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European Radiology Oct 2023Machine learning (ML) for medical imaging is emerging for several organs and image modalities. Our objectives were to provide clinicians with an overview of this field... (Review)
Review
OBJECTIVES
Machine learning (ML) for medical imaging is emerging for several organs and image modalities. Our objectives were to provide clinicians with an overview of this field by answering the following questions: (1) How is ML applied in liver computed tomography (CT) imaging? (2) How well do ML systems perform in liver CT imaging? (3) What are the clinical applications of ML in liver CT imaging?
METHODS
A systematic review was carried out according to the guidelines from the PRISMA-P statement. The search string focused on studies containing content relating to artificial intelligence, liver, and computed tomography.
RESULTS
One hundred ninety-one studies were included in the study. ML was applied to CT liver imaging by image analysis without clinicians' intervention in majority of studies while in newer studies the fusion of ML method with clinical intervention have been identified. Several were documented to perform very accurately on reliable but small data. Most models identified were deep learning-based, mainly using convolutional neural networks. Potentially many clinical applications of ML to CT liver imaging have been identified through our review including liver and its lesion segmentation and classification, segmentation of vascular structure inside the liver, fibrosis and cirrhosis staging, metastasis prediction, and evaluation of chemotherapy.
CONCLUSION
Several studies attempted to provide transparent result of the model. To make the model convenient for a clinical application, prospective clinical validation studies are in urgent call. Computer scientists and engineers should seek to cooperate with health professionals to ensure this.
KEY POINTS
• ML shows great potential for CT liver image tasks such as pixel-wise segmentation and classification of liver and liver lesions, fibrosis staging, metastasis prediction, and retrieval of relevant liver lesions from similar cases of other patients. • Despite presenting the result is not standardized, many studies have attempted to provide transparent results to interpret the machine learning method performance in the literature. • Prospective studies are in urgent call for clinical validation of ML method, preferably carried out by cooperation between clinicians and computer scientists.
Topics: Humans; Artificial Intelligence; Liver Neoplasms; Machine Learning; Prospective Studies; Tomography, X-Ray Computed
PubMed: 37171491
DOI: 10.1007/s00330-023-09609-w -
Radiotherapy and Oncology : Journal of... Jan 2022To suggest PTV margins for liver SBRT with different motion management strategies based on a systematic review and meta-analysis. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To suggest PTV margins for liver SBRT with different motion management strategies based on a systematic review and meta-analysis.
METHODS
In accordance with Preferred-Reporting-Items-for-Systematic-Reviews-and-Meta-Analyses (PRISMA), a systematic review in PubMed, Embase and Medline databases was performed for liver tumor position variability. From an initial 533 studies published before October 2020, 36 studies were categorized as 18 free-breathing (FB; n = 401), 9 abdominal compression (AC; n = 145) and 9 breath-hold (BH; n = 126). A meta-analysis was performed on inter- and intra-fraction position variability to report weighted-mean with 95% confidence interval (CI) in superior-inferior (SI), left-right (LR) and anterior-posterior (AP) directions. Furthermore, weighted-mean ITV margins were computed for FB (n = 15, n = 373) and AC (n = 6, n = 97) and PTV margins were computed for FB (n = 6, n = 95), AC (n = 7, n = 106) and BH (n = 8, n = 133).
RESULTS
The FB weighted-mean intra-fraction variability, ITV margins and weighted-standard-deviation in mm were SI-9.7, CI = 9.3-10.1, 13.5 ± 4.9; LR-5.4, CI = 5.3-5.6, 7.3 ± 7.9; and AP-4.2, CI = 4.0-4.4, 6.3 ± 7.6. The inter-fraction-based results were SI-4.7, CI = 4.3-5.1, 5.7 ± 1.7; LR-1.4, CI = 1.1-1.6, 3.6 ± 2.7; and AP-2.8, CI = 2.5-3.1, 4.8 ± 2.1. For AC intra-fraction results in mm were SI-1.8, CI = 1.6-2.0, 2.6 ± 1.2; LR-0.7, CI = 0.6-0.8, 1.7 ± 1.5; and AP-0.9, CI = 0.8-1.0, 1.9 ± 1.7. The inter-fraction results were SI-2.6, CI = 2.3-3.0, 5.2 ± 2.9; LR-1.9, CI = 1.7-2.1, 4.0 ± 2.2; and AP-2.9, CI = 2.5-3.2, 5.8 ± 2.7. For BH the inter-fraction variability, and the weighted-mean PTV margins and weighted-standard-deviation in mm were SI-2.4, CI = 2.1-2.7, 5.6 ± 2.9; LR-1.8, CI = 1.3-2.2, 5.5 ± 1.7; and AP-1.4; CI = 1.2-1.7, 6.1 ± 2.1.
