A method for verification of treatment times for high-dose-rate intraluminal brachytherapy treatment

Purpose: This study was aimed to increase the quality of high dose rate (HDR) intraluminal brachytherapy treatment. For this purpose, an easy, fast and accurate patient-specific quality assurance (QA) tool has been developed. This tool has been implemented at Bahawalpur Institute of Nuclear Medicine and Oncology (BINO), Bahawalpur, Pakistan.Methods: ABACUS 3.1 Treatment planning system (TPS) has been used for treatment planning and calculation of total dwell time and then results were compared with the time calculated using the proposed method. This method has been used to verify the total dwell time for different rectum applicators for relevant treatment lengths (2-7 cm) and depths (1.5-2.5 cm), different oesophagus applicators of relevant treatment lengths (6-10 cm) and depths (0.9 & 1.0 cm), and a bronchus applicator for relevant treatment lengths (4-7.5 cm) and depth (0.5 cm).Results: The average percentage differences between treatment time TM with manual calculation and as calculated by the TPS is 0.32% (standard deviation 1.32%) for rectum, 0.24% (standard deviation 2.36%) for oesophagus and 1.96% (standard deviation 0.55%) for bronchus, respectively. These results advocate that the proposed method is valuable for independent verification of patient-specific treatment planning QA.Conclusion: The technique illustrated in the current study is an easy, simple, quick and useful for independent verification of the total dwell time for HDR intraluminal brachytherapy. Our method is able to identify human error-related planning mistakes and to evaluate the quality of treatment planning. It enhances the quality of brachytherapy treatment and reliability of the system

Design of Anion Exchange Membranes and Electrodialysis Studies for Water Desalination

Anion exchange membranes are highly versatile and nowadays have many applications, ranging from water treatment to sensing materials. The preparation of anion exchange membranes (AEMs) from brominated poly(2,6-dimethyl-1,6-phenylene oxide) (BPPO) and methyl(diphenyl)phosphine (MDPP) for electrodialysis was performed. The physiochemical properties and electrochemical performance of fabricated membranes can be measured by changing MDPP contents in the membrane matrix. The influence of a quaternary phosphonium group associated with the removal of NaCl from water is discussed. The prepared membranes have ion exchange capacities (IEC) 1.09–1.52 mmol/g, water uptake (WR) 17.14%–21.77%, linear expansion ratio (LER) 7.96%–11.86%, tensile strength (TS) 16.66–23.97 MPa and elongation at break (Eb) 485.57%–647.98%. The prepared anion exchange membranes were employed for the electrodialytic removal of 0.1 M NaCl aqueous solution at a constant applied voltage. It is found that the reported membranes could be the promising candidate for NaCl removal via electrodialysi

A phantom study for in-vivo dosimetry of high dose rate brachytherapy applicators

Purpose: The aim of the current investigation was to calibrate the diode in-vivo dosimetry (IVD) system for high-dose-rate (HDR) brachytherapy and to design a phantom study for in-vivo dosimetry of HDR brachytherapy applicators.Methods: Gamma Med Plus with Abacus 3.1 treatment planning system (TPS), and diode dosimetry system has been used in this study. Calibration and different correction factors of diode have been measured in water phantom. Treatment simulation, planning of different applicators for esophagus, rectum/vagina and cervix (fletcher & ring), dose delivery and finally in-vivo verification at prescription point using diode in water phantom has been performed.Results: The mean calibration factor for diode for Ir-192 HDR source is 1.256 (N=15) with σ ± 0.0015. The overall average percentage difference between TPS dose and diode dose was 1.87% (σ ± 2.64) for all measurements, 1.86% (σ ± 2.73) for esophagus, 1.86% (σ± 2.94) for rectum/vagina and 1.67% (σ ±2.81) for fletcher and 2.07% (σ ± 2.26) for ring applicators, respectively. These results advocate that the dose calculated by TPS and dose measured using diode for the various clinical situations deliberated here are in good agreement (~2%) at the points of clinical importance.Conclusion: The in-vivo phantom dosimetry study gives both a confidence that the treatments are being delivered as prescribed and enhance the reliability of the HDR brachytherapy treatment. This may be used for acceptance testing/commissioning of new treatment planning system and to validate the new brachytherapy techniques in the clinics.

Deep Convolutional Neural Network Based Analysis of Liver Tissues Using Computed Tomography Images

Liver disease is one of the most prominent causes of the increase in the death rate worldwide. These death rates can be reduced by early liver diagnosis. Computed tomography (CT) is a method for the analysis of liver images in clinical practice. To analyze a large number of liver images, radiologists face problems that sometimes lead to the wrong classifications of liver diseases, eventually resulting in severe conditions, such as liver cancer. Thus, a machine-learning-based method is needed to classify such problems based on their texture features. This paper suggests two different kinds of algorithms to address this challenging task of liver disease classification. Our first method, which is based on conventional machine learning, uses texture features for classification. This method uses conventional machine learning through automated texture analysis and supervised machine learning methods. For this purpose, 3000 clinically verified CT image samples were obtained from 71 patients. Appropriate image classes belonging to the same disease were trained to confirm the abnormalities in liver tissues by using supervised learning methods. Our proposed method correctly quantified asymmetric patterns in CT images using machine learning. We evaluated the effectiveness of the feature vector with the K Nearest Neighbor (KNN), Naive Bayes (NB), Support Vector Machine (SVM), and Random Forest (RF) classifiers. The second algorithm proposes a semantic segmentation model for liver disease identification. Our model is based on semantic image segmentation (SIS) using a convolutional neural network (CNN). The model encodes high-density maps through a specific guided attention method. The trained model classifies CT images into five different categories of various diseases. The compelling results obtained confirm the effectiveness of the proposed model. The study concludes that abnormalities in the human liver could be discriminated and diagnosed by texture analysis techniques, which may also assist radiologists and medical physicists in predicting the severity and proliferation of abnormalities in liver diseases

