Harnessing health information technology to promote equitable care for patients with limited English proficiency and complex care needs.

BACKGROUND: Patients with language barriers encounter healthcare disparities, which may be alleviated by leveraging interpreter skills to reduce cultural, language, and literacy barriers through improved bidirectional communication. Evidence supports the use of in-person interpreters, especially for interactions involving patients with complex care needs. Unfortunately, due to interpreter shortages and clinician underuse of interpreters, patients with language barriers frequently do not get the language services they need or are entitled to. Health information technologies (HIT), including artificial intelligence (AI), have the potential to streamline processes, prompt clinicians to utilize in-person interpreters, and support prioritization. METHODS: From May 1, 2023, to June 21, 2024, a single-center stepped wedge cluster randomized trial will be conducted within 35 units of Saint Marys Hospital & Methodist Hospital at Mayo Clinic in Rochester, Minnesota. The units include medical, surgical, trauma, and mixed ICUs and hospital floors that admit acute medical and surgical care patients as well as the emergency department (ED). The transitions between study phases will be initiated at 60-day intervals resulting in a 12-month study period. Units in the control group will receive standard care and rely on clinician initiative to request interpreter services. In the intervention group, the study team will generate a daily list of adult inpatients with language barriers, order the list based on their complexity scores (from highest to lowest), and share it with interpreter services, who will send a secure chat message to the bedside nurse. This engagement will be triggered by a predictive machine-learning algorithm based on a palliative care score, supplemented by other predictors of complexity including length of stay and level of care as well as procedures, events, and clinical notes. DISCUSSION: This pragmatic clinical trial approach will integrate a predictive machine-learning algorithm into a workflow process and evaluate the effectiveness of the intervention. We will compare the use of in-person interpreters and time to first interpreter use between the control and intervention groups. TRIAL REGISTRATION: NCT05860777. May 16, 2023.

Comparison of STONE Score, Guy's Stone Score, CROES Nomogram, and Seoul National University Renal Stone Complexity Score in Prognosticating Outcomes of Multiple-Tract Mini-Percutaneous Nephrolithotomy: A Retrospective Study.

Objective  The objective of this study was to compare the STONE score (Size of the stone, Topography or location, degree of Obstruction of the urinary system, Number of stones, and Evaluation of Hounsfield units), Guy's stone score (GSS), Clinical Research Office of the Endourological Society (CROES) nomogram, and Seoul National University Renal Stone Complexity Score (RSCS) in prognosticating multiple tract mini-percutaneous nephrolithotomy (mPCNL) outcome. Methodology This descriptive retrospective analysis was carried out at the Urology Department, Lady Reading Hospital, Peshawar, Pakistan. Male and female patients in the age range of 18-70 years who underwent multiple tract mPCNL for renal stones from July 1, 2021, to June 30, 2023, were included in the analysis. Results  A total of 110 patients were registered. Stone-free status (SFS) was achieved in 78.2% (n=86), and complications were observed in 13.6% (n=15) patients. The odds ratio for STONE score, GSS, CROES scoring system, and RSCS for predicting the SFS was 7.093 (95%CI 2.40-20.89), 9.333 (95%CI 2.92-29.81), 11.70 (95%CI 2.56-53.38) and 3.450 (95%CI 1.25-9.53), respectively. Conclusion  Multiple tract mPCNL is a safe and effective technique for the management of renal stones, producing a high stone-free rate. This study demonstrated adequate efficacy and dependability of the four scoring systems in predicting SFS.

Consensus-Based Development of a Pediatric Echocardiography Complexity Score: Design, Rationale, and Results of a Quality Improvement Collaborative.

BACKGROUND: The complexity of congenital heart disease has been primarily stratified on the basis of surgical technical difficulty, specific diagnoses, and associated outcomes. We report on the refinement and validation of a pediatric echocardiography complexity (PEC) score. METHODS AND RESULTS: The American College of Cardiology Quality Network assembled a panel from 12 centers to refine a previously published PEC score developed in a single institution. The panel refined complexity categories and included study modifiers to account for complexity related to performance of the echocardiogram. Each center submitted data using the PEC scoring tool on 15 consecutive inpatient and outpatient echocardiograms. Univariate and multivariate analyses were performed to assess for independent predictors of longer study duration. Among the 174 echocardiograms analyzed, 68.9% had underlying congenital heart disease; 44.8% were outpatient; 34.5% were performed in an intensive care setting; 61.5% were follow-up; 46.6% were initial or preoperative; and 9.8% were sedated. All studies had an assigned PEC score. In univariate analysis, longer study duration was associated with several patient and study variables (age <2 years, PEC 4 or 5, initial study, preoperative study, junior or trainee scanner, and need for additional imaging). In multivariable analysis, a higher PEC score of 4 or 5 was independently associated with longer study duration after controlling for study variables and center variation. CONCLUSIONS: The PEC scoring tool is feasible and applicable in a variety of clinical settings and can be used for correlation with diagnostic errors, allocation of resources, and assessment of physician and sonographer effort in performing, interpreting, and training in pediatric echocardiography.

