Association of mandibular canine impaction and anatomical factors: A multicentre retrospective panoramic study in Latin America

INTRODUCTION

Mandibular canine impaction is infrequent in dental eruption anomalies and treatment is very challenging. The aim of this multicenter retrospective panoramic study in Latin America was to evaluate panoramic radiographic imaging characteristics of mandibular canine impaction (impaction area, mandibular base contact, transmigration, impaction height and sex) and their associations.

MATERIAL AND METHODS

This cross-sectional study evaluated 212 digital panoramic radiographs from three radiological centres in Tingo Maria (Peru), Bogota and Tunja (Colombia). The study included children of both sexes with impacted mandibular canines. Mandibular alpha angle, contact with mandibular basal bone (MBB), impacted sector according to 10 sectors with an adaptation of the Ericson and Kurol method, presence of transmigration and the impacted height were measured and the relationship among these measures was analyzed. Fisher's exact test, Chi-square and binary logistic regression were used. (P<0.05).

RESULTS

The mandibular canine impaction showed contact with the MBB (32.08%), dental transmigration (36.79%), mainly located at an apical (40.09%) and sub-apical (36.79%) level. Transmigration mainly occurred in sectors 6 (33.30%) and 10 (25.60%) (P<0.001). It was found that for each year of increase in age, the possibility of contact with the MBB decreased (β=0.89, P=0.010), and as the alpha angle increased by one degree the probability of contact with the MBB decreased (β=0.97, P=0.001) and the probability of transmigration increased (β=1.05, P<0.001).

CONCLUSIONS

One third of the impacted canines were in contact with the MBB, while another third presented dental transmigration and were mainly located apically and subapically of the incisor roots. These imaging features should be taken into account when planning orthodontic treatment.

Quality assurance in a phase III, multicenter, randomized trial of POstmastectomy radioThErapy in Node posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL): a planning benchmark case

PURPOSE

To report the planning benchmark case results of the POTENTIAL trial-a multicenter, randomized, phase 3 trial-to evaluate the value of internal mammary nodal (IMN) irradiation for patients with high-risk breast cancer.

METHODS

All participating institutions were provided the outlines of one benchmark case, and they generated radiation therapy plans per protocol. The plans were evaluated by a quality assurance team, after which the institutions resubmitted their revised plans. The information on beams arrangement, skin flash, inhomogeneity corrections, and protocol compliance was assessed in the first and final submission.

RESULTS

The plans from 26 institutions were analyzed. Some major deviations were found in the first submission. The protocol compliance rates of dose coverage for the planning target volume of chest wall, supraclavicular fossa plus axilla, and IMN region (PTVim) were all significantly improved in the final submission, which were 96.2% vs. 69.2%, 100% vs. 76.9%, and 88.4% vs. 53.8%, respectively. For OARs, the compliance rates of heart Dmean, left anterior descending coronary artery V40Gy, ipsilateral lung V5Gy, and stomach V5Gy were significantly improved. In the first and final submission, the mean values of PTVim V100% were 79.9% vs. 92.7%; the mean values of heart Dmean were 11.5 Gy vs. 9.7 Gy for hypofractionated radiation therapy and 11.5 Gy vs. 11.0 Gy for conventional fractionated radiation therapy, respectively.

CONCLUSION

The major deviations were corrected and protocol compliance was significantly improved after revision, which highlighted the importance of planning benchmark case to guarantee the planning quality for multicenter trials.

Wound drain in lumbar arthrodesis for degenerative disease: an experimental, multicenter, randomized controlled trial

INTRODUCTION

Drains for surgical wound management are frequently used in spine surgery. They are often used to decrease the incidence of postoperative hematoma and decrease wound tension. No conclusive evidence in the literature supports using drains to avoid complications in degenerative lumbar spine surgery.

PURPOSE

We aimed to evaluate wound drains in patients with lumbar arthrodesis for degenerative disorders based on clinical outcomes, complications, hematocrit, and length of stay.

STUDY DESIGN

A multicenter randomized prospective controlled clinical trial.

PATIENT SAMPLE

We enrolled surgical candidates for posterior lumbar decompression and fusion surgery for degenerative disorders from October 2019 to August 2021. Patients were randomized into the drain or nondrain group at nine hospitals. The inclusion criteria were as follows: patients aged 40 to 80 years with lumbar and radicular pain, lumbar degenerative disorder, and primary surgery up to three levels. The exclusion criteria were bleeding abnormalities, bleeding >2,500 mL and dural tears.

OUTCOME MEASURES

Preoperative data including Oswestry disability index (ODI), SF-36, lumbar and lower extremity visual analog scale (VAS), body mass index (BMI), hematocrit, and temperature were recorded. Surgical parameters, including surgical time, complications, estimated blood loss (EBL), postoperative temperature and hematocrit (days 1 and 4), dressing saturation, and length of hospital stay (LOS), were registered.

METHODS

The two groups were assessed preoperatively, perioperatively and at the 1-month follow-up. A REDCap database was used for registration. Data analysis was performed using classical statistics.