Machine vision-based Statistical texture analysis techniques for characterization of liver tissues using CT images

Objective: To characterize human liver tissues by demonstrating the ability of machine vision, and to propose a new auto-generated report based on texture analysis that may work with co-occurrence matrix statistics. Method: The retrospective study was conducted at Bahawal Victoria Hospital (BVH), Bahawalpur, Pakistan, and comprised clinically verified computed tomography imaging data between October 2018 and September 2020. The image samples and related data were used to segregate classes 1-4. Appropriate image classes belonging to the same disease were trained to confirm the abnormalities in liver tissues using supervised learning methods, principal component analysis, linear discriminant analysis, and non-linear discriminant analysis. Robust and reliable texture features were investigated by generating testing classes. Overall performance of the presented machine vision approach was analyzed using four parameters; precision, recall/sensitivity, F1-score, and accuracy. Statistical analysis was done using B11 software. Results: There were 312 image samples from 71 patients; 51(71.8%) males and 20(28.2%) females. Among the patients, 19(26.7%) had abscess, 15(21.1%) had metastatic disease, 23(32.4%) had tumour necrosis, 6(8.5%) had vascular disorder, and 8(11.3%) were normal. Principal component analysis, linear discriminant analysis, and non-linear discriminant analysis showed high >97.86% values, but the discrimination rate was 100% for class 4. Conclusion: Abnormalities in the human liver could be discriminated and diagnosed by texture analysis techniques using second-order statistics that may assist the radiologist and medical physicists in predicting the severity and proliferation of abnormalities in liver diseases. Key Words: Liver abscess, Computed tomography imaging, Liver diseases, Image processing

A method for verification of treatment times for high-dose-rate intraluminal brachytherapy treatment

Purpose: This study was aimed to increase the quality of high dose rate (HDR) intraluminal brachytherapy treatment. For this purpose, an easy, fast and accurate patient-specific quality assurance (QA) tool has been developed. This tool has been implemented at Bahawalpur Institute of Nuclear Medicine and Oncology (BINO), Bahawalpur, Pakistan.Methods: ABACUS 3.1 Treatment planning system (TPS) has been used for treatment planning and calculation of total dwell time and then results were compared with the time calculated using the proposed method. This method has been used to verify the total dwell time for different rectum applicators for relevant treatment lengths (2-7 cm) and depths (1.5-2.5 cm), different oesophagus applicators of relevant treatment lengths (6-10 cm) and depths (0.9 &amp; 1.0 cm), and a bronchus applicator for relevant treatment lengths (4-7.5 cm) and depth (0.5 cm).Results: The average percentage differences between treatment time TM with manual calculation and as calculated by the TPS is 0.32% (standard deviation 1.32%) for rectum, 0.24% (standard deviation 2.36%) for oesophagus and 1.96% (standard deviation 0.55%) for bronchus, respectively. These results advocate that the proposed method is valuable for independent verification of patient-specific treatment planning QA.Conclusion: The technique illustrated in the current study is an easy, simple, quick and useful for independent verification of the total dwell time for HDR intraluminal brachytherapy. Our method is able to identify human error-related planning mistakes and to evaluate the quality of treatment planning. It enhances the quality of brachytherapy treatment and reliability of the system.</p

Treatment planning evaluation of sliding window and multiple static segments technique in intensity modulated radiotherapy

BackgroundThe demand of improved dose conformity of the tumor has been increased in radiation therapy with the advent of recent imaging facilities and efficient computer technologies.AimWe compared the intensity modulated radiotherapy (IMRT) plans delivered with the sliding window (SW IMRT) and step and shoot (SS IMRT) techniques.Materials and methodsThirteen patients were planned on 15 MV X-ray for five, seven, nine and thirteen beams direction making the dose constraints analogous. Eclipse treatment planning system with Helios inverse planning software, and Linear Accelerator Varian 2100[[ce:hsp sp="0.25"/]]C/D with 120 multileaf collimators (MLCs) were used. Gamma analysis was applied to the data acquired with the MapCheck 2™ for different beam directions plan in the sliding window and step and shoot technique to meet the 95% pass criteria at 3%/3[[ce:hsp sp="0.25"/]]mm. The plans were scrutinized using Dmean, Dmax, D1%, D95%, dose uniformity index (UI), dose conformity index (CI), dose homogeneity index (HI) and monitor units (MUs).ResultsOur data show comparable coverage of the planning target volume (PTV) for both the sliding window and step and shoot techniques. The volume of PTV receiving the prescription dose was 99.8[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.05% and the volume of PTV receiving the maximum dose was 107.6[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]2.5% in both techniques. Bladder and rectum maximum mean doses for the sliding window and step and shoot plans were 38.1[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]2.6% and 42.9[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]10.7%. Homogeneity index (HI) for both techniques was 0.12[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.02 and 0.13[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.02, uniformity index (UI) was 1.07[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.02 and 108[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.01 and conformity index at 98% isodose (CI 98%) was 0.96[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.005 and 0.96[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]0.005 for the sliding window and step and shoot techniques, respectively, and MUs were 10[[ce:hsp sp="0.25"/]]±[[ce:hsp sp="0.25"/]]12% lower in the step and shoot compared to the sliding window technique.ConclusionAll these factors indicate that coverage for PTV was nearly identical but dose to organs-at-risk (OARs) was lower in the step and shoot technique