Subcutaneous administration, higher age and lower renal function are associated with erythrocyte methotrexate accumulation in Crohn's disease: a cross-sectional study

Background

Methotrexate is an immunomodulatory drug for patients with Crohn’s disease. Erythrocyte MTX-polyglutamates (MTX-PG_1-5) may be used for therapeutic drug monitoring (TDM) as MTX-PG is thought to mediate MTX’s efficacy. Information on determinants of the concentration of MTX-PG in patients with Crohn’s disease is lacking. We aim to identify clinical and biochemical determinants of the erythrocyte MTX-PG_1-5 and MTX-PG_total concentration in patients with Crohn’s disease.

Methods

Adults with Crohn’s disease on methotrexate treatment who visited the outpatient clinic of Amsterdam UMC were included. Erythrocyte MTX-PGs were measured by tandem mass spectrometry.

Results

Nineteen patients were included, with a median duration of MTX use of 77 months (range 7–202). Twelve patients received MTX monotherapy, whereas 7 patients were on concomitant TNF-α inhibitors. The mean dose of MTX was 15.5 mg (SD ± 2.8) and 12 (63%) patients used subcutaneous MTX. MTX-PG_1-5 were successfully measured in 18 patients, showing substantial variability in concentrations of MTX-PG_total and individual species. The median MTX-PG_total was 117.1 nmol/L (range 46.4–258.7) with preferential accumulation of MTX-PG₃ (43.1 nmol/L, range 15.3–96.1). Patients on subcutaneous compared to oral MTX had higher median MTX-PG_(4,5) levels (55 versus 9 nmol/L, p = 0.01). Higher age (β = 0.71) and lower estimated glomerular filtration rate (β = − 0.52) were associated with a significantly higher MTX-PG_total concentration (R² = 0.60, p = 0.001).

Conclusion

MTX-PG concentrations display a considerable inter-individual variability. Higher MTX-PG accumulation is associated with subcutaneous administration, higher age, and lower renal function in Crohn’s disease patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02439-y.

Optimization of the BCLC Staging System for Locoregional Therapy for Hepatocellular Carcinoma by Using Quantitative Tumor Burden Imaging Biomarkers at MRI

Background Patients with intermediate- and advanced-stage hepatocellular carcinoma (HCC) represent a highly heterogeneous patient collective with substantial differences in overall survival. Purpose To evaluate enhancing tumor volume (ETV) and enhancing tumor burden (ETB) as new criteria within the Barcelona Clinic Liver Cancer (BCLC) staging system for optimized allocation of patients with intermediate- and advanced-stage HCC to undergo transarterial chemoembolization (TACE). Materials and Methods In this retrospective study, 682 patients with HCC who underwent conventional TACE or TACE with drug-eluting beads from January 2000 to December 2014 were evaluated. Quantitative three-dimensional analysis of contrast-enhanced MRI was performed to determine thresholds of ETV and ETB (ratio of ETV to normal liver volume). Patients with ETV below 65 cm³ or ETB below 4% were reassigned to BCLC B_n, whereas patients with ETV or ETB above the determined cutoffs were restratified or remained in BCLC C_n by means of stepwise verification of the median overall survival (mOS). Results This study included 494 patients (median age, 62 years [IQR, 56-71 years]; 401 men). Originally, 123 patients were classified as BCLC B with mOS of 24.3 months (95% CI: 21.4, 32.9) and 371 patients as BCLC C with mOS of 11.9 months (95% CI: 10.5, 14.8). The mOS of all included patients (including the BCLC B and C groups) was 15 months (95% CI: 12.3, 17.2). A total of 152 patients with BCLC C tumors were restratified into a new BCLC B_n class, in which the mOS was then 25.1 months (95% CI: 21.8, 29.7; P < .001). The mOS of the remaining patients (ie, BCLC C_n group) (n = 222; ETV ≥65 cm³ or ETB ≥4%) was 8.4 months (95% CI: 6.1, 11.2). Conclusion Substratification of patients with intermediate- and advanced-stage hepatocellular carcinoma according to three-dimensional quantitative tumor burden identified patients with a survival benefit from transarterial chemoembolization before therapy. © RSNA, 2022 Online supplemental material is available for this article.

Direct and indirect strategies of deep-learning-based attenuation correction for general purpose and dedicated cardiac SPECT

PURPOSE

Deep-learning-based attenuation correction (AC) for SPECT includes both indirect and direct approaches. Indirect approaches generate attenuation maps (μ-maps) from emission images, while direct approaches predict AC images directly from non-attenuation-corrected (NAC) images without μ-maps. For dedicated cardiac SPECT scanners with CZT detectors, indirect approaches are challenging due to the limited field-of-view (FOV). In this work, we aim to 1) first develop novel indirect approaches to improve the AC performance for dedicated SPECT; and 2) compare the AC performance between direct and indirect approaches for both general purpose and dedicated SPECT.

METHODS

For dedicated SPECT, we developed strategies to predict truncated μ-maps from NAC images reconstructed with a small matrix, or full μ-maps from NAC images reconstructed with a large matrix using 270 anonymized clinical studies scanned on a GE Discovery NM/CT 570c SPECT/CT. For general purpose SPECT, we implemented direct and indirect approaches using 400 anonymized clinical studies scanned on a GE NM/CT 850c SPECT/CT. NAC images in both photopeak and scatter windows were input to predict μ-maps or AC images.

RESULTS

For dedicated SPECT, the averaged normalized mean square error (NMSE) using our proposed strategies with full μ-maps was 1.20 ± 0.72% as compared to 2.21 ± 1.17% using the previous direct approaches. The polar map absolute percent error (APE) using our approaches was 3.24 ± 2.79% (R² = 0.9499) as compared to 4.77 ± 3.96% (R² = 0.9213) using direct approaches. For general purpose SPECT, the averaged NMSE of the predicted AC images using the direct approaches was 2.57 ± 1.06% as compared to 1.37 ± 1.16% using the indirect approaches.

CONCLUSIONS

We developed strategies of generating μ-maps for dedicated cardiac SPECT with small FOV. For both general purpose and dedicated SPECT, indirect approaches showed superior performance of AC than direct approaches.

