Is 18 F-FDG/ 18 F-Choline Dual-Tracer PET Behavior a Surrogate of Tumor Differentiation in Hepatocellular Carcinoma : A Tertiary Center Dedicated Study

BACKGROUND

In hepatocellular carcinoma (HCC) setting, 18 F-FDG and 18 F-choline PET/CT radiotracers are classically considered surrogates of the degree of differentiation, a strong predictor of disease recurrence after curative treatment. Because the corresponding level of evidence has never been assessed as primary end point, the aim of this retrospective study was to specifically assess the relevance of 18 F-FDG combined to 18 F-choline PET imaging as a surrogate of tumor differentiation in HCC.

PATIENTS AND METHODS

A total of 49 histologically proven HCCs (46 patients treated by surgery or liver transplantation) with available baseline 18 F-FDG and 18 F-choline PET/CT, dedicated liver contrast-enhanced CT scan, and histological key features were retrospectively reviewed. Hepatocellular carcinoma tumors with well, moderately, and poorly differentiation (grades I, II, and III of the World Health Organization classification) were compared on their PET findings (double-blinded visual analysis and 8 usual semiquantitative metrics) by using nonparametric Kruskal-Wallis analyses of variance. In the case of statistical significance, pairwise post hoc tests with family-wise error rate adjustment were performed.

RESULTS

No statistical difference between the grades was observed for any of the patients' or lesions' characteristics ( P > 0.05), except for the macrovascular invasion between the grades I and II (adjusted P = 0.03). None of the PET findings showed statistical difference between the grades, except the tumor-to-background ratio of 18 F-FDG, higher for the grade III compared with grades I (adjusted P = 0.02) and II (adjusted P = 0.01). For less than one third of cases (14 lesions; 28.5%), the regional uptake was judged visually heterogeneous, but none of the related semiquantitative PET metrics were statistically discriminant ( P > 0.05).

CONCLUSIONS

Contrary to a common belief, 18 F-FDG/ 18 F-choline dual-tracer PET behavior is not a relevant surrogate of tumor differentiation in HCC. Future multitracer PET studies are mandatory to refine our knowledges of their deep biological meaning in this field.

Influence of key histological characteristics on 18F-fluorodeoxyglucose /18F-choline positron emission tomography positivity in hepatocellular carcinoma: A machine learning study

Purpose

To determine the characteristics influence of key histological on 18F-fluorodeoxyglucose (18F-FDG) and 18F-choline positron emission tomography (PET) positivity in hepatocellular carcinoma (HCC).

Materials and methods

The 18F-FDG/18F-choline PET imaging findings of 103 histologically proven HCCs (from 62 patients, of which 47 underwent hepatectomy and 15 received liver transplantation) were retrospectively examined to assess the following key histological parameters: Grade, capsule, microvascular invasion (mVI), macrovascular invasion (MVI), and necrosis. Using a ratio of 70/30 for training and testing sets, respectively, a penalized classification model (Elastic Net) was trained using 100 repeated cross-validation procedures (10-fold cross-validation for hyperparameter optimization). The contribution of each histological parameter to the PET positivity was determined using the Shapley Additive Explanations method. Receiver operating characteristic curves with and without dimensionality reduction were finally estimated and compared.

Results

Among the five key histological characteristics of HCC (Grade, capsule, mVI, MVI, and necrosis), mVI and tumor Grade (I-III) showed the highest relevance and robustness in explaining HCC uptake of 18F-FDG and 18F-choline. MVI and necrosis status both showed high instability in outcome predictions. Tumor capsule had a minimal influence on the model predictions. On retaining only mVI and Grades I-III for the final analysis, the area under the receiver operating characteristic (ROC) curve values were maintained (0.68 vs. 0.63, 0.65 vs. 0.64, and 0.65 vs. 0.64 for 18F-FDG, 18F-choline, and their combination, respectively).

Conclusion

18F-FDG/18F-choline PET positivity appears driven by both the Grade and mVI components in HCC. Consideration of the tumor microenvironment will likely be necessary to improve our understanding of multitracer PET positivity.

Aortic valve replacement for aortic stenosis in France – influence of centers' volumes on TAVR adoption rate and outcomes

Aims

Over the last decade, transcatheter aortic valve replacement (TAVR) became extensively used, now being the recommended as first line procedure for aortic valve replacement (AVR) in selected patients' populations. It is unknown whether TAVR adoption rate and variability in outcomes is influenced by centers' volume.

Methods

From a French administrative hospital-discharge database, we collected all AVR performed in France between 2007 and 2019. Centers were stratified to terciles based on their annual SAVR per year per center during 2007–2009 (“pre TAVR era”).

