Intraoperative 3D-US-mpMRI Elastic Fusion Imaging-Guided Robotic Radical Prostatectomy: A Pilot Study

INTRODUCTION

When performing a nerve-sparing (NS) robotic radical prostatectomy (RARP), cancer location based on multiparametric MRI (mpMRI) is essential, as well as the location of positive biopsy cores outside mpMRI targets. The aim of this pilot study was to assess the feasibility of intraoperative 3D-TRUS-mpMRI elastic fusion imaging to guide RARP and to evaluate its impact on the surgical strategy.

METHODS

We prospectively enrolled 11 patients with organ-confined mpMRI-visible prostate cancer (PCa), histologically confirmed at transperineal fusion biopsy using Koelis Trinity. Before surgery, the 3D model of the prostate generated at biopsy was updated, showing both mpMRI lesions and positive biopsy cores, and was displayed on the Da Vinci robotic console using TilePro™ function.

RESULTS

Intraoperative 3D modeling was feasible in all patients (median of 6 min). The use of 3D models led to a major change in surgical strategy in six cases (54%), allowing bilateral instead of monolateral NS, or monolateral NS instead of non-NS, to be performed. At pathologic examination, no positive surgical margins (PSMs) were reported. Bilateral PCa presence was detected in one (9%), four (36%), and nine (81%) patients after mpMRI, biopsy, and RARP, respectively. Extracapsular extension was found in two patients (18%) even if it was not suspected at MRI.

CONCLUSIONS

Intraoperative 3D-TRUS-mpMRI modeling with Koelis Trinity is feasible and reliable, helping the surgeon to maximize functional outcomes without increasing the risk of positive surgical margins. The location of positive biopsy cores must be registered in 3D models, given the rates of bilateral involvement not seen at mpMRI.

PARP1 proximity proteomics reveals interaction partners at stressed replication forks

PARP1 mediates poly-ADP-ribosylation of proteins on chromatin in response to different types of DNA lesions. PARP inhibitors are used for the treatment of BRCA1/2-deficient breast, ovarian, and prostate cancer. Loss of DNA replication fork protection is proposed as one mechanism that contributes to the vulnerability of BRCA1/2-deficient cells to PARP inhibitors. However, the mechanisms that regulate PARP1 activity at stressed replication forks remain poorly understood. Here, we performed proximity proteomics of PARP1 and isolation of proteins on stressed replication forks to map putative PARP1 regulators. We identified TPX2 as a direct PARP1-binding protein that regulates the auto-ADP-ribosylation activity of PARP1. TPX2 interacts with DNA damage response proteins and promotes homology-directed repair of DNA double-strand breaks. Moreover, TPX2 mRNA levels are increased in BRCA1/2-mutated breast and prostate cancers, and high TPX2 expression levels correlate with the sensitivity of cancer cells to PARP-trapping inhibitors. We propose that TPX2 confers a mitosis-independent function in the cellular response to replication stress by interacting with PARP1.

Role of Cardiovascular Magnetic Resonance in the Management of Atrial Fibrillation: A Review

Atrial fibrillation (AF) is the most common arrhythmia, and its prevalence is growing with time. Since the introduction of catheter ablation procedures for the treatment of AF, cardiovascular magnetic resonance (CMR) has had an increasingly important role for the treatment of this pathology both in clinical practice and as a research tool to provide insight into the arrhythmic substrate. The most common applications of CMR for AF catheter ablation are the angiographic study of the pulmonary veins, the sizing of the left atrium (LA), and the evaluation of the left atrial appendage (LAA) for stroke risk assessment. Moreover, CMR may provide useful information about esophageal anatomical relationship to LA to prevent thermal injuries during ablation procedures. The use of late gadolinium enhancement (LGE) imaging allows to evaluate the burden of atrial fibrosis before the ablation procedure and to assess procedural induced scarring. Recently, the possibility to assess atrial function, strain, and the burden of cardiac adipose tissue with CMR has provided more elements for risk stratification and clinical decision making in the setting of catheter ablation planning of AF. The purpose of this review is to provide a comprehensive overview of the potential applications of CMR in the workup of ablation procedures for atrial fibrillation.

Safety and Feasibility of Transperineal Targeted Microwave Ablation for Low- to Intermediate-risk Prostate Cancer

Background

Focal therapy has emerged as an interesting option for localized low- to intermediate-risk prostate cancer (PCa). Targeted microwave ablation (TMA) is a novel FT modality involving targeted delivery of microwave energy under multiparametric magnetic resonance imaging (MRI)/ultrasound guidance.