Impact of Chemoembolic Regimen on Immune Cell Recruitment and Immune Checkpoint Marker Expression following Transcatheter Arterial Chemoembolization in a VX2 Rabbit Liver Tumor Model

PURPOSE

To characterize the effects of commonly used transcatheter arterial chemoembolization (TACE) regimens on the immune response and immune checkpoint marker expression using a VX2 rabbit liver tumor model.

MATERIALS AND METHODS

Twenty-four VX2 liver tumor-bearing New Zealand white rabbits were assigned to 7 groups (n = 3 per group) undergoing locoregional therapy as follows: (a) bicarbonate infusion without embolization, (b) conventional TACE (cTACE) using a water-in-oil emulsion containing doxorubicin mixed 1:2 with Lipiodol, drug-eluting embolic-TACE with either (c) idarubicin-eluting Oncozene microspheres (40 μm) or (d) doxorubicin-eluting Lumi beads (40-90 μm). For each therapy arm (b-d), a tandem set of 3 animals with additional bicarbonate infusion before TACE was added, to evaluate the effect of pH modification on the immune response. Three untreated rabbits served as controls. Tissue was harvested 24 hours after treatment, followed by digital immunohistochemistry quantification (counts/μm² ± SEM) of tumor-infiltrating cluster of differentiation 3⁺ T-lymphocytes, human leukocyte antigen DR type antigen-presenting cells (APCs), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), and programmed cell death protein-1 (PD-1)/PD-1 ligand (PD-L1) pathway axis expression.

RESULTS

Lumi-bead TACE induced significantly more intratumoral T-cell and APC infiltration than cTACE and Oncozene-microsphere TACE. Additionally, tumors treated with Lumi-bead TACE expressed significantly higher intratumoral immune checkpoint markers compared with cTACE and Oncozene-microsphere TACE. Neoadjuvant bicarbonate demonstrated the most pronounced effect on cTACE and resulted in a significant increase in intratumoral cluster of differentiation 3⁺ T-cell infiltration compared with cTACE alone.

CONCLUSIONS

This preclinical study revealed significant differences in evoked tumor immunogenicity depending on the choice of chemoembolic regimen for TACE.

MR Imaging Biomarkers for the Prediction of Outcome after Radiofrequency Ablation of Hepatocellular Carcinoma: Qualitative and Quantitative Assessments of the Liver Imaging Reporting and Data System and Radiomic Features

PURPOSE

To assess the Liver Imaging Reporting and Data System (LI-RADS) and radiomic features in pretreatment magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in patients with nodular hepatocellular carcinoma (HCC) treated with radiofrequency (RF) ablation.

MATERIAL AND METHODS

Sixty-five therapy-naïve patients with 85 nodular HCC tumors <5 cm in size were included in this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, retrospective study. All patients underwent RF ablation as first-line treatment and demonstrated complete response on the first follow-up imaging. Gadolinium-enhanced MR imaging biomarkers were analyzed for LI-RADS features by 2 board-certified radiologists or by analysis of nodular and perinodular radiomic features from 3-dimensional segmentations. A radiomic signature was calculated with the most informative features of a least absolute shrinkage and selection operator Cox regression model using leave-one-out cross-validation. The association between both LI-RADS features and radiomic signatures with PFS was assessed via the Kaplan-Meier analysis and a weighted log-rank test.

RESULTS

The median PFS was 19 months (95% confidence interval, 16.1-19.4) for a follow-up period of 24 months. Multifocality (P = .033); the appearance of capsular continuity, compared with an absent or discontinuous capsule (P = .012); and a higher radiomic signature based on nodular and perinodular features (P = .030) were associated with poorer PFS in early-stage HCC. The observation size, presence of arterial hyperenhancement, nonperipheral washout, and appearance of an enhancing "capsule" were not associated with PFS (P > .05).

CONCLUSIONS

Although multifocal HCC clearly indicates a more aggressive phenotype even in early-stage disease, the continuity of an enhancing capsule and a higher radiomic signature may add value as MR imaging biomarkers for poor PFS in HCC treated with RF ablation.

LGG-52. Volumetry-based response characterization of recurrent pediatric low-grade gliomas in PNOC clinical Neuro-oncology trials

BACKGROUND: Endpoints in clinical trials using novel treatments are evaluated by RANO criteria, which provide an estimate of tumor size from two-dimensional measurements along the most prominent axial slice. However, pediatric low-grade gliomas (pLGG) commonly have variegated shapes with solid and cystic components, potentially resulting in misevaluation of true tumor volume and thus, ultimately, trial outcome. OBJECTIVES: We aim to characterize treatment response through volumetric assessment of progressive/recurrent pLGGs treated with single-agent everolimus on PNOC001 clinical trial. We seek to identify clinically relevant criteria that provide added value to response assessment beyond 2D measurements. METHODS: In a cohort of 44 patients we performed 3D-segmentation of solid, cystic and whole tumor within our PACS-framework and compared results to previously carried-out central imaging review by RANO criteria which had yielded 15 PD, 27 SD, 2 PR and 0 CR. RESULTS: 8 tumors were solid only and 36 had a mixed solid-cystic appearance. When evaluating the entire tumor (i.e. solid and cystic components combined) and using the same RANO cutoff criteria, one case changed from PR to SD, one changed from SD to PR, 3 changed from SD to PD, and 7 changed from PD to SD, resulting in an overall discordance of 27% of cases. CONCLUSION: We propose that incorporation of volumetrics into response assessment provides additional and potentially more accurate information beyond RANO-based measurements. It is crucial to note that the above-reported changes represent numerical discrepancies as opposed to true-to-reality changes in clinical outcome. Determining representative thresholds for the deployment of volumetric measures in clinical trials will be critical. Future work will include data from the PNOC002 clinical trial and evaluate inter-reader agreement and reader discordance. With the availability of PACS-based 3D-tools in neuroradiology practice, well-defined volumetric criteria could be incorporated prospectively into treatment response analysis in clinical trials.

