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This review article synthesizes key findings from studies on the use of diamond dosimeters in advanced radiotherapy techniques, showcasing their applications, challenges, and contributions to enhancing dosimetric accuracy. The article explores various dosimeters, highlighting synthetic diamond dosimeters as potential candidates especially due to their high spatial resolution and negligible ion recombination effect. The clinically validated commercial dosimeter, PTW microDiamond (mD), faces limitations in small fields, proton and hadron therapy and ultra‐high dose per pulse (UHDPP) conditions. Variability in reported values for field sizes <$<$2 ×$\times$ 2 cm2${\rm cm}^2$ is noted, reflecting the competition between volume averaging and density perturbation effects. PTW's introduction of flashDiamond (fD) holds promise for dosimetric measurements in UHDPP conditions and is reliable for commissioning ultra‐high dose rate (UHDR) electron beam systems, pending the clinical validation of the device. Other advancements in diamond detectors, such as in 3D configurations and real‐time dose per pulse x‐ray detectors, are considered valuable in overcoming challenges posed by modern radiotherapy techniques, alongside relative dosimetry and pre‐treatment verifications. The studies discussed collectively provide a comprehensive overview of the evolving landscape of diamond dosimetry in the field of radiotherapy, and offer insights into future directions for research and development in the field. [ABSTRACT FROM AUTHOR]

Among methacrylic acid-based gel dosimeters, the MAGAT hydrogel stands out for its tissue equivalence, making it a promising candidate for clinical applications. The incorporation of methylene blue (MB) or zinc oxide nanoparticles (ZnO NPs) into MAGAT hydrogel aims to improve its formulation, enhance dose absorption and facilitate detailed 3D dose verification. The optimization of MB and ZnO NPs has not yet been investigated with polymer gel before. We studied MAGAT hydrogel dosimeters with varying MB concentrations (0.001, 0.002, 0.003, 0.01, 0.02, and 0.03% w/w) and ZnO NPs concentrations (0.03–0.07% w/w), using a double-beam spectrophotometer for optical measurements. Our findings identified the optimal MB concentration in the MAGAT + MB formulation at 0.001% w/w, achieving a sensitivity of 0.0285 a.u./Gy and an accuracy of 0.9995. For the MAGAT + MB + ZnO NPs formulation, the optimal ZnO NPs concentration was 0.07% w/w, with a sensitivity of 0.03106 a.u./Gy and an accuracy of 0.9945. The absorbance peaks for both optimum formulations of (MAGAT + MB) and (MAGAT + MB + ZnO NPs) were observed at a wavelength of 665 and 668 nm, respectively. These advancements promise to reduce monitor units, ensure precise dose delivery, shorten treatment times, and minimize treatment errors. [ABSTRACT FROM AUTHOR]

Objectives. This study aimed to assess noise levels in various units in hospitals and explore the correlation between healthcare employees' daily noise exposure level (Lex,8h) and their stress and symptoms. Methods. A healthcare facility was selected to study noise pollution. Personal noise dosimeters were used during 8-h working shifts. Data were collected from 126 employees using the 36-item 'A stress scale' and a socio-demographic information form. Results. The results of noise measurements exceeded World Health Organization and US Environmental Protection Agency recommended limits at all sites. The lowest Lex,8h (52 dB) was detected in the endocrinology clinic, while the highest (91 dB) was recorded in the podology unit. According to the stress scale scores, the lowest mean psychological symptom score (PsSS), physiological symptom score (PhSS) and total scale score (TSS) were observed in diagnostic units with 35 ± 14, 41 ± 14 and 76 ± 27, respectively, while the highest mean PsSS, PhSS and TSS were observed in the polyclinics with 44 ± 6, 64 ± 10 and 107 ± 10, respectively. The PsSS of employees exposed to noise (Lex,8h) above 75 dB was found to be higher than for other employees. Conclusion. Lex,8h above 75 dB can increase psychological symptoms in healthcare employees. [ABSTRACT FROM AUTHOR]

Background Purpose Materials and methods Results Conclusion Radiochromic film (RCF) dosimeters with their high spatial resolution and tissue equivalent properties are conveniently used for two‐dimensional and small‐field dosimetry. OC‐1 is a new model of RCF dosimeter that was commercially introduced recently. Due to its novelty there is a need to characterize its response in various radiation beam types.To study the response of OC‐1 RCFs to megavoltage clinical x‐ray, electron, and proton beams, as well as kilovoltage x‐ray beams used in a small animal research irradiator.OC‐1 RCFs were cut into ∼4 × 4 cm2 pieces. RCF samples were irradiated at various dose levels in the range 0.5–120 Gy using different modalities; a small animal radiation research platform (SARRP) (220 kVp), a medical linear accelerator (6 MV, 10 MV, 15 MV, 6 MV FFF, 10 MV FFF photon beams, as well as 6 and 20 MeV electron beams), and a gantry‐mounted proton therapy synchrocyclotron. In order to study any dependency on the fractionation scheme, same dose was delivered at several fractions to a set of films. Different dose rates in the range 200–600 MU/min were delivered to a set of films to investigate any dose rate dependency. The films were scanned pre‐irradiation and at 48 h post‐irradiation using a flatbed scanner. The net optical density (OD) was measured for red, green, and blue color channel for each film. The orientation dependency was studied by scanning the films at eight different orientations. In order to study the temporal evolution of the response of the films, film samples were irradiated at 10 and 50 Gy using 6 MV photon beams and were scanned upon irradiation at certain time intervals up to 3 months. The spectral response of the films were studied over the visible range using a spectrometer.For megavoltage photon, electron, and plateau region of the proton beams, we did not observe a significant dependency on the beam quality, dose rate, and fractionation scheme. At the kV beam, an unusual over‐response was observed in the films’ net OD. An orientation dependency in the response of the films with a sinusoidal trend was observed. The response of the films increased with time following a double or triple exponential trend. The spectral absorption peaks were blue‐shifted with dose.OC‐1 RCFs were found to be reliable dosimeters with no significant energy dependency in MV range for photon and electron beams including the FFF beams. They over‐respond when irradiated by kV x‐ray beams compared to MV x‐ray beams. Caution must be exercised to maintain the orientation of the films when scanning. Due to the temporal growth in the net OD of the films, same post‐irradiation time interval must be used for scanning the calibration and test films. [ABSTRACT FROM AUTHOR]