Objective

To describe the step-by-step procedure for TMA and report early functional outcomes.

Design, setting, and participants

This was an experimental phase 1–2 trial in 11 patients diagnosed with a single, MRI-visible PCa lesion of up to 12 mm, scored as International Society of Urological Pathology grade group (GG) 1 or 2.

Surgical procedure

Transperineal TMA under MRI/ultrasound image fusion guidance.

Measurements

We recorded patient and PCa features; intraoperative and postoperative parameters; pain (Visual Analog Scale [VAS]) and adverse events (Common Terminology Criteria for Adverse Events v5.0); and prostate-specific antigen (PSA), International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF-5) scores at 1 wk and 1, 3, and 6 mo.

Results and limitations

The median patient age was 67 yr (interquartile range [IQR] 18). Median PSA was 5.4 ng/ml (IQR 1.8), median prostate volume was 51 cm³ (IQR 35), and median lesion size on MRI was 10 mm (IQR 4). Ten patients had GG 2 PCa and one had GG 1 disease. The median procedure time was 40 min (IQR 30). No intraoperative complications were reported. All treatments were performed on a day-case basis and no patients were discharged with a urinary catheter. Postoperatively, no grade ≥2 complications were reported. No significant changes in PSA (p = 0.46), IPSS (p = 0.39), or IIEF-5 scores (p = 0.18) scores were reported. The postoperative VAS score at 24 h was 0 for all patients.

Conclusions

TMA is safe, feasible, and well tolerated in patients with low- to intermediate-risk PCa. Oncological outcomes are still awaited.

Patient summary

Targeted microwave therapy is safe and feasible for selected patients with low- to intermediate-risk prostate cancer. The procedure is well tolerated and does not require a urinary catheter after the procedure. Cancer control outcomes are still awaited.

Liver magnetic resonance imaging for evaluation of response to treatment after stereotactic body radiation therapy of hepatocellular carcinoma

BACKGROUND

Although stereotactic body radiation therapy (SBRT) is increasingly used, its application has not yet been regulated by the main international guidelines, leaving the decision to multidisciplinary teams.

AIM

To assess magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) treated with SBRT, highlighting the efficacy of the treatment and the main aspects of the lesion before and after the procedure.

METHODS

As part of a retrospective study, 49 patients who underwent SBRT for HCC between January 2013 and November 2019 were recruited. Each patient underwent a pre-treatment MRI examination with a hepatospecific contrast agent and a similar follow-up examination within 6 mo of therapy. In addition, 22 patients underwent a second follow-up examination after the first 6 mo. The following characteristics were analysed: Features analysed compared to pre-treatment MRI examination, presence or absence of infield and outfield progression, ring-like enhancement, signal hyperintensity in T2-weighted sequences in the perilesional parenchyma, capsular retraction, and "band" signal hypointensity in T1-weighted gradient echo fat saturated sequences obtained during hepatobiliary excretion.

RESULTS

Signal hyperintensity in the T2-weighted sequences showed a statistically significant reduction in the number of lesions at the post-SBRT first control (P = 0.0006). Signal hyperintensity in diffusion-weighted imaging-weighted sequences was decreased at MRI first control (P < 0.0001). A statistically significant increase of apparent diffusion coefficient values from a median of 1.01 to 1.38 at the first post-control was found (P < 0.0001). Capsular retraction was increased at the late evaluation (P = 0.006). Band-like signal hypointensity in the hepatobiliary phase was present in 94% at the late control (P = 0.006). The study of the risk of outfield progression vs infield progression revealed a hazard ratio of 9.

CONCLUSION

The efficacy of SBRT should be evaluated not in the first 6 mo, but at least 9 mo post-SBRT, when infield progression persists at very low rates while the risk of outfield progression increases significantly.

