Verification Study of in Silico Computed Intracardiac Blood Flow With 4D Flow MRI

OBJECTIVE

Major challenges for clinical applications of in silico medicine are limitations in time and computational resources. Computational approaches should therefore be tailored to specific applications with relatively low complexity and must be verified and validated against clinical gold standards.

METHODS

This study performed computational fluid dynamics simulations of left ventricular hemodynamics of different complexity based on shape reconstruction from steady state gradient echo magnetic resonance imaging (MRI) data. Computed flow results of a rigid wall model (RWM) and a prescribed motion fluid-structure interaction (PM-FSI) model were compared against phase-contrast MRI measurements for three healthy subjects.

RESULTS

Extracted boundary conditions from the steady state MRI sequences as well as computed metrics, such as flow rate, valve velocities, and kinetic energy show good agreement with in vivo flow measurements. Regional flow analysis reveals larger differences.

CONCLUSION

Basic flow structures are well captured with RWM and PM-FSI. For the computation of further biomarkers like washout or flow efficiency, usage of PM-FSI is required. Regarding boundary-near flow, more accurate anatomical models are inevitable.

SIGNIFICANCE

These results delineate areas of application of both methods and lay a foundation for larger validation studies and sensitivity analysis for healthy and diseased cases, being an essential step upon clinical translations.

Phase III assessment of topotecan and cyclophosphamide and high-dose ifosfamide in rEECur: An international randomized controlled trial of chemotherapy for the treatment of recurrent and primary refractory Ewing sarcoma (RR-ES)

LBA2

Background: 5-year survival of RR-ES is about 15%. rEECur, the first randomized controlled trial in this setting, is defining standard care, balancing efficacy and toxicity. Methods: Patients aged 4-50 with RR-ES were randomly assigned to topotecan and cyclophosphamide (TC), irinotecan and temolozomide (IT), gemcitabine and docetaxel (GD), or high-dose ifosfamide (IFOS). Primary outcome was event-free survival (EFS) for the phase III comparison. Secondary outcomes included overall survival (OS), toxicity, and quality of life (QoL). A probability-based Bayesian approach was used with multiple pairwise comparisons. At the first and second interim assessments, patients allocated to GD and IT, respectively, had worse objective response (OR) and EFS than the other arms, halting recruitment to both. The final intent-to-treat assessment of the original four arms was a phase III evaluation of TC and IFOS. Results: 451 patients recruited between 18/12/14 and 31/08/21, were randomly assigned to TC (163 patients), IT (127 patients), GD (72 patients), and IFOS (83 patients). Median age was 19 years (range 4-49). Patients had: refractory disease (18%), first recurrence (66%), > first recurrence (17%). Initial disease site was bone in 70%. Sites of progression were: primary site only (15%), pleuropulmonary metastases only (34%), and other metastatic (51%). Baseline renal function was similar in both. Median follow-up (reverse Kaplan-Meier method) was 40 months. For the phase III comparison between TC and IFOS (both, 73 patients), median EFS was 3.7 months (95% CI, 2.1-6.2) for TC and 5.7 months (95% CI, 3.8-7.0) for IFOS. Median OS was 10.4 months (95% CI, 7.5-15.5) for TC and 16.8 months (95% CI, 11.1-25.8) for IFOS. Given the observed data, the posterior probability that EFS and OS were better after IFOS than after TC (ie Pr [true hazard ratio < 1 | data]) was 95% for both. A greater survival difference was observed for patients aged under 14 than those aged ≥ 14 for EFS and OS. Subgroup analyses favored IFOS for all minimization factors. The main grade 3/4 adverse events (% patients with an event) for TC (left-hand values) compared with IFOS were: febrile neutropenia (26% vs. 25%), infections (8% vs. 14%), vomiting (1% vs. 1%), nausea (0% vs. 3%), diarrhea (1% vs. 1%), encephalopathy (0% vs. 7%), and renal toxicity (0% vs. 8%). Descriptive statistics of quality of life scores appeared to favor the IFOS arm over the TC arm in children but not in adults. Conclusions: The first randomized trial in RR-ES has shown that high-dose ifosfamide is more effective in prolonging survival than TC, having previously beaten GD and IT, and should be considered as a control arm in future randomized phase II/III studies in RR-ES if combination with IFOS is logical. rEECur is the first study to provide comparative toxicity and survival data for the four most commonly used chemotherapy regimens in RR-ES. Clinical trial information: ISRCTN36453794.