Monitoring personal ultraviolet (UV) exposure facilitates risk mitigation against UV‐induced skin aging and skin cancer, the most common malignancy in North America, Europe, and Australia. UV radiometers convey real‐time information on local UV irradiance, while UV dosimeters count accumulated UV exposure over time. These devices can help users manage exposure levels in order to reach a healthy daily dose of UV light required for vitamin D production without exceeding erythemal limits that would increase skin cancer risk. However, personal UV detectors still suffer from several limitations. Wearable electronic UV sensors are relatively bulky, heavy, and expensive, while the more commonly used on‐skin disposable colorimetric UV sensors suffer from short service life, skin discomfort, and high accumulated costs when used daily as recommended. Intradermal colorimetric UV nanosensors can overcome these limitations, offering long‐term, comfortable, and inexpensive naked‐eye colorimetric indication of intradermal UV irradiance. Now, a new generation of UV‐sensing intradermal pigments with an improved design offers better tunability, stability, and biocompatibility. These UV‐photochromic nanosensors may be operated as UV dosimeters or simple sunscreen efficacy monitors, depending on the formulation, and can remain functional and re‐usable in the dermis for years. [ABSTRACT FROM AUTHOR]

Background: To retrospectively investigate scatter radiation (SCR) exposure among staff in the endourology operating theatre. Methods: During surgeries under fluoroscopic guidance, five professional groups (urological surgeon [US], surgical nurse [SN], assistant surgical nurse [ASN], anaesthetist [A], and anaesthesia care [AC]) wore real-time dosimeters (Philips DoseAware System) on their head and chest over lead aprons between July 2023 and February 2024. The SCR data were analysed and correlated with procedural and patient factors. Results: In total, 249 procedures were performed, including 86 retrograde intrarenal surgeries and 10 percutaneous nephrolithotomies. Median SCR exposure was 38.81, 17.20, 7.71, 11.58, 0.63, 0.23, 0.12, and 0.15 Microsievert (µSv) for US chest (USC), US head (USH), SN chest (SNC), SN head (SNH), A chest (AC), AC chest (ACC), ASN chest (ASNC), and ASN head (ASNH), respectively. There was a significant correlation between DAP and SCR doses detected by USC, USH, SNC, SNH, AC, and ACC dosimeters (p < 0.05). The median chest-to-eye conversion factor (CECF) was 2.11 for the US and 0.71 for the SN. Conclusions: This study, using real-time dosimetry, is among the first to assess staff occupational SCR exposure in endourology. It highlights a substantial SCR exposure, indicating an occupational health hazard that warrants further investigation. [ABSTRACT FROM AUTHOR]

3DCRT and IMRT out-of-field doses in pediatric patients were compared using Monte Carlo simulations with treatment planning system calculations and measurements. Purpose: Out-of-field doses are given to healthy tissues, which may allow the development of second tumors. The use of IMRT in pediatric patients has been discussed, as it leads to a "bath" of low doses to large volumes of out-of-field organs and tissues. This study aims to compare out-of-field doses in pediatric patients comparing IMRT and 3DCRT techniques using measurements, Monte Carlo (MC) simulations, and treatment planning system (TPS) calculations. Materials and methods: A total dose of 54 Gy was prescribed to a PTV in the brain of a pediatric anthropomorphic phantom, for both techniques. To assess the out-of-field organ doses for both techniques, two treatment plans were performed with the 3DCRT and IMRT techniques in TPS. Measurements were carried out in a LINAC using a pediatric anthropomorphic phantom and thermoluminescent dosimeters to recreate the treatment plans, previously performed in the TPS. A computational model of a LINAC, the associated multileaf collimators, and a voxelized pediatric phantom implemented in the Monte Carlo N-Particle 6.1 computer program were also used to perform MC simulations of the out-of-field organ doses, for both techniques. Results: The results obtained by measurements and MC simulations indicate a significant increase in dose using the IMRT technique when compared to the 3DCRT technique. More specifically, measurements show higher doses with IMRT, namely, in right eye (13,041 vs. 593 mGy), left eye (6,525 vs. 475 mGy), thyroid (79 vs. 70 mGy), right lung (37 vs. 28 mGy), left lung (27 vs. 20 mGy), and heart (31 vs. 25 mGy). The obtained results indicate that out-of-field doses can be seriously underestimated by TPS. Discussion: This study presents, for the first time, out-of-field dose measurements in a realistic scenario and calculations for IMRT, centered on a voxelized pediatric phantom and an MCmodel of amedical LINAC, including MLC with log file-based simulations. The results pinpoint significant discrepancies in out-of-field doses for the two techniques and are a cause of concern because TPS calculations cannot accurately predict such doses. The obtained doses may presumably increase the risk of development of second tumors. [ABSTRACT FROM AUTHOR]