Multimodality Imaging of Sudden Cardiac Death and Acute Complications in Acute Coronary Syndrome

Sudden cardiac death (SCD) is a potentially fatal event usually caused by a cardiac arrhythmia, which is often the result of coronary artery disease (CAD). Up to 80% of patients suffering from SCD have concomitant CAD. Arrhythmic complications may occur in patients with acute coronary syndrome (ACS) before admission, during revascularization procedures, and in hospital intensive care monitoring. In addition, about 20% of patients who survive cardiac arrest develop a transmural myocardial infarction (MI). Prevention of ACS can be evaluated in selected patients using cardiac computed tomography angiography (CCTA), while diagnosis can be depicted using electrocardiography (ECG), and complications can be evaluated with cardiac magnetic resonance (CMR) and echocardiography. CCTA can evaluate plaque, burden of disease, stenosis, and adverse plaque characteristics, in patients with chest pain. ECG and echocardiography are the first-line tests for ACS and are affordable and useful for diagnosis. CMR can evaluate function and the presence of complications after ACS, such as development of ventricular thrombus and presence of myocardial tissue characterization abnormalities that can be the substrate of ventricular arrhythmias.

Role of gadoxetic acid-enhanced liver magnetic resonance imaging in the evaluation of hepatocellular carcinoma after locoregional treatment

Locoregional treatments, as alternatives to surgery, play a key role in the management of hepatocellular carcinoma (HCC). Liver magnetic resonance imaging (MRI) enables a multiparametric assessment, going beyond the traditional dynamic computed tomography approach. Moreover, the use of hepatobiliary agents can improve diagnostic accuracy and are becoming important in the diagnosis and follow-up of HCC. However, the main challenge is to quickly identify classical responses to loco-regional treatments in order to determine the most suitable management strategy for each patient. The aim of this review is to provide a summary of the most common and uncommon liver MRI findings in patients who underwent loco-regional treatments for HCC, with a special focus on ablative therapies (radiofrequency, microwaves and cryoablation), trans-arterial chemoembolization, trans-arterial radio-embolization and stereotactic ablative radiotherapy techniques, considering the usefulness of gadoxetate disodium (Gd-EOB-DTPA) contrast agent.

A fully automatic deep learning algorithm to segment rectal Cancer on MR images: a multi-center study

The aim of the study is to present and tune a fully automatic deep learning algorithm to segment colorectal cancers (CRC) on MR images, based on a U-Net structure. It is a multicenter study, including 3 different Italian institutions, that used 4 different MRI scanners. Two of them were used for training and tuning the systems, while the other two for the validation. The implemented algorithm consists of a pre-processing step to normalize and to highlight the tumoral area, followed by the CRC segmentation using different U-net structures. Automatic masks were compared with manual segmentations performed by three experienced radiologists, one at each center. The two best performing systems (called mdl2 and mdl3), obtained a median Dice Similarity Coefficient of 0.68(mdl2) - 0.69(mdl3), precision of 0.75(md/2) - 0.71(md/3), and recall of 0.69(mdl2) - 0.73(mdl3) on the validation set. Both systems reached high detection rates, 0.98 and 0.95, respectively, on the validation set. These encouraging results, if confirmed on larger dataset, might improve the management of patients with CRC, since it can be used as a fast and precise tool for further radiomics analyses. Clinical Relevance - To provide a reliable tool able to automatically segment CRC tumors that can be used as first step in future radiomics studies aimed at predicting response to chemotherapy and personalizing treatment.

The SAFE Pilot Trial—SAlvage Focal Irreversible Electroporation—For Recurrent Localized Prostate Cancer: Rationale and Study Protocol

Introduction

Currently, the majority of prostate cancer (PCa) recurrences after non-surgical first-line treatment are managed with androgen-deprivation therapy (ADT). Salvage radical prostatectomy (sRP) is a curative alternative to ADT but yields significant morbidity. Preliminary evidence from focal salvage treatments shows similar oncological control but lower morbidity compared to sRP. Among available ablative focal energies, irreversible electroporation (IRE) is a treatment modality that proved promising, especially in treating apical lesions, where PCa most often recurs. Our aim is to test the safety of salvage IRE for recurrent PCa.

Methods

We performed a single-arm pilot feasibility study (IDEAL stage 2a): SAFE, SAlvage Focal irreversible Electroporation for recurrent localized PCa. Twenty patients with biopsy-proven PCa recurrence after primary non-surgical (radiation or ablation) treatment were included. All men will undergo mpMRI ± targeted biopsies, pre-operative PSMA-PET staging before inclusion and sIRE. Outcomes will be evaluated through internationally validated questionnaires and morbidity scales. All men will undergo a control biopsy at one year.

Results

Primary objectives were the evaluation of the safety of sIRE (and patients’ quality of life) after treatment. Secondary objectives were the evaluation of functional outcomes, namely, continence and erectile function changes and evaluation of short-term oncological efficacy.

