Background Mechanical ventilation remains a life-saving intervention but carries risks such as barotrauma, volutrauma, ergotrauma, and hemodynamic disturbances. Modern ventilators incorporate adaptive strategies to minimize the work of breathing (WOB), often relying on measurements of respiratory resistance and compliance. However, such measurements are prone to error and often unavailable in real time. This study presents a novel adaptive ventilation concept that dynamically identifies the optimal ventilation frequency minimizing WOB per minute without requiring resistance or compliance measurements.Material and methods Using a validated hybrid respiratory simulator, we conducted simulation experiments across three representative lung conditions: normal mechanics, decreased compliance, and increased resistance. The system conceptually searched for the ventilation frequency minimizing WOB/min while maintaining constant alveolar ventilation, with the optimization process emulated manually in this proof-of-concept study.Results Results confirmed that WOB/min follows a parabolic function of frequency, with optimal frequencies found at 18, 21, and 12 breaths per minute for normal, restrictive, and obstructive patterns, respectively. Importantly, the optimal frequencies aligned with ranges observed in clinical studies of adaptive support ventilation. Furthermore, the system demonstrated natural variability in ventilation rate and tidal volume, which may contribute to alveolar recruitment.Conclusion Our findings validate the concept of energy-based optimization of ventilation independent of online lung mechanics assessment. The proposed method is robust, physiologically grounded, and may become suitable for integration into next-generation intelligent ventilators after full automation of the adaptive algorithm. Future work will focus on full automation of the adaptive algorithm and its evaluation in preclinical and clinical studies targeting WOB and mechanical power minimization.
Introduction The study aims to evaluate the effectiveness of three methods for detecting fiducial points in the impedance cardiography (ICG) signal in the context of subtle hemodynamic changes induced by caffeine intake. The compared approaches include: time-domain detection (CPDA), extrema-based analysis (EBA) and wavelet transform analysis (WTA).Material and methods The study involved 20 healthy volunteers, with cardiovascular parameters such as stroke volume (SV), cardiac output (CO) and heart rate (HR) assessed before and after coffee consumption.Results Comparative analysis showed that WTA provided the lowest variability of hemodynamic parameters, with standard deviations of +/- 1.54 for CO and +/- 21.82 for SV, compared with +/- 1.76 and +/- 33.77 for EBA and +/- 1.92 and +/- 43.59 for CPDA, respectively. Repeated-measures ANOVA revealed significant differences between methods in HR estimation after decaffeinated coffee consumption (p = 0.001). Post-hoc analysis showed significant differences between EBA and CPDA (p = 0.0006), EBA and WTA (p = 0.0003), and EBA and pressure-gauge measurements (p = 0.002). Additional analyses confirmed significant effects of beverage type and method on HR (p = 0.003 for decaffeinated coffee; p = 0.02 for caffeinated coffee) and on CO after decaffeinated coffee (p = 0.03).Conclusions Overall, the wavelet-based approach demonstrated the greatest robustness to noise and the highest sensitivity to subtle physiological changes associated with caffeine intake. This work highlights the importance of selecting appropriate algorithms for remote cardiovascular monitoring and personalized healthcare and demonstrates their sensitivity to capture subtle changes induced by caffeine ingestion.