CONCLUSION
Our meta-analysis suggests a symmetric weighted-mean PTV margin of 6 mm might be appropriate for BH. For AC and FB, asymmetric PTV margins (weighted-mean margin of 4 mm (AP), 6 mm (SI/LR)) might be appropriate. For FB, if larger (>ITV margin) intra-fraction variability observed, the additional intra- and inter-fraction variability should be accounted in the PTV margin.
Topics: Breath Holding; Humans; Liver Neoplasms; Motion; Radiosurgery; Radiotherapy Planning, Computer-Assisted
PubMed: 34843841
DOI: 10.1016/j.radonc.2021.11.022 -
Langenbeck's Archives of Surgery May 2022Metastatic oesophageal cancer is commonly considered as a palliative situation with a poor prognosis. However, there is increasing evidence that well-selected patients... (Review)
Review
PURPOSE
Metastatic oesophageal cancer is commonly considered as a palliative situation with a poor prognosis. However, there is increasing evidence that well-selected patients with a limited number of liver metastases (ECLM) may benefit from a multimodal approach including surgery.
METHODS
A systematic review of the current literature for randomized trials, retrospective studies, and case series with patients undergoing hepatectomies for oesophageal and oesophagogastric junction cancer liver metastases was conducted up to the 31st of August 2021 using the MEDLINE (PubMed) and Cochrane Library databases.
RESULTS
A total of 661 articles were identified. After removal of duplicates, 483 articles were screened, of which 11 met the inclusion criteria. The available literature suggests that ECLM resection in patients with liver oligometastatic disease may lead to improved survival and even long-term survival in some cases. The response to concomitant chemotherapy and liver resection seems to be of significance. Furthermore, a long disease-free interval in metachronous disease, low number of liver metastases, young age, and good overall performance status have been described as potential predictive markers of outcome for the resection of liver metastases.
CONCLUSION
Surgery may be offered to carefully selected patients to potentially improve survival rates compared to palliative treatment approaches. Studies with standardized patient selection criteria and treatment protocols are required to further define the role for surgery in ECLM. In this context, particular consideration should be given to neoadjuvant treatment concepts including immunotherapies in stage IVB oesophageal and oesophagogastric junction cancer.
Topics: Esophageal Neoplasms; Esophagogastric Junction; Hepatectomy; Humans; Liver Neoplasms; Retrospective Studies
PubMed: 34860291
DOI: 10.1007/s00423-021-02387-3 -
HPB : the Official Journal of the... Oct 2021The dissemination of laparoscopic liver resection (LLR) has been based on non-randomized studies and reviews of these. Aim of this study was to evaluate if the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND/PURPOSE
The dissemination of laparoscopic liver resection (LLR) has been based on non-randomized studies and reviews of these. Aim of this study was to evaluate if the randomized evidence comparing LLR to open liver resection (OLR) supports these findings.
METHODS
A prospectively registered (reviewregistry866) systematic review and meta-analysis following Cochrane and PRISMA guidelines comparing LLR to OLR for benign and malignant diseases was performed via Medline, Web of Science, CENTRAL up to 31.12.2020. The main outcome was postoperative complications. Risk of bias was assessed with the Cochrane Risk of Bias tool 2.0, certainty of evidence was assessed using the GRADE approach.
RESULTS
The search yielded 2080 results. 13 RCTs assessing mostly minor liver resections with 1457 patients were included. There were reduced odds of experiencing any complication (Odds ratio (OR) [95% confidence interval (CI)]: 0·42 [0·30, 0·58]) and severe complications (OR[CI]: 0·51 [0·31, 0·84]) for patients undergoing LLR. LOS was shorter (Mean difference (MD) [CI]: -2·90 [-3·88, -1·92] days), blood loss was lower (MD: [CI]: -115·41 [-146·08, -84·75] ml), and functional recovery was better for LLR. All other outcomes showed no significant differences.
CONCLUSIONS
LLR shows significant postoperative benefits. RCTs assessing long-term outcomes and major resections are needed.