POS0411 COMPARISON OF MTX-POLYGLUTAMATE ACCUMULATION PROFILES IN PERIPHERAL BLOOD MONONUCLEAR CELLS AND ERYTHROCYTES DURING 6 MONTHS MTX-THERAPY IN THE METHOTREXATE MONITORING (MeMo) TRIAL

Background

Optimal dosing of methotrexate (MTX) in rheumatoid arthritis (RA) remains challenging. To this end, monitoring of intracellular MTX polyglutamates (MTX-PGs) in red blood cells (RBCs) has been investigated as a potential marker of MTX (non-)response, with contradictory results. As enucleated, non-proliferative cells, mature RBCs lack regulated folate metabolism and are devoid of folylpolyglutamate synthetase (FPGS) activity catalyzing the conversion of MTX to MTX-PGs. Therefore, it has been argued that analysis of MTX-PG in immune-effector cells, represented by peripheral blood mononuclear cells (PBMCs), would be more relevant. However, no prospective study has been performed measuring MTX-PG levels in PBMCs nor in comparison with RBCs.

Objectives

To investigate the pharmacokinetics of MTX-PG accumulation in RBCs and PBMCs in newly diagnosed RA patients in the early phase of MTX treatment.

Methods

In a clinical prospective cohort study (Methotrexate Monitoring (NTR7149)), RA patients were administered MTX op to 25 mg/week, as described before. (1) At 1, 2, 3 and 6 months after start of therapy, blood was collected and RBCs were isolated by centrifugation and PBMCs after Ficoll density gradient centrifugation. MTX-PG1-6 concentrations in these cells were analyzed using a UPLC-MS/MS method with including custom-made stable isotopes of MTX-PG1-6 as internal standards. (2) UPLC-MS/MS measurements for MTX-PG1-6 were performed with a Waters Acquity BEH C18 column coupled to an AB Sciex 6500+ with the ESI operating on the positive mode. MTX dosing and concomitant treatments were in conformity with clinical practice. (3)

Results

46 consecutive patients were included in this study; 76% female, mean age: 57.8 years, mean baseline DAS28-ESR: 3.5, as described before. (1) Mean dosage was 10.5 mg (SD: 1.5) at baseline, 16.3 mg (2.5) at month 1, 22.7 mg (4.5) at month 2, 19.5 mg (6.3) at month 3 and 19.1 mg (6.2) at month 6.

MTX-PG accumulation in PBMCs and RBCs revealed a disparate profile in both MTX-PG distribution and absolute accumulation levels (Figure 1A/B). Remarkably, MTX-PG distribution in PBMCs was mainly composed of MTX-PG1 (58%), and to a lesser extent MTX-PG2 (27%) and MTX-PG3 (15%). Longer chain MTX-PG4-6 were also detectable in PBMCs, but at lower levels (mean: 4.0 – 6.7 fmol/10^6 cells) than MTX-PG1-3. Moreover, this MTX-PG distribution profile in PBMCs remained constant over a MTX therapy period of 6 months (Figure 1A). The RBC MTX-PG accumulation profile shows mainly MTX-PG1 and lower levels of MTX-PG2-6 at 1 month after the start of therapy. After 3 months of therapy, MTX-PG3 is the main PG-moiety with also MTX-PG4,5,6 being detected. This profile is largely similar after 6 months of therapy. With respect to total intracellular MTX-PG1-6 accumulation, PBMCs had significantly (p<0.001) 10-20-fold higher levels than RBCs at all analyzed time points (Figure 1A/B). Total MTX-PG1-6 levels in RBCs and PBMCs at all time points were weakly correlated (r=0.41, p<0.01) (Figure 1C).

Figure 1.

Individual MTX-PG concentrations in PBMCs (A) and RBCs (B) during the first 6 months of MTX administration (note the different scaling of the y-axes). At 6 months, 36 patients were still on MTX treatment. Panel (C): Spearman’s correlation plot of total MTX-PGs in RBCs versus PBMCs of all time points.

The disparate MTX-PG accumulation and distribution profiles in PBMCs versus RBCs of RA patients may be associated with the shorter life span of PBMCs and the low FPGS activity in RBCs. (4)

No significant relation between MTX-PGs and DAS28 was found (data not shown).

Conclusion

This study shows that in newly diagnosed RA patients starting MTX therapy, MTX-PG concentrations in PBMCs are significantly 10-20-fold higher than in RBCs over a period of 6 months, with a disparate MTX-PG distribution profile in PBMCs (highest: MTX-PG1) than RBCs (highest: MTX-PG3).

References

[1]RCF Hebing, Arthr Rheum (2021)

[2]E den Boer, Anal Bioanal Chem (2013)

[3]J Smolen, Ann Rheum Dis (2020)

[4]IB Muller, Ther Drug Monit (2019)

Acknowledgements

Acknowledgements: We would like to thank all participating patients and Pfizer (grant 53233663 / WI230458), AmsterdamUMC (AI&II extension grant) and NVKC (Noyons grant 2018)

Disclosure of Interests

Renske Hebing Grant/research support from: Pfizer (grant 53233663 / WI230458), NVKC (Netherlands Society for Clinical Chemistry, Noyons grant 2018) and AmsterdamUMC (extension grant), Marry Lin: None declared, Eduard Struys: None declared, Sohaila Mahmoud: None declared, Ittai Muller: None declared, Sandra Heil: None declared, Pieter Griffioen: None declared, WIllem Lems: None declared, Bart van den Bemt Speakers bureau: Pfizer, UCB, Sanofi-Aventis, Galapagos, Amgen and Eli Lilly, Michael Nurmohamed Grant/research support from: Pfizer grant 53233663 / WI230458, Gerrit Jansen: None declared, Robert De Jonge Grant/research support from: NVKC (Netherlands Society for Clinical Chemistry, Noyons grant)

AB0061 PHARMACOKINETICS OF METHOTREXATE POLYGLUTAMATES IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF RA PATIENTS IS SIMILAR AFTER SUBCUTANEOUS OR ORAL ADMINISTRATION IN THE METHOTREXATE MONITORING (MeMo) TRIAL

Background

Pharmacokinetics of methotrexate (MTX) after oral and subcutaneous administration to RA patients differs: MTX levels in plasma and MTX-polyglutamate (MTX-PG) accumulation in erythrocytes are higher during equidosed subcutaneous compared to oral MTX treatment. (1,2) No data are available whether administration route of MTX differentially impacts the intracellular concentrations of MTX-PGs in peripheral blood mononuclear cells (PBMCs) during MTX therapy.