Objective. To develop and benchmark a novel 3D dose verification technique consisting of polymer gel dosimetry (PGD) with cone-beam-CT (CBCT) readout through a two-institution study. The technique has potential for wide and robust applicability through reliance on CBCT readout. Approach. Three treatment plans (3-field, TG119-C-shape spine, 4-target SRS) were created by two independent institutions (Institutions A and B). A Varian Truebeam linear accelerator was used to deliver the plans to NIPAM polymer gel dosimeters produced at both institutions using an identical approach. For readout, a slow CBCT scan mode was used to acquire pre- and post-irradiation images of the gel (1 mm slice thickness). Independent gel analysis tools were used to process the PGD images (A: VistaAce software, B: in-house MATLAB code). Comparing planned and measured doses, the analysis involved a combination of 1D line profiles, 2D contour plots, and 3D global gamma maps (criteria ranging between 2%1 mm and 5%2 mm, with a 10% dose threshold). Main results. For all gamma criteria tested, the 3D gamma pass rates were all above 90% for 3-field and 88% for the SRS plan. For the C-shape spine plan, we benchmarked our 2% 2 mm result against previously published work using film analysis (93.4%). For 2%2 mm, 99.4% (Institution A data), and 89.7% (Institution B data) were obtained based on VistaAce software analysis, 83.7% (Institution A data), and 82.9% (Institution B data) based on MATLAB. Significance. The benchmark data demonstrate that when two institutions follow the same rigorous procedures gamma passing rates up to 99%, for 2%2 mm criteria can be achieved for substantively different treatment plans. The use of different software and calibration techniques may have contributed to the variation in the 3D gamma results. By sharing the data across institutions, we observe the gamma passing rate is more consistent within each pipeline, indicating the need for standardized analysis methods. [ABSTRACT FROM AUTHOR]

Neurosurgeons often use radiation to visualize blood vessels and implants intraoperatively. However, high exposure to radiation increases one's cancer risk. This study aims to investigate intraoperative ionizing radiation exposure awareness and associated morbidity among neurosurgeons. An anonymized 30-question survey about their intraoperative radiation exposure, protective measures, radiation knowledge, and any conditions that can arise from protracted radiation exposure was disseminated to 3344 American Association of Neurological Surgeons members. A total of 227 (6.8%) neurosurgeons completed the survey. Most neurosurgeons (61, 27%) performed 2–4 surgeries per week necessitating radiation (61, 27%), did not use a dosimeter (134, 59%), and wore a lead apron (89%) and a thyroid shield (75%). Only 7 (3%) of respondents could correctly identify the safety limit for occupational radiation. One hundred and thirty-four (59%) respondents correctly identified the relationship between distance and radiation dose reduction. Two hundred and thirteen (94%) neurosurgeons reported concern about occupational radiation exposure. No significant association was found between occupational radiation exposure and the rate of cataracts, combined cancer, and skin cancer. Multivariate logistic regression adjusting for age and cancer history found that the likelihood of developing leukemia (P = 0.02) and nonmalignant thyroid nodular disease (P = 0.01) is positively associated with increased total occupational radiation exposure. There is a need for improved radiation safety awareness among neurosurgeons, especially in the context of rising usage of minimally invasive surgery. This can allow for a greater understanding of radiation-associated risks among neurosurgeons and guide the implementation of safer practices. [ABSTRACT FROM AUTHOR]

Background: Ultra‐high‐dose‐rate (UHDR) electron beams have been commonly utilized in FLASH studies and the translation of FLASH Radiotherapy (RT) to the clinic. The EDGE diode detector has potential use for UHDR dosimetry albeit with a beam energy dependency observed. Purpose: The purpose is to present the electron beam response for an EDGE detector in dependence on beam energy, to characterize the EDGE detector's response under UHDR conditions, and to validate correction factors derived from the first detailed Monte Carlo model of the EDGE diode against measurements, particularly under UHDR conditions. Methods: Percentage depth doses (PDDs) for the UHDR Mobetron were measured with both EDGE detectors and films. A detailed Monte Carlo (MC) model of the EDGE detector has been configured according to the blueprint provided by the manufacturer under an NDA agreement. Water/silicon dose ratios of EDGE detector for a series of mono‐energetic electron beams have been calculated. The dependence of the water/silicon dose ratio on depth for a FLASH relevant electron beam was also studied. An analytical approach for the correction of PDD measured with EDGE detectors was established. Results: Water/silicon dose ratio decreased with decreasing electron beam energy. For the Mobetron 9 MeV UHDR electron beam, the ratio decreased from 1.09 to 1.03 in the build‐up region, maintained in range of 0.98–1.02 at the fall‐off region and raised to a plateau in value of 1.08 at the tail. By applying the corrections, good agreement between the PDDs measured by the EDGE detector and those measured with film was achieved. Conclusions: Electron beam response of an UHDR capable EDGE detector was derived from first principles utilizing a sophisticated MC model. An analytical approach was validated for the PDDs of UHDR electron beams. The results demonstrated the capability of EDGE detector in measuring PDDs of UHDR electron beams. [ABSTRACT FROM AUTHOR]