Value of adjuvant radiotherapy in patients with localized Ewing sarcoma at the extremities: Report from the Ewing 2008 trial

11531

Background: In patients with Ewing Sarcoma (EWS), adjuvant radiotherapy is often performed after surgery that could not obtain wide margins or after poor histological response to surgery. However, the benefit of adjuvant radiotherapy needs further investigation. Therefore, we compared event-free survival (EFS) between surgery (SX) alone and SX combined with radiation therapy (RT), performed a subgroup analysis and identified independent prognostic factors. Methods: The data from localized EWS patients with tumors at the extremities that were treated in the Ewing 2008 trial from 2009-2018 were included in this analysis. Patients received induction chemotherapy according to the protocol and then underwent local therapy. Patients receiving SX or adjuvant RT (combined SX/RT) were included in this analysis. Hazard ratios (HRs) (95% Confidence Intervals (CIs)) were calculated using Cox regression. Results: 360 out of 863 patients (41.7%) presented with an EWS at the extremities with 81 tumors at the upper extremity, and 279 tumors at the lower extremity. Most patients were treated with surgery only (223, 61.94%), while 125 patients (34.72%) were treated with SX plus RT. Adjuvant radiotherapy was conducted after a median time of 69 days (1st quartile, 3rd quartile; 54, 109). Median EFS at 5-years for all patients was 0.74 (0.69, 0.80), 0.76 (0.70, 0.83) for patients after surgery only, and 0.73 (0.64, 0.83) after combined RT/SX. After adjusting for sex, age, tumor volume, histological response and surgical margins, the HR for combined RT/SX vs SX alone was 0.69 (0.37, 1.26), p = 0.22. In patients with poor histological response to surgery (≥10% vital tumor cells) and with high tumor volume (≥ 200mL), additional radiotherapy did not decrease the hazards of any event, HR 0.72 (0.25, 2.06), p = 0.54. We identified high tumor volume, poor histological response to surgery as well as intralesional resection of the tumor as independent prognostic factors after adjusting for other known prognostic factors with HRs of 1.73 (1.04, 2.90), p = 0.03; 2.79 (1.69, 4.62), p < 0.0001 and 215.9 (13.17, 3538.61), p = 0.0002, respectively. Surgical complication was not a prognostic factor after adjusting for above mentioned variables, HR 0.85 (0.31, 2.34), p = 0.75. Conclusions: In our cohort, adjuvant radiotherapy was not superior compared to surgery alone in all patients with localized EWS at the extremities and neither in a subgroup of patients with high-risk factors. Poor histological response, intralesional tumor resection as well as high tumor volume were identified as independent negative prognostic factors. Clinical trial information: NCT00987636.

Association of treatment delays with an unfavorable outcome in patients with localized Ewing sarcoma: A retrospective analysis of data from the GPOH Euro-E.W.I.N.G.99 trial

11502

Background: Outcome in EwS has improved by the implementation of dose or time intense systemic treatment. Aim of the study was evaluate whether treatment delays have impact on outcome of patients with localized Ewing sarcoma (EWS). Methods: Data from 692 patients with a tumor of the extremities, the pelvis, the chest wall and the trunk registered in the international database of the German Society for Pediatric Oncology and Hematology (GPOH) and treated in the Euro-E.W.I.N.G. 99 trial (NCT00020566) were analyzed. All patients underwent surgical treatment after induction chemotherapy. The optimal interval cut-off values for survival analyses were calculated with receiver operating characteristics curves. Hazard ratios (HR) were estimated with respective 95% confidence intervals (CI) in multivariate Cox regression models. Results: As per protocol, patients were to receive six cycles of VIDE induction chemotherapy in 21-day intervals. The duration between induction cycles as per protocol was fulfilled in only 5% of patients. In 72% of patients, the average interval duration between induction chemotherapy cycles was 25 days. Median interval between day 1 of the first induction chemotherapy cycle and definitive tumor surgery was 141 (IQR, 133 – 153) days in patients receiving six VIDE cycles prior to surgery. The optimal cut-off value for survival analyses in these patients amounted to 150 days. Patients with a duration of induction chemotherapy > 150 days were at higher risk to develop an event (HR, 1.546; 95% CI, 1.103 – 2.166) and had a higher risk of death (HR, 1.574; 95% CI, 1.095 – 2.262), compared to patients with a duration of induction chemotherapy < 150 days. Patients with delays during the induction chemotherapy also experienced a significant delay between VIDE 6 and surgery (36 vs. 27 days, p < 0.001) and were treated significantly more often at smaller low-volume centers (63% vs. 48%, p = 0.005). Patients with a prolonged interval > 21 days between surgery and day one of postoperative chemotherapy were at a higher risk to develop an event (HR, 1.406; 95% CI, 1.011 – 1.955), and also had a significantly higher rate of postoperative complications (26% vs. 11%, p < 0.001), compared to patients with a shorter interval. Conclusions: Delays between induction chemotherapy and surgery and between surgery and consolidation chemotherapy are independently associated with a poor outcome in patients with localized EWS. Our results also underscore the need to treat EWS patients in larger and experienced sarcoma centers. The implementation of new and standardized methods in the operative strategy and optimized supportive care during systemic therapy are required to reduce perioperative morbidity and treatment delays.

