bluuebunny/crossref_metadata_2025_split huggingface dataset:
Left Ventricle Myocardial Work Correlated with Functional Capacity in Severe Rheumatic Mitral Stenosis with Preserved Left Ventricular Ejection Fraction
Authors: Rudiktyo Estu , Cramer Maarten J. , Yonas Emir , Teske Arco J. , Siswanto Bambang Budi , Doevendans Pieter A. , Soesanto Amiliana M. 
Published: July 2024

Background and Aims:
Functional capacity is reduced in mitral stenosis (MS) patients. Previous studies showed a correlation between left atrial strain and functional capacity in this population. However, currently, no left ventricle (LV) echocardiographic parameters were associated with functional capacity in patients with MS. Noninvasive LV pressure-strain loop analysis is a new echocardiographic method for evaluating LV function, integrating longitudinal strain from speckle-tracking analysis and noninvasively measured blood pressure to estimate myocardial work (MW) that overcomes the preload-dependent characteristics conventional parameters by integrating afterload. This study aimed to evaluate the association between MW and functional capacity measured using exercise tests in patients with severe MS and preserved LV ejection fraction (LVEF).

Methods:
Adult patients with symptomatic severe rheumatic MS (mitral valve area <1.5 cm2), and preserved LVEF (>50%) and sinus rhythm who underwent echocardiography and exercise stress test in our hospital from 2019 to 2021 were included. Exclusion criteria were suboptimal image quality for myocardial deformation analysis, significant mitral regurgitation or aortic valve lesions, coronary artery disease, intracardiac shunt, and atrial fibrillation. Standard echocardiographic parameters were measured, and all MW parameters were included. Exercise treadmill testing was performed using the modified Bruce protocol.

Results:
A total of 33 individuals with isolated severe rheumatic MS in sinus rhythm (age 39.8 ± 9.8 years) were included in the study. Patients with severe isolated MS showed significantly impaired LV-global longitudinal strain values compared to normal reference values. Furthermore, patients with severe MS showed significantly lower values of global work index, global constructive work, and efficiency compared to normal values and higher wasted work. Global work efficiency was significantly correlated to the duration of exercise (P = 0.025, Pearson’s r = 0.389).

Conclusions:
In stable patients with isolated severe mitral stenosis, MW efficiency significantly correlated with functional capacity measured objectively through exercise testing.
Exploring the Potential of Machine Learning Algorithms to Improve Diffusion Nuclear Magnetic Resonance Imaging Models Analysis
Authors: Prieto-González Leonar Steven , Agulles-Pedrós Luis 
Published: July 2024

Purpose:
This paper explores different machine learning (ML) algorithms for analyzing diffusion nuclear magnetic resonance imaging (dMRI) models when analytical fitting shows restrictions. It reviews various ML techniques for dMRI analysis and evaluates their performance on different b-values range datasets, comparing them with analytical methods.

Materials and Methods:
After standard fitting for reference, four sets of diffusion-weighted nuclear magnetic resonance images were used to train/test various ML algorithms for prediction of diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), and kurtosis (K). ML classification algorithms, including extra-tree classifier (ETC), logistic regression, C-support vector, extra-gradient boost, and multilayer perceptron (MLP), were used to determine the existence of diffusion parameters (D, D*, f, and K) within single voxels. Regression algorithms, including linear regression, polynomial regression, ridge, lasso, random forest (RF), elastic-net, and support-vector machines, were used to estimate the value of the diffusion parameters. Performance was evaluated using accuracy (ACC), area under the curve (AUC) tests, and cross-validation root mean square error (RMSECV). Computational timing was also assessed.

Results:
ETC and MLP were the best classifiers, with 94.1% and 91.7%, respectively, for the ACC test and 98.7% and 96.3% for the AUC test. For parameter estimation, RF algorithm yielded the most accurate results The RMSECV percentages were: 8.39% for D, 3.57% for D*, 4.52% for f, and 3.53% for K. After the training phase, the ML methods demonstrated a substantial decrease in computational time, being approximately 232 times faster than the conventional methods.

Conclusions:
The findings suggest that ML algorithms can enhance the efficiency of dMRI model analysis and offer new perspectives on the microstructural and functional organization of biological tissues. This paper also discusses the limitations and future directions of ML-based dMRI analysis.
Investigating the Dosimetric Leaf Gap Correction Factor of Mobius3D Dose Calculation for Volumetric-modulated Arc Radiotherapy Plans
Authors: Sawapabmongkon Thitipong , Changkaew Pimolpun , Puttanawarut Chanon , Tangboonduangjit Puangpen , Khachonkham Suphalak 
Published: July 2024

Aims:
The dosimetric leaf gap (DLG) is a parameter for correcting radiation transmission through the round leaf end of multileaf collimators. The purpose of this study was to determine and investigate the optimal DLG correction factor for 6 MV volumetric-modulated arc radiotherapy (VMAT) plan dose calculations in Mobius3D.