Objectives

To investigate the pharmacokinetics of MTX-PGs in PBMCs of newly diagnosed RA patients receiving oral or subcutaneous MTX in the early phase (1, 2, 3 and 6 months) of MTX treatment.

Methods

In a clinical prospective cohort study (MeMo study (NTR7149)), RA patients were

administered oral (n=24) or subcutaneous (n=22) MTX up to 25 mg MTX/week, as described before. (1) At 1, 2, 3 and 6 months after the start of therapy, PBMCs were isolated via Ficoll density gradient centrifugation. Individual MTX-PG forms (MTX-PG1-6) in PBMCs were analyzed by a UPLC-MS/MS method including custom-made stable isotopes of MTX-PG1-6 as internal standards (3). UPLC-MS/MS measurements of the PBMCs were performed with a Waters Acquity BEH C18 column coupled to an AB Sciex 6500+ with the ESI operating on the positive mode. Dosing, concomitant treatments and DAS28-ESR assessments were in conformity with clinical practice. (4)

Results

46 consecutive patients were included in this study; 76% female, mean age: 57.8 years, BMI: 25.8, smokers: 20%, mean baseline DAS28-ESR: 3.5, as described before. (1) MTX dose at baseline was 10.5 mg (SD: 1.5) for both groups, 15.4 mg (4.4) and 16.8 mg (1.8) at 1 month, 22.8 mg (3.9) and 22.4 mg (5.2) at 2 months, 20.1 mg (6.3) and 20.8 mg (5.6) at 3 months, and 19.7 mg (6.1) and 18.5 mg (6.7) at 6 months for oral and subcutaneous use, respectively. MTX-PG analyses in PBMCs for individual and total MTX-PGs revealed no significant differences between oral and subcutaneous administration groups at 1, 2, 3, and 6 months (Figure 1). Linear regression of LN transformed MTX-PG levels in PBMCs and administration route, corrected for age, baseline DAS28, smoking, BMI, eGFR and MTX dose, showed a trend towards higher MTX-PG levels in PBMCs after subcutaneous MTX administration compared to oral administration (data not shown). MTX-PG distribution in PBMCs was mainly composed of MTX-PG1 (58%), and to a lesser extent MTX-PG2 (27%) and MTX-PG3 (15%). Longer chain MTX-PGs beyond MTX-PG4 were detectable in PBMCs, but at levels lower than MTX-PG1-3 (mean: 4.0 – 6.7 fmol/106 cells). Total MTX-PG accumulation in PBMCs was approximately 10-20 fold higher than in erythrocytes. PBMC accumulation was rather stable, whereas RBC MTX-PG accumulation increased between 1 to 3 months to reach a plateau (Figure 1).

Figure 1.

Loess regression of MTX-PG concentrations in PBMCs (MTX-PG1-3) and RBCs (MTX-PG1-6) of RA patients during the first 6 months of oral or subcutaneous MTX administration. At 6 months, 18 patients using oral and 18 patients using subcutaneous MTX were still continuing MTX treatment. Means (lines) and SE (grey areas) are depicted.

Conclusion

This study demonstrated that MTX-PG accumulation in PBMCs early on in the MTX treatment of RA patients was not significantly different between oral or subcutaneous MTX administration routes.

References

[1]RCF Hebing et al, Arthritis Rheum (2021); 60:339-348

[2]M Hoekstra et al, J Rheumatol (2004); 31:645-8

[3]E Den Boer et al, Anal Bioanal Chem (2013); 405: 1673-1681

[4]J Smolen et al, Ann Rheum Dis (2020); 79:685-699

Acknowledgements

We would like to thank all participating patients and Pfizer (grant 53233663 / WI230458), NVKC (Noyons grant) and AmsterdamUMC (AI&II extension grant).

Disclosure of Interests

Renske Hebing Grant/research support from: Pfizer, grant number 53233663 / WI230458, Amsterdam UMC (AI&II extension grant), NVKC (Netherlands Society for Clinical Chemistry, Noyons grant), Marry Lin: None declared, Eduard Struys: None declared, Sohaila Mahmoud: None declared, Ittai Muller: None declared, WIllem Lems: None declared, Bart van den Bemt Speakers bureau: Pfizer, UCB, Sanofi-Aventis, Galapagos, Amgen and Eli Lilly, Gerrit Jansen: None declared, Robert De Jonge Grant/research support from: NVKC (Netherlands Society for Clinical Chemistry, Noyons grant), Michael Nurmohamed Grant/research support from: Pfizer grant

Machine Learning Tools for Image-Based Glioma Grading and the Quality of Their Reporting: Challenges and Opportunities

Technological innovation has enabled the development of machine learning (ML) tools that aim to improve the practice of radiologists. In the last decade, ML applications to neuro-oncology have expanded significantly, with the pre-operative prediction of glioma grade using medical imaging as a specific area of interest. We introduce the subject of ML models for glioma grade prediction by remarking upon the models reported in the literature as well as by describing their characteristic developmental workflow and widely used classifier algorithms. The challenges facing these models-including data sources, external validation, and glioma grade classification methods -are highlighted. We also discuss the quality of how these models are reported, explore the present and future of reporting guidelines and risk of bias tools, and provide suggestions for the reporting of prospective works. Finally, this review offers insights into next steps that the field of ML glioma grade prediction can take to facilitate clinical implementation.

Machine Learning Models for Classifying High- and Low-Grade Gliomas: A Systematic Review and Quality of Reporting Analysis

Objectives

To systematically review, assess the reporting quality of, and discuss improvement opportunities for studies describing machine learning (ML) models for glioma grade prediction.