Conclusions

SAFE is the second pilot study to evaluate sIRE and the first one performed according to the most recent diagnostic and staging imaging standards. sIRE may provide a curative option for recurrent PCa together with lower comorbidities compared to sRP.

AB1019 THE EFFECTS OF THREE DIFFERENT VITAMIN D3 SUPPLEMENTATION REGIMENS IN DEFICIENT SUBJECTS ON INFLAMMATORY CYTOKINES – A RANDOMISED OPEN-LABEL PARALLEL GROUPS STUDY

Background

The effects of cholecalciferol supplementation on the regulation of inflammatory cytokines are still unclear.

Objectives

This is a preliminary analysis on exploratory outcomes the DIBA/11 RCT [1,2] and aimed to compare the effects on serum inflammatory cytokines of three different regimes of cholecalciferol supplementation in vitamin D-deficient subjects.

Methods

We evaluated, in healthy subjects affected by vitamin D deficiency (defined as 25OHD<20 ng/mL), 18 to 60 years of age, the efficacy of three different oral supplementation regimens: daily 10,000Iu administered for 8 weeks (group A), weekly 50,000Iu (group B) for 12 weeks and biweekly 100,000Iu (group C) for 12 weeks.

Serum TNFα, interleukin-6 (IL6), interleukin-17 (IL17) and interleukin-10 (IL10) were dosed at baseline, Day 28, 53, 84 and 112. This study was approved by the institutional research committee (protocol identification: DIBA/11,EudraCT Number:2017-000194-36). Supported by Abiogen Pharma, Italy).

Results

A total of 75 subjects were randomized to receive one supplementation regimen. The descriptive of the sample at baseline and relative cytokines levels at the various observation points are reported in Table 1. The absolute changes of IL6, IL17 and IL10 are depicted in Figure 1. No significant differences were found among the three groups. TNFα was undetectable at baseline and at any time point.

Table 1.

anthropometrics and laboratory parameters at baseline (mean values ± standard deviation)

ParameterAll patients (N=75)Daily 10.000 Ui(N = 25)Weekly 50.000 Ui(n = 25)Biweekly 100.000 Ui(N = 25)p-value (ANOVA)M:F31:4412:137:1812:13NSAge (years)34.1 ± 10.230.2 ± 9.936.7 ± 8.735.4 ± 11.00.059Body Weight (kg)66.7 ± 12.465.8 ± 13.267.8 ± 10.866.6 ± 13.7NSBMI23.1 ± 2.622.55 ± 2.723.8 ± 2.222.8 ± 2.7NSBaseline 25OHD (ng/mL)13.5 ± 3.714.6 ± 3.912.8 ± 313.5 ± 4.1NSBaseline IL-6 (pg/mL)1.3 ± 1.20.9 ± 0.61.4 ± 1.61.6 ± 1.3NSBaseline IL-17 (pg/mL)0.4 ± 1.80.7 ± 30.2 ± 1.10.2 ± 0.7NSBaseline IL-10 (pg/mL)0.9 ± 0.90.8 ± 0.71.2 ± 1.20.8 ± 0.7NSFigure 1.

absolute changes of IL17, IL6 and IL10. *p<0.05 vs baseline.

Conclusion

In the overall cohort we found slight decreases in serum IL6 and IL17 serum levels. No differences were found among groups.

References

[1]Fassio A, Adami G, Rossini M, et al. Pharmacokinetics of Oral Cholecalciferol in Healthy Subjects with Vitamin D Deficiency: A Randomized Open-Label Study. Nutrients. 2020;12(6).

[2]Fassio A, Gatti D, Rossini M, et al. Pharmacodynamics of Oral Cholecalciferol in Healthy Individuals with Vitamin D Deficiency: A Randomized Open-Label Study. Nutrients. 2021;13(7):2293.

Disclosure of Interests

Angelo Fassio: None declared, Davide Gatti Speakers bureau: Amgen, Celgene Eli-Lilly, MSD-Italia, Organon, UCB., Paid instructor for: Amgen, Celgene Eli-Lilly, MSD-Italia, Organon, UCB., Matteo Gatti: None declared, Maurizio Rossini Speakers bureau: Abiogen, Amgen, Abbvie, BMS, Celgene, Eli-Lilly, Galapagos, Grunenthal, MSD, Novartis, Pfizer, Sanofi, Sandoz, Theramex, UCB., Eugenia Bertoldo: None declared, Giovanni Adami: None declared

AB1017 RADIOFREQUENCY ECHOGRAPHIC MULTI-SPECTROMETRY (REMS) AND DUAL-ENERGY X-RAYS ABSORPTIOMETRY FOR THE EVALUATION OF BONE MINERAL DENSITY IN A PERITONEAL DIALYSIS SETTING

Background

Radiofrequency echographic multi-spectrometry (REMS) is a novel ultrasound-based technique that has shown good reliability in the assessment of bone mineral density (BMD).