Materials and Methods:
Seventeen VMAT plans were selected for the DLG correction factor optimization process. The optimal DLG correction factor was defined as the minimum difference between the measured dose and the Mobius3D-calculated dose on the Mobius Verification Phantom™ with different DLG correction factors. Subsequently, the optimal DLG correction factor was applied for Mobius3D dose calculation, and accuracy was assessed by comparing the measured and calculated doses. For verification and validation, the 17 previous plans and 10 newly selected plans underwent Mobius3D calculations with the optimal DLG correction factor, and gamma analysis was performed to compare them to the treatment planning system (TPS). Gamma analysis was also performed between the electronic portal imaging device (EPID) and the TPS for cross-comparison between systems.

Results:
The DLG correction factor was optimized to −1.252, which reduced the average percentage differences between measured and Mobius3D-calculated doses from 2.23% ±1.21% to 0.03% ±1.82%. The cross-comparison between Mobius3D/TPS and EPID/TPS revealed a similar trend in gamma passing rate (>95%) in both the verification and validation plans.

Conclusion:
The DLG correction factor strongly influences the accuracy of Mobius3D-calculated doses. Applying the optimal DLG correction factor can increase dose agreement and gamma passing rate between calculation and delivered doses of VMAT plans, which emphasizes the importance of optimizing this factor during the commissioning process.
Determination of Critical Organ Doses with 177Lu Prostate-specific Membrane Antigen Dosimetry in Metastatic Prostate Cancer Treatment
Authors: Yilidir Gulcihan , Demir Mustafa 
Published: July 2024

Aim:
This study aimed to perform dosimetry in patients with metastatic prostate cancer treated with 177Lutetium (Lu) prostate-specific membrane antigen (PSMA)-617 radiopharmaceutical, calculating organ blood clearance and consequently determining the maximum tolerable treatment activity.

Materials and Methods:
Eighteen patients with metastatic prostate cancer were enrolled in the study. Patients were administered 5.55 gigabecquerel (GBq) of 177Lu-PSMA-617 radiopharmaceutical per treatment cycle through infusion. Blood samples (2 mL each) were collected at 2, 4, 6, 8, 18, 24, 36, and 44 h postinjection to assess the bone marrow absorbed dose. Organ doses were calculated using the OLINDA/EXM software based on scintigraphic images of the 18 patients who received 177Lu-PSMA-617.

Results:
The blood clearance of 177Lu-PSMA-617 radiopharmaceutical was determined to be bi-exponential. The mean absorbed doses for the parotid glands, kidneys, bone marrow, and liver were found to be 1.18 ± 0.27, 1.05 ± 0.3, 0.07 ± 0.05, and 0.31 ± 0.2 Gy/GBq, respectively. The radiation dose to the bone marrow was significantly lower than that to the kidneys and parotid glands. No dose limitations were necessary for kidneys and bone marrow in any of the patients.

Conclusions:
Our dosimetry results indicate that 177Lu-PSMA-617 therapy is safe in terms of radiation toxicity.
Evaluation of Ion Recombination Correction for Indigenously Developed Farmer Ion Chamber in Flattening Filter-Free Photon Beams
Authors: Patwe Parimal T. , Deshpande Sudesh S. , Mahajan Gajanan R. 
Published: July 2024

Purpose and Aim:
Modern generation linear accelerator (linac) either generates X-rays with a flattening filter (WFF beam) or without flattening filter free (FFF beam). The FFF beams are associated with a significantly higher dose per pulse compared to WFF beams due to the absence of a flattening filter and the corresponding attenuation caused by it. This results in increased ion recombination and a larger saturation correction factor (ks). In accordance with the IAEA TRS 398 dosimetry protocol, ks is necessary for the accurate measurement of absorbed dose at a point in water. The objective of this study was to evaluate the ks for the indigenous FAR 65-GB ion chamber (IC) for the FFF X-rays.

Materials and Methods:
The study was carried out on TrueBeam linac (Varian, A Siemens Healthineers company) which offers 6 MV WFF, 6 MV FFF, 10 MV WFF and 10 MV FFF beams. The two-voltage method was employed to measure ks in a solid water phantom at a depth of 10 cm for a FAR 65-GB and SNC 600c and 0.6cc PTW 30013 Farmer chambers at 100 cm and 150 cm source-to-chamber distances for a 10 cm × 10 cm field size.