Methods

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy (PRISMA-DTA) statement. A systematic search was performed in September 2020, and repeated in January 2021, on four databases: Embase, Medline, CENTRAL, and Web of Science Core Collection. Publications were screened in Covidence, and reporting quality was measured against the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) Statement. Descriptive statistics were calculated using GraphPad Prism 9.

Results

The search identified 11,727 candidate articles with 1,135 articles undergoing full text review and 85 included in analysis. 67 (79%) articles were published between 2018-2021. The mean prediction accuracy of the best performing model in each study was 0.89 ± 0.09. The most common algorithm for conventional machine learning studies was Support Vector Machine (mean accuracy: 0.90 ± 0.07) and for deep learning studies was Convolutional Neural Network (mean accuracy: 0.91 ± 0.10). Only one study used both a large training dataset (n>200) and external validation (accuracy: 0.72) for their model. The mean adherence rate to TRIPOD was 44.5% ± 11.1%, with poor reporting adherence for model performance (0%), abstracts (0%), and titles (0%).

Conclusions

The application of ML to glioma grade prediction has grown substantially, with ML model studies reporting high predictive accuracies but lacking essential metrics and characteristics for assessing model performance. Several domains, including generalizability and reproducibility, warrant further attention to enable translation into clinical practice.

Systematic Review Registration

PROSPERO, identifier CRD42020209938.

Comparison of metabolic and immunologic responses to transarterial chemoembolization with different chemoembolic regimens in a rabbit VX2 liver tumor model

OBJECTIVES

The goal of this study was to investigate the effects of TACE using Lipiodol, Oncozene™ drug-eluting embolics (DEEs), or LUMI™-DEEs alone, or combined with bicarbonate on the metabolic and immunological tumor microenvironment in a rabbit VX2 tumor model.

METHODS

VX2 liver tumor-bearing rabbits were assigned to five groups. MRI and extracellular pH (pHe) mapping using Biosensor Imaging of Redundant Deviation in Shifts (BIRDS) were performed before and after intra-arterial therapy with conventional TACE (cTACE), DEE-TACE with Idarubicin-eluting Oncozene™-DEEs, or Doxorubicin-eluting LUMI™-DEEs, each with or without prior bicarbonate infusion, and in untreated rabbits or treated with intra-arterial bicarbonate only. Imaging results were validated with immunohistochemistry (IHC) staining of cell viability (PCNA, TUNEL) and immune response (HLA-DR, CD3). Statistical analysis was performed using Mann-Whitney U test.

RESULTS

pHe mapping revealed that combining cTACE with prior bicarbonate infusion significantly increased tumor pHe compared to control (p = 0.0175) and cTACE alone (p = 0.0025). IHC staining revealed peritumoral accumulation of HLA-DR+ antigen-presenting cells and CD3 + T-lymphocytes in controls. cTACE-treated tumors showed reduced immune infiltration, which was restored through combination with bicarbonate. DEE-TACE with Oncozene™-DEEs induced moderate intratumoral and marked peritumoral infiltration, which was slightly reduced with bicarbonate. Addition of bicarbonate prior to LUMI™-beads enhanced peritumoral immune cell infiltration compared to LUMI™-beads alone and resulted in the strongest intratumoral immune cell infiltration across all treated groups.

CONCLUSIONS

The choice of chemoembolic regimen for TACE strongly affects post-treatment TME pHe and the ability of immune cells to accumulate and infiltrate the tumor tissue.

KEY POINTS

• Combining conventional transarterial chemotherapy with prior bicarbonate infusion increases the pHe towards a more physiological value (p = 0.0025). • Peritumoral infiltration and intratumoral accumulation patterns of antigen-presenting cells and T-lymphocytes after transarterial chemotherapy were dependent on the choice of the chemoembolic regimen. • Combination of intra-arterial treatment with Doxorubicin-eluting LUMI™-beads and bicarbonate infusion resulted in the strongest intratumoral presence of immune cells (positivity index of 0.47 for HLADR+-cells and 0.62 for CD3+-cells).

Efficacy and safety of combination therapy with vildagliptin and metformin vs. metformin monotherapy for Type 2 Diabetes Mellitus therapy: a meta-analysis

OBJECTIVE

The aim is to assess the comparative efficacy and safety of combination therapy with vildagliptin and metformin vs. metformin monotherapy in the treatment of type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

We searched on PubMed, Cochrane Library, Web of Science, and Embase databases for randomized controlled trials (RCTs) of combination therapy with vildagliptin and metformin vs. metformin monotherapy in patients with T2DM published up to 30 February 2021. The Cochrane tool and Revman 5.3 software was used to assess the risk of bias and conducted the meta-analysis in the included RCTs. Evidence level was assessed by the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

A total of 11 RCTs and 8533 patients were included. For the efficacy, we found that combination therapy with vildagliptin and metformin (dose of metformin ≥1500mg/d) had a significantly higher reduction in hemoglobin A1c (HbA1c) [mean differences (MD)= -0.59, 95% CI (-0.28, -0.16), p<0.00001] and fasting plasma glucose (FPG) level [MD= -0.82, 95% CI (-1.09, -0.56), p<0.00001] than combination therapy with vildagliptin and metformin (dose of metformin <1500 mg/d). Vildagliptin plus metformin as combination therapy reduced body weight loss ratio [MD=0.22, 95% CI (0.17, 0.27), p<0.00001] when compared with metformin monotherapy. In terms of safety, the vildagliptin plus metformin as combination therapy did not increase risk of total adverse events (AEs) [RR=0.98, 95% CI (0.94,1.02), p=0.29], however there were significant statistical difference and did not increase the risk of diarrhea [RR=0.55, 95% CI (0.40, 0.76), p=0.0003] and Gastrointestinal (GI) disorders [RR=0.72, 95% CI (0.58, 0.91), p=0.006], but significantly increased risk of dizziness [RR=1.41, 95% CI (1.06, 1.88), p=0.02] when compared with metformin monotherapy.

CONCLUSIONS

Compared with metformin, vildagliptin combined with metformin could significantly reduce FPG, HbA1c and body weight. When the dose of metformin in the combination group of vildagliptin and metformin is ≥1500mg/d, the results showed significant reduction in HbA1c and FPG. In addition, it had no risk of increase in total AEs, diarrhea, and GI disorders, but had significant risk of increase in dizziness. GRADE showed that the quality of evidence had high certainty in FPG and moderate certainty in HbA1c, body weight and all AEs.