Background: The TRS‑483, an IAEA/AAPM International Code of Practice on dosimetry of small static photon fields, underwent testing via an IAEA coordinated research project (CRP). Alongside small field output factors (OFs) measurements using active dosimeters by CRP participants, the IAEA Dosimetry Laboratory received a mandate to formulate a remote small field dosimetry audit method using its passive dosimetry systems. Purpose: This work aimed to develop a small field dosimetry audit methodology employing radiophotoluminescent dosimeters (RPLDs) and radiochromic films. The methodology was subsequently evaluated through a multicenter pilot study with CRP participants. Methods: The developments included designing and manufacturing a dosimeter holder set and the characterization of an RPLD system for measurements in small photon fields using the new holder. The audit included verification of small field OFs and lateral beam profiles for small fields. At first, treatment planning system (TPS) calculated OFs were checked against a reference data set that was available for conventional linacs. Second, calculated OFs were verified through the RPLD measurement of point doses in a machine‐specific reference field, 4 cm × 4 cm, 2 cm × 2 cm, and 1 cm × 1 cm, corresponding size circular fields or nearest achievable field sizes. Lastly, profile checks in in‐plane and cross‐plane directions were done for the two smallest fields by comparing film measurements with TPS calculations at 20%, 50%, and 80% isodose levels. Results: RPLD correction factors for small field measurements were approximately unity. However, they influenced the dose determination's overall uncertainty in small fields, estimated at 2.30% (k = 1 level). Considering the previous experience in auditing reference beam output following the TRS‐398 Code of Practice, the acceptance limit of 5% for the ratio of the dose determined by RPLD to the dose calculated by TPS, DRPLD/DTPS, was considered adequate. The multicenter pilot study included 15 participants from 14 countries (39 beams). Consistent with the previous findings, the results of the OF check against the reference data confirmed that TPSs tend to overestimate OFs for the smallest fields included in this exercise. All except three RPLD measurement results were within the acceptance limit, and the spread of results increased for smaller field sizes. The differences between the film measured and TPS calculated dose profiles were within 3 mm for most of the beams checked; deviated results revealed problems with TPS commissioning and calibration of the treatment unit collimation systems. Conclusion: The newly developed small field dosimetry audit methodology proved effective and successfully complemented the CRP OF measurements by participants with RPLD audit results. [ABSTRACT FROM AUTHOR]

Background: While careful planning and pre‐treatment checks are performed to ensure patient safety during external beam radiation therapy (EBRT), inevitable daily variations mean that in vivo dosimetry (IVD) is the only way to attain the true delivered dose. Several countries outside the US require daily IVD for quality assurance. However, elsewhere, the manual labor and time considerations of traditional in vivo dosimeters may be preventing frequent use of IVD in the clinic. Purpose: This study expands upon previous research using plastic scintillator discs for optical dosimetry for electron therapy treatments. We present the characterization of scintillator discs for in vivo x‐ray dosimetry and describe additional considerations due to geometric complexities. Methods: Plastic scintillator discs were coated with reflective white paint on all sides but the front surface. An anti‐reflective, matte coating was applied to the transparent face to minimize specular reflection. A time‐gated iCMOS camera imaged the discs under various irradiation conditions. In post‐processing, background‐subtracted images of the scintillators were fit with Gaussian‐convolved ellipses to extract several parameters, including integral output, and observation angle. Results: Dose linearity and x‐ray energy independence were observed, consistent with ideal characteristics for a dosimeter. Dose measurements exhibited less than 5% variation for incident beam angles between 0° and 75° at the anterior surface and 0–60∘$^\circ $ at the posterior surface for exit beam dosimetry. Varying the angle between the disc surface and the camera lens did not impact the integral output for the same dose up to 55°. Past this point, up to 75°, there is a sharp falloff in response; however, a correction can be used based on the detected width of the disc. The reproducibility of the integral output for a single disc is 2%, and combined with variations from the gantry angle, we report the accuracy of the proposed scintillator disc dosimeters as ±5.4%. Conclusions: Plastic scintillator discs have characteristics that are well‐suited for in vivo optical dosimetry for x‐ray radiotherapy treatments. Unlike typical point dosimeters, there is no inherent readout time delay, and an optical recording of the measurement is saved after treatment for future reference. While several factors influence the integral output for the same dose, they have been quantified here and may be corrected in post‐processing. [ABSTRACT FROM AUTHOR]

This research uses two different dosimetry techniques (films and gels) to evaluate how γ-rays affect Cyanidin chloride. The first method relies on combining CC with poly (vinyl alcohol) to create a thin film dosimeter, while the second uses CC with gelatin to create a gel dosimeter that is more sensitive to γ-rays. The produced film or gel changes visually from red to colorless when exposed to γ-rays. The usable dose range of films was up to 35 kGy, and for gels, it was between 10 and 150 Gy. All dosimetric characteristics were studied. [ABSTRACT FROM AUTHOR]