Topics: Hepatectomy; Humans; Laparoscopy; Liver Neoplasms; Postoperative Complications; Randomized Controlled Trials as Topic
PubMed: 33820689
DOI: 10.1016/j.hpb.2021.03.006 -
Lung Cancer (Amsterdam, Netherlands) Aug 2023Stereotactic body radiation therapy (SBRT) is the standard of care for inoperable early stage non-small cell lung cancer (NSCLC). Use of image guided thermal ablation... (Meta-Analysis)
Meta-Analysis Review
RATIONALE
Stereotactic body radiation therapy (SBRT) is the standard of care for inoperable early stage non-small cell lung cancer (NSCLC). Use of image guided thermal ablation (IGTA; including microwave ablation [MWA] and radiofrequency ablation [RFA]) has increased in NSCLC, however there are no studies comparing all three.
OBJECTIVE
To compare the efficacy of IGTA (including MWA and RFA) and SBRT for the treatment of NSCLC.
METHODS
Published literature databases were systematically searched for studies assessing MWA, RFA, or SBRT. Local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were assessed with single-arm pooled analyses and meta-regressions in NSCLC patients and a stage IA subgroup. Study quality was assessed with a modified methodological index for non-randomized studies (MINORS) tool.
RESULTS
Forty IGTA study-arms (2,691 patients) and 215 SBRT study-arms (54,789 patients) were identified. LTP was lowest after SBRT at one and two years in single-arm pooled analyses (4% and 9% vs. 11% and 18%) and at one year in meta-regressions when compared to IGTA (OR = 0.2, 95%CI = 0.07-0.63). MWA patients had the highest DFS of all treatments in single-arm pooled analyses. In meta-regressions at two and three-years, DFS was significantly lower for RFA compared to MWA (OR = 0.26, 95%CI = 0.12-0.58; OR = 0.33, 95%CI = 0.16-0.66, respectively). OS was similar across modalities, timepoints, and analyses. Older age, male patients, larger tumors, retrospective studies, and non-Asian study region were also predictors of worse clinical outcomes. In high-quality studies (MINORS score ≥ 7), MWA patients had better clinical outcomes than the overall analysis. Stage IA MWA patients had lower LTP, higher OS, and generally lower DFS, compared to the main analysis of all NSCLC patients.
CONCLUSIONS
NSCLC patients had comparable outcomes after SBRT and MWA, which were better than those with RFA.
Topics: Humans; Male; Carcinoma, Non-Small-Cell Lung; Retrospective Studies; Treatment Outcome; Radiosurgery; Lung Neoplasms; Catheter Ablation; Liver Neoplasms
PubMed: 37321074
DOI: 10.1016/j.lungcan.2023.107259 -
International Journal of Molecular... May 2023Nonalcoholic fatty liver disease (NAFLD) has emerged as a global health problem that affects people even at young ages due to unhealthy lifestyles. Without intervention,... (Meta-Analysis)
Meta-Analysis Review
Nonalcoholic fatty liver disease (NAFLD) has emerged as a global health problem that affects people even at young ages due to unhealthy lifestyles. Without intervention, NAFLD will develop into nonalcoholic steatohepatitis (NASH) and eventually liver cirrhosis and hepatocellular carcinoma. Although lifestyle interventions are therapeutic, effective implementation remains challenging. In the efforts to establish effective treatment for NAFLD/NASH, microRNA (miRNA)-based therapies began to evolve in the last decade. Therefore, this systematic review aims to summarize current knowledge on the promising miRNA-based approaches in NAFLD/NASH therapies. A current systematic evaluation and a meta-analysis were conducted according to the PRISMA statement. In addition, a comprehensive exploration of PubMed, Cochrane, and Scopus databases was conducted to perform article searches. A total of 56 different miRNAs were reported as potential therapeutic agents in these studies. miRNA-34a antagonist/inhibitor was found to be the most studied variant ( = 7), and it significantly improved the hepatic total cholesterol, total triglyceride, Aspartate Aminotransferase (AST), and Alanine Transaminase (ALT) levels based on a meta-analysis. The biological processes mediated by these miRNAs involved hepatic fat accumulation, inflammation, and fibrosis. miRNAs have shown enormous therapeutic potential in the management of NAFLD/NASH, wherein miRNA-34a antagonist has been found to be an exceptional potential agent for the treatment of NAFLD/NASH.