RESULTS

One hundred one patients were enrolled using the Redcap database, and 93 patients were evaluated at the final follow-up. Forty-five patients were randomized to the drain group, and 48 were randomized to the nondrain group. The preoperative characteristics were equivalent in both groups: demographic aspects, pain, ODI, SF-36, BMI, hematocrit, and spine pathology. Surgical time, EBL and complications were similar, with no difference between the groups. No difference was found between BMI and complications. No difference was observed in dressing saturation or postoperative temperature between the groups. The postoperative day 4 hematocrit was higher in the nondrain group [36.4% (32-39)] than in the drain group [34% (29.7-37.6)] without statistically differences (p=.054). The LOS was higher in the drain group [4 (3-5) days] than in the nondrain group [3 (2-4) days] (p=.007). The quality-of-life score, SF-36, was higher in the nondrain group [67.9 (53.6-79.2)] than in the drain group [56.7 (49.1-66)] (p=.043).

CONCLUSIONS

Nondrain patients presented shorter LOS and better outcomes, with similar complication rates. No difference was found between BMI and complications. Based on this study, in patients undergoing primary posterior spinal decompression and fusion up to three levels for degenerative lumbar disorders, we do not recommend the use of postoperative drains.

Joining Forces: How to Coordinate Large, Multicenter Randomized Trials

This article details the pros, cons, challenges/pitfalls, and elements required for the successful conduct of multicenter randomized trials, with specific focus on trials related to pleural diseases. Several networks dedicated to the multicenter study of important pleural conditions have developed, yielding practice-changing studies in pleural disease. This review describes the importance of multicenter trials, major elements required for the conduct of such trials, and lessons learned from the ongoing development of the Interventional Pulmonary Outcomes Group, a consortium of interventional pulmonologists dedicated to advancing diagnostic and management strategies in pleural, pulmonary parenchymal, and airway disease by generating high-quality multicenter evidence.

Clinical effectiveness of patient-oriented depression feedback in primary care: The empirical method of the GET.FEEDBACK.GP multicenter randomized controlled trial

GET.FEEDBACK.GP₁ is a multicenter randomized controlled trial testing the efficacy of patient-oriented depression feedback in primary care. This paper describes the complex methods and procedures of the trial. The primary outcome is depression severity six months after feedback, and we vary who is the target of the feedback as follows: no one receives feedback, only general practitioners receive feedback, and both patients and general practitioners receive feedback. The procedure includes a baseline assessment in primary care practices and three telephone follow-up interviews after one, six, and twelve months. The patients completed a baseline assessment, which determined their depression severity. Those with at least a moderate depression severity (PHQ-9₅ ≥ 10) were randomly allocated to three groups stratified by depression severity. A standardized mean difference of d = 0.25 with power 1 - β = 0.80 required a total sample size of N = 699. The patients provided responses regarding the primary and secondary outcomes at follow-up. The extensive planning for GET.FEEDBACK.GP involved experts from diverse medical specialties and external corporations. Of particular importance were (a) blinding in the study inclusion and random assignment with data capture software, (b) representative and unbiased patient selection in practice waiting rooms, (c) a data management and safety plan supplied by a specialized trial center, and (d) the use of participant pseudonyms supplied by a specialized service (Mainzelliste). The data collection started in July 2019 and will continue until June 2022. Five university study centers in Germany are participating in the trial.

Rationale and design of the OPTIMIZE trial: OPen label multicenter randomized trial comparing standard IMmunosuppression with tacrolimus and mycophenolate mofetil with a low exposure tacrolimus regimen In combination with everolimus in de novo renal transplantation in Elderly patients

BACKGROUND

In 2019, more than 30 % of all newly transplanted kidney transplant recipients in The Netherlands were above 65 years of age. Elderly patients are less prone to rejection, and death censored graft loss is less frequent compared to younger recipients. Elderly recipients do have increased rates of malignancy and infection-related mortality. Poor kidney transplant function in elderly recipients may be related to both pre-existing (i.e. donor-derived) kidney damage and increased susceptibility to nephrotoxicity of calcineurin inhibitors (CNIs) in kidneys from older donors. Hence, it is pivotal to shift the focus from prevention of rejection to preservation of graft function and prevention of over-immunosuppression in the elderly. The OPTIMIZE study will test the hypothesis that reduced CNI exposure in combination with everolimus will lead to better kidney transplant function, a reduced incidence of complications and improved health-related quality of life for kidney transplant recipients aged 65 years and older, compared to standard immunosuppression.

METHODS

This open label, randomized, multicenter clinical trial will include 374 elderly kidney transplant recipients (≥ 65 years) and consists of two strata. Stratum A includes elderly recipients of a kidney from an elderly deceased donor and stratum B includes elderly recipients of a kidney from a living donor or from a deceased donor < 65 years. In each stratum, subjects will be randomized to a standard, tacrolimus-based immunosuppressive regimen with mycophenolate mofetil and glucocorticoids or an adapted immunosuppressive regimen with reduced CNI exposure in combination with everolimus and glucocorticoids. The primary endpoint is 'successful transplantation', defined as survival with a functioning graft and an eGFR ≥ 30 ml/min per 1.73 m2 in stratum A and ≥ 45 ml/min per 1.73 m2 in stratum B, after 2 years, respectively.