Background Accurate representation of lung geometry is a prerequisite for reliable computational modelling of cardiopulmonary interaction, particularly for simulating regional ventilation-perfusion (V/Q) heterogeneity driven by gravity and vascular anatomy. Most existing models either simplify lung geometry or lack explicit spatial anchoring to physiological reference points.Material and methods In this study, diagnostic computed tomography (CT) images were used to reconstruct anatomically faithful lung geometry and subdivide both lungs into 80 spatially coherent regions. For each region, a set of geometric parameters was extracted, including volume and three-dimensional coordinates of the centre of gravity relative to the pulmonary trunk and to horizontal and vertical reference planes. Image preprocessing, vectorization, and geometric reconstruction were performed using widely available software tools, and the resulting feature matrix was implemented in a mathematical model of cardiopulmonary interaction within a virtual patient environment.Results The CT-based approach enabled precise localization of the pulmonary trunk and consistent definition of a global coordinate system, allowing simultaneous representation of vertical (gravitational) and radial (vascular resistance-related) perfusion gradients. Example simulations demonstrated physiologically plausible distributions of ventilation and perfusion across lung regions, including reduced ventilation in dependent areas and heterogeneous perfusion within iso-gravitational planes.Conclusions CT-based reconstruction of lung geometry from diagnostic images enables high-resolution regional partitioning and generation of a robust geometric matrix suitable for cardiopulmonary simulations. Although limited to a single anatomical dataset and static geometry, the presented model provides a solid foundation for future integration of regional mechanics, dynamic deformation, and validation with functional imaging, supporting advanced research, educational, and clinical applications.
Introduction Effective prostate radiotherapy requires integrating radiobiological parameters like the alpha/beta ratio with planning factors such as dose gradients, margins, and adaptive strategies. Predicting late rectal bleeding (LRB) remains challenging but essential for optimizing safety. This study presents a preliminary model to predict LRB using only patient imaging data, offering a practical tool to assess toxicity risk daily and support personalized treatment decisions. Material and methods We retrospectively analyzed a cohort of 116 prostate cancer patients treated with radiotherapy, divided into standard (2.0 Gy/fraction) and m-Hypo (2.5 Gy/fraction) groups. The toxicity endpoint was late rectal bleeding (LRB); its incidence was characterized and the rectal alpha/beta ratio estimated and used in subsequent analyses. To assess relationships between toxicity and patient/treatment/planning factors, six metrics were defined: one geometric parameter, P-0, representing the rectum-PTV intersection volume, and five DVH parameters. We combined these findings in a sector analysis using linear and logistic models between selected parameters. Results Late rectal bleeding (LRB) occurred in 11% of the standard group and 26% of the hypofractionated group. The estimated alpha/beta for the LRB endpoint was 1.5 Gy (95% CI: 0-12 Gy). Dose-volume metrics P-2 and P-4 were significantly associated with binary toxicity in logistic regression. Sector analysis using P-0 as the independent variable identified regions with high toxicity rates (>40%), predominantly within the hypofractionated cohort, as well as regions with negligible toxicity. Conclusions A linear relationship between the P-0 parameter and toxicity predictors (P-3, P-4) suggests that volumetric parameters can be integrated into patient-specific risk assessments and treatment planning. Our findings indicate that regions with P-0 < 10 cc (L1, H1) may tolerate variations in fractionation and dose, while regions with higher P-0 (L2, H2) require cautious strategies such as dose reduction, margin optimization, and advanced imaging to minimize toxicity. This framework provides a foundation for personalized radiotherapy optimization, pending further validation.
Introduction The primary objectives of replacing a natural hip joint with a prosthesis are to restore the function of a joint damaged by degenerative disease, advanced rheumatoid conditions, or mechanical injury, to eliminate pain caused by pathological joint changes, and to re-establish proper load transfer. Additionally, the procedure aims to restore motor functions, enabling the patient to move and perform essential daily activities such as walking, lifting, and carrying objects.Material and methods This article outlines the requirements for biomaterials used in the components of hip joint prostheses, presents various groups of titanium alloys, and describes their properties in detail. Special attention is paid to titanium and titanium alloys, including their mechanical and physical characteristics. The influence of Young's modulus on fretting and fatigue cracking in metallic alloys used in modular prosthetic components is also examined.Results Titanium alloys are generally not used for femoral heads due to their poor tribological performance. Without appropriate surface modification, titanium alloys are unsuitable for use in articulating components such as heads and acetabular cups, as they exhibit low abrasion resistance. They also demonstrate limited resistance to fretting damage, particularly at the junctions between the stem neck and head in modular prostheses.Conclusions To improve abrasion resistance, diffusion-based thermochemical surface treatments can be employed to harden the material's outer layer. However, the issue of fretting-induced damage at the neck region of hip endopros-theses remains unresolved. This problem is critical, as it often leads to corrosion and fatigue cracking of the stem neck, ultimately requiring prosthesis revision and incurring significant clinical and economic consequences. Plasma (ionic) nitriding has been shown to enhance surface properties such as hardness, wear resistance, resistance to fretting damage, fretting corrosion, and fretting fatigue, as well as overall fatigue cracking resistance.