Results:
The ks values for the FAR 65-GB, PTW 30,013, and SNC 600c were 1.0055 (1.0113), 1.0051 (1.0071), and 1.0033 (1.0066) for the 6 MV WFF (FFF) beams, respectively, and 1.0066 (1.0178), 1.0061 (1.0137), and 1.0035 (1.0119) for the 10MV WFF (FFF) beams, respectively. The ks values calculated by two-voltage method matches with ks values obtained from Jaffe’s plot. The chamber exhibited a linear dose-response up to 3000 cGy, beyond which a saturation effect was observed.

Conclusions:
Our study reveals that this chamber is suitable for the reference dosimetry for the FFF beams.
Evaluation of the Minimum Segment Width and Fluence Smoothing Tools for Intensity-modulated Techniques in Monaco Treatment Planning System
Authors: Jiménez-Puertas Sara , Rodríguez Andrea González , Cordero Sergio Lozares , González Tomás González , Chamarro Javier Díez , Hernández Mónica Hernández , Moreno Raquel Castro , Casi Marta Sánchez , Gazulla David Carlos Villa , Martínez Almudena Gandía , Bonel Arantxa Campos , Valiño Maria del Mar Puertas , Gómez José Antonio Font 
Published: July 2024

Purpose:
This study aims to minimize monitor units (MUs) of intensity-modulated treatments in the Monaco treatment planning system while preserving plan quality by optimizing the “Minimum Segment Width” (MSW) and “Fluence Smoothing” parameters.

Materials and Methods:
We retrospectively analyzed 30 prostate, 30 gynecological, 15 breast cancer, 10 head and neck tumor, 11 radiosurgery, and 10 hypo-fractionated plans. Original prostate plans employed “Fluence Smoothing” = Off and were reoptimized with Low, Medium, and High settings. The remaining pathologies initially used MSW = 0.5 cm and were reoptimized with MSW = 1.0 cm. Plan quality, including total MU, delivery time, and dosimetric constraints, was statistically analyzed with a paired t-test.

Results:
Prostate plans exhibited the highest MU variation when changing “Fluence Smoothing” from Off to High (average ΔMU = −5.1%; P < 0.001). However, a High setting may increase overall MU when MSW = 0.5 cm. Gynecological plans changed substantially when MSW increased from 0.5 cm to 1.0 cm (average ΔMU = −29%; P < 0.001). Organs at risk sparing and planning target volumes remained within 1.2% differences. Replanning other pathologies with MSW = 1.0 cm affected breast and head and neck tumor plans (average ΔMU = −168.38, average Δt = −11.74 s, and average ΔMU = −256.56, average Δt = −15.05 s, respectively; all with P < 0.004). Radiosurgery and hypofractioned highly modulated plans did not yield statistically significant results.

Conclusions:
In breast, pelvis, head and neck, and prostate plans, starting with MSW = 1.0 cm optimally reduces MU and treatment time without compromising plan quality. MSW has a greater impact on MU than the “Fluence Smoothing” parameter. Plans with high modulation might present divergent behavior, requiring a case-specific analysis with MSW values higher than 0.5 cm.
Breast Cancer Subtype Prediction Model Employing Artificial Neural Network and 18F-Fluorodeoxyglucose Positron Emission Tomography/ Computed Tomography
Authors: Hossain Alamgir , Chowdhury Shariful Islam 
Published: July 2024

Introduction:
Although positron emission tomography/computed tomography (PET/CT) is a common tool for measuring breast cancer (BC), subtypes are not automatically classified by it. Therefore, the purpose of this research is to use an artificial neural network (ANN) to evaluate the clinical subtypes of BC based on the value of the tumor marker.

Materials and Methods:
In our nuclear medical facility, 122 BC patients (training and testing) had 18F-fluoro-D-glucose (18F-FDG) PET/CT to identify the various subtypes of the disease. 18F-FDG-18 injections were administered to the patients before the scanning process. We carried out the scan according to protocol. Based on the tumor marker value, the ANN’s output layer uses the Softmax function with cross-entropy loss to detect different subtypes of BC.

Results:
With an accuracy of 95.77%, the result illustrates the ANN model for K-fold cross-validation. The mean values of specificity and sensitivity were 0.955 and 0.958, respectively. The area under the curve on average was 0.985.