Synthetic Database of Aortic Morphometry and Hemodynamics: Overcoming Medical Imaging Data Availability

Modeling of hemodynamics and artificial intelligence have great potential to support clinical diagnosis and decision making. While hemodynamics modeling is extremely time- and resource-consuming, machine learning (ML) typically requires large training data that are often unavailable. The aim of this study was to develop and evaluate a novel methodology generating a large database of synthetic cases with characteristics similar to clinical cohorts of patients with coarctation of the aorta (CoA), a congenital heart disease associated with abnormal hemodynamics. Synthetic data allows use of ML approaches to investigate aortic morphometric pathology and its influence on hemodynamics. Magnetic resonance imaging data (154 patients as well as of healthy subjects) of aortic shape and flow were used to statistically characterize the clinical cohort. The methodology generating the synthetic cohort combined statistical shape modeling of aortic morphometry and aorta inlet flow fields and numerical flow simulations. Hierarchical clustering and non-linear regression analysis were successfully used to investigate the relationship between morphometry and hemodynamics and to demonstrate credibility of the synthetic cohort by comparison with a clinical cohort. A database of 2652 synthetic cases with realistic shape and hemodynamic properties was generated. Three shape clusters and respective differences in hemodynamics were identified. The novel model predicts the CoA pressure gradient with a root mean square error of 4.6 mmHg. In conclusion, synthetic data for anatomy and hemodynamics is a suitable means to address the lack of large datasets and provide a powerful basis for ML to gain new insights into cardiovascular diseases.

Circulatory efficiency in patients with severe aortic valve stenosis before and after aortic valve replacement

BACKGROUND

Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quantify left ventricular (LV) efficiency in patients with severe AS before and after surgical AVR.

METHODS

Circulatory efficiency was computed from cardiovascular magnetic resonance (CMR) imaging derived volumetric data, echocardiographic and clinical data in patients with severe AS (n = 41) before and 4 months after AVR and in age and sex-matched healthy subjects (n = 10).

RESULTS

In patients with AS circulatory efficiency was significantly decreased compared to healthy subjects (9 ± 3% vs 12 ± 2%; p = 0.004). There were significant negative correlations between circulatory efficiency and LV myocardial mass (r = - 0.591, p < 0.001), myocardial fibrosis volume (r = - 0.427, p = 0.015), end systolic volume (r = - 0.609, p < 0.001) and NT-proBNP (r = - 0.444, p = 0.009) and significant positive correlation between circulatory efficiency and LV ejection fraction (r = 0.704, p < 0.001). After AVR, circulatory efficiency increased significantly in the total cohort (9 ± 3 vs 13 ± 5%; p < 0.001). However, in 10/41 (24%) patients, circulatory efficiency remained below 10% after AVR and, thus, did not restore to normal values. These patients also showed less reduction in myocardial fibrosis volume compared to patients with restored circulatory efficiency after AVR.

CONCLUSION

In our cohort, circulatory efficiency is reduced in patients with severe AS. In 76% of cases, AVR leads to normalization of circulatory efficiency. However, in 24% of patients, circulatory efficiency remained below normal values even after successful AVR. In these patients also less regression of myocardial fibrosis volume was seen. Trial Registration clinicaltrials.gov NCT03172338, June 1, 2017, retrospectively registered.

Towards improving the accuracy of aortic transvalvular pressure gradients: rethinking Bernoulli

The transvalvular pressure gradient (TPG) is commonly estimated using the Bernoulli equation. However, the method is known to be inaccurate. Therefore, an adjusted Bernoulli model for accurate TPG assessment was developed and evaluated. Numerical simulations were used to calculate TPG_CFD in patient-specific geometries of aortic stenosis as ground truth. Geometries, aortic valve areas (AVA), and flow rates were derived from computed tomography scans. Simulations were divided in a training data set (135 cases) and a test data set (36 cases). The training data was used to fit an adjusted Bernoulli model as a function of AVA and flow rate. The model-predicted TPG_Model was evaluated using the test data set and also compared against the common Bernoulli equation (TPG_B). TPG_B and TPG_Model both correlated well with TPG_CFD (r > 0.94), but significantly overestimated it. The average difference between TPG_Model and TPG_CFD was much lower: 3.3 mmHg vs. 17.3 mmHg between TPG_B and TPG_CFD. Also, the standard error of estimate was lower for the adjusted model: SEE_Model = 5.3 mmHg vs. SEE_B = 22.3 mmHg. The adjusted model's performance was more accurate than that of the conventional Bernoulli equation. The model might help to improve non-invasive assessment of TPG. Graphical abstract Processing pipeline for the definition of an adjusted Bernoulli model for the assessment of transvalvular pressure gradient. Using CT image data, the patient specific geometry of the stenosed AVs were reconstructed. Using this segmentation, the AVA as well as the volume flow rate was calculated and used for model definition. This novel model was compared against classical approaches on a test data set, which was not used for the model definition.