Recent advancements in medical dosimetry have significantly improved the precision and effectiveness of radiation therapy by accurately quantifying absorbed doses from ionizing radiation. In the past, conventional one-dimensional and two-dimensional dosimeters were commonly used, but recent years have seen a surge in interest in 3D dosimeters for complex radiation therapies. This review aims to elucidate the applications of 3D polymer gel dosimeters in radiation therapies, covering diverse radiation and energy fields. Utilizing an extensive search strategy across various electronic databases, the review synthesizes insights from recent studies on polymer gel dosimeters, exploring their properties and applications in ultrasound, optical coherence tomography, magnetic resonance imaging, and computed tomography. Furthermore, the review investigates the consideration of Monte Carlo simulations in modeling dosimeter applications in radiation therapy, examining specific parameters affecting dosimeter performance. It provides a comprehensive synthesis of available data over the past decade, shedding light on the medical applications of 3D polymer gel dosimeters and their potential limitations. Finally, the review discusses challenges in widespread implementation and future directions, emphasizing the need for further research on novel gel dosimeters and the incorporation of nanoparticles to enhance sensitivity and functionality in medical dosimetry. [ABSTRACT FROM AUTHOR]

While ionizing radiation plays a pivotal role in precise diagnosis and treatment, it concurrently engenders risks, including an elevated incidence of cancer. The research speaks to the discernible decline in quality assurance programmes and dose measurement endeavors within Nigerian imaging facilities, with a substantial portion lacking established protocols for routine machine calibration and dose measurement. This study encompasses a large-scale survey involving 307 adult patients undergoing routine X-ray procedures in two hospitals in Nigeria. Thermo-luminescent dosimeters (TLDs) were used for measuring Entrance Skin Dose (ESD). The mean ESD values ranged from 1.16 mGy to a maximum of 3.94 mGy. Notably, these values were predominantly below the dose reference levels (DRLs) established by reputable bodies such as NRPB, CEC, IAEA, and UK for most examinations. The main purpose of this study was to determine the diagnostic reference level (DRL) for routine digital radiography examinations in Nigeria. [ABSTRACT FROM AUTHOR]

The Persistent development of quick and accessible readout tools promises to remove one of the barriers to the adoption of gel dosimetry as an applicable method in treatment clinics. Research and development in the imaging of polymer gel dosimeters continues with a focus on imaging in three dimensions. Each technique comes with its own set of advantages and challenges. In gel dosimeter research, efforts have been made to identify and develop alternative imaging methods for polymer gel dosimeters. Gel dosimeters can obtain reliable and accurate three-dimensional dose distributions from the correlation of different polymerization stages caused by radiation. The irradiated samples are examined using magnetic resonance imaging, optical computed tomography, and X-ray computed tomography. This research describes the basic features of imaging devices and the readout of irradiated dose data. Costs, availability, portability, contrast and resolution, high-resolution image reconstruction algorithm, and image reconstruction time of radiation absorption dosimeters for imaging devices are investigated in this research. This review has been done to present the mentioned imaging features and review the research done in this field for the optimal use of different imaging methods. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the potential of a commercially available plastic scintillator, the Exradin W2, as a real‐time dosimeter for ultra‐high‐dose‐rate (UHDR) electron beams. This work aimed to characterize this system's performance under UHDR conditions and addressed limitations inherent to other conventional dosimetry systems. Methods and materials: We assessed the W2's performance as a UHDR electron dosimeter using a 16 MeV UHDR electron beam from the FLASH research extension (FLEX) system. Additionally, the vendor provided a beta firmware upgrade to better handle the processing of the high signal generated in the UHDR environment. We evaluated the W2 regarding dose‐per‐pulse, pulse repetition rate, charge versus distance, and pulse linearity. Absorbed dose measurements were compared against those from a plane‐parallel ionization chamber, optically stimulated luminescent dosimeters and radiochromic film. Results: We observed that the 1 × 1 mm W2 scintillator with the MAX SD was more suitable for UHDR dosimetry compared to the 1 × 3 mm W2 scintillator, capable of matching film measurements within 2% accuracy for dose‐per‐pulse up to 3.6 Gy/pulse. The W2 accurately ascertained the inverse square relationship regarding charge versus virtual source distance with R2 of ∼1.00 for all channels. Pulse linearity was accurately measured with the W2, demonstrating a proportional response to the delivered pulse number. There was no discernible impact on the measured charge of the W2 when switching between the available repetition rates of the FLEX system (18–180 pulses/s), solidifying consistent beam output across pulse frequencies. Conclusions: This study tested a commercial plastic scintillator detector in a UHDR electron beam, paving the way for its potential use as a real‐time, patient‐specific dosimetry tool for future FLASH radiotherapy treatments. Further research is warranted to test and improve the signal processing of the W2 dosimetry system to accurately measure in UHDR environments using exceedingly high dose‐per‐pulse and pulse numbers. [ABSTRACT FROM AUTHOR]