Conclusion:
Subtypes of BC may be categorized using the suggested approach. The PET/CT may be updated to diagnose BC subtypes using the appropriate tumor maker value when the suggested model is clinically implemented.
Evaluation of the Treatment Planning and Delivery for Hip Implant Cases on Tomotherapy
Authors: Singh Pawan Kumar , Verma Rohit , Tripathi Deepak , Singh Sukhvir , Bhushan Manindra , Kumar Lalit , Barik Soumitra , Gairola Munish 
Published: July 2024

Purpose:
The metal present in the implant creates artifacts during the treatment simulation, which impacts the treatment planning and delivery of the prescribed dose to the target and sparing normal tissues. This retrospective study evaluated the uncertainties in the planning and delivery of doses for prosthesis cases with dedicated phantom.

Materials and Methods:
In this retrospective study, 11 patients with a hip prosthesis having cervix carcinoma were selected. Two treatment plans were generated on treatment planning system (TPS) for each case. Plan_No_Res was without any beam restriction, and Plan_exit_only was the plan with restricted beam entry through the metallic implant. An indigenous phantom was utilized to verify the accuracy of the treatment. In the phantom, some groves were present, which could be filled by implants that mimic the patient’s geometries, like left, right and bilateral femur implants. The delivered doses were recorded using optically stimulated luminescence dosimeters (OSLDs), which were placed at different positions in the phantom. The plans were further calculated using megavoltage computed tomography (MVCT) scans acquired during treatment.

Results:
The patient data showed no significant dose changes between the two planning methods. The treatment time increases from 412.18 ± 86.65 to 427.36 ± 104.80 with P = 0.03 for Plan_No_Res and Plan_exit_only, respectively. The difference between planned and delivered doses of various points across phantom geometries was within ± 9.5% in each case as left, right, and bilateral implant. The variations between OSLDs and MVCT calculated doses were also within ± 10.8%.

Conclusion:
The study showed the competency of tomotherapy planning for hip prosthesis cases. The phantom measurements demonstrate the errors in dosimetry near the implant material, suggesting the need for precise methods to deal with artifact-related issues.
Analyzing Global Cancer Control: Progress of National Cancer Control Programs through Composite Indicators and Regression Modeling
Authors: Chauhan Rohit Singh , Munshi Anusheel , Pradhan Anirudh 
Published: July 2024

Aim:
Cancer is a significant public health concern, and National Cancer Control Programs (NCCPs) are crucial for reducing its burden. However, assessing the progress of NCCPs is challenging due to the complexity of cancer control outcomes and the various factors that influence them. Composite indicators can provide a comprehensive and accurate assessment of NCCP progress.

Materials and Methods:
The dataset was compiled for 144 countries and comprised eight composite indices and two high-level comparative indicators (mortality-to-cancer incidence ratio [MIR] and 5-year cancer prevalence-to-incidence ratio [PCIR]) representing NCCP outcomes. Two large databases and six annual composite index reports were consulted. Linear regression analysis and Pearson correlation coefficients were used to establish a relationship between indicators and NCCP outcomes. A multiple regression machine learning model was generated to further improve the accuracy of NCCP outcome prediction.

Results:
High-income countries had the highest cancer incidence, whereas low-income countries had the highest MIR. Linear regression analysis indicated a negative trend between all composite indicators and MIR, whereas a positive trend was observed with PCIR. The Human Development Index and the Legatum Prosperity Index had the highest adjusted R
2 values for MIR (0.74 and 0.73) and PCIR (0.86 and 0.81), respectively. Multiple linear regression modeling was performed, and the results indicated a low mean squared error score (−0.02) and a high R
2 score (0.86), suggesting that the model accurately predicts NCCP outcomes.

Conclusions:
Overall, composite indicators can be an effective tool for evaluating NCCP, and the results of this study can aid in the development and keeping track of NCCP progress for better cancer control.
Effect of Magnetic Resonance Imaging on the Motion Accuracy of Magnetic Resonance Imaging-compatible Focused Ultrasound Robotic System
Authors: Antoniou Anastasia , Evripidou Nikolas , Chrysanthou Antreas , Georgiou Leonidas , Ioannides Cleanthis , Spanoudes Kyriakos , Damianou Christakis 
Published: July 2024

Purpose:
The current study provides insights into the challenges of safely operating a magnetic resonance imaging (MRI)-guided focused ultrasound (MRgFUS) robotic system in a high-field MRI scanner in terms of robotic motion accuracy.