Introduction Advances in teleradiotherapy, such as SRS and SBRT, have improved treatment by delivering higher doses in fewer sessions, reducing duration, and sparing healthy tissue. These techniques require precise patient positioning, achieved through systems like SGRT (surface tracking) and IGRT (X-ray imaging). The ExacTrac Dynamic system (Brainlab AG, Germany) combines both, offering submillimetric accuracy for cranial radiotherapy. This study evaluates its quality assurance (QA) protocols, focusing on calibration, accuracy, and clinical performance.Background and Purpose SRS and SBRT allow targeted treatment with minimal margins, reducing complications. Precise alignment is essential, particularly for cranial cases. The study assesses the QA processes of the ExacTrac Dynamic system and evaluates its accuracy and reliability.Results Daily logs revealed differences between Surface Tracking and X-ray imaging. X-ray was more reliable, especially for longitudinal translational deviations, while Surface Tracking was affected by thermal artifacts. Rotational deviations remained within tolerance, with the largest shifts in yaw. Histogram analysis showed skewed distributions, underscoring the importance of combining both methods and regular QA.Conclusion Regular QA and recalibration of the ExacTrac Dynamic system are essential to address discrepancies between SGRT and X-ray methods. X-ray offers greater precision, while Surface Tracking is prone to environmental artifacts. Combining SGRT and IGRT ensures accuracy but requires consistent QA to maintain treatment precision.
Introduction Intraoperative radiotherapy (IORT) delivers a single high-dose radiation fraction directly to the tumor or tumor bed during surgery, minimizing exposure to healthy tissue. The INTRABEAM 600 system, with its compact design and low-energy X-rays, requires thorough commissioning and quality assurance. This study performs dosimetric measurements, establishes an independent verification method, and compares Calibration v4.0 and TARGIT approaches to ensure accurate, safe, and reliable IORT delivery, supporting improved clinical outcomes.Materials and Methods The INTRABEAM 600 system delivers low-energy X-rays via a XRS generator for precise intraoperative radiotherapy. Commissioning involved depth dose rate measurements in a water phantom using ionization chambers, with probe tip positioned along X, Y, and Z axes. Dose rates were determined using Calibration v4.0 and TARGIT methods, correlated via a conversion function. QA checks included PAICH output, IRM baseline, and isotropy verification, ensuring accurate, reproducible treatment delivery.Results Dynamic offset analysis showed minimal deviations, confirming accurate beam targeting. The Output Check confirmed stable system performance. Depth dose rate curve measurements revealed a mean difference of -1.3 +/- 1% from certification data. Treatment time calculations using spherical applicators showed minor differences between INTRABEAM600 and radiance, with the largest at -1.9 +/- 1.1% for the 20 mm applicator. TARGIT results were similar, with the largest differences at -1.8 +/- 0.6% for the 15 mm and 20 mm applicators.Conclusion Comprehensive commissioning and QA confirmed that the INTRABEAM 600 system is stable, precise, and clinically reliable. Dynamic offsets showed minimal deviations, verifying correct beam alignment, while Output Check tests confirmed XRS generator stability. Depth dose rate measurements agreed closely with certification data -1.3 +/- 1.0%. Treatment time comparisons using Calibration v4.0 and TARGIT showed minor discrepancies, largest for small applicators (15-20 mm). Independent verification and radiance simulations support accurate dose delivery.