CONCLUSIONS

The OPTIMIZE study will help to determine the optimal immunosuppressive regimen after kidney transplantation for elderly patients and the cost-effectiveness of this regimen. It will also provide deeper insight into immunosenescence and both subjective and objective outcomes after kidney transplantation in elderly recipients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03797196 , registered January 9th, 2019. EudraCT: 2018-003194-10, registered March 19th, 2019.

Actual versus ideal body weight dosing of sugammadex in morbidly obese patients offers faster reversal of rocuronium- or vecuronium-induced deep or moderate neuromuscular block: a randomized clinical trial

Background

This randomized, double-blind trial evaluated sugammadex-mediated recovery time from rocuronium- or vecuronium-induced moderate (M-) or deep (D-) neuromuscular block in morbidly obese adults dosed by actual (ABW) or ideal body weight (IBW).

Methods

Adults with BMI ≥40 kg/m² were randomized to 1 of 5 groups: M-neuromuscular block, sugammadex 2 mg/kg ABW; M-neuromuscular block, sugammadex 2 mg/kg IBW; M-neuromuscular block, neostigmine 5 mg, and glycopyrrolate 1 mg; D-neuromuscular block, sugammadex 4 mg/kg ABW; or D-neuromuscular block, sugammadex 4 mg/kg IBW. Supramaximal train of four (TOF) stimulation of the ulnar nerve (TOF-watch SX®) monitored recovery. Primary endpoint was time to TOF ratio ≥ 0.9 for ABW and IBW groups pooled across neuromuscular blocking agent (NMBA)/blocking depth, analyzed by log-rank test stratified for agent and depth. Prespecified safety outcomes included treatment-emergent bradycardia, tachycardia, and other arrhythmias, and adjudicated hypersensitivity and anaphylaxis.

Results

Of 207 patients randomized, 188 received treatment (28% male, BMI 47 ± 5.1 kg/m², age 48 ± 13 years). Recovery was 1.5 min faster with ABW vs IBW dosing. The sugammadex 2 mg/kg groups recovered 9-fold faster [time 0.11-fold, 95% CI 0.08 to 0.14] than the neostigmine group. ABW (5.3%) and IBW (2.7%) groups had similar incidences of recovery time > 10 min (95% CI of difference: − 4.8 to 11.0%); 84% for neostigmine group. Re-curarization occurred in one patient each in the 2 mg/kg IBW and neostigmine groups. Prespecified safety outcomes occurred with similar incidences.

Conclusions

ABW-based sugammadex dosing yields faster reversal without re-curarization, supporting ABW-based sugammadex dosing in the morbidly obese, irrespective of the depth of neuromuscular block or NMBA used.

Trial registration

Registered on November 17, 2017, at ClinicalTrials.gov under number NCT03346070.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01278-w.

Subcutaneous tocilizumab in adults with severe and critical COVID-19: A prospective open-label uncontrolled multicenter trial

Potential therapeutic approaches in coronavirus disease 2019 (COVID-19) comprise antiviral and immunomodulatory agents; however, no immunomodulator drug has been approved. This multicenter, prospective, open-label, uncontrolled study aimed to assess the use of subcutaneous tocilizumab in adult patients with severe and critical COVID-19. Tocilizumab was added to the standard care of therapy at a dose of 324 mg (<100 kg bodyweight) or 486 mg (≥100 kg bodyweight). The study endpoints were all-cause mortality rate, changes in oxygen-support level, oxygen saturation, body temperature, respiratory rate, and laboratory variables during the study, and drug safety. Of 126 patients enrolled, 86 had severe and 40 had critical disease. Most patients were male (63.49%) and aged below 65 (78.57%). By day 14 of the study, 4.65% (4/86) of severe patients and 50.00% (20/40) of critical patients died. By the end, 6.98% (6/86) of severe patients and 60.00% (24/40) of critical patients died.Outcomes concerning three additional endpoints (oral temperature, oxygen saturation, and respiratory rate)were significantly improved as early as three days after tocilizumab administration in both groups of subjects, more considerably in severe patients. Significant improvement in the required level of oxygenation was reported in severe patients seven days after tocilizumab administration. No tocilizumab-related serious adverse event occurred in this study. Subcutaneous tocilizumab might improve some clinical parameters and reduce the risk of death in COVID-19 patients, particularly if used in the early stages of respiratory failure.

Analysis of multicenter clinical trials with very low event rates

INTRODUCTION

In a five-arm randomized clinical trial (RCT) with stratified randomization across 54 sites, we encountered low primary outcome event proportions, resulting in multiple sites with zero events either overall or in one or more study arms. In this paper, we systematically evaluated different statistical methods of accounting for center in settings with low outcome event proportions.

METHODS

We conducted a simulation study and a reanalysis of a completed RCT to compare five popular methods of estimating an odds ratio for multicenter trials with stratified randomization by center: (i) no center adjustment, (ii) random intercept model, (iii) Mantel-Haenszel model, (iv) generalized estimating equation (GEE) with an exchangeable correlation structure, and (v) GEE with small sample correction (GEE-small sample correction). We varied the number of total participants (200, 500, 1000, 5000), number of centers (5, 50, 100), control group outcome percentage (2%, 5%, 10%), true odds ratio (1, > 1), intra-class correlation coefficient (ICC) (0.025, 0.075), and distribution of participants across the centers (balanced, skewed).