Topics: Humans; Non-alcoholic Fatty Liver Disease; MicroRNAs; Liver; Liver Cirrhosis; Liver Neoplasms
PubMed: 37298120
DOI: 10.3390/ijms24119168 -
Diagnostic and Interventional Imaging 2020The purpose of this study was to perform a systematic review of current literature describing the efficacy and technical outcomes of transarterial liver therapies using... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The purpose of this study was to perform a systematic review of current literature describing the efficacy and technical outcomes of transarterial liver therapies using automated feeder detection (AFD) software.
MATERIALS AND METHODS
This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. A structured search was performed in the PubMed, SCOPUS, and Embase databases of patients undergoing locoregional therapy of liver tumors utilizing AFD software. Demographic data, procedure data (including radiometrics) and tumor response rate were recorded. Where available, performance of AFD was compared to conventional digital subtraction angiography (DSA) and cone-beam CT (CBCT) without AFD.
RESULTS
A total of 14 full-text manuscripts met inclusion criteria, comprising 1042 tumors in 604 patients (305 men, 156 women; mean age, 68.6±6.0 [SD] years), including 537 patients with hepatocellular carcinoma, 8 with metastases from neuroendocrine tumors, and 59 patients without reported etiology. Reported sensitivity of AFD ranged between 86% and 98.5%, compared to DSA alone (38% - 64%) or DSA in combination with CBCT (69% - 81%). Three studies reported tumor response by modified response evaluation criteria in solid tumors (mRECIST) guidelines, with complete response in the range of 60% - 69%.
CONCLUSION
AFD is a promising new technology for the identification of intrahepatic and extrahepatic tumor-feeding arteries and should be considered a useful adjunct to conventional DSA and CBCT in the treatment of liver tumors.
Topics: Aged; Angiography, Digital Subtraction; Carcinoma, Hepatocellular; Chemoembolization, Therapeutic; Cone-Beam Computed Tomography; Female; Humans; Liver Neoplasms; Male; Middle Aged; Software
PubMed: 32035822
DOI: 10.1016/j.diii.2020.01.011 -
Frontiers in Immunology 2023To identify the risk factors associated with prognosis in patients with hepatocellular carcinoma (HCC) treated with immune checkpoint inhibitors (ICI) via meta-analysis.... (Meta-Analysis)
Meta-Analysis
Development and validation of prognostic risk prediction models for hepatocellular carcinoma patients treated with immune checkpoint inhibitors based on a systematic review and meta-analysis of 47 cohorts.
OBJECTIVE
To identify the risk factors associated with prognosis in patients with hepatocellular carcinoma (HCC) treated with immune checkpoint inhibitors (ICI) via meta-analysis. And to construct prediction models to aid in the prediction and improvement of prognosis.
METHODS
We searched PubMed, Embase, Web of Science and Cochrane Library for relevant studies from inception to March 29, 2023. After completing literature screening and data extraction, we performed meta-analysis, sensitivity analysis, and subgroup analysis to identify risk factors associated with OS and PFS. Using the pooled hazard ratio value for each risk factor, we constructed prediction models, which were then validated using datasets from 19 centers in Japan and two centers in China, comprising a total of 204 patients.
RESULTS
A total of 47 studies, involving a total of 7649 ICI-treated HCC patients, were included in the meta-analysis. After analyzing 18 risk factors, we identified AFP, ALBI, NLR, ECOG performance status, Child-Pugh stage, BCLC stage, tumor number, vascular invasion and combination therapy as predictors for OS prediction model, while AFP, ALBI, NLR, ECOG performance status, Child-Pugh stage, BCLC stage, tumor number and vascular invasion were selected as predictors for PFS model. To validate the models, we scored two independent cohorts of patients using both prediction models. Our models demonstrated good performance in these cohorts. In addition, in the pooled cohort of 204 patients, Our models also showed good performance with area under the curve (AUC) values of 0.712, 0.753, and 0.822 for the OS prediction model at 1-year, 2-year, and 3-year follow-up points, respectively, and AUC values of 0.575, 0.749 and 0.691 for the PFS prediction model Additionally, the calibration curve, decision curve analysis, and Kaplan-Meier curves in the pooled cohort all supported the validity of both models.
CONCLUSION
Based on the meta-analysis, we successfully constructed the OS and PFS prediction models for ICI-treated HCC patients. We also validated the models externally and observed good discrimination and calibration. The model's selected indicators are easily obtainable, making them suitable for further application in clinical practice.