Stratification of the risk of ovarian dysfunction by studying the complexity of intermediate and premutation alleles of the FMR1 gene.

FMR1 premutation female carriers are at risk of developing premature/primary ovarian insufficiency (POI) with an incomplete penetrance. In this study, we determined the CGG repeat size among 1095 women with diminished ovarian reserve (DOR) / POI and characterized the CGG/AGG substructure in 44 women carrying an abnormal FMR1 repeat expansion number, compared to a group of 25 pregnant women carrying an abnormal FMR1 CGG repeat size. Allelic complexity scores of the FMR1 gene were calculated and compared between the two groups. In the DOR/POI cohort, 2.1% of women presented with an intermediate repeat size and 1.9% with a premutation. Our results suggest that the risk of POI is highest in the mid-range of CGG repeats. We observed that the allelic score is significantly higher in POI women compared to the pregnant women group (p-value = 0.02). We suggest that a high allelic score due to more than 2 AGG interspersions in the context of an intermediate number of repetitions could favor POI. Larger studies are still needed to evaluate the relevance of this new tool for the determination of the individual risk of developing POI in women with abnormal number of CGG repeats.

Development of a Medical Complexity Score for Pediatric Aerodigestive Patients.

OBJECTIVE: To develop a complexity scoring system to characterize the diverse population served in pediatric aerodigestive clinics and help predict their treatment outcomes. STUDY DESIGN: A 7-point medical complexity score was developed through an iterative group consensus of relative stakeholders to capture the spectrum of comorbidities among the aerodigestive population. One point was assigned for each comorbid diagnosis in the following categories: airway anomaly, neurologic, cardiac, respiratory, gastrointestinal, genetic diagnoses, and prematurity. A retrospective chart review was conducted of patients seen in the aerodigestive clinic who had ≥2 visits between 2017 and 2021. The predictive value of the complexity score for the selected outcome of feeding progression among children with dysphagia was analyzed with univariate and multivariable logistic regression. RESULTS: We analyzed 234 patients with complexity scores assigned, showing a normal distribution (Shapiro Wilk P = .406) of the scores 1-7 (median, 4; mean, 3.50 ± 1.47). In children with dysphagia, there was waning success in the improvement of oral feeding with increasing complexity scores (OR, 0.66; 95% CI, 0.51-0.84; P = .001). Tube-fed children with higher complexity scores were incrementally less likely to achieve full oral diet (OR, 0.60; 95% CI, 0.40-0.89; P = .01). On multivariable analysis, neurologic comorbidity (OR, 0.26; P < .001) and airway malformation (OR, 0.35; P = .01) were associated with a decreased likelihood to improve in oral feeding. CONCLUSIONS: We propose a novel complexity score for the pediatric aerodigestive population that is easy to use, successfully stratifies diverse presentations, and shows promise as a predictive tool to assist in counseling and resource use.

A novel method for assessment of human midpalatal sutures using CBCT-based geometric morphometrics and complexity scores.