Results of the second interim assessment of rEECur, an international randomized controlled trial of chemotherapy for the treatment of recurrent and primary refractory Ewing sarcoma (RR-ES)

11502

Background: Five-year survival of RR-ES is about 15%. Several chemotherapy regimens are used, but without robust evidence. rEECur, the first randomised controlled trial in this setting, is defining a standard of care, balancing efficacy and toxicity. Methods: Patients aged 4 to 50 with RR-ES and fit to receive chemotherapy were randomised between topotecan & cyclophosphamide (TC), irinotecan & temolozomide (IT), gemcitabine & docetaxel (GD) or high-dose ifosfamide (IFOS). Primary outcome measure was objective response (OR) after 4 cycles by RECIST 1.1. Secondary outcomes included PFS, OS and toxicity. A probability-based Bayesian approach was used with multiple pairwise comparisons. At the first interim analysis patients allocated to GD had worse OR and PFS than the other arms and accrual to the GD arm was halted. The second interim assessment was planned to determine which arm should be closed when at least 75 evaluable patients had been recruited to the remaining arms and evaluated for the primary outcome measure. Results: 366 patients (87% RECIST-evaluable), recruited between 18/12/14 and 17/12/19, were randomised to TC (n=124), IT (118), GD (72) and IFOS (53). Median age was 20 years (range 4-49). Patients had: refractory disease (19%), first recurrence (66%), > first recurrence (14%). Initial disease site was bone in (66%). Sites of progression were: primary site only (16%) pleuropulmonary only (32%), other metastatic (52%). At median follow up of 9.2 months, outcome in the IT arm was: response rate 20%, median PFS 4.7 months (95% CI: 3.4 to 5.7), median OS 13.9 months (95% CI: 10.6 to 18.1). The table shows, for each pairwise comparison of IT with the other open arms (randomly labelled A and B to maintain blinding), the probabilities that OR, PFS and OS were better for X than for each other arm (RR = risk ratio, HR = hazard ratio). For OR, PFS and OS, all comparisons favoured arms A and B. The main grade 3/4 adverse events (% patients with an event) for IT (left hand values) compared with A and B pooled were: vomiting (6% v 1%), nausea (6% v 0%), diarrhoea (17% v 0%), fatigue (3% v 1%) and febrile neutropenia (3% v 24%). Conclusions: The first randomised trial in RR-ES has shown that IT, used as a control arm in planned and ongoing randomised phase II studies in RR-ES, is less effective than A and B in achieving tumour shrinkage or prolonging PFS and OS. The remaining two arms are continuing to recruit patients. Clinical trial information: ISRCTN36453794 . [Table: see text]

Correlation of response with progression-free (PFS) and overall (OS) survival in relapsed/refractory Ewing sarcoma (RR-ES): Results from the rEECur trial

11524

Background: Survival for RR-ES at 5 years remains < 15%, so novel treatments are needed. Almost all Phase II trials for RR-ES use response as the primary outcome measure. It is unclear whether response is a valid surrogate for survival outcomes. Methods: Patients (pts) were eligible if they had RR-ES and were evaluable for imaging response (primary outcome) if they had measurable disease by RECIST 1.1. The randomization was initially between four chemotherapy regimens: topotecan-cyclophosphamide, irinotecan-temozolomide, gemcitabine-docetaxel (GD), high-dose ifosfamide. Response was assessed after 2, 4 (primary) and 6 cycles of therapy and was classified as complete response (CR), partial response (PR), stable disease (SD), progressive disease (PD). PFS and OS were secondary outcomes. Survival from each assessment point by response status was analyzed, by Cox models, with hazard ratios (HR) given for PR v. SD and CR+PR v. SD. Results: From 2015-19, 241 pts with response data were entered. The relationship between response status and PFS and OS is shown in the table (HR < 1.0 indicates better outcome for PR or CR+PR than SD). Both PFS and OS were similar for pts with PR or CR+PR compared to those with SD. OS was inferior for patients with PD (all p < 0.01) (PFS is by definition zero for patients with PD at that timepoint). Small numbers mean CR results are not reliable. Results were consistent across all treatments and between refractory and relapsed disease. At the first interim assessment the GD arm was dropped, with risk ratios for response compared to the other three arms (blinded as still open) of 0.3, 0.5 and 0.5. If a new outcome – disease control (CR+PR+SD) – is defined, the risk ratios are 0.7, 0.8 and 0.7; i.e. still inferior for GD, but less so. Conclusions: Response does not correlate with survival outcomes in RR-ES, so considering PR, or even CR, a success and SD a failure when evaluating treatments may be misleading. We propose PFS as a better primary outcome for future trials and it will be introduced as such in the rEECur trial. Clinical trial information: ISRCTN36453794 . [Table: see text]