Objectives

The aim of this study was to compare the performance of the REMS BMD assessment with dual-energy X-rays absorptiometry (DXA) in a cohort of patients affected by end-stage renal disease undergoing peritoneal dialysis (PD).

Methods

Consecutive patients referring to the PD clinic of our hospital were enrolled. Lumbar spine and proximal femur REMS scans were performed, and lumbar spine (anteroposterior and laterolateral) and proximal femur DXA scans were performed as well. Clinical data were extracted from medical records. The risk assessment outputs of two fracture risk algorithms (FRAX and DeFRA), calculated upon the worst BMD obtained from either technique were compared as well. Analysis of variance (ANOVA) with post hoc analysis (Bonferroni) and a two-sided Student’s t-test were used to estimate the absolute differences between groups.

Written informed consent was obtained from all participants included (protocol 1483 CESC).

Results

41 total patients were enrolled (Table 1). No significant differences were documented between the BMD T-scores measured through DXA or REMS at the proximal femur. At the lumbar spine, the DXA laterolateral T-score was not significantly different from that of REMS, while the DXA anteroposterior T-score was significantly higher than both the anteroposterior DXA and the REMS measurements (Figure 1, panel A and B). When either DXA or REMS was adopted, no significant difference in the fracture risk estimate was found for both algorithms (Figure 1, panel C and D).

Table 1.

anthropometrics, clinical and biochemical characteristics of the enrolled sample. CKD, chronic kidney disease; PTH, parathyroid hormone; ALP, alkaline phosphatase; IQR, interquartile range; VFA, vertebral fracture assessment.

Sample size (M)41 (29)Age (y)Median [IQR]62 [52-73]Height (cm)Median [IQR]170 [165-176]Body weight (Kg)Median [IQR]74 [61-83]Body mass index (Kg/m2)Median [IQR]25 [22-27.8]Disease duration – CKD (months)Median [IQR]132 [48-140]Dialysis duration (months)Median [IQR]10 [3-24]S-calcium (mg/dL)Median [IQR]9.1 [8.6-9.4]S-phosphorous (mg/dL)Median [IQR]5.4 [4.6-6.4]PTH (pg/mL)Median [IQR]31.4 [22.8-46.8]25OH Vitamin D (nmol/L)Median [IQR]53 [36-72]Patients with morphometric fractures (VFA)15%Patients with femoral fractures2.4%Total n° of morphometric fractures12Figure 1.

comparison of the mean T-scores (error bars represent 95%CI) measured with DXA and REMS at the lumbar spine (panel A), and at the femur (panel B). Comparison between the DeFRA DXA and REMS-derived outputs (panel C) and FRAX DXA and REMS-derived outputs (panel D) raw and after correction for TBS. DeFRA, FRAX-derived risk assessment tool; FRAX, Fracture Risk Assessment tool; AP, anteroposterior; LL, latero-lateral; TH, total hip; FN, femoral neck; TBS, trabecular bone score.

Conclusion

Our data showed a good agreement, in a real-life PD setting, between the DXA and REMS-derived BMDs and in the consequent fracture risk assessment obtained with the FRAX or DeFRA tools.

Disclosure of Interests

Angelo Fassio: None declared, Stefano Andreola: None declared, Davide Gatti Paid instructor for: Amgen, Celgene Eli-Lilly, MSD-Italia, Organon, UCB., Consultant of: Amgen, Celgene Eli-Lilly, MSD-Italia, Organon, UCB., Matteo Gatti: None declared, Giovanni Gambaro Speakers bureau: Vifor Pharma, Maurizio Rossini Speakers bureau: Abiogen, Amgen, Abbvie, BMS, Celgene, Eli-Lilly, Galapagos, Grunenthal, MSD, Novartis, Pfizer, Sanofi, Sandoz, Theramex, UCB., Ombretta Viapiana: None declared, Giulia Zanetti: None declared, Francesca Pistillo: None declared, Valeri Messina: None declared, Giovanni Adami: None declared

AB1018 RELATIONSHIP BETWEEN AORTIC CALCIFICATIONS AND DXA AND RADIOFREQUENCY ECHOGRAPHIC MULTI-SPECTROMETRY (REMS) ACQUISITIONS

Background

Data on the relationship between peritoneal dialysis (PD), BMD and aortic calcifications (AOC) are lacking.