INTRODUCTION: Management of dentofacial deficiencies requires knowledge about sutural morphology and complexity. The present study assesses midpalatal sutural morphology based on human cone-beam computed tomography (CBCT) using geometric morphometrics (GMM) and complexity scores. The study is the first to apply a sutural complexity score to human CBCT datasets and demonstrates the potential such a score has to improve objectiveness and comparability when analysing the midpalatal suture. MATERIALS AND METHODS: CBCTs of various age and sex groups were analysed retrospectively (n = 48). For the geometric morphometric analysis, landmark acquisition and generalised Procrustes superimposition were combined with principal component analysis to detect variability in sutural shape patterns. For complexity analysis, a windowed short-time Fourier transform with a power spectrum density (PSD) calculation was applied to resampled superimposed semi-landmarks. RESULTS: According to the GMM, younger patients exhibited comparable sutural patterns. With increasing age, the shape variation increased among the samples. The principal components did not sufficiently capture complexity patterns, so an additional methodology was applied to assess characteristics such as sutural interdigitation. According to the complexity analysis, the average PSD complexity score was 1.465 (standard deviation = 0.010). Suture complexity increased with patient age (p < 0.0001), but was not influenced by sex (p = 0.588). The intra-class correlation coefficient exceeded 0.9, indicating intra-rater reliability. CONCLUSION: Our study demonstrated that GMM applied to human CBCTs can reveal shape variations and allow the comparison of sutural morphologies across samples. We demonstrate that complexity scores can be applied to study human sutures captured in CBCTs and complement GMM for a comprehensive sutural analysis.

Plan quality and treatment efficiency assurance of two VMAT optimization for cervical cancer radiotherapy.

To investigate the difference of the fluence map optimization (FMO) and Stochastic platform optimization (SPO) algorithm in a newly-introduced treatment planning system (TPS). METHODS: 34 cervical cancer patients with definitive radiation were retrospectively analyzed. Each patient has four plans: FMO with fixed jaw plans (FMO-FJ) and no fixed jaw plans (FMO-NFJ); SPO with fixed jaw plans (SPO-FJ) and no fixed jaw plans (SPO-NFJ). Dosimetric parameters, Modulation Complexity Score (MCS), Gamma Pass Rate (GPR) and delivery time were analyzed among the four plans. RESULTS: For target coverage, SPO-FJ plans are the best ones (P ≤ 0.00). FMO plans are better than SPO-NFJ plans (P ≤ 0.00). For OARs sparing, SPO-FJ plans are better than FMO plans for mostly OARs (P ≤ 0.04). Additionally, SPO-FJ plans are better than SPO-NFJ plans (P ≤ 0.02), except for rectum V45Gy. Compared to SPO-NFJ plans, the FMO plans delivered less dose to bladder, rectum, colon V40Gy and pelvic bone V40Gy (P ≤ 0.04). Meanwhile, the SPO-NFJ plans showed superiority in MU, delivery time, MCS and GPR in all plans. In terms of delivery time and MCS, the SPO-FJ plans are better than FMO plans. FMO-FJ plans are better than FMO-NFJ plans in delivery efficiency. MCSs are strongly correlated with PCTV length, which are negatively with PCTV length (P ≤ 0.03). The delivery time and MUs of the four plans are strongly correlated (P ≤ 0.02). Comparing plans with fixed or no fixed jaw in two algorithms, no difference was found in FMO plans in target coverage and minor difference in Kidney_L Dmean, Mu and delivery time between PCTV width≤15.5 cm group and >15.5 cm group. For SPO plans, SPO-FJ plans showed more superiority in target coverage and OARs sparing than the SPO-NFJ plans in the two groups. CONCLUSIONS: SPO-FJ plans showed superiority in target coverage and OARs sparing, as well as higher delivery efficiency in the four plans.

Difficulty score for the treatment of isolated gingival recessions with the coronally advanced flap: a preliminary reliability study.

OBJECTIVES: The treatment of gingival recessions (GRs) is operator-sensitive and dependent upon several local anatomical factors. The aim of this study was to introduce a difficulty score for the treatment of localized GRs with the coronally advanced flap (CAF) and to test its consistency among different operators. MATERIALS AND METHODS: A rubric (difficulty score) consisting of the assessment and grading of 8 anatomical parameters (anatomical papilla, apical and lateral keratinized tissue width, apical and lateral frenum, vestibulum depth, scar tissue, and mucosal invagination) is described based on the available evidence and the authors' experience. Inter-examiner agreement, with the score, was tested on 32 localized GRs among four different experienced practitioners. RESULTS: Minor discrepancies were observed in the total scores between the reviewers (intraclass correlation coefficient [ICC] 0.95). A good reproducibility, with ICCs ranging from 0.56 to 0.98, was found for the individual parameters. All models showed high absolute variance contribution conveying true differences among the cases, and small examiner variance, demonstrating minor systematic variability among the four reviewers and reproducible evaluations. CONCLUSIONS: The proposed difficulty score for the treatment of GRs with CAF was reproducible among different operators. Clinical interventional studies are the next step to validate the clinical magnitude of the present score. CLINICAL RELEVANCE: A novel tool for evaluating the difficulty of the treatment of isolated gingival recession using CAF was described. Clinicians can benefit from this score when assessing the expected level of complexity of the surgical case.