Use of real-time artificial intelligence in detection of abnormal image patterns in standard sonographic reference planes in screening for fetal intracranial malformations

OBJECTIVES

To develop and validate an artificial intelligence system, the Prenatal ultrasound diagnosis Artificial Intelligence Conduct System (PAICS), to detect different patterns of fetal intracranial abnormality in standard sonographic reference planes for screening for congenital central nervous system (CNS) malformations.

METHODS

Neurosonographic images from normal fetuses and fetuses with CNS malformations at 18-40 gestational weeks were retrieved from the databases of two tertiary hospitals in China and assigned randomly (ratio, 8:1:1) to training, fine-tuning and internal validation datasets to develop and evaluate the PAICS. The system was built based on a real-time convolutional neural network (CNN) algorithm, You Only Look Once, version 3 (YOLOv3). An image dataset from a third tertiary hospital was used to further validate, externally, the performance of the PAICS and to compare its performance with that of sonologists with different levels of expertise. Furthermore, a prospective video dataset was employed to evaluate the performance of the PAICS in a real-time scan scenario. The diagnostic accuracy, sensitivity, specificity and area under the receiver-operating-characteristics curve (AUC) were calculated to assess the performance of the PAICS and to compare this with the performance of sonologists with different levels of experience.

RESULTS

In total, 43 890 images from 16 297 pregnancies and 169 videos from 166 pregnancies were used to develop and validate the PAICS. The system achieved excellent performance in identifying 10 types of intracranial image pattern, with macro- and microaverage AUCs, respectively, of 0.933 (95% CI, 0.798-1.000) and 0.977 (95% CI, 0.970-0.985) for the internal validation image dataset, 0.902 (95% CI, 0.816-0.989) and 0.898 (95% CI, 0.885-0.911) for the external validation image dataset and 0.969 (95% CI, 0.886-1.000) and 0.981 (95% CI, 0.974-0.988) in the real-time scan setting. The performance of the PAICS was comparable to that of expert sonologists in terms of macro- and microaverage accuracy (P = 0.863 and P = 0.775, respectively), sensitivity (P = 0.883, P = 0.846) and AUC (P = 0.891, P = 0.788), but required significantly less time (0.025 s per image for PAICS vs 4.4 s for experts, P < 0.001).

CONCLUSIONS

Both in the image dataset and in the real-time scan setting, the PAICS achieved excellent diagnostic performance for various fetal CNS abnormalities. Its performance was comparable to that of experts, but it required less time. A CNN algorithm can be trained to detect fetal CNS abnormalities. The PAICS has the potential to be an effective and efficient tool in screening for fetal CNS malformations in clinical practice. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Thyrotoxic periodic paralysis associated with Graves’ disease: a case series

Summary

Thyrotoxic periodic paralysis (TPP) is a rare condition characterised by acute onset hypokalaemia and paralysis which most commonly affects men of Asian descent between the ages of 20 and 40 years (1, 2). It has been reported in approximately 2% of patients with thyrotoxicosis in China and Japan (1, 2, 3). Hypokalaemia in TPP results from a massive intracellular shift of potassium induced by the thyroid hormone sensitisation of Na⁺/K⁺-ATPase (4). Treatment of TPP includes prevention of this shift by using beta-blockade, rapid potassium replacement and treatment of the underlying hyperthyroidism. We present two cases of TPP with differing outcomes. In the first case, a 33-year-old Filipino gentleman presented to our emergency department (ED) with a 3-month history of recurrent proximal lower limb weakness. Serum potassium was 2.2 mmol/L (3.3–5.1) and he was given i.v. potassium replacement. Thyroid function tests (TFTs) and thyroid antibodies were consistent with Graves thyrotoxicosis. He was discharged home on carbimazole and remains well controlled on long-term medical therapy. In the second case, a 22-year-old Malaysian gentleman presented to our ED with new-onset bilateral lower limb painless paralysis. Serum potassium was 1.9 mmol/L with TFTs demonstrating Graves thyrotoxicosis. He was treated with i.v. potassium replacement and discharged home on carbimazole and propranolol. He represented to the hospital on two further occasions with TPP and was advised to consider total thyroidectomy given his refractory Graves’ disease. These cases highlight the importance of prompt recognition of this rare life-threatening complication of Graves’ disease, especially in patients of Asian descent.

Learning points

Real-time PACS-integrated longitudinal brain metastasis tracking tool provides comprehensive assessment of treatment response to radiosurgery

Background

Treatment of brain metastases can be tailored to individual lesions with treatments such as stereotactic radiosurgery. Accurate surveillance of lesions is a prerequisite but challenging in patients with multiple lesions and prior imaging studies, in a process that is laborious and time consuming. We aimed to longitudinally track several lesions using a PACS-integrated lesion tracking tool (LTT) to evaluate the efficiency of a PACS-integrated lesion tracking workflow, and characterize the prevalence of heterogenous response (HeR) to treatment after Gamma Knife (GK).

Methods

We selected a group of brain metastases patients treated with GK at our institution. We used a PACS-integrated LTT to track the treatment response of each lesion after first GK intervention to maximally seven diagnostic follow-up scans. We evaluated the efficiency of this tool by comparing the number of clicks necessary to complete this task with and without the tool and examined the prevalence of HeR in treatment.

Results

A cohort of eighty patients was selected and 494 lesions were measured and tracked longitudinally for a mean follow-up time of 374 days after first GK. Use of LTT significantly decreased number of necessary clicks. 81.7% of patients had HeR to treatment at the end of follow-up. The prevalence increased with increasing number of lesions.

Conclusions

Lesions in a single patient often differ in their response to treatment, highlighting the importance of individual lesion size assessments for further treatment planning. PACS-integrated lesion tracking enables efficient lesion surveillance workflow and specific and objective result reports to treating clinicians.