Results

There was 218,489 AVRs (153,747 SAVR and 74,732 TAVR) performed in 46 centers between 2007–2019. Number of total AVR and even more so number of number of TAVR significantly and linearly increased from 2007 to 2019 in all terciles but faster in the high volume tercile (+17, +17 and +31 AVR/center/year in the low, middle and high terciles respectively, P [ANCOVA]<0.001; +11, + 19 and +33 TAVR/center/year in the low, medium and high tercile respectively, P [ANCOVA] <0.00, Figure 1). The age of patients underwent TAVR remained grossly unchanged in all three terciles, however, the Charlson index declined from 2010 to 2019 (from 1.35±1.42 to 0.65±1.04, from 1.21±1.40 to 0.65±1.05 and from 1.53±1.58 to 0.81±1.21, in the low, middle and high terciles, P for trend <0.001, 0.021, and <0.001, respectively). Charlson score in the years 2017–2019, was higher in the high than middle and low terciles (0.87±1.22, 0.76±1.11 and 0.65±1.04, respectively, P<0.0001). The in-hospital mortality rate for TAVR significantly declined from 2010 to 2019 for TAVR in all terciles (from 8.3% to 2.1%, from 7.5% to 2.5% and from 8.2% to 2.1% for low, middle and high TAVR terciles, respectively; p for trend = 0.002, 0.001 and <0.001, respectively, Figure 2). Average mortality in 2017–2019 was similar in all terciles (2.3%, 2.5% and 2.2% for low, middle and high terciles, respectively, P=0.47). After adjusting for age, sex and Charlson score, mortality was higher in the low tercile compared with middle and high terciles (OR 1.15, P<0.001, confidence interval [CI] 1.0–1.2, and OR 1.18, P<0.001, CI 1.1–1.2, respectively).

Conclusions

From 2007 to 2019 total AVR linearly increased, mostly due to increase in TAVR, irrespective of centers' volume, but increase rate was higher in high volume centers. A constant decline in patients risk profile, with a striking decrease in mortality rate, was observed in all volume terciles. High-volume centers patients' have higher risk profile, with adjusted mortality slightly lower than medium and low volume centers.

Funding Acknowledgement

Type of funding sources: None.

Treatment of acromegaly has substantial effects on body composition: a long-term follow-up study

BACKGROUND

Acromegaly is associated with changes in body composition. Long-term changes following acromegaly treatment and the impact of different treatments have been less investigated.

METHODS

We performed a retrospective study in 201 patients with acromegaly. Body composition was assessed by dual-energy X-ray absorptiometry. To investigate the specific effects of treatment vs aging, changes in body composition were compared in one group of patients evaluated both at the time of active and controlled disease (active-to-controlled (A>C); n = 31) and in another group of patients evaluated two times while the disease was controlled (controlled-to-controlled (C>C); n = 32).

RESULTS

In the whole cohort, insulin-like growth factor I (IGF-I) was correlated with fat (r = -0.369; P < 0.001) and lean mass (r = 0.383; P < 0.001). Patients from A>C and C>C groups were comparable for age, sex, BMI and follow-up duration (P = n.s.). Reduction in IGF-I levels was associated with an increase in fat mass and a decrease in lean mass in the A>C group, which was four and eight times more pronounced compared to the C>C group (fat mass: +39 ± 34% vs +10 ± 15%, P < 0.001; lean mass: -8 ± 8% vs -0.2 ± 6%, P < 0.001, respectively). Changes in fat mass were negatively associated with IGF-I (r = -0.450; P = 0.011) and independent of the individual therapy. The daily dose of pegvisomant correlated with fat mass (r = 0.421; P = 0.002) and insulin sensitivity index (r = -0.466; P < 0.001).

CONCLUSIONS

Treatment of acromegaly strongly impacts body composition until biochemical disease remission, characterized by an increase in fat mass and a decrease in lean mass. These changes are closely associated with the normalization of IGF-I. Thereafter, body composition changes are similar to what is observed with aging.

[stent thrombosis : A won battle ? (data from the France PCI registry)]

GOAL

The aim of the study is to assess the incidence, risk factors and prognosis of definite stent thrombosis (ST) at 1 year in the France PCI multicenter prospective registry.

PATIENTS AND METHODS

Only patients who underwent coronary angioplasty with at least one stent implantation between 1^st January 2014 and 31 December 2019 were included. The population was separated into 2 groups: the "ST" group with stent thrombosis and the "control" group without stent thrombosis.

RESULTS

35,435 patients were included. 256 patients (0.72%) presented a ST at 1 year. The rate of ST decreased significantly in acute coronary syndrome (1.5% in 2014 vs. 0.73% in 2019; p = 0.05) but not in chronic coronary syndrome (0.46% in 2014 vs 0.40%; p = 0.98). The risk factors are young age (65.8 years vs 68.2; p = 0.002), clinical context (35.27% vs 16.68%; p = 0.0001), diabetes (35.2 % vs 26.4%; p = 0.002), renal failure (11.7% vs 8%; p = 0.009) and history of coronary angioplasty (28.63% vs 21.86%; p = 0.009) and peripheral arterial disease (14.5% vs 10.1%; p = 0.021), LV dysfunction (37% vs 27.5%; p = 0.003), mean length (39.6 mm vs 31, 7mm; p <0.0001) and the mean number of stents per procedure (1.9 vs 1.6; p <0.0001), a TIMI flow ≤1 pre procedure (21.5% vs 12.4%; p <0.0001) and an intrastent restenosis (11% vs 6%; p <0.0001). The 1-year mortality of the ST group was significantly higher than that of the control group (19.14% vs 5.82%; p <0.0001).