RESULTS

Mantel-Haenszel methods generally performed poorly in terms of power and bias and led to the exclusion of participants from the analysis because some centers had no events. Failure to account for center in the analysis generally led to lower power and type I error rates than other methods, particularly with ICC = 0.075. GEE had an inflated type I error rate except in some settings with a large number of centers. GEE-small sample correction maintained the type I error rate at the nominal level but suffered from reduced power and convergence issues in some settings when the number of centers was small. Random intercept models generally performed well in most scenarios, except with a low event rate (i.e., 2% scenario) and small total sample size (n ≤ 500), when all methods had issues.

DISCUSSION

Random intercept models generally performed best across most scenarios. GEE-small sample correction performed well when the number of centers was large. We do not recommend the use of Mantel-Haenszel, GEE, or models that do not account for center. When the expected event rate is low, we suggest that the statistical analysis plan specify an alternative method in the case of non-convergence of the primary method.

Infliximab for pediatric patients with ulcerative colitis: a phase 3, open-label, uncontrolled, multicenter trial in Japan

BACKGROUND

Pediatric ulcerative colitis (UC) is typically more extensive and has a more active disease course than adult UC, and requires early treatment augmentation to achieve and maintain disease remission. The present study aimed to investigate the efficacy, safety, and pharmacokinetic profile of infliximab (IFX) in pediatric patients with moderate-to-severe UC and inadequate response to existing treatment.

METHODS

This open-label, uncontrolled, multicenter, Phase 3 trial was conducted at 17 centers in Japan between April 2012 and September 2014. Pediatric patients (aged 6-17 years) diagnosed with moderate-to-severe UC received a treatment protocol comprising 5 mg/kg IFX at Weeks 0, 2, and 6, and Clinical Activity Index (CAI)-based responders at Week 8 also received treatment at 8-week intervals at Weeks 14 and 22, with a final evaluation at Week 30.

RESULTS

A total of 21 patients were treated in this study. IFX therapy rapidly improved clinical symptoms, and this effect was maintained for up to 30 weeks. Overall CAI-based remission rate was 42.9% and overall Pediatric Ulcerative Colitis Activity Index (PUCAI)-based remission rate was 19.0%. Median partial Mayo score was 6.0 at baseline and 4.0 at Week 30 (overall). Among the eight patients who underwent sigmoidoscopy, Mayo response was achieved at Week 30 (overall) in three patients (37.5%). Trough serum IFX concentrations in Week 8 CAI-based responders were maintained throughout the study period. Adverse events and serious adverse events were observed in 95.2 and 14.3% of patients, respectively.

CONCLUSIONS

These results support the use of IFX in the treatment of pediatric patients with UC with inadequate response to existing treatment.

TRIAL REGISTRATION

ClinicalTrials.gov, registration number: NCT01585155 .

Effect of Losartan and Fish Oil on Plasma IL-6 and Mobility in Older Persons. The ENRGISE Pilot Randomized Clinical Trial

BACKGROUND

Low-grade chronic inflammation, characterized by elevations in plasma Interleukin-6 (IL-6), is an independent risk factor of impaired mobility in older persons. Angiotensin receptor blockers and omega-3 polyunsaturated fatty acids (ω-3) may reduce IL-6 and may potentially improve physical function. To assess the main effects of the angiotensin receptor blocker losartan and ω-3 as fish oil on IL-6 and 400 m walking speed, we conducted the ENRGISE Pilot multicenter randomized clinical trial.

METHODS

The ENRGISE Pilot enrolled participants between April 2016 and June 2017, who participated for 12 months. Participants were aged ≥70 years with mobility impairment, had IL-6 between 2.5 and 30 pg/mL, and were able to walk 400 m at baseline. Participants were randomized in three strata 2 × 2 factorial to: (i) losartan 50-100 mg/d or placebo (n = 43), (ii) fish oil 1,400-2,800 mg/d or placebo (n = 180), and (iii) with both (n = 66).

RESULTS

Two hundred eighty-nine participants were randomized (mean age 78.3 years, 47.4% women, 17.0% black). There was no effect of losartan (difference of means = -0.065 ± 0.116 [SE], 95% confidence interval [CI]: -0.293-0.163, p = .58) or fish oil (-0.020 ± 0.077, 95% CI: -0.171-0.132, p = .80) on the log of IL-6. Similarly, there was no effect of losartan (-0.025 ± 0.026, 95% CI: -0.076-0.026, p = .34) or fish oil (0.010 ± 0.017, 95% CI: -0.025-0.044, p = .58) on walking speed (m/s).

CONCLUSIONS

These results do not support the use of these interventions to prevent mobility loss in older adults at risk of disability with low-grade chronic inflammation.

REGISTRATION

Clinicaltrials.gov NCT02676466.

