation argon plasma coagulation (VIO APC) with respect to the tissue destruction capacity, and to compare it with standard APC and Nd:YAG laser. METHODS: 2nd generation APC (VIO APC2, Erbe, Germany), standard APC (APC 300/Erbotom ICC 200, Erbe) and Nd:YAG laser (KTP/YAG XP 800; Laserscope, San Jose, California) were applied in 35 porcine livers. Using APC, power settings (30-120 W), application time (2 and 5 sec) and gas flow (1 and 2 l/min) were varied. Using Nd:YAG laser, 30-60 W were applied (flow 21/min). Diameter and depth of tissue coagulation were evaluated. RESULTS: Using VIO APC, maximum coagulation depth was 6 mm (maximum diameter 15 mm). In comparison to standard APC, the coagulation effect was significantly higher (p < 0.001). There was no significant difference in the mean depth achieved by VIO APC and Nd:YAG laser using 30- 60 W and an application time of 2 sec (p < 0.05). Using maximum energy available for the 2 systems, maximum depth achieved by VIO APC (6 mm) was higher than the one caused by Nd:YAG laser (4 mm). CONCLUSIONS: VIO APC was more effective than standard APC. Using medium power and a limited application time, it was as effective as Nd:YAG laser. The high effectiveness of VIO APC should be a topic of clinical education.