Identifying clinically applicable machine learning algorithms for glioma segmentation: recent advances and discoveries

Background

While there are innumerable machine learning (ML) research algorithms used for segmentation of gliomas, there is yet to be a US FDA cleared product. The aim of this study is to explore the systemic limitations of research algorithms that have prevented translation from concept to product by a review of the current research literature.

Methods

We performed a systematic literature review on 4 databases. Of 11 727 articles, 58 articles met the inclusion criteria and were used for data extraction and screening using TRIPOD.

Results

We found that while many articles were published on ML-based glioma segmentation and report high accuracy results, there were substantial limitations in the methods and results portions of the papers that result in difficulty reproducing the methods and translation into clinical practice.

Conclusions

In addition, we identified that more than a third of the articles used the same publicly available BRaTS and TCIA datasets and are responsible for the majority of patient data on which ML algorithms were trained, which leads to limited generalizability and potential for overfitting and bias.

Quantitative Automated Segmentation of Lipiodol Deposits on Cone Beam CT Imaging acquired during Transarterial Chemoembolization for Liver Tumors: A Deep Learning Approach

PURPOSE

The purpose of this study was to show that a deep learning-based, automated model for Lipiodol segmentation on CBCT after cTACE performs closer to the "ground truth segmentation" than a conventional thresholding-based model.

MATERIALS & METHODS

This post-hoc analysis included 36 patients with a diagnosis of HCC or other solid liver tumor who underwent cTACE with an intra-procedural CBCT. Semi-automatic segmentation of Lipiodol were obtained. Then, a convolutional U-net model was used to output a binary mask that predicts Lipiodol deposition. A threshold value of signal intensity on CBCT was used to obtain a Lipiodol mask for comparison. Dice similarity coefficient (DSC), Mean-squared error (MSE), and Center of Mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist segmented Lipiodol deposits) to obtain accuracy metrics for the two masks. These results were used to compare the model vs. the threshold technique.

RESULTS

For all metrics, the U-net outperformed the threshold technique: DSC (0.65±0.17 vs. 0.45±0.22,p<0.001) and MSE (125.53±107.36 vs. 185.98±93.82,p=0.005). Difference between the CM predicted, and the actual CM was (15.31±14.63mm vs. 31.34±30.24mm,p<0.001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22±0.84vs.2.58±3.52,p=0.048 for our model's prediction and threshold technique, respectively.

CONCLUSION

This study showed that a deep learning framework could detect Lipiodol in CBCT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intra-procedurally.

Longitudinal Analysis of the Effect of Repeated Transarterial Chemoembolization for Liver Cancer on Portal Venous Pressure

Objectives

Investigate long-term effects of repeated transarterial chemoembolization (TACE) on portal venous pressure (PVP) using non-invasive surrogate markers of portal hypertension.

Methods

Retrospective, Institutional Review Board-approved study. 99 patients [hepatocellular carcinoma (HCC) group (n=57); liver metastasis group (n=42)] who underwent 279TACEs and had longitudinal pre-/post-therapy contrast-enhanced-MRI (n=388) and complete blood work were included. Outcomes of interest were platelet count (PC), spleen volume, ascites and portosystemic collaterals. Variables included TACE type/number, tumor type, microcatheter location, Child-Pugh, baseline tumor burden (tumor number/total/largest size), vessel invasion, alpha-fetoprotein, Eastern Cooperative Oncology Group (ECOG) performance status, and Model for End-Stage Liver Disease (MELD) score. Generalized Estimating Equations assessed the associations between TACE and outcomes. Power analysis determined the sample size was sufficient.

Results

No significant change in PC over time was observed in either groups, regardless of liver function (P>0.05). Baseline spleen volume was 226 cm³ for metastatic group, and was larger by 204 cm³ for HCC group (P<0.001). Spleen volume increased by 20 cm³ (95%CI: 8-32; P=0.001) for both groups after 1^stTACE and by 16cm³/TACE (P=0.099) over the full follow-up (up to 9TACEs). Spleen volume also tended to increase by 23cm³ (95%CI: -1–48; P=0.064) with higher tumor burden. Odds of developing moderate/severe ascites for metastatic patients was decreased by 0.5 (95%CI: 0.3–0.9; P=0.014), regardless of the Child-Pugh, and increased by 1.5 (95%CI: 1.2–1.9; P<0.001) among HCC patients with unstable Child-Pugh, whereas no change was noted with stable Child-Pugh. HCC patients with unstable Child-Pugh demonstrated a significant increase in portosystemic collaterals number over time (P=0.008). PVP-related complications such as variceal bleeding post-TACE were low (0.4%).

Conclusion

Repeated TACEs did seem to have an impact on PVP. However, the increase in PVP had marginal effects with low portal hypertension-related complications.

Evaluation of different late left ventricular remodeling definitions for predicting long-term outcomes in acute myocardial infarction patients undergoing percutaneous coronary intervention

Background

Late left ventricular remodeling (LLVR) after the index acute myocardial infarction (AMI) is a common complication, and is associated with poor outcome. However, the optimal definition of LLVR has been debated because of its different incidence and influence on prognosis. At present, there are limited data regarding the influence of different LLVR definitions on long-term outcomes in AMI patients undergoing percutaneous coronary intervention (PCI).

Purpose

To explore the impact of different definitions of LLVR on long-term mortality, re-hospitalization or an urgent visit for heart failure, and identify which definition was more suitable for predicting long-term outcomes in AMI patients undergoing PCI.

Methods

We prospectively observed 460 consenting first-time AMI patients undergoing PCI from January 2012 to December 2018. LLVR was defined as a ≥20% increase in left ventricular end-diastolic volume (LVEDV), or a &gt;15% increase in left ventricular end-systolic volume (LVESV) from the initial presentation to the 3–12 months follow-up, or left ventricular ejection fraction (LVEF) &lt;50% at follow up. These parameters of the cardiac structure and function were measuring through the thoracic echocardiography. The association of LLVR with long-term prognosis was investigated by Cox regression analysis.