Materials and Methods:
Grid sonications were carried out in phantoms and excised porcine tissue in a 3T MRI scanner using an existing MRgFUS robotic system. Fast low-angle shot-based magnetic resonance thermometry was employed for the intraprocedural monitoring of thermal distribution.

Results:
Strong shifting of the heated spots from the intended points was observed owing to electromagnetic interference (EMI)-induced malfunctions in system’s operation. Increasing the slice thickness of the thermometry sequence to at least 8 mm was proven an efficient method for preserving the robotic motion accuracy.

Conclusions:
These findings raise awareness about EMI effects on the motion accuracy of MRgFUS robotic devices and how they can be mitigated by employing suitable thermometry parameters.
Validation of Microionization Chambers in Small-field Dosimetry
Authors: Kannan Mageshraja , Saminathan Sathiyan , Shwetha B. , Chandraraj Varatharaj , Raj D. Gowtham , Ganesh K. M. 
Published: July 2024

Aim:
This study aims to validate the Razor Nano Chamber (RNC) and Razor Chamber (RC) dosimetric characteristics in a small field. The dosimetric parameters of the two chambers were compared.

Materials and Methods:
The chamber characteristics of leakage (pre and post), stability, energy dependency, dose linearity, dose rate effect, stem effect, angular dependency, ion recombination effect, and polarity effect were studied. Relative dose measurements of the percentage depth dose, profile measurement, and output factor (OF) measurements were performed for small fields. All measurements were performed in a Theratron 780E telecobalt unit and an Elekta Versa HD™ Linear Accelerator.

Results and Discussion:
The measured pre- and postirradiation leakage and energy dependency were within 0.5% of the acceptable limit. In the stability check, the standard error and standard error of mean were 0.047% and 0.068%, respectively, for both RNC and RC. The deviation in the angular responses of the RNC and RC ion chambers was negligible. In the ion recombination measurements, both the RNC and RC were overestimated for the 10 flattening filter-free photon beam. In small fields, there were no significant differences in the kpol values for either chamber. The RNC showed good agreement in the relative dose measurements compared to the RC.

Conclusion:
RNC and RC showed good agreement in small-field dosimetry. The RNC angular dependency and OF showed a superior response compared to the RC because of the small volume spherical shape and high spatial resolution, which gives a reduced penumbra and no volume averaging effect.
A young male with non-resolving consolidation and hepatosplenomegaly
Authors: Bajad Pradeep , Pahuja Sourabh , Agarwal Satyam , Khanna Gaurav , Khanna Arjun 
Published: July 2024

ABSTRACT
Non-resolving consolidation refers to the persistence of radiographic abnormalities beyond the anticipated timeframe. Conditions such as infection, malignancy, inflammatory disorders, and connective tissue diseases can all manifest as non-resolving consolidation. We share a clinicopathological case study involving a 30-year-old male who exhibits non-resolving consolidation accompanied by hepatosplenomegaly.
Ventilator-associated pneumonia – What price does the public health system pay?
Authors: Thimmaiah Guruprasad , Pandey Navin , Prinja Shankar , Jain Kajal , Biswal Manisha , Agarwal Ritesh , Koushal Vipin , Sethi Saru 
Published: July 2024

ABSTRACT

Background:
Ventilator-associated pneumonia (VAP) is the commonest healthcare-associated infection (HAI) in intensive care units (ICU), especially in trauma patients. VAP imposes a significant cost burden on the healthcare ecosystem. However, there are few data from the developing world.

Methodology:
We conducted this study in the trauma ICU (TICU) of PGIMER, Chandigarh, from October 2021 to December 2022. The incidence, incidence density, and average length of stay (ALOS) of both VAP and non-VAP patients were established. The health system cost was assessed using a mixed (top-down and bottom-up) micro-costing approach. We collected data for all the resources (direct and indirect costs) utilized during service delivery and estimated the health system cost per bed per day.

Results:
In this study, 494 patients were admitted to TICU, of which 484 received Mechanical Ventilation (MV) and 47 developed VAP. We included 41 and 44 patients with and without VAP. The VAP incidence rate was 9.7% and the VAP incidence density was 10.79/1000 MV days. The ALOS for VAP patients was 21 days, and for non- VAP patients was 8.2 days. Our study estimated a total health system cost of INR 25,927 per bed per day. The health system cost of treating a VAP patient was INR 544,467 compared to INR 207,416 for a non-VAP patient.

Conclusion:
Treatment of VAP poses substantial costs for the health system and patients. There is a need to focus on preventing VAP, which would eventually reduce the length of stay and the resultant financial impact on the health system and the patient.