CONCLUSION

Since 2014, the incidence of ST at 1 year has been decreasing but remains stuck at a floor level of 0.54% in 2019. The battle for ST seems to have been partly won and its risk factors well identified, but its mortality is still high.

Right ventricular dysfunction before transcatheter aortic valve implantation: incidence, predictive factors and prognostic impact

Background

Right ventricular dysfunction (RVD) is considered to be a late marker of advanced aortic stenosis (AS) and is associated with poor prognosis. Currently. there are conflicting data on the impact of RVD on clinical outcomes in patients with severe AS treated with TAVI. Moreover, few studies have studied the evolution (recovery or persistence) of RVD and its prognostic impact.

Objectives

To assess the incidence and predictive factors of RVD before TAVI, its prognostic impact and its evolution after TAVI.

Methods

All patients treated with TAVI for severe AS were included in a prospective single center database. Only patients who had a quantitative assessment of RV including Tricuspid Annular Plane Systolic Excursion (TAPSE) and/or doppler tissue imaging-derived tricuspid lateral annular systolic velocity (S') measurements, were eligible to this study. RVD was defined by a TAPSE &lt;17 mm or S' &lt;9.5 cm/s if TAPSE was not available.

Results

Between May 2014 and April 2019, 503 patients with RV function evaluation were included. Incidence of RVD before TAVI was 18.7%. Predictors of RVD were diabetes (P=0.03), atrial fibrillation (P=0.001), altered left ventricular ejection fraction (P&lt;0.0001), left ventricular dilatation (P=0.007), and previous cardiac surgery (P=0.002). Long-term survival was altered in patients with RVD before TAVI as compared to those without RVD (HR 1.97, 95% CI: 1.1–3.4, P=0.01). One year after TAVI, 58.7% of patients with baseline RVD had a normal RV function and had similar outcome as compared to those without RVD at baseline. In contrast, patients with persistent RVD had the worst prognosis.

Conclusions

RVD is not rare and has a deleterious prognostic impact in patients treated by TAVI. Recovery of normal RV function is frequent after TAVI whereas persistence of RVD is associated with poor outcomes.

Funding Acknowledgement

Type of funding sources: None.

[ 18 F]FDG Positron Emission Tomography for Initial Staging and Healing Assessment at the End of Therapy in Lymph Nodes and Bone Tuberculosis

Objective: In extra-pulmonary tuberculosis, therapeutic management is difficult in the absence of reliable tool to affirm healing at the end of treatment. In this prospective multicenter study, we evaluated [¹⁸F]FDG-PET for this purpose.

Methods: Forty-two patients out of 55 included patients could be analyzed. Additionally to usual biological, histological and morphological explorations, [¹⁸F]FDG-PET was performed at diagnosis (PET1), at the end of treatment (PET2), indeed 6 months later. Then patients were followed until 12 months after end of prescribed treatment.

Results: PET1 was positive in 97.6% of patients and discovered unknown injured sites in 52.7% of cases. PET2 was positive in 83.3% of uncured patients, and in 82.3% of cured patients. The sum and mean value of SUV_max measured in PET/CT lesions decreased between PET1 and PET2 in all patients. Mean value of SUV_max (MSUV) and sum value of SUVmax on PET2 showed the highest AUC on ROC curves for the diagnosis of healing at the end of prescribed treatment; MSUV 3.5 on PET2 had a sensitivity of 76.5% and a specificity of 80.0% to affirm healing at the end of prescribed treatment.

Conclusions: [¹⁸F]FDG-PET/CT was useful at diagnosis, discovering unknown lesions in 52.7% of cases. MSUV on PET2 was the best criteria to affirm healing at the end of prescribed treatment.

Fully Integrated Quantitative Multiparametric Analysis of Non-Small Cell Lung Cancer at 3-T PET/MRI: Toward One-Stop-Shop Tumor Biological Characterization at the Supervoxel Level

INTRODUCTION

The aim of this study was to study the feasibility of a fully integrated multiparametric imaging framework to characterize non-small cell lung cancer (NSCLC) at 3-T PET/MRI.

PATIENTS AND METHODS

An 18F-FDG PET/MRI multiparametric imaging framework was developed and prospectively applied to 11 biopsy-proven NSCLC patients. For each tumor, 12 parametric maps were generated, including PET full kinetic modeling, apparent diffusion coefficient, T1/T2 relaxation times, and DCE full kinetic modeling. Gaussian mixture model-based clustering was applied at the whole data set level to define supervoxels of similar multidimensional PET/MRI behaviors. Taking the multidimensional voxel behaviors as input and the supervoxel class as output, machine learning procedure was finally trained and validated voxelwise to reveal the dominant PET/MRI characteristics of these supervoxels at the whole data set and individual tumor levels.

RESULTS

The Gaussian mixture model-based clustering clustering applied at the whole data set level (17,316 voxels) found 3 main multidimensional behaviors underpinned by the 12 PET/MRI quantitative parameters. Four dominant PET/MRI parameters of clinical relevance (PET: k2, k3 and DCE: ve, vp) predicted the overall supervoxel behavior with 97% of accuracy (SD, 0.7; 10-fold cross-validation). At the individual tumor level, these dimensionality-reduced supervoxel maps showed mean discrepancy of 16.7% compared with the original ones.