Comparison of risk stratification scoring system as a predictor of mortality and morbidity in congenital heart disease patients requiring surgery.

Backgrounds: Risk stratification systems have been important in reducing morbidity and mortality among congenital heart disease (CHD) patients requiring cardiac surgery. Multiple risk stratification scoring systems have been developed, including Aristotle Basic Complexity Score (ABC), Aristotle Comprehensive Complexity Score (ACC), Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery (STS-EACTS), and Risk Adjustment in Congenital Heart Surgery (RACHS-1). This study aims to access the superior risk stratification scoring system model in predicting mortality and morbidity. Methods: The authors used Embase, PubMed, Scopus, and ProQuest as the primary databases for searching and included studies from hand searching. The area under the receiver operating characteristic curve was compared. Results: A total of 11 articles were included in this review. The AUC of ABC for predicting mortality ranges from 0.59 to 0.71, and morbidity ranges from 0.673 to 0.743. The AUC of ACC score for predicting mortality ranges from 0.704 to 0.87, and a study revealed the AUC of morbidity is 0.730. The AUC of RACHS-1 for predicting mortality ranges from 0.68 to 0.782. The AUC of STS-EACTS for predicting mortality ranges from 0.739 to 0.8 and 0.732 for predicting morbidity. Conclusion: ABC, ACC, RACHS-1, and STS-EACTS have acceptable to excellent discriminatory ability in predicting mortality and morbidity among CHD patients requiring cardiac surgery.

Association of Residual Ischemic Disease With Clinical Outcomes After Percutaneous Coronary Intervention.

BACKGROUND: Anatomical scoring systems have been used to assess completeness of revascularization but are challenging to apply to large real-world datasets. OBJECTIVES: The aim of this study was to assess the prevalence of complete revascularization and its association with longitudinal clinical outcomes in the U.S. Department of Veterans Affairs (VA) health care system using an automatically computed anatomic complexity score. METHODS: Patients undergoing percutaneous coronary intervention (PCI) between October 1, 2007, and September 30, 2020, were identified, and the burden of prerevascularization and postrevascularization ischemic disease was quantified using the VA SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score. The association between residual VA SYNTAX score and long-term major adverse cardiovascular events (MACE; death, myocardial infarction, repeat revascularization, and stroke) was assessed. RESULTS: A total of 57,476 veterans underwent PCI during the study period. After adjustment, the highest tertile of residual VA SYNTAX score was associated with increased hazard of MACE (HR: 2.06; 95% CI: 1.98-2.15) and death (HR: 1.50; 95% CI: 1.41-1.59) at 3 years compared to complete revascularization (residual VA SYNTAX score = 0). Hazard of 1- and 3-year MACE increased as a function of residual disease, regardless of baseline disease severity or initial presentation with acute or chronic coronary syndrome. CONCLUSIONS: Residual ischemic disease was strongly associated with long-term clinical outcomes in a contemporary national cohort of PCI patients. Automatically computed anatomic complexity scores can be used to assess the longitudinal risk for residual ischemic disease after PCI and may be implemented to improve interventional quality.

Evaluating the effect of high-density measurement mode on patient-specific quality assurance for head and neck cancer with ArcCHECK.

The high-density measurement (HDm) mode of the ArcCHECK device can achieve a twofold resolution enhancement compared to the standard measurement (Sm) mode. The aim of this study was to evaluate the effect of HDm on the gamma passing rate (GPR) for the patient-specific quality assurance (PSQA) in head and neck cancer. We retrospectively evaluated 30 patients who underwent volumetric modulated arc therapy (VMAT) for head and neck cancer. Absolute gamma analysis was performed on Sm and HDm data. We also investigated correlations between the modulation complexity score for VMAT (MCSv) and differences in the GPR between the two measurement modes. The global GPR of Sm and HDm was 81.0% ± 8.4% and 82.6% ± 7.6% for the 2%/2 mm criterion, 94.0% ± 4.1% and 94.9% ± 3.6% for the 3%/2 mm criterion, and 96.6% ± 2.4% and 97.0% ± 2.4% for the 3%/3 mm criterion, respectively. HDm slightly improved GPR (p < 0.01) for the 2%/2 mm criterion. Differences in GPR between Sm and HDm for the 2%/2 mm, 3%/2 mm, and 3%/3 mm criteria were 1.6% ± 3.0%, 0.8% ± 2.0%, and 0.4% ± 1.2%, respectively. No correlation was identified between the MCSv and the difference in GPR between Sm and HDm. Despite an improvement in GPR with HDm, the difference in GPR between Sm and HDm was approximately 2% even when the tighter criteria were used. Moreover, the change in the GPR between Sm and HDm did not depend on plan complexity. Thus, the effect of HDm on GPR is limited for the PSQA in VMAT for head and neck cancer.