Background Purpose Methods Results Conclusions Stereotactic radiosurgery (SRS) is a widely employed strategy for intracranial metastases, utilizing linear accelerators and volumetric modulated arc therapy (VMAT). Ensuring precise linear accelerator performance is crucial, given the small planning target volume (PTV) margins. Rapid dose falloff is vital to minimize brain radiation necrosis. Despite advances in SRS planning, tools for end‐to‐end testing of SRS treatments are lacking, hindering confidence in the procedure.This study introduces a novel end‐to‐end three‐dimensional (3D) anthropomorphic dosimetry system for characterization of a radiosurgery platform, aiming to measure planning metrics, dose gradient index (DGI), brain volumes receiving at least 10 and 12 Gy (V10, V12), as well as assess delivery uncertainties in multitarget treatments. The study also compares metrics from benchmark plans to enhance understanding and confidence in SRS treatments.The developed anthropomorphic 3D dosimetry system includes a modified Stereotactic End‐to‐End Verification (STEEV) phantom with a customized insert integrating 3D dosimeters and a fiber optic CT scanner. Labview and MATLAB programs handle optical scanning, image preprocessing, and dosimetric analysis. SlicerRT is used for 3D dose visualization and analysis. A film stack insert was used to validate the 3D dosimeter measurements at specific slices. Benchmark plans were developed and measured to investigate off‐axis errors, dose spillage, small field dosimetry, and multi‐target delivery.The accuracy of the developed 3D dosimetry system was rigorously assessed using radiochromic films. Two two‐dimensional (2D) dose planes, extracted from the 3D dose distribution, were compared with film measurements, resulting in high passing rates of 99.9% and 99.6% in gamma tests. The mean relative dose difference between film and 3D dosimeter measurements was −1%, with a standard deviation of 2.2%, well within dosimeter uncertainties. In the first module, evaluating single‐isocenter multitarget treatments, a 1.5 mm dose distribution shift was observed when targets were 7 cm off‐axis. This shift was attributed to machine mechanical errors and image‐guided system uncertainties, indicating potential limitations in conventional gamma tests. The second module investigated discrepancies in intermediate‐to‐low dose spillage, revealing higher measured doses in the connecting region between closely positioned targets. This discrepancy was linked to uncertainties in treatment planning system (TPS) modeling of out‐of‐field dose and multileaf collimator (MLC) characteristics, resulting in lower DGI values and higher V10 and V12 values compared to TPS calculations. In the third module, irradiating multiple targets showed consistent V10 and V12 values within 1 cm3 agreement with dose calculations. However, lower DGI values from measurements compared to calculations suggested intricacies in the treatment process. Conducting vital end‐to‐end testing demonstrated the anthropomorphic 3D dosimetry system's capacity to assess overall treatment uncertainty, offering a valuable tool for enhancing treatment accuracy in radiosurgery platforms.The study introduces a novel anthropomorphic 3D dosimetry system for end‐to‐end testing of a radiosurgery platform. The system effectively measures plan quality metrics, captures mechanical errors, and visualizes dose discrepancies in 3D space. The comprehensive evaluation capability enhances confidence in the commissioning and verification process, ensuring patient safety. The system is recommended for commissioning new radiosurgery platforms and remote auditing of existing programs. [ABSTRACT FROM AUTHOR]

The study aims to evaluate the absorbed dose (Dabs) in high-dose-rate brachytherapy treatments with a source of 192Ir, considering the heterogeneities of the tissues, types of applicators and patient dimensions. To this end, isodose calculations by Monte Carlo (MC) simulation and a test of accuracy of the dose delivered to a simulator object were performed, comparing the Dabs planned in the treatment planning system (TPS) with the dose recorded by the optically stimulated luminescence dosimeter. It was found that the TPS adequately calculates the distribution of Dabs when the medium is water; however, it is necessary to include libraries that consider heterogeneities in order to perform a more precise calculation of the distribution of Dabs in patients. It is concluded that performing a CM simulation is a good option to test whether the TPS calculates the Dabs in the presence of heterogeneities. [ABSTRACT FROM AUTHOR]

The interest in microdosimetry is growing thanks to the advancement in microdosimetric technologies, improving detector performance and reliability. Herein, the fabrication and characterization of a novel diamond‐based microdosimeter are proposed. The microdosimeter consists of an array of single‐crystal diamond Schottky diodes about 1.5 μm thick connected in parallel. The detector prototypes are characterized using the ion beam‐induced charge technique, employing a 6 MeV carbon ions microbeam. Despite a good overall response, the first prototypes are affected by the "bridge effect": a charge collection beneath the metallic bridges connecting the sensitive volumes (SVs), which alters the energy deposition spectrum. To mitigate the bridge effect, different technological solutions are explored: the selective growth of intrinsic diamond layers and the use of an insulating material such as photoresist. These second prototypes reveal a good SV spatial definition without any charge collection from the bridges and a good response homogeneity within the SVs ranging between 3% and 5% full‐width‐half‐maximum among the different prototypes. While the cell‐like thickness and lateral dimensions of SVs make the diamond microdosimeter array ideal for radiobiological applications, its array configuration can make it highly versatile to perform under different fluence rate conditions in particle therapy. [ABSTRACT FROM AUTHOR]