Reduced vs. standard dose native E. coli-asparaginase therapy in childhood acute lymphoblastic leukemia: long-term results of the randomized trial Moscow-Berlin 2002

Purpose

Favorable outcomes were achieved for children with acute lymphoblastic leukemia (ALL) with the first Russian multicenter trial Moscow–Berlin (ALL-MB) 91. One major component of this regimen included a total of 18 doses of weekly intramuscular (IM) native Escherichia coli-derived asparaginase (E. coli-ASP) at 10000 U/m² during three consolidation courses. ASP was initially available from Latvia, but had to be purchased from abroad at substantial costs after the collapse of Soviet Union. Therefore, the subsequent trial ALL-MB 2002 aimed at limiting costs to a reasonable extent and also at reducing toxicity by lowering the dose for standard risk (SR−) patients to 5000 U/m² without jeopardizing efficacy.

Methods

Between April 2002 and November 2006, 774 SR patients were registered in 34 centers across Russia and Belarus, 688 of whom were randomized. In arm ASP-5000 (n = 334), patients received 5000 U/m² and in arm ASP-10000 (n = 354) 10 000 U/m² IM.

Results

Probabilities of disease-free survival, overall survival and cumulative incidence of relapse at 10 years were comparable: 79 ± 2%, 86 ± 2% and 17.4 ± 2.1% (ASP-5000) vs. 75 ± 2% and 82 ± 2%, and 17.9 ± 2.0% (ASP-10000), while death in complete remission was significantly lower in arm ASP-5000 (2.7% vs. 6.5%; p = 0.029).

Conclusion

Our findings suggest that weekly 5000 U/m²E. coli-ASP IM during consolidation therapy are equally effective, more cost-efficient and less toxic than 10000 U/m² for SR patients with childhood ALL.

Electronic supplementary material

The online version of this article (10.1007/s00432-019-02854-x) contains supplementary material, which is available to authorized users.

Radiochemical and analytical aspects of inter-institutional quality control measurements on radiopharmaceuticals

Background

Clinically applied radiopharmaceuticals have to meet quality release criteria like a high radiochemical yield and radiochemical purity. Many radiopharmaceuticals do not have marketing authorization and have no dedicated monograph within the European pharmacopeia, therefore general monographs on quality control have to be applied for clinical applications. These criteria require standardization and validation in labeling and preparation, including QC measurements according to well-defined standard operation procedures. QC measurements however, are often based on detection techniques specific for a certain LC-system. Multi-institutional research and development of new radiopharmaceuticals lead to an increase in multicenter trials. Although all institutes’ radiopharmacies are using the same standardized labeling and operation procedures, they often use different LC and radiodetection systems. Here we present a comparison of QC assessments for 3 radiopharmaceuticals with focus on the interpretation of chromatograms, data-output and potential differences in local practical performances of QC on (U)HPLC.

Methods

QC assessments for [¹¹¹In]In-CCK, [⁶⁸Ga]Ga-Bombesin and [¹⁷⁷Lu]Lu-PSMA analogs were compared. Two of the radiopharmaceutical QC assessments were also applied in other institutes using their own HPLC-systems and concordant software. Data from the HPLC-injections and measurements is processed and summarized in chromatograms, based on a variety of smoothing algorithms for which different software programs are applied. Described radiopeptides were labeled and analyzed according their standardized labeling and operation procedures.

Results

Integration of main peaks on chromatograms resulted in a range of RCP, depending on the smoothing algorithm used. [¹¹¹In]In-CCK(A), ⁶⁸Ga-Bombesin(B) and [¹⁷⁷Lu]Lu-PSMA(C) analogs had a RCP range of 88%–96%(A), 89–95%(B) and 92–99%(C) respectively. Important factors affecting final RCP value were site specific background radiation-levels, intrinsic system properties such as noise and sensitivity, personal interpretation e.g. peak-tailing and smoothing algorithms.

Conclusion

Measurement of RCP shows a strong method- and system-dependency, even when parameters are validated, standardized and SOP are followed. Release criteria are frequently based on RCP data from one central location. The lack of inter inter institutional validation and standardization in RCP determination makes the results therefore rather arbitrary. For multicenter trials, we recommend to compare locally determined RCP under validated and standardized conditions of in-line activity detection between institutes for each radiopharmaceutical.

PsychotherapyPlus: augmentation of cognitive behavioral therapy (CBT) with prefrontal transcranial direct current stimulation (tDCS) in major depressive disorder-study design and methodology of a multicenter double-blind randomized placebo-controlled trial