Introduction This work aims to examine image quality and dose based on Cone Beam Computed Tomography using phantoms in the two institutionsMaterials and methods The Rando and Catphan Phantoms were scanned using identical image acquisition and reconstruction settings with Cone Beam Computed Tomography (CBCT). The calibration curve was obtained based on the Hounsfiled Unit (HU) values on the Gammex 467 Phantom.. This study was performed at two institutions equipped with the same CBCT and CT Simulator. The acquisition with CBCT HU values that closely matched CT HU values employed a protocol of 120 kVp, Bowtie Filter (F1), and 80 mA for 10 ms within a Small Field of View (FOV). For the Medium FOV, the closest protocol also used 120 kVp, a Bowtie Filter, and 64 mA for 32 ms, while for the Large FOV, it was set at 120 kVp, F1, and 50 mA for 40 ms. The parameters chosen from each reconstructed FOV served as calibration curves for planning head and neck and pelvic treatments. Planning followed the Task Group 119 recommendations incorporating IMRT techniques.Result The best acquisition protocol for accurate dose calculations in head and neck cases is Field of View Small with 20 collimation using bowtie filter with 120 kVp and 80 mA for 10 ms/frame, while for Pelvic cases, it is FOVMedium with 20 collimation using bowtie filter with 120 kVp and 64 mA for 32 ms/frame. In image quality assessments, the lowest contrast visibility and uniformity scores were observed with FOV Small with 20 collimation using bowtie filter with 120 kVp and 80 mA for 10 ms/frame, using the reconstruction parameters Quality Image (QI) of 0.65% and 1%.Conclusion Selecting the appropriate CBCT acquisition protocol can lead to favorable outcomes in both dose calculation and image quality.
Introduction Breast cancer remains a major global health challenge, with Africa and other developing countries experiencing its greatest impact. Knowledge of breast density (an independent risk factor) is essential for early breast cancer diagnosis. However, such data is scarce across Africa and absent in Ghana. The aim of this work was to investigate the association between mammographic breast density patterns and BI-RADS assessment categories among women in Ghana. Material and methods A retrospective cross-sectional study was conducted on 2,108 women who underwent mammography between October 2011 and December 2022. Breast density was visually assessed by radiologists using the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS). Associations between breast density, age, and BI-RADS assessment categories were analysed using Fisher's Exact Test. Results Breast density category B (scattered fibroglandular tissue) was most common (44%, n = 935), followed by category A (almost entirely fatty; 39%, n = 821), category C (heterogeneously dense; 16%, n = 397), and category D (extremely dense; 1%, n = 23). More than 50% of all categories received benign diagnoses (BI-RADS 2), while less than 10% recorded negative diagnoses (BI-RADS 1). Higher-density categories demonstrated a greater proportion of suspicious and malignant findings: in category D, 17% were BI-RADS 3, 17% BI-RADS 4, and 13% BI-RADS 5, compared to lower proportions in categories A and B. Confirmed malignancies (BI-RADS 6) were observed across categories A-C (1% each). A significant association was found between breast density and cancer diagnoses (p < 0.05), as well as between age and breast density (p < 0.05). Conclusion There is a significant association between breast density and BI-RADS assessment categories, with lower breast density observed in older women, a finding consistent with published literature. These results highlight the need for tailored breast cancer screening strategies in Ghana.