BACKGROUND: The inherent problems in the existence of electron equilibrium and steep dose fall-off pose difficulties for small- and narrow-field dosimetry. OBJECTIVE: To investigate the cutout factors for keloid electron radiotherapy using various dosimetry detectors for small and narrow fields. METHOD: The measurements were performed in a solid water phantom with nine different cutout shapes. Five dosimetry detectors were used in the study: pinpoint 3D ionization chamber, Farmer chamber, semiflex chamber, Classic Markus parallel plate chamber, and EBT3 film. RESULTS: The results demonstrated good agreement between the semiflex and pinpoint chambers. Furthermore, there was no difference between the Farmer and pinpoint chambers for large cutouts. For the EBT3 film, half of the cases had differences greater than 1%, and the maximum discrepancy compared with the reference chamber was greater than 2% for the narrow field. CONCLUSION: The parallel plate, semiflex chamber and EBT3 film are suitable dosimeters that are comparable with pinpoint 3D chambers in small and narrow electron fields. Notably, a semiflex chamber could be an alternative option to a pinpoint 3D chamber for cutout widths≥3 cm. It is very important to perform patient-specific cutout factor calibration with an appropriate dosimeter for keloid radiotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: The current devices and methods for dosimetry of personalized photodynamic therapy of tumors have several disadvantages. For instance, they are unable to evaluate the entire tumor volume at great depth, and they lack the capacity to provide an accurate estimate of the effective light dose. Furthermore, they are limited by their ability to evaluate either only the photosensitizer concentration or only the hemoglobin oxygenation at a specific point on the tissue surface or the average value based on the finite tissue volume at little depth. Despite the advances in photodynamic therapy, the development of a precise and dependable methodology to ascertain the optimal light dosage for a given tumor remains a significant challenge. This is due to the pivotal role of light dosage in determining the efficacy of treatment outcomes. Significance: Despite the widespread use of photodynamic therapy in clinical practice, there is a lack of personalized methods for assessing the sufficiency of photodynamic exposure on tumors, depending on tissue parameters that change during light irradiation. This can lead to different treatment results. Aim: The objective of this article was to conduct a comprehensive review of devices and methods employed for the implicit dosimetric monitoring of personalized photodynamic therapy for tumors. Methods: The review included 88 peer-reviewed research articles published between January 2010 and April 2024 that employed implicit monitoring methods, such as fluorescence imaging and diffuse reflectance spectroscopy. Additionally, it encompassed computer modeling methods that are most often and successfully used in preclinical and clinical practice to predict treatment outcomes. The Internet search engine Google Scholar and the Scopus database were used to search the literature for relevant articles. Results: The review analyzed and compared the results of 88 peer-reviewed research articles presenting various methods of implicit dosimetry during photodynamic therapy. The most prominent wavelengths for PDT are in the visible and near-infrared spectral range such as 405, 630, 660, and 690 nm. Conclusions: The problem of developing an accurate, reliable, and easily implemented dosimetry method for photodynamic therapy remains a current problem, since determining the effective light dose for a specific tumor is a decisive factor in achieving a positive treatment outcome. [ABSTRACT FROM AUTHOR]

Passive dosimeters enabling accurate measurement of doses from gamma rays to visible light are necessary to ensure efficient utilization of electromagnetic radiation in numerous fields like medical diagnostics and industrial manufacturing. The specific requirements for dosimeters in terms of dosimetry range, sensitivity, accuracy, and stability for each application have led to the development of various dosimeters based on new materials and new mechanisms. Here, a comprehensive review of different types of dosimeters classified according to the response signal, namely electron paramagnetic resonance, electrical, and optical, is provided. This review starts with a general introduction to dosimetry, a classification of dosimeters, and an elucidation of the necessity of dosimeters in various ranges of the electromagnetic spectrum. This is followed by an overview of the fundamental requirements of dosimeters, an explanation of the general dosimetry procedure, and the dosimetric quantities. Emphasis is given to the working mechanism, the design concept, and applications of each type of dosimeter as well as their respective strengths and drawbacks. Challenges and prospects are presented at the end of the review. This review provides an insightful overview of the material‐mechanism‐characteristics‐application relationship of different types of dosimeters that hopefully can serve as inspiration for the development of new devices. [ABSTRACT FROM AUTHOR]

New borosilicate glass (BSG) systems doped with different rare earth (RE) ions; Dy, Y, Nd and Ho, were molten by the common melting-quenching technique. XRD analysis exhibited the amorphous glassy states of the samples. Some optical, physical, and spectral features of the glasses were inspected within the influence of progressive gamma irradiation doses up to 300 kGy. FTIR spectra displayed the large structural stability against 200 kGy of gamma radiation which is correlated to the dual contribution of silicate (SiO 4), and borate (BO 3 and BO 4) vibrational bands. Optical UV–visible spectra revealed common peaks in the range 215–340 nm owing to the various valence states of the present transition metal (TM) ions e.g., Fe2+/Fe3+, Cu+/Cu2+, Ti3+/Ti4+, Zn2+ and the introduced RE ions. By following the dosimetric characteristics of the glasses up to 300 kGy, only Nd-BSG and Ho-BSG were sensitive to gamma rays, and a systematic obvious increase was detected for the characteristic peaks of Nd- BSG at 582 nm and Ho-BSG at 450 nm, however, the remaining samples (BSG, Dy-BSG, and Y-BSG) did not achieve a systematic change. Both Nd-BCG and Ho-BSG response curves showed a linear part extended up to 150 kGy. Nd-BCG and Ho-BSG are humidity-independent with satisfactory stability through 30 days of storage. Many optical and physical parameters for Nd- and Ho- BSGs were studied at the whole dose range up to 300 kGy e.g, optical band gap energy (Eopt), density (ρ), refractive index values (n Eopt , n k-s , n m and n R–S), electronegativity (χ), electron polarizability (∝°) and optical basicity (⋀), all revealed either a gradual increase or decrease with the progressive irradiation doses. The study recommends the hopeful usage of the prepared Nd and Ho- BSGs as high-dose radiation dosimeters in a useful high-dose range up to 300 kGy of gamma radiation. [ABSTRACT FROM AUTHOR]