Factors Predicting Surgical Effort Using Explainable Artificial Intelligence in Advanced Stage Epithelial Ovarian Cancer.

(1) Background: Surgical cytoreduction for epithelial ovarian cancer (EOC) is a complex procedure. Encompassed within the performance skills to achieve surgical precision, intra-operative surgical decision-making remains a core feature. The use of eXplainable Artificial Intelligence (XAI) could potentially interpret the influence of human factors on the surgical effort for the cytoreductive outcome in question; (2) Methods: The retrospective cohort study evaluated 560 consecutive EOC patients who underwent cytoreductive surgery between January 2014 and December 2019 in a single public institution. The eXtreme Gradient Boosting (XGBoost) and Deep Neural Network (DNN) algorithms were employed to develop the predictive model, including patient- and operation-specific features, and novel features reflecting human factors in surgical heuristics. The precision, recall, F1 score, and area under curve (AUC) were compared between both training algorithms. The SHapley Additive exPlanations (SHAP) framework was used to provide global and local explainability for the predictive model; (3) Results: A surgical complexity score (SCS) cut-off value of five was calculated using a Receiver Operator Characteristic (ROC) curve, above which the probability of incomplete cytoreduction was more likely (area under the curve [AUC] = 0.644; 95% confidence interval [CI] = 0.598−0.69; sensitivity and specificity 34.1%, 86.5%, respectively; p = 0.000). The XGBoost outperformed the DNN assessment for the prediction of the above threshold surgical effort outcome (AUC = 0.77; 95% [CI] 0.69−0.85; p < 0.05 vs. AUC 0.739; 95% [CI] 0.655−0.823; p < 0.95). We identified "turning points" that demonstrated a clear preference towards above the given cut-off level of surgical effort; in consultant surgeons with <12 years of experience, age <53 years old, who, when attempting primary cytoreductive surgery, recorded the presence of ascites, an Intraoperative Mapping of Ovarian Cancer score >4, and a Peritoneal Carcinomatosis Index >7, in a surgical environment with the optimization of infrastructural support. (4) Conclusions: Using XAI, we explain how intra-operative decisions may consider human factors during EOC cytoreduction alongside factual knowledge, to maximize the magnitude of the selected trade-off in effort. XAI techniques are critical for a better understanding of Artificial Intelligence frameworks, and to enhance their incorporation in medical applications.

Definition of the Surgical Case Complexity in the Treatment of Soft Tissue Tumors of the Extremities and Trunk.

BACKGROUND: We intend to establish a complexity score for soft tissue tumor surgeries to compare the complexities of different soft tissue tumor surgeries and to ultimately assign affected patients to appropriate treatments. METHODS: We developed a soft tissue tumor complexity score (STS-SCS) based on three pillars: in addition to patient-related factors, tumor biology and surgery-associated parameters were taken into account. The STS-SCS was applied to our sampling group of 711 patients. RESULTS: The minimum STS-SCS was 4, the maximum score was 34 and the average score 11.4 ± 5.9. The scores of patients with malignant diagnoses were notably higher and more widely scattered than those of patients with benign or intermediate malignant tumors. To better categorize the complexities of individual surgeries, we established four categories using the collected data as a reference dataset. Each of the categories contained approximately one-quarter of the registered patients. DISCUSSION: The STS-SCS allows soft tissue tumor surgeries to be retrospectively evaluated for their complexity and forms the basis for the creation of a prospective concept to provide patients with the right intervention in the right geographic location, which can lead to better results and provision of the most cost-effective overall treatment.

Evaluating Surgical Complexity of Endoscopic Hysterectomy: An Inter-rater and Intra-rater Agreement Study of Novel Scoring Tool.