Introduction: Chronic obstructive pulmonary disease (COPD) and dysphonia are prevalent disorders associated with altered respiratory patterns, posing significant diagnostic and therapeutic challenges. Accurate and efficient assessment of thoracic respiratory movements is essential for individualized therapy and monitoring. The Teager-Kaiser Energy Operator (TKEO), originally developed for speech analysis, offers a single-parameter approach to evaluate both amplitude and frequency characteristics of biosignals. This study aimed to determine the utility of TKEO in assessing thoracic respiratory patterns in healthy individuals, COPD patients, and those with dysphonia. Material and methods: Sixty-one participants were enrolled: 30 healthy controls, 16 with COPD, and 15 with dysphonia. Thoracic and abdominal respiratory movements were recorded using Respiratory Inductive Plethysmography (RIP) in both standing and seated positions. The TKEO parameter was calculated from the displacement signals, and its values were compared with conventional respiratory parameters (inspiratory and expiratory depths) obtained via RIP. Statistical analysis included the Kruskal-Wallis test and Spearman's rank correlation to assess group differences and parameter relationships. Results: In the seated position, TKEO values and conventional respiratory parameters significantly differentiated between healthy subjects, COPD, and dysphonia groups (p < 0.01). Healthy and COPD subjects exhibited higher diaphragmatic activity, while dysphonia patients showed a dominant upper rib pattern. TKEO values closely paralleled traditional respiratory measures, with strong to very strong positive correlations observed across all groups and positions (Spearman's rho, p < 0.001). In the standing position, group differences were less pronounced, but TKEO still reflected underlying respiratory patterns. Conclusions: TKEO is a sensitive and efficient parameter for assessing thoracic respiratory movements, correlating strongly with established respiratory metrics. Its application may accelerate and refine the diagnosis of respiratory pattern disorders in clinical practice. Further research should explore TKEO's integration with artificial intelligence-based diagnostic tools and its utility in larger, age-matched cohorts.
A reliable dosimetric assessment in internal radiotherapy is a key element in ensuring the effectiveness and safety of the treatment. The aim of the presented work was to perform model dosimetric calculations in patients undergoing treatment with a somatostatin analog labeled with radioactive lutetium-177, [ 177 Lu]Lu-DOTA-TOC, for GEP-NET. Dosimetric modeling was performed for 17 patients (11 women, 6 men, aged 32–77). Each patient received 2-4 injections of the radiopharmaceutical [ 177 Lu]Lu-DOTA-TOC during treatment, with an activity range of 2–8 GBq. Subsequently, patients underwent SPECT-CT scanning. The obtained images were segmented and quantitatively analyzed using the GE Dosimetry Toolkit software package. VOIs were delineated for the liver, kidneys, spleen, heart, and areas of pathological radiopharmaceutical accumulation. Model TAC were determined for these areas. Dosimetric calculations were performed using the OLINDA/EXM version 2.1 software. The average absorbed dose values in a single therapeutic cycle were 2.5 Gy for the liver, 3.8 Gy for the kidneys, 2.9 Gy for the spleen, and 28 mGy for the heart. The calculated absorbed dose from these organs for the bone marrow averaged 11.6 mGy. The average cumulative absorbed dose values for these organs were: 6.9 Gy, 10.6 Gy, 7.8 Gy, and 72.3 mGy, respectively. Areas of localized, non-physiological accumulation of [ 177 Lu]Lu-DOTA-TOC received an average absorbed dose of 16.2 Gy in a single therapy cycle and 48 Gy in total over the entire treatment process. The results of internal dosimetry in the studied group of patients are characterized by high variability. The kidneys were the organs most exposed to high radiation doses, and their function was monitored during treatment using biochemical markers. The good tolerance of high absorbed doses may be due to the microscopic characteristics of the dose distribution from the 177 Lu radionuclide radiation. The highest absorbed doses were observed in areas of pathological radiopharmaceutical accumulation.
This systematic review examines the establishment of Diagnostic Reference Levels (DRLs) in digital mammography across 18 European countries, based on studies from 2005-2025. A total of 353 articles were identified through the comprehensive search of academic networks: Google Scholar, PubMed, Research Gate, Academia. Only 18 peer-reviewed studies met inclusion criteria – reporting Mean Glandular Dose (MGD)-based DRLs from Finland to Malta. Eight studies used patient data, four used phantom measurements, and six used both. To overcome the challenging comparison of the variety of reported parameters, we undertook some data harmonisation procedures, focusing on a common Compressed Breast Thickness (CBT) range of 50-59 mm. The DRLs varied notably by country, with 75 th percentile MGDs ranging from 1.1 to 2.6 mGy and 95 th percentile from 1.6 to 2.9 mGy, averaging to 1.44 mGy, which is lower than the achievable European level (2 mGy). The harmonisation approach enabled the derivation of a comparable dataset of average MGDs, facilitating cross-country comparisons and insights into radiation dose optimisation in digital mammography across Europe.
