Percutaneous Navigation under Local Anesthesia for Computed Tomography-Guided Microwave Ablation of Malignant Liver Lesions Located in the Hepatic Dome

Background and Objectives: The aim of the present study was to report the safety and efficacy of percutaneous navigation under local anesthesia for computed tomography-guided microwave ablation of malignant liver lesions located in the hepatic dome. Patients with primary and secondary malignant liver lesions located in the hepatic dome who underwent percutaneous computed tomography-guided microwave ablation using a computer-assisted navigation system under local anesthesia were prospectively evaluated. The primary objective was technical success. Materials and Methods: The sample consisted of 10 participants (16 lesions) with a mean age of 60.60 years (SD = 9.25 years) and a mean size of 20.37 ± 7.29 cm, and the mean follow-up time was 3.4 months (SD = 1.41) months. Results: Primary technical success was 93.75%. Tumor remnant was noticed at one month follow-up in a single metastatic lesion, which was re-treated with an ablation session, and no tumor remnant was depicted in the subsequent imaging follow-up (secondary technical success 100%). Grade I self-limited complications (according to the CIRSE classification system) included small pleural effusion (n = 1) and minor bleeding post antenna removal (n = 1) requiring nothing but observation. Conclusions: the findings of the present study indicate that percutaneous navigation under local anesthesia is a safe and efficacious approach for computed tomography-guided microwave ablation of malignant liver lesions located in the hepatic dome. Large randomized controlled studies are warranted to observe treatment effectiveness and compare the results with those of other options.

Diagnostic accuracy of apparent diffusion coefficient (ADC) value in differentiating malignant from benign solid liver lesions: a systematic review and meta-analysis

Objectives: We undertook a systematic review and meta-analysis of the diagnostic performance of mean apparent diffusion coefficient (ADC) values derived by diffusion-weighted (DW)-MRI in the characterization of solid benign and malignant liver lesions, and to assess their value in discriminating these lesions in daily routine practice. Methods: A systematic review of PubMed, Embase, Scopus, and Web of Science was conducted to retrieve studies that used ADC values for differentiating solid benign/dysplastic nodules and malignant liver lesions. A bivariate random-effects model with pooled sensitivity and specificity values with 95% CI (confidence interval) was used. This meta-analysis was performed on the per-lesion basis. Summary receiver operating characteristic (SROC) plot and area under curve (AUC) were created. Results: A total of 14 original articles were retrieved. The combined (95% CI) sensitivity and specificity of mean ADC values for differentiating solid benign from malignant lesions were 78% (67 to 86%) and 74% (64 to 81%), respectively. The pooled (95% CI) positive and negative LRs were respectively 3 (2.3 to 3.8) and 0.3 (0.21 to 0.43). The DOR (95% CI) was 10 (7 to 15). The AUC (95% CI) of the SROC plot was 82% (78 to 85%). Reporting bias was negligible (P value of regression test = 0.36). Mean size of malignant lesions and breathing pattern of MRI were found to be sources of heterogeneity of pooled sensitivity. Conclusion: ADC measurement independently may not be an optimal diagnostic imaging method for differentiating solid malignant from solid benign hepatic lesions. The meta-analysis showed that ADC measurement had moderate diagnostic accuracy for characterizing solid liver lesions. Further prospective and comparative studies with pre-specified ADC thresholds could be performed to investigate the best MRI protocol and ADC threshold for characterizing solid liver lesions. Advances in knowledge: ADC measurement by DW-MRI does not have a good diagnostic performance to differentiate solid malignant from solid benign lesions. Therefore, we suggest not using ADC values in clinical practice to evaluate solid liver lesions.

Radiotherapeutic treatment options for oligotopic malignant liver lesions

Background Several radiotherapeutic approaches for patients with oligotopic malignant liver lesions unfit for surgical resection exist. The most advanced competitive techniques are high-dose-rate (HDR) brachytherapy, Cyberknife, volume-modulated-arc therapy (VMAT) and Tomotherapy. We evaluated the optimal technique by a planning study for a single ablative dose with different lesion sizes. Methods We compared dose distributions of HDR-brachytherapy with stereotactic ablative radiotherapy using the Cyberknife, VMAT or Tomotherapy. Tumor-control-probabilities (TCP), normal-tissue-complication-probabilities (NTCP) were determined in a theoretical framework applying a single dose of 20 Gy (demanding 95% coverage) for intrahepatic lesions of 1–5 cm in size. We evaluated therapeutic ratios by TCP (mean dose in the lesion) relative to high-dose (conformality) or low-dose liver exposition in dependency on the lesion size for each technique. In addition, we considered treatment times and accuracy (clinical target volume vs planning target volume). Results HDR-brachtherapy has the highest therapeutic ratios with respect to high-dose as well as low-dose liver exposition even for extended lesions, and the Cyberknife being suited second best. However, for lesions ≥ 3 cm diameter the therapeutic ratios of all ablative techniques are increasingly converging, and better tolerance and shorter treatment times of noninvasive external techniques become more important. On the other hand, mean tumor doses of HDR-brachytherapy of near 60 Gy are unattainable by the other techniques gaining only 22–34 Gy, and the conformality of HDR-brachytherapy is still rather good for lesions ≥ 3 cm diameter. Conclusions HDR-brachytherapy is by far the most effective technique to treat intrahepatic lesions by a single fraction, but sparing of the surroundings declines with increasing lesion size and approaches the benchmarks of external beam radiosurgery techniques. External beam radiotherapy has the advantage to use suitable fractionation schedules.