CONCLUSIONS

One-stop-shop PET/MRI multiparametric quantitative analysis of NSCLC is clinically feasible. Both PET and MRI parameters are useful to characterize the behavior of tumors at the supervoxel level. In the era of precision medicine, the full capabilities of PET/MRI would give further insight of the characterization of NSCLC behavior, opening new avenues toward image-based personalized medicine in this field.

Assessment of long-term structural deterioration of transcatheter aortic bioprosthetic valves

Background

The durability of transcatheter aortic bioprosthetic valves is a crucial issue in the context of extension of indications in younger and lower-risk patients, but data are scarce, especially beyond 5 years of follow-up. This study sought to evaluate the incidence of structural valve degeneration (SVD) 5 to 10 years post-procedure.

Methods

Demographic, procedural, and in-hospital outcome data on patients who underwent transcatheter aortic valve implantation (TAVI) from 2002 to 2014 were obtained from our prospective institutional database. Patients in whom echocardiographic data were available both at baseline and 5 years post-TAVI were included. Clinical and echocardiographic follow-up were performed on site annually. Hemodynamic SVD was determined according to European task force committee guidelines.

Results

A total of 208 patients (82.5±7.6 years of age; 53% female) with paired post-procedure and late echocardiographic follow-up (median 5.3 years, range 5 to 11.4 years) were included. Eleven (5.3%) patients were treated with a self-expandable valve and 197 (94.7%) patients with a balloon-expandable valve. Mean aortic valve gradient and effective aortic valve area remained unchanged during follow-up. There were 2 cases (1.0%) of severe SVD 6 and 7 years after implantation requiring redo-TAVI. There were 4 cases (1.9%) of moderate SVD (mean 6.0 years post-implantation; range 5 to 7 years).

Conclusions

Our data do not demonstrate any alarm on transcatheter aortic valve durability. Careful prospective assessment in younger and lower risk patients and comparison with surgical bioprosthetic valves are required to further assess long-term durability of transcatheter valves.

Funding Acknowledgement

Type of funding source: None

AZTEK: Adaptive zero TE k-space trajectories

PURPOSE

Because of short signal lifetimes and respiratory motion, 3D lung MRI is still challenging today. Zero-TE (ZTE) pulse sequences offer promising solutions as they overcome the issue of short T 2 ∗ . Nevertheless, as they rely on continuous readout gradients, the trajectories they follow in k-space are not adapted to retrospective gating and inferred motion correction.

THEORY AND METHODS

We propose AZTEK (adaptive ZTE k-space trajectories), a set of 3D radial trajectories featuring three tuning parameters, to adapt the acquisition to any moving organ while keeping seamless transitions between consecutive spokes. Standard ZTE and AZTEK trajectories were compared for static and moving phantom acquisitions as well as for human thoracic imaging performed on 3 volunteers (1 healthy and 2 patients with lung cancer).

RESULTS

For the static phantom, we observe comparable image qualities with standard and AZTEK trajectories. For the moving phantom, spatially coherent undersampling artifacts observed on gated images with the standard trajectory are alleviated with AZTEK. The same improvement in image quality is obtained in human, so details are more delineated in the lung with the use of the adaptive trajectory.

CONCLUSION

The AZTEK technique opens the possibility for 3D dynamic ZTE lung imaging with retrospective gating. It enables us to uniformly sample the k-space for any arbitrary respiratory motion gate, while preserving static image quality, improving dynamic image quality and guaranteeing continuous readout gradient transitions between spokes, which makes it appropriate to ZTE.

Dry heat and microwave-generated steam protocols for the rapid decontamination of respiratory personal protective equipment in response to COVID-19-related shortages

BACKGROUND

In the wake of the SARS-CoV-2 pandemic and unprecedented global demand, clinicians are struggling to source adequate access to personal protective equipment. Respirators can be in short supply, though are necessary to protect workers from SARS-CoV-2 exposure. Rapid decontamination and reuse of respirators may provide relief for the strained procurement situation.

METHOD

In this study, we investigated the suitability of 70°C dry heat and microwave-generated steam (MGS) for reprocessing of FFP2/N95-type respirators, and Type-II surgical face masks. Staphylococcus aureus was used as a surrogate as it is less susceptible than enveloped viruses to chemical and physical processes.

RESULTS

We observed >4 log10 reductions in the viability of dry S. aureus treated by dry heat for 90 min at 70°C and >6 log10 reductions by MGS for 90 s. After 3 reprocessing cycles, neither process was found to negatively impact the bacterial or NaCl filtration efficiency of the respirators that were tested. However, MGS was incompatible with Type-II surgical masks tested, as we confirmed that bacterial filtration capacity was completely lost following reprocessing. MGS was observed to be incompatible with some respirator types due to arcing observed around some types of metal nose clips and by loss of adhesion of clips to the mask.

CONCLUSION

Considering the advantages and disadvantages of each approach, we propose a reprocessing personal protective equipment/face mask workflow for use in medical areas.