STUDY OBJECTIVE: Evaluate inter-rater and intrarater reliability of a novel scoring tool for surgical complexity assessment of endoscopic hysterectomy. DESIGN: Validation study. SETTING: Academic medical center. PARTICIPANTS: Total of 11 academic obstetrician-gynecologists with varying years of postresidency training, clinical practice, and surgical volumes. INTERVENTIONS: Application of a novel scoring tool to evaluate surgical complexity of 150 sets of images taken in a standardized fashion before surgical intervention (global pelvis, anterior cul-de-sac, posterior cul-de-sac, right adnexa, left adnexa). Using only these images, raters were asked to assess uterine size, number, and location of myomas, adnexal and uterine mobility, need for ureterolysis, and presence of endometriosis or adhesions in relevant locations. Surgical complexity was staged on a scale of 1 to 4 (low to high complexity). MEASUREMENTS AND MAIN RESULTS: Number of postresidency years in practice for participating surgeons ranged from 2 to 15, with an average of 8 years. A total of 8 obstetrician-gynecologists (72.7%) had completed a fellowship in minimally invasive gynecologic surgery. Six (54.6%) reported an annual volume of >50 hysterectomies. Raters reported that 95.4% of the images were satisfactory for assessment. Of the 150 sets of images, most were found to be stage 1 to 2 complexity (stage 1: 23.8%, stage 2: 41.6%, stage 3: 32.8%, stage 4: 1.8%). The level of inter-rater agreement regarding stage 1 to 2 vs 3 to 4 complexity was moderate (κ = 0.49; 95% confidence interval [CI], 0.42-0.56). Moderate inter-rater agreement was also found between surgeon raters with an annual hysterectomy volume >50 (κ = 0.49; 95% CI, 0.40-0.57) as well as between surgeon raters with fellowship experience (κ = 0.50; 95% CI, 0.42-0.58). Intrarater agreement averaged 80.2% among all raters and also achieved moderate agreement (mean weighted κ = 0.53; range, 0.38-0.72). CONCLUSION: This novel scoring tool uses clinical assessment of preintervention anatomic images to stratify the surgical complexity of endoscopic hysterectomy. It has rich and comprehensive evaluation capabilities and achieved moderate inter-rater and intrarater agreement. The tool can be used in conjunction with or instead of traditional markers of surgical complexity such as uterine weight, estimated blood loss, and operative time.

Effective Organs-at-Risk Dose Sparing in Volumetric Modulated Arc Therapy Using a Half-Beam Technique in Whole Pelvic Irradiation.

BACKGROUND: Although there are some controversies regarding whole pelvic radiation therapy (WPRT) due to its gastrointestinal and hematologic toxicities, it is considered for patients with gynecological, rectal, and prostate cancer. To effectively spare organs-at-risk (OAR) doses using multi-leaf collimator (MLC)'s optimal segments, potential dosimetric benefits in volumetric modulated arc therapy (VMAT) using a half-beam technique (HF) were investigated for WPRT. METHODS: While the size of a fully opened field (FF) was decided to entirely include a planning target volume in all beam's eye view across arc angles, the HF was designed to use half the FF from the isocenter for dose optimization. The left or the right half of the FF was alternatively opened in VMAT-HF using a pair of arcs rotating clockwise and counterclockwise. Dosimetric benefits of VMAT-HF, presented with dose conformity, homogeneity, and dose-volume parameters in terms of modulation complex score, were compared to VMAT optimized using the FF (VMAT-FF). Consequent normal tissue complication probability (NTCP) by reducing the irradiated volumes was evaluated as well as dose-volume parameters with statistical analysis for OAR. Moreover, beam-on time and MLC position precision were analyzed with log files to assess plan deliverability and clinical applicability of VMAT-HF as compared to VMAT-FF. RESULTS: While VMAT-HF used 60%-70% less intensity modulation complexity than VMAT-FF, it showed superior dose conformity. The small intestine and colon in VMAT-HF showed a noticeable reduction in the irradiated volumes of up to 35% and 15%, respectively, at an intermediate dose of 20-45 Gy. The small intestine showed statistically significant dose sparing at the volumes that received a dose from 15 to 45 Gy. Such a dose reduction for the small intestine and colon in VMAT-HF presented a significant NTCP reduction from that in VMAT-FF. Without sacrificing the beam delivery efficiency, VMAT-HF achieved effective OAR dose reduction in dose-volume histograms. CONCLUSIONS: VMAT-HF led to deliver conformal doses with effective gastrointestinal-OAR dose sparing despite using less modulation complexity. The dose of VMAT-HF was delivered with the same beam-on time with VMAT-FF but precise MLC leaf motions. The VMAT-HF potentially can play a valuable role in reducing OAR toxicities associated with WPRT.