Triple-Phase Multidetector Computed Tomography in Distinguishing Canine Hepatic Lesions

The liver has a unique vascular supply, and triple-phase contrast-enhanced computed tomography examinations are being performed in order to characterize liver lesions. This study aimed to look for any associations between the attenuation values of liver lesions and their histological classification. The inclusion criteria for this retrospective study were focal or multifocal liver lesions and histological diagnosis. All of the dogs underwent pre-contrast and triple-phase postcontrast computed tomography (CT) examinations with identical timings of the postcontrast series. Thirty-one dogs were included in the study, and various benign and malignant pathologies were identified. The results did not identify any significant differences between the benign and malignant liver lesions, nor between the individual histological diagnoses. Inflammatory lesions were significantly different compared to the normal liver parenchyma, and significant hypoattenuation was found in the portal and delayed venous phases. Hemangiosarcomas were significantly hypoattenuating to the normal liver parenchyma in the pre-contrast and arterial phases, and also to all of the benign lesions in the arterial phase. The other pathologies showed variable attenuation patterns in the different postcontrast phases, and differentiation was not possible. On the basis of this study, triple-phase contrast-enhanced computed tomography cannot differentiate between benign and malignant liver lesions, and biopsy and further histological analysis are necessary.

The Value of Monomer Hydrogen Proton Magnetic Resonance Spectra in the Diagnosis of Liver Benign and Malignant Lesions

The early diagnosis and treatment of liver disease are very important in clinics. Magnetic resonance spectroscopy (MRS) provides a non-invasive 'window' on the biochemical processes in the body. This study deployed research based on application of monomer element 1HMRS in the diagnosis of benign or malignant liver lesions. Patients with different liver diseases were recruited along with healthy controls. GE Signa Twinspeed 1.5T MRI was performed on livers along with monomeric hydrogen MRS, followed by SAGE software analysis. In healthy patient's livers, both choline and lipid peaks were observed under MRS, with occasionally glutamine and glutamic acid complex (Glx) peak and glucogen and glucose complex (Glu) peak. Malignant liver lesions had significantly elevated choline peak and choline/lipid ratio compared to control or benign lesions (P < 0.05). The accuracy, sensitivity and specificity of MRI against malignant tumors were 89.4%, 86.2% and 91.1%, respectively. These figures for choline/lipid and MRI plus choline/lipid were 87.2%, 92.3% and 90.1%, and 94.1%, 89.1% and 90.4%, respectively. Our study shows that monomeric hydrogen proton MRS might be used as the diagnostic evidences for malignant liver diseases, especially for choline peak level and choline/lipid ratio. However, large cohort multi-center study is required to confirm the findings in the future.

Color Coded Perfusion Imaging with Contrast Enhanced Ultrasound (CEUS) for Post-Interventional Success Control Following Irreversible Electroporation (IRE) of Primary and Secondary Malignant Liver Lesions

Aim: Evaluation of the post-interventional success following irreversible electroporation (IRE) using a new color coded perfusion quantification software with contrast-enhanced ultrasound (CEUS) in patients with malignant lesions of the liver. Methods: Thirty-eight patients with 68 malignant liver lesions underwent IRE. All malignant lesions were investigated with CEUS before and within 24 hours following IRE to detect residual tumor tissue. The parameters analyzed by color coded perfusion quantification software were: the peak enhancement (pE), time to peak (TTP), mean transit time (mTT), rise (Ri) and wash-in area under the curve (WiAUC). Perfusion in the center, the margins of the lesions and in the surrounding liver were evaluated using these parameters. Results: Hepatocellular carcinoma (HCC) with complete ablation showed significantly different changes between the center and the margin of the lesions for WiAUC (p<0.05) and pE (p<0.01). Also significant differences were noted between the center of the lesions and the surrounded tissue for the same parameters (p<0.01). In the completely ablated metastatic lesions, significant differences were found between the center of the lesion and the margins (p < 0.01) and between the center of the lesion and the surrounding liver (p < 0.05) for WiAUC. mTT, TTP and Ri showed no significant changes between the center of the lesions, margin of the lesions or surrounding tissue. Also, no significant differences were found for these parameters in the different regions of interest for HCC or the metastatic lesions with partial ablation success. Conclusion: CEUS with perfusion imaging is a valuable supporting tool for the post-interventional evaluation of liver lesions following IRE. Focus should be placed on the peak enhancement (pE) and the wash-in area under the curve (WiAUC).