Cherubism as a systemic skeletal disease: evidence from an aggressive case

Background

Cherubism is a rare autosomal dominant genetic condition caused by mutations in the SH3BP2 gene. This disease is characterized by osteolysis of the jaws, with the bone replaced by soft tissue rich in fibroblasts and multinuclear giant cells. SH3BP2 is a ubiquitous adaptor protein yet the consequences of SH3BP2 mutation have so far been described as impacting only face. Cherubism mouse models have been generated and unlike human patients, the knock-in mice exhibit systemic bone loss together with a systemic inflammation.

Case presentation

In light of these observations, we decided to search for a systemic cherubism phenotype in a 6-year-old girl with an aggressive cherubism. We report here the first case of cherubism with systemic manifestations. Bone densitometry showed low overall bone density (total body Z-score = − 4.6 SD). Several markers of bone remodelling (CTx, BALP, P1NP) as well as inflammation (TNFα and IL-1) were elevated. A causative second-site mutation in other genes known to influence bone density was ruled out by sequencing a panel of such genes.

Conclusions

If this systemic skeletal cherubism phenotype should be confirmed, it would simplify the treatment of severe cherubism patients and allay reservations about applying a systemic treatment such as those recently published (tacrolimus or imatinib) to a disease heretofore believed to be localised to the jaws.

18F-FDG PET and DCE kinetic modeling and their correlations in primary NSCLC: first voxel-wise correlative analysis of human simultaneous [18F]FDG PET-MRI data

OBJECTIVES

To decipher the correlations between PET and DCE kinetic parameters in non-small-cell lung cancer (NSCLC), by using voxel-wise analysis of dynamic simultaneous [18F]FDG PET-MRI.

MATERIAL AND METHODS

Fourteen treatment-naïve patients with biopsy-proven NSCLC prospectively underwent a 1-h dynamic [18F]FDG thoracic PET-MRI scan including DCE. The PET and DCE data were normalized to their corresponding T1-weighted MR morphological space, and tumors were masked semi-automatically. Voxel-wise parametric maps of PET and DCE kinetic parameters were computed by fitting the dynamic PET and DCE tumor data to the Sokoloff and Extended Tofts models respectively, by using in-house developed procedures. Curve-fitting errors were assessed by computing the relative root mean square error (rRMSE) of the estimated PET and DCE signals at the voxel level. For each tumor, Spearman correlation coefficients (rs) between all the pairs of PET and DCE kinetic parameters were estimated on a voxel-wise basis, along with their respective bootstrapped 95% confidence intervals (n = 1000 iterations).

RESULTS

Curve-fitting metrics provided fit errors under 20% for almost 90% of the PET voxels (median rRMSE = 10.3, interquartile ranges IQR = 8.1; 14.3), whereas 73.3% of the DCE voxels showed fit errors under 45% (median rRMSE = 31.8%, IQR = 22.4; 46.6). The PET-PET, DCE-DCE, and PET-DCE voxel-wise correlations varied according to individual tumor behaviors. Beyond this wide variability, the PET-PET and DCE-DCE correlations were mainly high (absolute rs values > 0.7), whereas the PET-DCE correlations were mainly low to moderate (absolute rs values < 0.7). Half the tumors showed a hypometabolism with low perfused/vascularized profile, a hallmark of hypoxia, and tumor aggressiveness.

CONCLUSION

A dynamic "one-stop shop" procedure applied to NSCLC is technically feasible in clinical practice. PET and DCE kinetic parameters assessed simultaneously are not highly correlated in NSCLC, and these correlations showed a wide variability among tumors and patients. These results tend to suggest that PET and DCE kinetic parameters might provide complementary information. In the future, this might make PET-MRI a unique tool to characterize the individual tumor biological behavior in NSCLC.

Hyperparathyroidism in Patients With X-Linked Hypophosphatemia

X-linked hypophosphatemia (XLH) is characterized by increased activity of circulating FGF23 resulting in renal phosphate wasting and abnormal bone mineralization. Hyperparathyroidism may develop in XLH patients; however, its prevalence, pathogenesis, and clinical presentation are not documented. This observational study (CNIL 171036 v 0) recruited XLH adult patients in a single tertiary referral center. Each patient was explored in standardized conditions and compared with two healthy volunteers, matched for sex, age, and 25-OH vitamin D concentrations. The primary endpoint was the proportion of patients with hyperparathyroidism. The secondary endpoints were the factors influencing serum parathyroid hormone (PTH) concentrations and the prevalence of hypercalcemic hyperparathyroidism. Sixty-eight patients (51 women, 17 men) were enrolled and matched with 136 healthy volunteers. Patients had higher PTH concentrations compared with healthy controls (53.5 ng/L, interquartile range [IQR] 36.7-72.7 versus 36.0 ng/L, IQR 27.7-44.0, p < .0001). Hyperparathyroidism was observed in 17 patients of 68 (25%). In patients, a positive relationship between PTH and calcium concentrations and a negative relationship between PTH and phosphate concentrations were observed. Seven (10%) patients (3 premenopausal women, 1 postmenopausal woman, and 3 men) were diagnosed with hypercalcemic hyperparathyroidism. All underwent parathyroid surgery, with consecutive normalization of calcium and PTH concentrations. Hyperparathyroidism is a frequent complication in XLH adult patients. Disruption of the physiological regulation of PTH secretion contributes to parathyroid disease. Early-onset hypercalcemic hyperparathyroidism can be effectively and safely cured by surgical resection. © 2020 American Society for Bone and Mineral Research.