This educational review provides a comprehensive overview of adaptive radiation therapy (ART), an advanced approach to adjusting radiotherapy plans in response to anatomical or physiological changes during treatment. It classifies ART into three methods, i.e. offline, online, and real-time, distinguished by the timing of plan modifications relative to the treatment session. The review emphasises the importance of monitoring discrepancies between planned and delivered doses through advanced imaging and dose-tracking techniques, and how timely adaptation can exploit this information to maintain target coverage and minimise unnecessary exposure of healthy tissues. Key enabling technologies are discussed, including high-quality on-board imaging modalities (CT, cone-beam CT, MRI, PET) for accurate visualisation of current anatomy, deformable image registration and automated contour propagation for efficient mapping of anatomical changes, and reliable dose recalculation on images from the treatment machine to ensure dosimetric accuracy of adapted plans. Equally important, rigorous quality assurance (QA) protocols are outlined, including validation of image registration accuracy (to verify deformable alignment), end-to-end testing of the entire adaptive workflow, patient-specific plan verification via independent dose checks or in vivo dosimetry, and thorough risk analysis (such as failure mode and effects analysis) to anticipate potential errors. Clear adaptation criteria and multidisciplinary team oversight are recommended to ensure that adaptive interventions fulfil the promise of improved tumour control and reduced toxicity without compromising patient safety.
Abstract Introduction: This systematic review evaluates various studies on deep learning algorithms for generating synthetic CT images from MRI data, focusing on challenges in image quality and accuracy in current synthetic CT generation methods. Magnetic resonance imaging (MRI) is increasingly important in clinical settings due to its detailed visualization and noninvasive nature, making it a valuable tool for advancing patient care and identifying new areas for research. Materials and Methods: In this study we conducted a thorough search across several databases to identify studies published between January 2009 and January 2024 on using deep learning to generate synthetic CT (sCT) images from MRI for radiotherapy. The review focused on peer-reviewed, English-language studies and excluded unpublished, non-English, and irrelevant studies. Data on deep learning methods, input modalities, and anatomical sites were extracted and analyzed using a result-based synthesis approach. The review categorized 84 studies by anatomical site, following PRISMA guidelines for summarizing the findings. Results: The U-Net model is the most frequently used deep learning model for generating synthetic CT images from MRI data, with 34 articles highlighting its effectiveness in capturing fine details, Conditional GANs are also widely used, while Cycle-GANs and Pix2pix are effective in image translation tasks. Significant differences in performance metrics, such as MAE and PSNR, were observed across anatomical regions and models, highlighting the variability in accuracy among different deep learning approaches. Conclusion: This review underscores the need for continued refinement and standardization in deep learning approaches for medical imaging to address variability in performance metrics across anatomical regions and models.
Introduction Regular quality control and verification of medical ultrasound systems are essential for maintaining high diagnostic accuracy. However, the high cost of commercial phantoms often limits their use, particularly in smaller healthcare facilities. This study aimed to develop a low-cost agar-based phantom and evaluate its suitability for ultra-sound quality control.Material and methods The phantom was constructed using a plexiglass container filled with a 30 g/L agar solution. Test structures of different sizes were incorporated using nylon threads, small wooden pieces, and agar mixed with graphite. Measurements were performed with Voluson 730 Expert and GE Healthcare LOGIQ alpha 100 systems.Results Quality control tests included assessments of image uniformity, contrast resolution, spatial resolution, dead zone, maximum penetration depth, and geometric accuracy. The presence of targets of varying sizes enabled evaluations consistent with international quality assurance guidelines. During testing, several image artifacts and minor malfunctions were observed, likely resulting from trapped air bubbles or transducer imperfections, which could influence image interpretation. Nevertheless, the results indicate that the developed phantom performs reliably for key ultrasound quality control procedures.Results Quality control tests included assessments of image uniformity, contrast resolution, spatial resolution, dead zone, maximum penetration depth, and geometric accuracy. The presence of targets of varying sizes enabled evaluations consistent with international quality assurance guidelines. During testing, several image artifacts and minor malfunctions were observed, likely resulting from trapped air bubbles or transducer imperfections, which could influence image interpretation. Nevertheless, the results indicate that the developed phantom performs reliably for key ultrasound quality control procedures.Conclusions Its simple design, inexpensive materials, and adaptability make it particularly suitable for routine checks and training applications. Furthermore, its easy reproducibility allows customization for different clinical needs and equipment types. Overall, this study demonstrates that an agar-based phantom can serve as an effective, low-cost alternative to commercial models, supporting systematic quality control in ultrasound imaging. Such accessible solutions may help standardize testing procedures, enhance diagnostic consistency, and ultimately improve patient safety.