Efficacy of maintenance therapy with zoledronic acid in patients with localized Ewing sarcoma: Report from the international Ewing 2008 trial

11523

Background: Ewing 2008R1 (EudraCT2008-003658-13, Sponsor UKM) was conducted in 12 countries. It evaluated the effect of zolendronic acid (ZOL) maintenance therapy on event-free (EFS, primary endpoint) and overall survival (OS) from randomization in standard risk Ewing Sarcoma (EwS). Methods: Phase III, open label, prospective, multi-center, randomized controlled clinical trial. Eligible patients (pts) had localized EwS with either good histological response to induction chemotherapy and/or small tumors ( < 200ml). Pts received 6 cycles VIDE induction and 8 VAI (male) or 8 VAC consolidation (female) and were randomized to receive either 9 cycles of maintenance ZOL or no further treatment (control;ctrl). ZOL cycles started parallel to the 6th consolidation cycle. Randomization was stratified by tumor site (pelvis/no pelvis). Two-sided adaptive inverse-normal 4-stage design, changed after the 1st interim analysis via Müller-Schäfer method. Initial sample size 448 pts, type I error rate 5%, power 80%. Results: 284 pts were randomized between 2009 and 2018 (142 ZOL / 142 ctrl). With a median follow-up of 3.9 years, the primary endpoint EFS was not significantly different between the ZOL and ctrl group in the adaptive design (HR 0.74, 95% CI 0.43-1.28, intention to treat). 3-year (3y) EFS rates were 84.0% (95% CI 77.7-90.8%) for ZOL vs 81.7% (95% CI 75.2-88.8%) for ctrl. Results were similar in the per protocol collective. Cause-specific HR for local recurrence in ZOL was csHR 0.30 (95% CI 0.08 -1.09; p = 0.07), for metastatic progress/new metastases csHR 1.0 (CI 0.5-2.2), for combined relapse/progress csHR 0.3 (95% CI 0.1-1.7), for second malignancies csHR 4.0 (95% CI 0.45-36.1) compared to ctrl. The 3y OS was 92.8% (95% CI 88.4-97.5%) for ZOL and 94.6% (95% CI 90.9-98.6%) for ctrl. For ZOL the 5y OS was 87.3% (95% CI 80.7-94.5%) and 89% (95% CI 83.7-95.9%) for ctrl. Noticeable more renal, neurological and gut toxicities were observed for ZOL (p < 0.05), with severe renal toxicities occurring more often in the ZOL arm (p = 0.003). Conclusions: In patients with standard risk localized Ewing Sarcoma there is no benefit from maintenance treatment with zoledronic acid, but significant side effects were observed. Clinical trial information: NCT00987636 .

Efficacy of add-on treosulfan and melphalan high-dose therapy in patients with high-risk metastatic Ewing sarcoma: Report from the International Ewing 2008R3 trial

11501

Background: Ewing 2008R3 (EudraCT2008-003658-13) was conducted in 12 countries. It evaluated the effect of treosulfan and melphalan high dose chemotherapy followed by re-infusion of autologous hematopoietic stem cells (HDTreoMel) on event-free (EFS, primary endpoint) and overall survival (OS) in high-risk Ewing Sarcoma (EwS). Methods: Phase III, open label, prospective, multi-center, randomized controlled clinical trial. Eligible patients (pts) had disseminated EwS with metastases to bone and/or other sites, excluding pts with only pleuropulmonary metastases. Pts received 6 cycles of VIDE induction and 8 cycles of VAC consolidation therapy. Patients were randomized to receive additional HDTreoMel chemotherapy or no further treatment (control), They were further stratified by number of bone metastases (1, 2-5, > 5). One-sided adaptive inverse-normal 4-stage design, changed after the 1st interim analysis via Müller-Schäfer method. Initial sample size 185 pts, type I error rate 2.5%, power 80%. Results: 109 pts were randomized between 2009 and 2018: 55 were randomized to HDTreoMel. With a median follow-up of 3.3 years, the primary endpoint EFS was not significantly different between HDTreoMel and control in the adaptive design (HR 0.85, 95% CI 0.55-1.32, intention-to-treat). 3-year (3y) EFS was 20.9 % (95% CI 11.5-37.9%) in HDTreoMel and 19.2 % (95% CI 10.8-34.4%) in control pts. Results were similar in the per protocol collective. Subgroup analyses showed that independent of treatment, male patients had a worse outcome than female patients: 3y EFS 13.3% (95% CI 5.7-31.1%) vs 25.2% (95% CI 15.5-40.8%); p = 0.07. Patients aged < 14 had a better outcome when treated in the HDTreoMel group: 3y EFS 39.3% (95% CI 20.4-75.8%) vs 9% (95% CI 2.4-34%); p = 0.016; HR 0.40 (0.19-0.87). These effects were similar in the per protocol collective. Severe toxicities of hematology, gut, general condition and infection were more pronounced in the HDTreoMel group (p < 0.05). Conclusions: In patients with very high risk EwS, additional HDTreoMel was of no benefit for the entire cohort of patients. HDTreoMel may be of benefit for children age < 14. This observation is supported by comparable results from a non-randomized trial EE99 R3 (Ladenstein et al. JCO, 2010). Clinical trial information: NCT00987636 .