Major Depressive Disorder (MDD) is one of the most prevalent psychiatric disorders worldwide. About 20-30% of patients do not respond to the standard psychopharmacological and/or psychotherapeutic interventions. Mounting evidence from neuroimaging studies in MDD patients reveal altered activation patterns in lateral prefrontal brain areas. Successful cognitive behavioral therapy (CBT) is associated with a recovery of these neural alterations. Moreover, it has been demonstrated that transcranial direct current stimulation (tDCS) is capable of influencing prefrontal cortex activity and cognitive functions such as working memory and emotion regulation. Thus, a clinical trial investigating the effects of an antidepressant intervention combining CBT with tDCS seems promising. The present study investigates the antidepressant efficacy of a combined CBT-tDCS intervention as compared to CBT with sham-tDCS or CBT alone. A total of 192 patients (age range 20-65 years) with MDD (Hamilton Depression Rating Scale Score ≥ 15, 21-item version) will be recruited at four study sites across Germany (Berlin, Munich, Tuebingen, and Freiburg) and randomly assigned to one of the following three treatment arms: (1) CBT + active tDCS; (2) CBT + sham-tDCS; and (3) CBT alone. All participants will attend a 6-week psychotherapeutic intervention comprising 12 sessions of CBT each lasting 100 min in a closed group setting. tDCS will be applied simultaneously with CBT. Active tDCS includes stimulation with an intensity of 2 mA for 30 min with the anode placed over F3 and the cathode over F4 according to the EEG 10-20 system, if assigned. The primary outcome measure is the change in Montgomery-Åsberg Depression Rating Scale scores from baseline to 6, 18, and 30 weeks after the first session. Participants also undergo pre- and post-treatment neuropsychological testing and functional magnetic resonance imaging (fMRI) to assess changes in prefrontal functioning and connectivity. The study investigates whether CBT can be augmented by non-invasive brain stimulation techniques such as tDCS in the treatment of MDD. It is designed as a proof-of-principle trial for the combined tDCS-CBT treatment, but also allows the investigation of the neurobiological underpinnings of the interaction between both interventions in MDD. Trial registration ClinicalTrials.gov Identifier NCT02633449.

Contouring of prostate tumors on multiparametric MRI: Evaluation of clinical delineations in a multicenter radiotherapy trial

PURPOSE

To date no guidelines are available for contouring prostate cancer inside the gland, as visible on multiparametric (mp-) MRI. We assessed inter-institutional differences in interpretation of mp-MRI in the multicenter phase III FLAME trial.

METHODS

We analyzed clinical delineations on mp-MRI and clinical characteristics from 260 patients across three institutes. We performed a logistic regression analysis to examine each institute's weighting of T2w, ADC and K^trans intensity maps in the delineation of the cancer. As reviewing of all delineations by an expert panel is not feasible, we made a selection based on discrepancies between a published tumor probability (TP) model and each institute's clinical delineations using Areas Under the ROC Curve (AUC) analysis.

RESULTS

Regression coefficients for the three institutes were -0.07, -0.27 and -0.11 for T2w, -1.96, -0.53 and -0.65 for ADC and 0.15, 0.20 and 0.62 for K^trans, with significant differences between institutes for ADC and K^trans. AUC analysis showed median AUC values of 0.92, 0.80 and 0.79. Five patients with lowest AUC values were reviewed by a uroradiologist.

CONCLUSION

Regression coefficients revealed considerably different interpretations of mp-MRI in tumor contouring between institutes and demonstrated the need for contouring guidelines. Based on AUC values outlying delineations could efficiently be identified for review.

Japanese multicenter database of healthy controls for [123I]FP-CIT SPECT

PURPOSE

The aim of this multicenter trial was to generate a [¹²³I]FP-CIT SPECT database of healthy controls from the common SPECT systems available in Japan.

METHODS

This study included 510 sets of SPECT data from 256 healthy controls (116 men and 140 women; age range, 30-83 years) acquired from eight different centers. Images were reconstructed without attenuation or scatter correction (NOACNOSC), with only attenuation correction using the Chang method (ChangACNOSC) or X-ray CT (CTACNOSC), and with both scatter and attenuation correction using the Chang method (ChangACSC) or X-ray CT (CTACSC). These SPECT images were analyzed using the Southampton method. The outcome measure was the specific binding ratio (SBR) in the striatum. These striatal SBRs were calibrated from prior experiments using a striatal phantom.

RESULTS

The original SBRs gradually decreased in the order of ChangACSC, CTACSC, ChangACNOSC, CTACNOSC, and NOACNOSC. The SBRs for NOACNOSC were 46% lower than those for ChangACSC. In contrast, the calibrated SBRs were almost equal under no scatter correction (NOSC) conditions. A significant effect of age was found, with an SBR decline rate of 6.3% per decade. In the 30-39 age group, SBRs were 12.2% higher in women than in men, but this increase declined with age and was absent in the 70-79 age group.

CONCLUSIONS

This study provided a large-scale quantitative database of [¹²³I]FP-CIT SPECT scans from different scanners in healthy controls across a wide age range and with balanced sex representation. The phantom calibration effectively harmonizes SPECT data from different SPECT systems under NOSC conditions. The data collected in this study may serve as a reference database.

Multicenter validation of cancer gene panel-based next-generation sequencing for translational research and molecular diagnostics

The simultaneous detection of multiple somatic mutations in the context of molecular diagnostics of cancer is frequently performed by means of amplicon-based targeted next-generation sequencing (NGS). However, only few studies are available comparing multicenter testing of different NGS platforms and gene panels. Therefore, seven partner sites of the German Cancer Consortium (DKTK) performed a multicenter interlaboratory trial for targeted NGS using the same formalin-fixed, paraffin-embedded (FFPE) specimen of molecularly pre-characterized tumors (n = 15; each n = 5 cases of Breast, Lung, and Colon carcinoma) and a colorectal cancer cell line DNA dilution series. Detailed information regarding pre-characterized mutations was not disclosed to the partners. Commercially available and custom-designed cancer gene panels were used for library preparation and subsequent sequencing on several devices of two NGS different platforms. For every case, centrally extracted DNA and FFPE tissue sections for local processing were delivered to each partner site to be sequenced with the commercial gene panel and local bioinformatics. For cancer-specific panel-based sequencing, only centrally extracted DNA was analyzed at seven sequencing sites. Subsequently, local data were compiled and bioinformatics was performed centrally. We were able to demonstrate that all pre-characterized mutations were re-identified correctly, irrespective of NGS platform or gene panel used. However, locally processed FFPE tissue sections disclosed that the DNA extraction method can affect the detection of mutations with a trend in favor of magnetic bead-based DNA extraction methods. In conclusion, targeted NGS is a very robust method for simultaneous detection of various mutations in FFPE tissue specimens if certain pre-analytical conditions are carefully considered.