Results

The incidence rate of LLVR was 38.1% (n=171). The occurrence of LLVR according to LVESV, LVEDV and LVEF definition were 26.6% (n=117), 31.9% (n=142) and 11.5% (n=51), respectively. During a median follow-up of 2 years, after adjusting other potential risk factors, multivariable Cox regression analysis revealed LLVR of LVESV definition [hazard ratio (HR): 2.50, 95% confidence interval (CI): 1.19–5.22, P=0.015], LLVR of LVEF definition (HR: 16.46, 95% CI: 6.96–38.92, P&lt;0.001) and LLVR of Mix definition (HR: 5.86, 95% CI: 2.45–14.04, P&lt;0.001) were risk factors for long-term mortality, re-hospitalization or an urgent visit for heart failure. But only LLVR of LVEF definition was a risk predictor for long-term mortality (HR: 6.84, 95% CI: 1.98–23.65, P=0.002).

Conclusions

LLVR defined by LVESV or LVEF may be more suitable for predicting long-term mortality, re-hospitalization or an urgent visit for heart failure in AMI patients undergoing PCI. However, only LLVR defined by LVEF could be used for predicting long-term mortality.

Funding Acknowledgement

Type of funding sources: None. Association Between LLVR and outcomesKaplan-Meier Estimates of the Mortality

Predictive value of neutrophil percentage-to-albumin ratio for contrast-associated acute kidney injury in patients without chronic kidney disease undergoing elective percutaneous coronary intervention

Background

Although previous studies have demonstrated that neutrophil and albumin are biomarkers of inflammation and malnutrition, which are highly related with contrast-associated acute kidney injury (CA-AKI). However, there has been no study investigated the combined evaluation of neutrophil and albumin in predicting CA-AKI.

Purpose

To explore the predictive value of neutrophil percentage-to-albumin ratio (NPAR) for CA-AKI in patients undergoing elective percutaneous coronary intervention (PCI).

Methods

We prospectively observed 5083 consenting patients without chronic kidney disease (CKD) undergoing elective PCI from January 2012 to December 2018. NPAR was calculated as neutrophil percentage numerator divided by serum albumin concentration. CA-AKI was defined as an increase in serum creatinine (SCr) ≥50% or 0.3 mg/dL within 48 hours after contrast medium exposure. The association between NPAR and CA-AKI was investigated by logistic regression analysis. The area under the receiver-operating characteristic curve (AUC), continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to make comparison for CA-AKI prediction.

Result

The incidence of CA-AKI was 5.6% (n=286). The median NPAR was 14.9 (13.0–17.1). According to the receiver operating characteristic curves (ROC), the best cut-off value of NPAR for predicting CA-AKI was 15.7 with 66.8% sensitivity and 61.9% specificity (C statistic=0.679; 95% CI, 0.666–0.691). NPAR displayed higher AUC value in comparison to neutrophil percentage (p&lt;0.001), but not albumin (P=0.063), as a predictor of CA-AKI. However, NPAR significantly improved the prediction of CA-AKI in the continuous NRI and IDI over neutrophil percentage (NRI: 0.353, 95% CI: 0.234–0.472, P&lt;0.001; IDI: 0.017, 95% CI: 0.010–0.024, p&lt;0.001) and albumin (NRI: 0.141, 95% CI: 0.022–0.260, P=0.020; IDI: 0.009, 95% CI: 0.003–0.015, p=0.003) alone. After adjusting for potential confounding risk factors of CA-AKI, multivariable logistic analysis showed that NPAR &gt;15.7 was a strong independent predictor of CA-AKI (OR=1.998, 95% CI, 1.511–2.643, p&lt;0.001).

Conclusion

NPAR is an independent predictor of CA-AKI, which significantly improved the prediction of CA-AKI over neutrophil and albumin alone in patients without CKD undergoing elective PCI.

Funding Acknowledgement

Type of funding sources: None. ROC for NPAR to predict CA-AKIPredictors of CA-AKI

The De-Ritis ratio is associated with contrast-associated acute kidney injury in patients undergoing elective percutaneous coronary intervention

Background

Preoperative liver dysfunction has been demonstrated as a poor prognostic factor after major surgery. Recent researches discovered that an increased De-Ritis ratio (aspartate aminotransferase-to-alanine aminotransferase ratio) reflects the liver dysfunction and was associated with adverse cardiovascular and renal outcomes. However, there is a lack of data exploring the predictive value of the De-Ritis ratio on contrast-associated acute kidney injury (CA-AKI) in patients undergoing elective percutaneous coronary intervention (PCI).

Purpose

To evaluate the predictive value of the De-Ritis ratio for CA-AKI in patients undergoing elective PCI.

Methods

We conducted a prospective, observational study with 5780 consenting patients undergoing elective PCI from January 2012 to December 2018. CA-AKI was defined as an increase in serum creatinine (SCr) ≥50% or 0.3 mg/dL within 48 hours after contrast medium exposure. The relationship between the De-Ritis ratio and CA-AKI was investigated by logistic regression analysis. The predictive utility of the De-Ritis ratio was determined and compared using the area under the receiver-operating characteristic curve (AUC).

Result

CA-AKI developed in 363 (6.3%) patients. The median De-Ritis ratio was 1.00 (0.77–1.33). The De-Ritis ratio showed an AUC of 0.636 (95% confidence interval (CI): 0.624–0.649; P&lt;0.001) in predicting CA-AKI, which was significantly greater than aspartate aminotransferase (AST) (AUC: 0.636 vs 0.589, p=0.015) and alanine aminotransferase (ALT) (AUC: 0.636 vs 0.506, p&lt;0.001). The best cut-off value of the De-Ritis ratio for predicting CA-AKI was 1.30 with 47.1% sensitivity and 74.7% specificity. Multivariable logistic analysis showed that the De-Ritis ratio &gt;1.30 was a remarkable independent predictor of CA-AKI (OR=1.757, 95% CI, 1.385–2.229, p&lt;0.001) even after adjusting for other CA-AKI risk factors.

Conclusion

The De-Ritis ratio is an independent risk factor for predicting CA-AKI in patients undergoing elective PCI.

Funding Acknowledgement

Type of funding sources: None. ROC for De-Ritis ratio to predict CA-AKIPredictors of CA-AKI