High-Dose Chemotherapy Compared With Standard Chemotherapy and Lung Radiation in Ewing Sarcoma With Pulmonary Metastases: Results of the European Ewing Tumour Working Initiative of National Groups, 99 Trial and EWING 2008

PURPOSE

The R2Pulm trial was conducted to evaluate the effect of busulfan-melphalan high-dose chemotherapy with autologous stem-cell rescue (BuMel) without whole-lung irradiation (WLI) on event-free survival (main end point) and overall survival, compared with standard chemotherapy with WLI in Ewing sarcoma (ES) presenting with pulmonary and/or pleural metastases.

METHODS

From 2000 to 2015, we enrolled patients younger than 50 years of age with newly diagnosed ES and with only pulmonary or pleural metastases. Patients received chemotherapy with six courses of vincristine, ifosfamide, doxorubicin, and etoposide (VIDE) and one course of vincristine, dactinomycin, and ifosfamide (VAI) before either BuMel or seven courses of VAI and WLI (VAI plus WLI) by randomized assignment. The analysis was conducted as intention to treat. The estimates of the hazard ratio (HR), 95% CI, and P value were corrected for the three previous interim analyses by the inverse normal method.

RESULTS

Of 543 potentially eligible patients, 287 were randomly assigned to VAI plus WLI (n = 143) or BuMel (n = 144). Selected patients requiring radiotherapy to an axial primary site were excluded from randomization to avoid excess organ toxicity from interaction between radiotherapy and busulfan. Median follow-up was 8.1 years. We did not observe any significant difference in survival outcomes between treatment groups. Event-free survival was 50.6% versus 56.6% at 3 years and 43.1% versus 52.9% at 8 years, for VAI plus WLI and BuMel patients, respectively, resulting in an HR of 0.79 (95% CI, 0.56 to 1.10; P = .16). For overall survival, the HR was 1.00 (95% CI, 0.70 to 1.44; P = .99). Four patients died as a result of BuMel-related toxicity, and none died after VAI plus WLI. Significantly more patients in the BuMel arm experienced severe acute toxicities than in the VAI plus WLI arm.

CONCLUSION

In ES with pulmonary or pleural metastases, there is no clear benefit from BuMel compared with conventional VAI plus WLI.

The relation of radiological tumor volume response to histological response and outcome in patients with localized Ewing Sarcoma

Background

Magnetic resonance imaging (MRI) is the modality of choice for local staging and response evaluation of Ewing sarcoma (EwS). Aim of this study was to determine the relevance of tumor volume response (TVR) in relation to histological response (HisRes) and survival, in order to evaluate if early modification of chemotherapy might be indicated in patients with inadequate TVR.

Methods

Three dimensional (3D)‐tumor volume data at diagnosis, during early induction phase (1‐3 courses of chemotherapy; n = 195) and/or late induction phase (4‐6 courses; n = 175) from 241 localized patients were retrospectively analyzed. A distinction was made between adequate response (reduction ≥67%) and inadequate response (reduction <67% or progression). Correlations between TVR, HisRes, event free survival (EFS), and overall survival (OS) were analyzed using chi‐square tests, log‐rank tests, and the Cox‐regression model.

Results

Early adequate TVR, noted in 41% of patients, did not correlate with EFS (P = 0.92) or OS (P = 0.38). During late induction phase 62% of patients showed an adequate TVR. EFS for patients with late adequate TVR was better (78%) than for those with inadequate late TVR (61%) (P = 0.01); OS was 80% and 69% (P = 0.26), respectively. No correlation was found between TVR and HisRes. Multivariate analysis showed that poor HisRes, pelvic location and late inadequate TVR were associated with poor outcome.

Conclusions

Early inadequate TVR does not predict adverse outcome; therefore, changing the treatment to second line chemotherapy is not indicated in case of inadequate early TVR. Late adequate TVR and good HisRes correlate with better EFS; patients with late inadequate TVR might benefit from augmented therapy.