Objectives

to study the relationship between the degree of AOC and DXA and Radiofrequency Echographic Multi-Spectrometry (REMS) acquisitions.

Methods

Consecutive patients referring to the PD our clinic were enrolled. Lumbar spine (LS) and proximal femur REMS scans were performed, and LS (anteroposterior and laterolateral) and proximal femur DXA scans were performed as well. The degree of AOC was assessed through the semiquantitative score described by Kauppila et al, and applied to the laterolateral LS DXA scans. To test for correlations between different variables, we used the Pearson’s correlation for continuous variables and Spearman’s rho for discrete variables. Multiple regression analysis was performed to adjust for age and body mass index (BMI) the correlation between BMD and the CKD duration. Written informed consent was obtained from all participants (protocol 1483CESC).

Results

41 total patients were enrolled (29 males, 19 females). Median disease duration of CKD [IQR]: 132 months [48-140]. 15% had vertebral fractures at the DXA Vertebral Fracture Assessment (VFA). The median calcification score [IQR] was 2 [0-6] (min-max 0-20).

We found a statistically significant positive correlation of moderate strength between the total calcification score and the difference between the DXA AP T-score and the DXA LL T-score at the LS (p<0.01, Spearman’s rho = 0.402), Figure 1.

Figure 1.

scatter plot reporting the relationship between the difference between the AP and LL T-scores and the aortic calcifications score.

After adjustment for confounders, we found a significant negative between the LS and femoral neck BMD measured through REMS and CKD duration (Table 1). The same correlation was not significant then BMD was assessed with DXA.

Table 1.

multiple linear regression analysis for REMS T-score at each site after adjustment for age and BMI. BMI, body mass index; β, standardised coefficient.

REMS lumbar spine T-scoreβpCKD duration (months)-0.2280.035Age (years)-0.511<0.01BMI (kg/m2)0.566<0.01REMS femoral neck T-scoreβpCKD duration (months)-0.2100.04Age (years)-0.612<0.01BMI (kg/m2)0.484<0.01REMS total hip T-scoreβpCKD duration (months)-0.1530.219Age (years)-0.523<0.01BMI (kg/m2)0.560<0.01

Conclusion

Our study confirmed that the overestimation of DXA BMD assessed with the anteroposterior scan is indeed influenced by AOC. Furthermore, our data suggest that REMS might be an interesting tool for the investigation of bone changes in CKD.

Disclosure of Interests

Angelo Fassio: None declared, Stefano Andreola: None declared, Davide Gatti Speakers bureau: Amgen, Celgene Eli-Lilly, MSD-Italia, Organon, UCB, Paid instructor for: Amgen, Celgene Eli-Lilly, MSD-Italia, Organon, UCB, Matteo Gatti: None declared, Giovanni Gambaro Speakers bureau: Vitor Pharma, Ombretta Viapiana: None declared, Valeri Messina: None declared, Giulia Zanetti: None declared, Francesca Pistillo: None declared, Maurizio Rossini Speakers bureau: Abiogen, Amgen, Abbvie, BMS, Celgene, Eli-Lilly, Galapagos, Grunenthal, MSD, Novartis, Pfizer, Sanofi, Sandoz, Theramex, UCB., Giovanni Adami: None declared

Benign focal liver lesions: The role of magnetic resonance imaging

Liver lesions are common findings in radiologists’ daily routine. They are a complex category of pathology that range from solitary benign lesions to primary liver cancer and liver metastases. Benign focal liver lesions can arise from different liver cell types: Epithelial (hepatocytes and biliary cells) and nonepithelial (mesenchymal cells). Liver magnetic resonance imaging (MRI) is a fundamental radiological method in these patients as it allows with its multiparametric approach optimal non-invasive tissue characterization. Furthermore, advanced liver MRI techniques such as diffusion-weighted imaging and hepatobiliary contrast agents have improved the detection of focal liver lesions and can be highly effective in differentiating pseudotumor from tumors, as well as benign from malignant lesions, and can also be used for differential diagnosis. Although histological examination can be useful in making a definitive diagnosis, MRI is an important modality in the diagnosis of liver lesions with a significant impact on patient care. This aim of this review is to provide a comprehensive overview of benign liver lesions on MRI.