Diffusion-weighted Imaging Voxelwise-matched Analyses of Lung Cancer at 3.0-T PET/MRI: Reverse Phase Encoding Approach for Echo-planar Imaging Distortion Correction

Background PET/MRI has drawn increasing interest in thoracic oncology due to the simultaneous acquisition of PET and MRI data. Geometric distortions related to diffusion-weighted imaging (DWI) limit the evaluation of voxelwise multimodal analyses. Purpose To assess the effectiveness of reverse phase encoding in correcting DWI geometric distortion for multimodal PET/MRI voxelwise lung tumor analyses. Materials and Methods In this prospective study, reverse phase encoding method was implemented with 3.0-T PET/MRI to correct geometric distortions related to DWI. The method was validated in dedicated phantom and then applied to 12 consecutive patients (mean age, 66 years ± 13 [standard deviation]; 10 men) suspected of having lung cancer who underwent fluorodeoxyglucose PET/MRI between October 2018 and April 2019. The effects on DWI-related image matching and apparent diffusion coefficient (ADC) regional map computation were assessed. Consequences on multimodal PET/MRI voxelwise lung tumor analyses were evaluated. Spearman correlation coefficients (r_s) between the standardized uptake value (SUV) and ADC data corrected for distortion were computed from optimal realigned DWI PET data, along with bootstrap confidence intervals. Results Phantom results showed that in highly distorted areas, correcting the distortion significantly reduced the mean error against the ground truth (-25% ± 10.6 to -18.4% ± 12.6; P < .001) and the number of voxels with more than 20% error (from 85.3% to 31.4%). In the 12 patients, the coregistration of multimodal PET/MRI tumor data was improved by using the reverse phase encoding method (0.4%-44%). In all tumors, voxelwise correlations (r_s) between ADC and SUV revealed null or weak monotonic relationships (mean r_s of 0.016 ± 0.24 with none above 0.5). Conclusion Reverse phase encoding is a simple-to-implement method for improved diffusion-weighted multimodal PET/MRI voxelwise-matched analyses in lung cancer. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Colletti in this issue.

Predictive Value for Outcome and Evolution of Geriatric Parameters after Transcatheter Aortic Valve Implantation

OBJECTIVES

To identify parameters of comprehensive geriatric assessment (CGA) CGA including ABCDEF score, a multidomain frailty assessment, associated with poor outcome after TAVI and to assess the evolution of CGA parameters at 6-months follow-up.

DESIGN

one-year monocentric prospective cohort study.

SETTING

Departments of geriatric medicine and cardiology in Rouen University Hospital, Normandy, France.

PARTICIPANTS

all patients over 70, selected for TAVI by a multidisciplinary "heart team".

MEASUREMENTS

8-areas CGA was performed before TAVI and at 6-months follow-up. Poor outcome was defined as decrease in 1 BADL or unplanned readmission at 6 months or death within the first year after TAVI. Geriatric characteristics associated with poor outcome were assessed by logistic regression with surgical scores as bivariable. Geriatric characteristics were compared between baseline and 6-months follow-up.

RESULTS

114 patients (mean age 85.8±5.3 years) were included. Mean EuroSCORE was 19.1±10.6%. Poor outcome occurred in 57(50.0%) patients. Loss of one BADL (OR:1.66, 95CI[1.11-2.48]), decrease in IADL (OR:1.41, 95CI[1.14-1.74]), in plasmatic albumin (OR:1.10, 95CI[1.01-1.20]), in MMSe (OR:1.13, 95CI[1.02-1.26]), low walking speed (OR:1.53, 95CI[1.01-2.33]) and ABCDEF score ≥2 (OR:1.63, 95CI[1.09-2.42]) were independently associated with poor outcome. In survivors with complete follow-up (n=80), most geriatric parameters were maintained 6 months after TAVI, but IADL decreased (5.6±1.9 to 4.9±2.2, p<0.001). MMSe increased in patients with previous cognitive impairments whereas it decreased in those without (p<0.001).

CONCLUSION

CGA parameters are independently associated with poor outcome after TAVI. These parameters, but IADL, are maintained at 6 months and course of the MMSe depends on previous cognitive status.

Efficacy and Safety of Intra-gastric Balloon Placement in Dialyzed Patients Awaiting Kidney Transplantation

BACKGROUND

The number of obese patients who are candidates for renal transplantation has considerably increased, but obesity can be a barrier to kidney transplantation. Weight loss is often difficult through diet alone. We studied the efficacy and tolerance of the intra-gastric balloon (IGB) procedure in obese patients who were undergoing dialysis and were candidates for a renal transplantation.

PATIENTS AND METHODS

Obese patients (BMI > 30 kg/m²) who were candidates for renal transplantation were prospectively included in the study between 2010 and 2012. The balloon was inserted and removed during a gastric endoscopy under general anesthesia. The treatment lasted 6 months. The end point was a decrease in BMI after 6 months. Body impedance spectrometry (BIS) and nutritional statute were evaluated initially and then after IGB removal.