Image-Based Personalization of Cardiac Anatomy for Coupled Electromechanical Modeling

Computational models of cardiac electromechanics (EM) are increasingly being applied to clinical problems, with patient-specific models being generated from high fidelity imaging and used to simulate patient physiology, pathophysiology and response to treatment. Current structured meshes are limited in their ability to fully represent the detailed anatomical data available from clinical images and capture complex and varied anatomy with limited geometric accuracy. In this paper, we review the state of the art in image-based personalization of cardiac anatomy for biophysically detailed, strongly coupled EM modeling, and present our own tools for the automatic building of anatomically and structurally accurate patient-specific models. Our method relies on using high resolution unstructured meshes for discretizing both physics, electrophysiology and mechanics, in combination with efficient, strongly scalable solvers necessary to deal with the computational load imposed by the large number of degrees of freedom of these meshes. These tools permit automated anatomical model generation and strongly coupled EM simulations at an unprecedented level of anatomical and biophysical detail.

Image-Based Personalization of Cardiac Anatomy for Coupled Electromechanical Modeling

Computational models of cardiac electromechanics (EM) are increasingly being applied to clinical problems, with patient-specific models being generated from high fidelity imaging and used to simulate patient physiology, pathophysiology and response to treatment. Current structured meshes are limited in their ability to fully represent the detailed anatomical data available from clinical images and capture complex and varied anatomy with limited geometric accuracy. In this paper, we review the state of the art in image-based personalization of cardiac anatomy for biophysically detailed, strongly coupled EM modeling, and present our own tools for the automatic building of anatomically and structurally accurate patient-specific models. Our method relies on using high resolution unstructured meshes for discretizing both physics, electrophysiology and mechanics, in combination with efficient, strongly scalable solvers necessary to deal with the computational load imposed by the large number of degrees of freedom of these meshes. These tools permit automated anatomical model generation and strongly coupled EM simulations at an unprecedented level of anatomical and biophysical detail.

Optimized chemical proteomics assay for kinase inhibitor profiling

Solid supported probes have proven to be an efficient tool for chemical proteomics. The kinobeads technology features kinase inhibitors covalently attached to Sepharose for affinity enrichment of kinomes from cell or tissue lysates. This technology, combined with quantitative mass spectrometry, is of particular interest for the profiling of kinase inhibitors. It often leads to the identification of new targets for medicinal chemistry campaigns where it allows a two-in-one binding and selectivity assay. The assay can also uncover resistance mechanisms and molecular sources of toxicity. Here we report on the optimization of the kinobead assay resulting in the combination of five chemical probes and four cell lines to cover half the human kinome in a single assay (∼ 260 kinases). We show the utility and large-scale applicability of the new version of kinobeads by reprofiling the small molecule kinase inhibitors Alvocidib, Crizotinib, Dasatinib, Fasudil, Hydroxyfasudil, Nilotinib, Ibrutinib, Imatinib, and Sunitinib.

EURAMOS-1, an international randomised study for osteosarcoma: results from pre-randomisation treatment

BACKGROUND

Four international study groups undertook a large study in resectable osteosarcoma, which included two randomised controlled trials, to determine the effect on survival of changing post-operative chemotherapy based on histological response.

PATIENTS AND METHODS

Patients with resectable osteosarcoma aged ≤40 years were treated with the MAP regimen, comprising pre-operatively of two 5-week cycles of cisplatin 120 mg/m(2), doxorubicin 75 mg/m(2), methotrexate 12 g/m(2) × 2 (MAP) and post-operatively two further cycles of MAP and two cycles of just MA. Patients were randomised after surgery. Those with ≥10% viable tumour in the resected specimen received MAP or MAP with ifosfamide and etoposide. Those with <10% viable tumour were allocated to MAP or MAP followed by pegylated interferon. Longitudinal evaluation of quality of life was undertaken.

RESULTS

Recruitment was completed to the largest osteosarcoma study to date in 75 months. Commencing March 2005, 2260 patients were registered from 326 centres across 17 countries. About 1334 of 2260 registered patients (59%) were randomised. Pre-operative chemotherapy was completed according to protocol in 94%. Grade 3-4 neutropenia affected 83% of cycles and 59% were complicated by infection. There were three (0.13%) deaths related to pre-operative chemotherapy. At definitive surgery, 50% of patients had at least 90% necrosis in the resected specimen.

CONCLUSIONS

New models of collaboration are required to successfully conduct trials to improve outcomes of patients with rare cancers; EURAMOS-1 demonstrates achievability. Considerable regulatory, financial and operational challenges must be overcome to develop similar studies in the future. The trial is registered as NCT00134030 and ISRCTN 67613327.

Mortality and morbidity in different immunization protocols for experimental autoimmune myocarditis in rats

AIM

We aimed to investigate the histological and clinical presentations of experimental autoimmune myocarditis (EAM) induced by different immunization schemes.