P388 CORONARY PLAQUE CHARACTERISTICS ASSOCIATED WITH MAJOR ADVERSE CARDIOVASCULAR EVENTS AMONG ATHEROSCLEROTIC PATIENTS AND LESIONS: A SYSTEMATIC REVIEW AND META–ANALYSIS

Background

The clinical value of coronary plaque characteristics (CPCs) to inform intensified medical therapy or revascularization of non–flow–limiting lesion remains uncertain. We performed a systematic review and meta–analysis to study the prognostic impact of CPCs comprehensively assessed with invasive and non–invasive imaging technologies on patient–level and lesion–level major cardiovascular adverse events (MACE).

Methods

We systematically reviewed MEDLINE, EMBASE, and the Cochrane database for studies evaluating the association of CPC with patient–level and lesion–level (MACE). CPCs included high plaque burden, low minimal lumen area, thin cap fibroatheroma, high lipid core burden index, low attenuation plaque, spotty calcification, napkin ring sign or positive remodelling.

Results

Thirty studies (21 retrospective, 9 prospective) with 30.369 patients were included. CPCs were evaluated by invasive intravascular techniques in 9 studies (optical coherence tomography=4, intravascular ultrasound imaging=3, near–infrared spectroscopy intravascular ultrasound imaging=2) and by coronary computed tomography angiography (CCTA) in 21 studies. CPCs were significantly predictive of patient–level and lesion–level MACE, also when only adjusted data where considered. For each CPC, the odds appeared higher for lesion–level (HR range 3.2–16.8) as compared to patient–level MACE (HR range 1.8–4.1). Accuracy was modest to moderate for most CPCs at the patient–level (AUC for MACE ranging between 0.53 and 0.84) and moderate to good for most CPCs at the lesion–level (AUC for MACE ranging between 0.71 and 0.83). Plaques with more than one CPC had the highest accuracy for lesion–level MACE (AUC 0.87, 95%CI 0.84–0.90). CPC pooled sensitivities for lesion–level MACE ranged between 40% and 63% and specificities between 73% and 98%. As the pooled prevalence of CPCs among plaques was low (3% to 28%), the estimated positive predictive values for lesion–level MACE were modest (range 33% to 45%).

Conclusion

CCTA and intravascular imaging characterization of CPCs provides independent prognostic value among atherosclerotic patients and lesions. However, the modest sensitivity and positive predictive value observed across all CPCs seem to suggest modest clinical value, especially to predict lesion–level events (PROSPERO identifier: CRD42021251810).

MRI-based radiomics to predict response in locally advanced rectal cancer: comparison of manual and automatic segmentation on external validation in a multicentre study

Background

Pathological complete response after neoadjuvant chemoradiotherapy in locally advanced rectal cancer (LARC) is achieved in 15–30% of cases. Our aim was to implement and externally validate a magnetic resonance imaging (MRI)-based radiomics pipeline to predict response to treatment and to investigate the impact of manual and automatic segmentations on the radiomics models.

Methods

Ninety-five patients with stage II/III LARC who underwent multiparametric MRI before chemoradiotherapy and surgical treatment were enrolled from three institutions. Patients were classified as responders if tumour regression grade was 1 or 2 and nonresponders otherwise. Sixty-seven patients composed the construction dataset, while 28 the external validation. Tumour volumes were manually and automatically segmented using a U-net algorithm. Three approaches for feature selection were tested and combined with four machine learning classifiers.

Results

Using manual segmentation, the best result reached an accuracy of 68% on the validation set, with sensitivity 60%, specificity 77%, negative predictive value (NPV) 63%, and positive predictive value (PPV) 75%. The automatic segmentation achieved an accuracy of 75% on the validation set, with sensitivity 80%, specificity 69%, and both NPV and PPV 75%. Sensitivity and NPV on the validation set were significantly higher (p = 0.047) for the automatic versus manual segmentation.

Conclusion

Our study showed that radiomics models can pave the way to help clinicians in the prediction of tumour response to chemoradiotherapy of LARC and to personalise per-patient treatment. The results from the external validation dataset are promising for further research into radiomics approaches using both manual and automatic segmentations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41747-022-00272-2.