Topics: Humans; Carcinoma, Hepatocellular; Prognosis; Immune Checkpoint Inhibitors; Liver Neoplasms; alpha-Fetoproteins
PubMed: 37520554
DOI: 10.3389/fimmu.2023.1215745 -
Current Oncology Reports Jun 2022Based on good local control rates and an excellent safety profile, guidelines consider thermal ablation the gold standard to eliminate small unresectable colorectal... (Meta-Analysis)
Meta-Analysis Review
Microwave Ablation, Radiofrequency Ablation, Irreversible Electroporation, and Stereotactic Ablative Body Radiotherapy for Intermediate Size (3-5 cm) Unresectable Colorectal Liver Metastases: a Systematic Review and Meta-analysis.
PURPOSE OF REVIEW
Based on good local control rates and an excellent safety profile, guidelines consider thermal ablation the gold standard to eliminate small unresectable colorectal liver metastases (CRLM). However, efficacy decreases exponentially with increasing tumour size. The preferred treatment for intermediate-size unresectable CRLM remains uncertain. This systematic review and meta-analysis compare safety and efficacy of local ablative treatments for unresectable intermediate-size CRLM (3-5 cm).
RECENT FINDINGS
We systematically searched for publications reporting treatment outcomes of unresectable intermediate-size CRLM treated with thermal ablation, irreversible electroporation (IRE) or stereotactic ablative body-radiotherapy (SABR). No comparative studies or randomized trials were found. Literature to assess effectiveness was limited and there was substantial heterogeneity in outcomes and study populations. Per-patient local control ranged 22-90% for all techniques; 22-89% (8 series) for thermal ablation, 44% (1 series) for IRE, and 67-90% (1 series) for SABR depending on radiation dose. Focal ablative therapy is safe and can induce long-term disease control, even for intermediate-size CRLM. Although SABR and tumuor-bracketing techniques such as IRE are suggested to be less susceptible to size, evidence to support any claims of superiority of one technique over the other is unsubstantiated by the available evidence. Future prospective comparative studies should address local-tumour-progression-free-survival, local control rate, overall survival, adverse events, and quality-of-life.
Topics: Colorectal Neoplasms; Electroporation; Humans; Liver Neoplasms; Microwaves; Radiofrequency Ablation
PubMed: 35298796
DOI: 10.1007/s11912-022-01248-6 -
European Review For Medical and... Dec 2023This study aimed to systematically review and quantitatively synthesize the existing evidence to better identify the high-risk population of hepatocellular carcinoma... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
This study aimed to systematically review and quantitatively synthesize the existing evidence to better identify the high-risk population of hepatocellular carcinoma (HCC) in nonalcoholic fatty liver disease (NAFLD).
MATERIALS AND METHODS
We searched databases including MEDLINE, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials.gov up to February 2023. The meta-analysis was performed using RevMan5.3 software, and we calculated the estimated combined effect using inverse variance weighting of OR. I2 statistics were used to quantify the inter-study heterogeneity. Funnel plots and Egger test were used to assess publication bias, and sensitivity analysis was carried out through the transformation effect model or the removal of literature one by one.
RESULTS
Finally, 29 articles were included in the study, which involved a total of 726,656 patients with NAFLD. A total of 15 major risk factors were evaluated. Statistically significant risk factors were: advanced liver fibrosis (OR=6.40), diabetes (OR=2.38), obesity (OR=1.46), hypertension (OR=1.75), older age (OR=3.57), male (OR=2.45), alcohol intake (OR=2.98), smoking (OR=1.44), PNPLA3 genotype variation (OR=1.76), elevated liver enzymes (OR=2.92), low platelet counts (OR=4.61), and low albumin levels (OR=2.11).
CONCLUSIONS
Our results showed that advanced liver fibrosis, diabetes, obesity, hypertension, older age, male, alcohol intake, smoking, PNPLA3 genotype variation, elevated liver enzymes, low platelet counts, and low albumin levels were all significant risk factors for HCC in NAFLD. However, dyslipidemia was not found to be a risk factor. Further exploration is needed to confirm whether Hispanic ethnicity and high ferritin levels are also risk factors.
Topics: Humans; Male; Albumins; Carcinoma, Hepatocellular; Diabetes Complications; Hypertension; Liver Cirrhosis; Liver Neoplasms; Non-alcoholic Fatty Liver Disease; Obesity; Risk Factors; Female; Sex Factors
PubMed: 38164853
DOI: 10.26355/eurrev_202312_34788