Comparison of calculation algorithms to predict the IQM detector response for various modulation degrees of VMAT treatment plans on linear accelerator equipped with the HD120 MLC.

PURPOSE: The calculation model for the integral quality monitor (IQM) system does not take into account the characteristics of the HD120 multileaf collimator (MLC), which some Varian accelerators are equipped with. Some treatment plans prepared with this collimator are characterized by a high level of modulation. The aim of the work was to prepare a model for that collimator and to determine the influence of modulation on results of the verification carried out with the use of IQM system. METHODS: The short and long stabilities of the IQM detector response were verified by measuring the signal for a 6 MV flattening filter-free (FFF) beam with the static field of 10 × 10 cm2 size. The obtained results were compared with the measurements performed with the PTW Farmer chamber. Next, the signals for 35 static square fields 4 × 4 cm2 , covering the whole field 38 × 20 cm2 , were measured with the IQM. Based on the results of these measurements, the original calculation model has been changed in order to achieve the smallest differences between calculations and measurements. While tuning the model, the characteristics of the HD120 MLC were included. Measurements were performed for 30 clinical plans (86 arcs) prepared with 6 MV FFF beams. Among those 30 plans, there were were multitarget plans with single isocenter. For each plan, the modulation complexity score (MCS) was calculated. The measurement results were compared with the calculation results performed with the original and authors' calculation model. RESULTS: Very good stability of the short and long stabilities of the IQM detector response was obtained. Measurements performed for 35 static fields revealed that for the manufacturer's and for the authors' models, the deviation exceeded 3% for 12 and five of the 35 static fields, respectively. The differences for the manufacturer's and authors' algorithms were in the range of ±2% for the 15 and 26 of the fields, respectively. For original and the authors' models, the differences between measured and calculated signals (starting with the segment number 40) were within the range of ±3.5% for 87.6% and 96.7% of all arcs for the respective models. For both models, the dependence of the compliance of measurements and calculations on the MCS was observed. For most of the very modulated arcs, the measured signal was at least 3% lower than the calculated one. The largest differences between measurements and calculations were obtained for single-isocenter multitarget plans. CONCLUSIONS: The signal predicted by an algorithm taking into account the real geometry of the collimating system of the Edge accelerator (equipped with the HD120 MLC) made it possible to obtain greater consistency between the measurements and calculations. We characterized the dependence between the MCS of each arc and the compliance of the measurements and calculations. Much worse results were obtained for single-isocenter multitarget plans.

Outcomes of surgical treatment for active infective endocarditis of mitral valve compared using complexity scoring.

OBJECTIVE: The aim of this study was to evaluate our surgical treatment outcomes of active infective endocarditis (IE) of mitral valve in relation to the patients' complexity scores. METHODS: We reviewed 51 patients who underwent surgical treatment for active IE on the mitral valve, in our hospital between September 2002 and November 2016. We adapted a complexity scoring scale to describe the range of parts suffering vegetation and damage, assigning the following weighting: weight 1 for each posterior segment; weight 2 for each anterior segment, commissural segment, left atrium, or left ventricle; weight 3 if the annulus was involved or if pathology extended to a prior mitral operation site. A total of 51 patients were identified and categorized by complexity score into two groups: 1-2: Simple (n = 19); ≥ 3: Complex (n = 32). RESULTS: MV repair was achieved in 18 patients (95%) in the Simple group and 26 patients (81%) in the Complex group. In the Complex there were 2 in-hospital deaths (6%). There were none in the Simple. The 5-year survival rates were 100% in the Simple and 79.6% in the Complex (P < 0.05). The 5-year rates of freedom from mitral regurgitation were 77.8% in the Simple and 91.5% in the Complex (P = 0.63). The 5-year rates of freedom from recurrence of IE were 93.3% in the Simple and 92.2% in the Complex (P = 0.76). CONCLUSIONS: We found consistent outcomes in terms of recurrent mitral regurgitation and recurrence of IE, regardless of lesion complexity.

On the complexity of helical tomotherapy treatment plans.