Introduction Skin surface brachytherapy is a highly targeted radiation therapy used for treating superficial malignancies, offering precise dose delivery with minimal impact on surrounding healthy tissues. However, in-vivo dose verification remains a critical challenge in brachytherapy. Thermoluminescent dosimeters (TLDs) provide a promising solution for increased precision of dose delivery to cancer patients. This study proposes a TLD-based method to assess radiation exposure during skin surface brachytherapy, with a particular focus on TLDs calibration process and validation leading to the opportunity to reduce dose of radiosensitive structures such as the lens of the eye.Materials and Methods TL detectors were calibrated using both an Iridium-192 (Ir-1(9)2) source and a 6 MV photon beam, incorporating correction factors to enhance measurement accuracy. During measurements, TLDs were positioned on the skin surface of the anthropomorphic head phantom to absolute point dose measurements. The measured TLD doses were compared with treatment planning system (TPS) calculations to validate the proposed method. Additionally a specific analysis was conducted to compare the radiation exposure of the eye lens with and without the use of a protective eye shield with use of the anthropomorphic head phantom.Results TLDs response to a uniform radiation dose were within the range of +/- 10% of the mean. For the method of calibration used 6MV photons from medical linear accelerator, a value 3% for the energy correction factor was applied to account for the difference in sensitivity of the TLDs in 192Ir and 6MV. For both calibration methods, with used appropriate calibration factors, obtained dose values for the anthropomorphic head phantom were within +/- 5% of the TPS dose values. The use of a lead shield placed in the phantom's eye socket reduced the dose to the eye lens by up to 20%.Conclusions The developed TLD dosimetry method provides a precise and reliable approach for in-vivo dose verification in skin surface brachytherapy. By integrating calibrated TLD-based measurements, the correct implementation of radiotherapy plans can be verified. The study also confirms the protective efficacy of an eye shield in minimizing radiation exposure to the lens, reinforcing the importance of shielding strategies in clinical practice. Further validation and clinical implementation will contribute to improved patient safety and therapeutic outcomes in brachytherapy.
Introduction The analysis of the differences in the daily volumes and the predicted dose to the actual dose in the bladder, rectum, and targets in prostate radiotherapy is presented.Material and methods The analysis was performed for 30 patients treated with prostate cancer. Precision treatment planning system was used to calculate the dose distribution. Patients were set up on the treatment table in the treatment position every day. kVCT images were acquired. kVCT images were imported into the PreciseART module. Organs at Risk and the prostate (PTV) volumes were copied onto these daily actual CT images and then automatically deformed to their current shapes. They were used to recalculate the updated therapeutic treatment plan. 726 CT examinations were analyzed. The volumes and dose values from clinical treatment plan have been used as reference values for the PTV, bladder, and rectum. Changes in volumes and doses for reference values and daily CT images were analyzed.Results The average daily changes in PTV, bladder and rectum volumes ranged from -0.3% to 14.4%, -21.7% to 32.5% and -10.5% to 32.5%, respectively. Corresponding standard deviations ranged from 1.0% to 5.5%, 4.9% to 35.5% and 5.8% to 25.2%, respectively. Corresponding median values ranged from -0.2% to 14.1%, -22.0% to 37.8% and -10.9 to 32.8, respectively. The average daily changes in PTV, bladder and rectum projected doses ranged from -1.4% to 2.9%, -9.0% to 24.8% and -25.4% to 15.9%, respectively. Corresponding standard deviations ranged from -1.4% to 2.6%, 0.0% to 14.8% and 0,0% to 17,2%, respectively. Corresponding median values ranged from -1.5% to 2.7%, -8.8% to 28.7% and -25.9% to 17.2%, respectively.Conclusions Qualitative data analysis showed that the greatest differences in volumes and doses occurred for these structures. For the prostate, these changes were lower than for other organs.