RESULTS

Seventeen patients (nine females and eight males) with a mean age of 53.4 years [19.4-69.4] were included. The decrease in body mass index (BMI) during the 6-month placement was 3 kg/m² (from 37.7 to 34.4 kg/m²). The mean weight loss was 7 kg. The mean percentage of excess weight loss after 6 months was 20.2 (± 11.4). The tolerance was good without any complications. Eleven patients underwent kidney transplantation.

CONCLUSION

IGB in obese dialyzed patients who are candidates for renal transplantation is safe and effective. However, the amount of weight loss can vary.

P3664Infective endocarditis after transcatheter aortic valve implantation, a comparison with endocarditis occurring in surgical aortic prosthesis and native aortic valve patients

Background

Infective endocarditis is rare but serious. Epidemiology is well known in standard population and surgical valve patients (Pts). The recent development of Transcatheter Aortic Valve Implantation (TAVI) raises new questions about endocarditis in this population.

Purpose

The aim of this study was to assess outcomes of endocarditis in TAVI Pts and to compare the results to surgical aortic valve (SV) owners and native aortic valve (NV) patients.

Methods

We included all patients hospitalized in our institution and presenting with endocarditis after TAVI between 2012 and 2018. We compared these patients to those discussed within the “endocarditis team” and presenting with endocarditis located on SV or on NV.

Results

A total of 34 TAVI Pts were included and compared to a population of 45 SV and 68 NV Pts. TAVI Pts were older (83.1±1.1 yrs, vs 73.3±1.7 and 66.0±1.7, respectively; p<0.001) and had a higher Charlson score (6.2±0.4, vs 5.6±0.4 and 4.1±0.3; p<0.001). TAVI Pts underwent more frequently invasive procedures during the 6 months prior to the diagnosis of endocarditis (38.2%, vs 11.4 and 8.8%; p<0.001). They had less incidence of a new valvular murmur (0%, vs 28.9 and 33.8%; p=0.001) and less heart failure symptoms (26.5%, vs 28.9 and 33.8%; p=0.007). Clinical complications were similar between the 3 groups and mortality was high and comparable at 1 year (29.2%, vs 36.4 and 29.7% p=0.730). However, TAVI Pts were more frequently re-hospitalized (41.2% vs 26.7% and 16.2%, p=0.02) and were treated less invasively (surgery or pacemaker extraction in 14.7% vs 35.6% and 42.6%, p=0.019). Only one TAVI Pt needed surgical aortic valve replacement.

Conclusion

Despite more frequent comorbidities, TAVI patients affected by infective endocarditis have the same mortality during the first year after diagnosis compared to SV and NV patients but are more often rehospitalized.

P907Respective pronostic value of the valvular aortic calcifications and the thoracic aorta calcifications in patients with and without low gradient aortic stenosis after TAVI

Background

Both the valvular aortic calcifications (VAC) and the thoracic aorta calcifications (TAC) have a prognostic impact in patients with aortic stenosis. Their respective prognostic values in patients with and without low gradient aortic stenosis (LGAS) remain unknown after TAVI.

Objectives

To assess the prognostic significance of VAC and TAC in patients with and without LGAS regarding cardiovascular mortality after 3 years follow-up.

Methods

The CAPRI-LGAS is an ancillary study of the C4CAPRI trial (NCT02935491) including 1282 consecutive TAVI patients. Calcifications were measured on pre-TAVI CT. The primary outcome was defined as cardiovascular mortality 3 years after TAVI.

Results

Among the 1282 patients, 397 (31%) had a LGAS. Compared to the other patients, LGAS patients were more prone to be men, younger, with atrial fibrillation, and lower left ventricular ejection fraction (LVEF), p<0.05 for all. No statistically significant difference was noticed for pulmonary systolic pressures, history of diabetes, chronic respiratory disease, renal insufficiency or peripheral vascular disease. VAC was lower in LGAS compared to non-LGAS patients (1.05 cm3±0.7 vs 0.75 cm3±0.5), p<0.001, the contrary was noticed for TAC, (3.1 cm3±3 vs 3.7 cm3±3.7), p=0.011. After 3 years follow-up, 227 (17.7%) patients died from cardiovascular causes; respectively 85 (21.4%) and 142 (16.1%) patients with and without LGAS, p=0.02. In univariate analysis, in LGAS patients each increase of 1cm3 TAC was associated with cardiovascular mortality while VAC was not, respectively Hazard Ratio (HR) 1.07 and confidence interval (CI) (1.023–1.119) p=0.003, and HR 0.822 CI (0.523–1.292), p=0.39. In patients without LGAS both TAC and VAC were associated with mortality, respectively HR 1.054 CI (1.006–1.104), p=0.028 and HR 1.363 CI (1.092–1.701), p=0.006. Multivariate analysis was adjusted for TAC, VAC, age, gender, atrial fibrillation, and LVEF. In LGAS patients TAC but not VAC was still a predictor of cardiovascular mortality, respectively HR 1.092 CI (1.031–1.158), p=0.003, and HR 0.743 CI (0.464–1.191), p=0.21. In patients without LGAS TAC was no more associated with cardiovascular mortality while VAC was, respectively HR 1.306 CI (1.024–1.666), p=0.031, and HR 1.038 CI (0.985–1.094), p=0.161. When further adjusting on pulmonary systolic pressures, history of diabetes, chronic respiratory disease, renal insufficiency and peripheral vascular disease, the results remained similar ie in LGAS patients, TAC HR 1.090 CI (1.022–1.162), p=0.009 while in patients without LGAS VAC HR 1.377 CI (1.049–1.809), p=0.021.