Persistent effect at 30-month post intervention of a community-based randomized trial of KM2H2 in reducing stroke and heart attack among senior hypertensive patients

BACKGROUND

The effect of the Keep Moving toward Healthy Heart and Healthy Brain (KM2H2) program at 6-month post intervention has been assessed.  The purpose of this study is to evaluate the KM2H² program at 30-month post intervention.

METHODS

A total of 450 senior hypertensive patients from 12 community health centers were randomized by center to either receive KM2H² plus standard care (6 centers, n = 232) or standard care only (6 centers, n = 218). Data for outcome measures at 30-month post intervention were analyzed. New cases of stroke and heart attack were verified with medical records; levels of physical activity were assessed using self-reported questionnaire. In addition to comparative analysis, adjusted incidence rate and program effects were determined using mixed effects modeling method.

RESULTS

At the 30-month follow-up, the adjusted incidence rate [95% CI] of stroke was 11.81% [5.90, 17.72] for patients in the intervention group and 19.78% [14.07, 25.50] (p = 0.03) for the control group. The adjusted incidence rate of heart attack was 3.34% [1.91, 8.58] and 6.68% [1.64, 11.73] for the intervention and control groups (p = 0.16), respectively; the proportion and the duration of engaging in regular physical activity were significantly greater for the intervention group than the control group. The reductions in blood pressure between the intervention and the control was not statistically significant.

CONCLUSIONS

The KM2H² program showed a persistent effect up to 30 months post intervention in enhancing physical activity and reducing the risk of cardio-cerebrovascular events, particularly stroke. These findings demonstrate the persistent effect of the KM2H² and suggest the need for a full-scale evaluation of the intervention program for practical use.

TRIAL REGISTRATION

ISRCTN Register ISRCTN12608966 . Registered 03 March 2015. Retrospectively registered.

Preoperative prediction of microvascular invasion of hepatocellular carcinoma using 18F-FDG PET/CT: a multicenter retrospective cohort study

PURPOSE

The aim of this study was to assess the potential of tumor ¹⁸F-fluorodeoxyglucose (FDG) avidity as a preoperative imaging biomarker for the prediction of microvascular invasion (MVI) of hepatocellular carcinoma (HCC).

METHODS

One hundred and fifty-eight patients diagnosed with Barcelona Clinic Liver Cancer stages 0 or A HCC (median age, 57 years; interquartile range, 50-64 years) who underwent ¹⁸F-FDG positron emission tomography with computed tomography (PET/CT) before curative surgery at seven university hospitals were included. Tumor FDG avidity was measured by tumor-to-normal liver standardized uptake value ratio (TLR) of the primary tumor on FDG PET/CT imaging. Logistic regression analysis was performed to identify significant parameters associated with MVI. The predictive performance of TLR and other clinical variables was assessed using receiver operating characteristic (ROC) curve analysis.

RESULTS

MVI was present in 76 of 158 patients with HCCs (48.1%). Multivariable logistic regression analysis revealed that TLR, serum alpha-fetoprotein (AFP) level, and tumor size were significantly associated with the presence of MVI (P < 0.001). Multinodularity was not significantly associated with MVI (P = 0.563). The area under the ROC curve (AUC) for predicting the presence of MVI was best with TLR (AUC = 0.704), followed by tumor size (AUC = 0.685) and AFP (AUC = 0.670). We were able to build an improved prediction model combining TLR, tumor size, and AFP by using multivariable logistic regression modeling (AUC = 0.756).

CONCLUSIONS

Tumor FDG avidity measured by TLR on FDG PET/CT is a preoperative imaging biomarker for the prediction of MVI in patients with HCC.

Evaluation of platelet adhesion and activation on polymers: Round-robin study to assess inter-center variability

The regulatory agencies provide recommendations rather than protocols or standard operation procedures for the hemocompatibility evaluation of novel materials e.g. for cardiovascular applications. Thus, there is a lack of specifications with regard to test setups and procedures. As a consequence, laboratories worldwide perform in vitro assays under substantially different test conditions, so that inter-laboratory and inter-study comparisons are impossible. Here, we report about a prospective, randomized and double-blind multicenter trial which demonstrates that standardization of in vitro test protocols allows a reproducible assessment of platelet adhesion and activation from fresh human platelet rich plasma as possible indicators of the thrombogenicity of cardiovascular implants. Standardization of the reported static in vitro setup resulted in a laboratory independent scoring of the following materials: poly(dimethyl siloxane) (PDMS), poly(ethylene terephthalate) (PET) and poly(tetrafluoro ethylene) (PTFE). The results of this in vitro study provide evidence that inter-laboratory and inter-study comparisons can be achieved for the evaluation of the adhesion and activation of platelets on blood-contacting biomaterials by stringent standardization of test protocols.