Introduction Radiotherapy is a crucial method of treating lung cancer. However, potential toxicity such as radiation-induced lung injury (RILI) must be considered. In order to quantitatively describe different forms of RILI, a next generation of a previously discussed system has been developed to analyse the subsequent series of CT scans performed by patients during radiation therapy and post-RT follow-up.Materials and methods A 3D CT scan registration module has been developed as part of the system. The analysis management module has been expanded compared to previous versions of the system. The environment has been prepared and the system has been deployed. In order to determine the effectiveness of the system, 1598 analyses, based on automated image pre-processing (registration and segmentation) and first-order delta-radiomics features, have been performed on a data set from 50 Patients.Results The efficiency of the execution of the analysis was evaluated in terms of time, including a breakdown into individual stages of the pipeline. The results of the analyses were visualised and exported to a CSV file, then evaluated from a clinical perspective.Conclusions The system allows, thanks to the use of a 3D registration algorithm, to analyse changes more accurately than before, and thanks to the use of a more flexible architecture, to introduce subsequent registration and calculation algorithms more easily. The current main research and development areas of the system include the extension of the analytical capabilities of the system in the field of radiomics and the expansion of the number of image analysis algorithms used within the system.
Introduction Low-level laser therapy (LLLT), also known as photobiomodulation, has emerged as a promising therapeutic option for various medical applications, including pain management and wound healing. This study aims to investigate the dose parameters of LLLT to optimize therapeutic efficacy.Materials and Methods We utilized Finite Element Analysis within the COMSOL Multiphysics software package to model light-tissue interactions and refine dosing protocols. Lasers with wavelengths of 660 nm, 780 nm, and 808 nm were selected due to their widespread use in therapy. Additionally, we examined several factors that impact the effectiveness of the treatment. Key parameters considered include energy, energy density, power, power density, irradiation time, and tissue penetration depth.Results The recommended stimulation time should not exceed six minutes (480 seconds) at a power density of 15.62 mW/cm(2). However, if the power density is reduced to a maximum of 3.10 mW/cm2, the stimulation time can be safely extended to 10 minutes (600 seconds) without causing undesirable thermal effects, as long as the tissue temperature does not exceed 40 degrees C during the extended stimulation. It is important to note that the dose applied to the surface of the tissue significantly decreases as it penetrates deeper. The average energy loss is approximately 11% per millimetre of tissue. Our simulations indicate that effective doses range from 0.38 J/cm(2) to 9.37 J/cm(2) while maintaining safe tissue temperatures, which are consistent with WALT recommendations.Results The recommended stimulation time should not exceed six minutes (480 seconds) at a power density of 15.62 mW/cm(2). However, if the power density is reduced to a maximum of 3.10 mW/cm2, the stimulation time can be safely extended to 10 minutes (600 seconds) without causing undesirable thermal effects, as long as the tissue temperature does not exceed 40 degrees C during the extended stimulation. It is important to note that the dose applied to the surface of the tissue significantly decreases as it penetrates deeper. The average energy loss is approximately 11% per millimetre of tissue. Our simulations indicate that effective doses range from 0.38 J/cm(2) to 9.37 J/cm(2) while maintaining safe tissue temperatures, which are consistent with WALT recommendations.Conclusion Our findings help identify factors influencing stimulation, guiding therapists to standardize treatment parameters such as wavelength, exposure time, and dosages measured in joules, watts, W/cm(2), and J/cm(2) for consistency and safety across studies.