Conclusions

The present study shows that VAC and TAC involve different prognostic information in patients with and without LGAS after TAVI. While VAC may be a marker of early and periprocedural mortality and aortic regurgitation in non-LGAS patients, TAC may continue to be harmful and increase afterload in patients with LGAS whom LVEF is often impaired.

4069From first in man transcatheter aortic valve implantation, a 15-year experience

Background

Since the first-in-man transcatheter aortic valve implantation (TAVI) performed in 2002, the number of procedures has dramatically increased. However, long-term data regarding outcome and valve durability remain poor.

Purpose

We aimed to evaluate the evolution of 30-day outcomes over years and long-term mortality and valve durability after TAVI.

Methods

All consecutive patients presenting with severe symptomatic aortic stenosis treated by TAVI in our center were included prospectively. Clinical and echocardiographic follow-up was performed at 30 days and annually thereafter. Survival curves were constructed using Kaplan-Meier analysis. We also evaluated valve durability according to the European standardized definition of structural valve deterioration.

Results

Between 2002 and 2018, 1530 consecutive patients underwent TAVI including 1285 (84.0%) patients via a femoral approach. A balloon-expandable transcatheter heart valve was predominantly used (1421 patients; 92.9%). The annual transfemoral approach rate increased progressively to reach 93.3%. Age of patients remained stable over time with a global mean age of 83.7±6.5 years old. Logistic EuroSCORE decreased from 49.2±8.2% to 14.3±8.6% (p<0.0001). Thirty-day mortality dramatically decreased below 3% since 2015 and was 0% in 2018. Similarly, major vascular complications decreased from 50.0% in the first year to less than 1% since 2017 (p=0.001). The length of hospital-stay progressively shortened up to a median of 2 days in 2018. The Kaplan-Meier survival estimation was 82.3%, 60.3%, 33.0%; 11.7% and 8.9% respectively at 1, 3, 5, 8 and 10 years. On long-term follow-up the mean aortic gradient remained unchanged (Figure), and only five patients presented a severe prosthetic valve deterioration. Among them, four patients successfully benefited from a valve in valve TAVI procedure. The competing risk analysis at 10 years estimates risk for severe and moderate-or-severe valve deterioration of 1.9±0.9% and 4.3±1.3% respectively.

TEE mean transaortic gradient

Conclusions

Long-term (up to 10 years) follow-up of our large pioneer series of patients treated by TAVI shows a dramatic improvement of outcomes and no warning signs of valve deterioration suggesting very encouraging valve durability, using predominantly, a balloon expandable prosthesis. Further studies are warranted to study valve durability after TAVI before extension to lower risk patients.

Comparative Study Between Functional MR Urography and Renal Scintigraphy to Evaluate Drainage Curves and Split Renal Function in Children With Congenital Anomalies of Kidney and Urinary Tract (CAKUT)

Background: Obstructive congenital anomalies of the kidney and urinary tract have a high risk of kidney failure if not surgically corrected. Dynamic renal scintigraphy is the gold standard technique to evaluate drainage curves and split renal function (SRF). Objectives: To compare functional magnetic resonance (MR) urography with dynamic renal scintigraphy in measuring volumetric SRF and in the classification of drainage curves in patients with congenital anomalies of the kidney and urinary tract. Materials and Methods: We retrospectively collected patients with hydroureteronephrosis or pelvicalyceal dilatation at renal ultrasound, who underwent both functional MR urography and dynamic renal scintigraphy (DRS) within 6 months. DRS studies were evaluated by a single nuclear medicine physician with a double reading. Functional MR urography renograms were blind evaluated twice by two radiologists. The functional MR urographyintra- and inter-reading agreements as well as the agreement between the two imaging techniques were calculated. SRF was evaluated by Area Under the Curve and Rutland-Patlak methods. Drainage curves were classified as normal, borderline or accumulation patterns by both the techniques. Results: Fifty-two children were studied, 14 with bilateral involvement. A total of 104 kidney-urinary tracts were considered: 38 normal and 66 dilated. Considering Area Under the Curve and Rutland-Patlak for SRF, the intra- and inter-reader agreements of functional MR urography had excellent and good results, respectively, and the two techniques demonstrated a good concordance (r2: 67% for Area Under the Curve and 72% for Rutland-Patlak). Considering drainage curves, the inter-readers agreement for functional MR urography and the concordance between the two techniques were moderate (Cohen's k, respectively, 55.7 and 56.3%). Conclusions: According to our results, there are no significant differences between functional MR urography and DRS in measuring volumetric SRF and in the classification of drainage curves in patients with congenital anomalies of the kidney and urinary tract.