Performance of models for estimating absolute risk difference in multicenter trials with binary outcome

BACKGROUND

Reporting of absolute risk difference (RD) is recommended for clinical and epidemiological prospective studies. In analyses of multicenter studies, adjustment for center is necessary when randomization is stratified by center or when there is large variation in patients outcomes across centers. While regression methods are used to estimate RD adjusted for baseline predictors and clustering, no formal evaluation of their performance has been previously conducted.

METHODS

We performed a simulation study to evaluate 6 regression methods fitted under a generalized estimating equation framework: binomial identity, Poisson identity, Normal identity, log binomial, log Poisson, and logistic regression model. We compared the model estimates to unadjusted estimates. We varied the true response function (identity or log), number of subjects per center, true risk difference, control outcome rate, effect of baseline predictor, and intracenter correlation. We compared the models in terms of convergence, absolute bias and coverage of 95 % confidence intervals for RD.

RESULTS

The 6 models performed very similar to each other for the majority of scenarios. However, the log binomial model did not converge for a large portion of the scenarios including a baseline predictor. In scenarios with outcome rate close to the parameter boundary, the binomial and Poisson identity models had the best performance, but differences from other models were negligible. The unadjusted method introduced little bias to the RD estimates, but its coverage was larger than the nominal value in some scenarios with an identity response. Under the log response, coverage from the unadjusted method was well below the nominal value (<80 %) for some scenarios.

CONCLUSIONS

We recommend the use of a binomial or Poisson GEE model with identity link to estimate RD for correlated binary outcome data. If these models fail to run, then either a logistic regression, log Poisson regression, or linear regression GEE model can be used.

Prognostic value of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with Barcelona Clinic Liver Cancer stages 0 and A hepatocellular carcinomas: a multicenter retrospective cohort study

PURPOSE

We evaluated the prognostic value of pretreatment (18)F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG PET/CT) in patients with Barcelona Clinic Liver Cancer (BCLC) stage 0 or A hepatocellular carcinoma (HCC) who had received curative treatment or transarterial chemoembolization (TACE).

METHODS

Between 2009 and 2010, 317 patients diagnosed with HCC at seven hospitals were enrolled. Among these, 195 patients underwent curative treatments including resection, liver transplantation, and radiofrequency ablation. TACE was performed in 122 patients. The tumor-to-normal liver standardized uptake value ratio (TLR) of the primary tumor was measured using pretreatment FDG PET/CT. The prognostic significance of TLR and other clinical variables was assessed using Cox regression models. Differences in the overall survival (OS) associated with TLR or other significant clinical factors were examined using the Kaplan-Meier method.

RESULTS

Over a median follow-up period of 46 months, 77 patients died from cancer. In the curative cohort, higher TLR (≥2) was significantly associated with death (hazard ratio [HR] = 2.68; 95 % CI, 1.16-6.15; P = 0.020) in multivariable analysis. Patients with a higher TLR had significantly worse OS than patients with a lower TLR (5-year overall survival, 61 % vs. 79.4 %; P = 0.006). In the TACE cohort, the Model for End-Stage Liver Disease (MELD) score (≥8) was a significant independent prognostic factor for OS (HR = 3.34; 95 % CI, 1.49-7.48; P = 0.003), whereas TLR was not associated with OS. The Kaplan-Meier curves showed significantly poorer OS in patients with higher MELD scores (≥8) than in those with lower MELD scores (5-year survival rate, 33.1 % vs. 79.6 %; P < 0.001).

CONCLUSIONS

Pretreatment TLR measured using FDG PET/CT was an independent prognostic factor for OS in patients with BCLC stage 0 or A HCC undergoing curative treatment. In contrast, underlying liver function appeared to be important in predicting the prognosis of patients undergoing TACE.

Many multicenter trials had few events per center, requiring analysis via random-effects models or GEEs

OBJECTIVES

Adjustment for center in multicenter trials is recommended when there are between-center differences or when randomization has been stratified by center. However, common methods of analysis (such as fixed-effects, Mantel-Haenszel, or stratified Cox models) often require a large number of patients or events per center to perform well.

STUDY DESIGN AND SETTING

We reviewed 206 multicenter randomized trials published in four general medical journals to assess the average number of patients and events per center and determine whether appropriate methods of analysis were used in trials with few patients or events per center.

RESULTS

The median number of events per center/treatment arm combination for trials using a binary or survival outcome was 3 (interquartile range, 1-10). Sixteen percent of trials had less than 1 event per center/treatment combination, 50% fewer than 3, and 63% fewer than 5. Of the trials which adjusted for center using a method of analysis which requires a large number of events per center, 6% had less than 1 event per center-treatment combination, 25% fewer than 3, and 50% fewer than 5. Methods of analysis that allow for few events per center, such as random-effects models or generalized estimating equations (GEEs), were rarely used.

CONCLUSION

Many multicenter trials contain few events per center. Adjustment for center using random-effects models or GEE with model-based (non-robust) standard errors may be beneficial in these scenarios.