PURPOSE: Multiple metrics are proposed to characterize and compare the complexity of helical tomotherapy (HT) plans created for different treatment sites. METHODS: A cohort composed of 208 HT plans from head and neck (105), prostate (51) and brain (52) tumor sites was considered. For each plan, 14 complexity metrics were calculated. Those metrics evaluate the percentage of leaves with small opening times or approaching the projection duration, the percentage of closed leaves, the amount of tongue-and-groove effect, and the overall modulation of the planned sinogram. To enable data visualization, an approach based on principal component analysis was followed to reduce the dataset dimensionality. This allowed the calculation of a global plan complexity score. The correlation between plan complexity and pretreatment verification results using the Spearman's rank correlation coefficients was investigated. RESULTS: According to the global score, the most complex plans were the head and neck tumor cases, followed by the prostate and brain lesions irradiated with stereotactic technique. For almost all individual metrics, head and neck plans confirmed to be the plans with the highest complexity. Nevertheless, prostate cases had the highest percentage of leaves with an opening time approaching the projection duration, whereas the stereotactic brain plans had the highest percentage of closed leaves per projection. Significant correlations between some of the metrics and the pretreatment verification results were identified for the stereotactic brain group. CONCLUSIONS: The proposed metrics and the global score demonstrated to be useful to characterize and quantify the complexity of HT plans of different treatment sites. The reported differences inter- and intra-group may be valuable to guide the planning process aiming at reducing uncertainties and harmonize planning strategies.

[Impact of Aperture Shape Controller on Volumetric Modulated Arc Therapy Treatment Planning for Nasopharyngeal Cancer].

PURPOSE: The aperture shape controller (ASC) decreases the complexity of the multi-leaf collimator (MLC) aperture for volumetric modulated arc therapy (VMAT). The purpose of this study was to evaluate the effect of ASC settings on the VMAT plan quality. METHOD: First, VMAT plans were created (ASC=off) for three test patterns of The American Association of Physicists in Medicine (AAPM) Task Group 119 (TG-119) and 20 cases of nasopharyngeal cancer. Next, for these VMAT plans, only the ASC settings were changed from very low (complexity reduction: low) to very high (complexity reduction: high) in five steps, and VMAT plans were created respectively. To evaluate the created VMAT plans per each ASC settings, we analyzed the modulation complexity score (MCSV) and dosimetric parameters for the planning target volume (PTV) and organ at risk (OAR). RESULT: In three test patterns, there were no major dosimetric differences between the VMAT plans. In nasopharyngeal cancer, the mean MCSV were 0.413, 0.325, 0.320, 0.307, 0.303, and 0.272 for very high, high, moderate, low, very low, off settings, respectively. Therefore, the most complex MLC aperture was off, followed by very low, low, moderate, high, and very high. In terms of dosimetric parameters, the VMAT plans created using the very high setting showed an increase of D2% in the PTV and worse OAR sparing than that using other ASC settings. On the other hand, the dosimetric results for the very low to moderate setting obtained similar results to those for the off setting, respectively. CONCLUSION: The ASC was able to decrease the complexity of the MLC aperture according to the setting level. From very low to moderate settings, a plan equivalent to the off setting could be created in terms of dose parameters.

Evaluation of the complexity of treatment plans from a national IMRT/VMAT audit - Towards a plan complexity score.

PURPOSE: This work aimed to characterize and compare the complexity of the plans created in the context of a national IMRT/VMAT audit. A plan complexity score is proposed to summarize all the evaluated complexity features. MATERIALS AND METHODS: Nine complexity metrics have been computed for the audit plans, evaluating different complexity aspects. An approach based on Principal Component Analysis was followed to explore the correlation between the metrics and derive a smaller set of new uncorrelated variables (principal components, PCs). The resulting PCs were then used to calculate a plan complexity score. Plan quality was also assessed and the correlation between plan complexity, quality and deliverability investigated using the Spearman's rank correlation coefficient. RESULTS: The first two PCs explained over 90% of the total variance in the original dataset. Their representation allowed to identify patterns in the data, namely a clear separation between plans created using different technologies/techniques. The calculated plan complexity score quantified these differences. Sliding window Eclipse plans were found to be the most complex and VMAT Eclipse group presented the highest complexity variability, for the evaluated parameters. Concerning plan quality, no differences between treatment technology/technique have been identified. However, plans with larger number of monitor units tended to be associated with higher deviations between calculated and measured doses. CONCLUSIONS: The proposed plan complexity score allowed to summarize the differences not only inter- but also intra-groups of technologies/techniques, paving the way for improvement of the planning strategies at the national level through knowledge sharing.