METHODS

Male young Lewis rats were divided into five groups immunized by porcine myocardial myosin: subcutaneously (SC) 2 mg (in two 1-mg doses on day 0 and 7), 0 mg (sham group) subcutaneously into rear footpads (RF), 0.25 mg RF, 0.5 mg RF or 1 mg RF (all RF once on day 0). On day 21, left ventricular (LV) function was assessed by cardiac magnetic resonance imaging and cardiac catheterization. The type and degree of myocardial inflammatory infiltrates were determined by conventional histology and immunohistochemistry.

RESULTS

In the SC immunized rats and in the RF sham group, we observed 0% mortality, while in the actively RF immunized rats, mortality was 20, 20 and 44% for the 0.25 mg, 0.5 mg and 1 mg myosin doses respectively. Morbidity as defined by inflammatory infiltrates on haematoxylin and eosin (HE) staining was 22% in the SC immunized rats, 0% in the RF sham group and 100% in all actively RF immunized groups. We observed augmented relative ventricle weight and spleen weight, increased LV end-diastolic pressure, reduced LV developed pressure and reduced LV ejection fraction in all with myosin-immunized RF groups without any systematic dose effect.

CONCLUSION

Subcutaneous immunization to the neck and flanks did not induce a reproducible EAM, while RF myosin administration reliably led to EAM. Lower myosin doses seem to induce the complete histological and clinical picture of EAM while being associated with lower mortality, non-specific symptoms and animal distress.

Magnetic resonance imaging guided catheterisation for assessment of pulmonary vascular resistance: in vivo validation and clinical application in patients with pulmonary hypertension

OBJECTIVES

To validate in vivo a magnetic resonance imaging (MRI) method for measurement of pulmonary vascular resistance (PVR) and subsequently to apply this technique to patients with pulmonary hypertension (PHT).

METHODS AND RESULTS

PVR was assessed from velocity encoded cine MRI derived pulmonary artery (PA) flow volumes and simultaneously determined invasive PA pressures. For pressure measurements flow directed catheters were guided under magnetic resonance fluoroscopy at 1.5 T into the PA. In preliminary validation studies (eight swine) PVR was determined with the thermodilution technique and compared with PVR obtained by MRI (0.9 (0.5) v 1.1 (0.3) Wood units.m2, p = 0.7). Bland-Altman test showed agreement between both methods. Inter-examination variability was high for thermodilution (6.2 (2.2)%) but low for MRI measurements (2.1 (0.3)%). After validation, the MRI method was applied in 10 patients with PHT and five controls. In patients with PHT PVR was measured at baseline and during inhalation of nitric oxide. Compared with the control group, PVR was significantly increased in the PHT group (1.2 (0.8) v 13.1 (5.6) Wood units.m2, p < 0.001) but decreased significantly to 10.3 (4.6) Wood units.m2 during inhalation of nitric oxide (p < 0.05). Inter-examination variability of MRI derived PVR measurements was 2.6 (0.6)%. In all experiments (in vivo and clinical) flow directed catheters were guided successfully into the PA under MRI control.

CONCLUSIONS

Guidance of flow directed catheters into the PA is feasible under MRI control. PVR can be determined with high measurement precision with the proposed MRI technique, which is a promising tool to assess PVR in the clinical setting.

Sequential magnetic resonance monitoring of pulmonary flow with endovascular stents placed across the pulmonary valve in growing Swine

BACKGROUND

Patients with endovascular stent implantation for the treatment of right ventricular outflow tract obstruction are often left with incomplete relief of the obstruction and significant pulmonary regurgitation. A noninvasive and reproducible method for monitoring such patients is desirable. MRI in the presence of a stent, however, has to overcome the problem of potential metallic artifacts.

METHODS AND RESULTS

Under x-ray fluoroscopic guidance, endovascular nitinol stents were placed across the pulmonary valve in 6 young pigs to induce pulmonary regurgitation. Five additional pigs served as controls. Initial MRI was performed after 2 days (13.5+/-1.8 kg) and follow-up after 3 months (32+/-2.9 kg). Pulmonary flow volumes and regurgitant fraction were quantified by velocity-encoded cine (VEC) MRI through (VEC-TS) and distal to (VEC-DS) the stent. VEC-TS was compared with VEC-DS and volumetric measurements of left and right ventricular stroke volumes provided by cine MRI ("gold standard"). Antegrade and retrograde pulmonary flow volumes by VEC-TS were slightly but significantly less than those with VEC-DS and cine MRI. Excellent correlations (r>0.97) for phasic pulmonary flow volumes as measured by VEC-TS and VEC-DS were shown. Pulmonary regurgitant fraction increased from 32.8+/-15% to 49.6+/-17% (P<0.05) over the course of 3 months with VEC-TS.

CONCLUSIONS

MRI demonstrates the progression of pulmonary regurgitation in growing swine. VEC MRI has the ability to quantify pulmonary blood flow inside the lumen of nitinol stents. MRI appears to be ideally suited for monitoring patients with endovascular nitinol stents in the pulmonary artery or pulmonary valve position.