Background: Electronic portal imaging devices (EPIDs) are applied to measure the dose and verify patients' position. Objective: The present study aims to evaluate the performance of EPID for measuring dosimetric parameters in small photon fields. Material and Methods: In this experimental study, the output factors and beam profiles were obtained using the amorphous silicon (a-Si) EPID for square field sizes ranging from 1×1 to 10×10 cm² at energies 6 and 18 mega-voltage (MV). For comparison, the dosimetric parameters were measured with the pinpoint, diode, and Semiflex dosimeters. Additionally, the Monaco treatment planning system was selected to calculate the output factors and beam profiles. Results: There was a significant difference between the output factors measured using the EPID and that measured with the other dosimeters for field sizes lower than 8×8 cm². In the energy of 6 MV, the gamma passing rates (3%/3 mm) between EPID and diode profile were 98%, 98%, 95%, 94%, 93%, and 94% for 1×1, 2×2, 3×3, 4×4, 5×5, and 10×10 cm², respectively. The measured penumbra width with EPID was higher compared to that measured by the diode dosimeter for both energies. Conclusion: The EPID can measure the dosimetric parameters in small photon fields, especially for beam profiles and penumbra measurements. [ABSTRACT FROM AUTHOR]

Background Modern advanced technologies in the neonatal intensive care unit (NICU) have created more noise sources of varying frequencies and intensities, increasing the risk of hearing loss in infants. This study aimed to determine the effect of earmuffs on neonatal behavior. Materials and Methods This study was conducted in the 13-bed level III-A NICU of a 1,000-bed tertiary care teaching hospital. Preexperimental, one-group pretest, posttest design was adopted in the study. Twenty-seven neonates were selected using nonprobability and purposive sampling techniques. The noise level was checked using a dosimeter (sound level meter SL-4030), the baseline variables were collected, and earmuffs were applied to the neonates for 2 hours in the morning and 2 hours in the evening for 3 consecutive days. An observational checklist was used to assess neonatal behavior. Results The mean age in days was 2.19 ± 0.96, the mean weight in kilograms was 2.92 ± 0.43, and the mean gestational week was 37.56 ± 1.50. The mean sound level in the NICU was 56.7 + 14, which was higher than the NICU's recommended noise level. The most noise-generating events and equipment found in NICU were human-made noise and ventilator bubbling sounds. There was a significant difference in the mean behavioral score among neonates using earmuffs, as the " p -value was < 0.05." However, there was no association between pretest neonatal behavior with baseline data (p > 0.05). Conclusion This study revealed that wearing earmuffs had a beneficial impact on enhancing newborn behavior. [ABSTRACT FROM AUTHOR]

Thermoluminescent dosimeters (TLD) and optically stimulated luminescent dosimeters (OSLD) are practical, accurate, and precise tools for point dosimetry in medical physics applications. The objective of this study is to investigate the luminescence properties—both OSL and TL—of lithium fluoride (LiF) doped with magnesium (Mg), copper (Cu), and phosphorous (P) (LiF: Mg, Cu, P), commercially known as TLD-100H. The goal is to devise a methodological approach for dose measurement that allows for obtaining two independently measured dose values at each irradiation point, thereby improving accuracy and precision. The luminescence properties of TLD-100H were studied using a beta irradiation source (90Sr/90Y) integrated into the TL/OSL DA-15 automated Risø reader. This study identified the ideal experimental conditions for optimal dose evaluation and used them for dosimeter calibration across doses ranging from 0.5 to 4.0 Gy. The results demonstrated that, under optimal measurement parameters, the OSL and residual thermoluminescence (ResTL) signals—correlated to two trap systems within the dosimeter—exhibited high reproducibility, stability over multiple cycles, and high precision and accuracy (≤2%). Specifically, the OSL response showed good linear behavior across the investigated dose range, while the ResTL signal exhibited linear behavior between 0.5 and 2 Gy and sublinear behavior for doses >2 Gy. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the accuracy of different dosimeters and the treatment planning system (TPS) for assessing the skin dose due to the electron streaming effect (ESE) on a 1.5 T magnetic resonance (MR)‐linac. Method: Skin dose due to the ESE on an MR‐linac (Unity, Elekta) was investigated using a solid water phantom rotated 45° in the x‐y plane (IEC61217) and centered at the isocenter. The phantom was irradiated with 1 × 1, 3 × 3, 5 × 5, 10 × 10, and 22 × 22 cm2 fields, gantry at 90°. Out‐of‐field doses (OFDs) deposited by electron streams generated at the entry and exit surface of the angled phantom were measured on the surface of solid water slabs placed ±20.0 cm from the isocenter along the x‐direction. A high‐resolution MOSkin™ detector served as a benchmark due to its shallower depth of measurement that matches the International Commission on Radiological Protection (ICRP) recommended depth for skin dose assessment (0.07 mm). MOSkin™ doses were compared to EBT3 film, OSLDs, a diamond detector, and the TPS where the experimental setup was modeled using two separate calculation parameters settings: a 0.1 cm dose grid with 0.2% statistical uncertainty (0.1 cm, 0.2%) and a 0.2 cm dose grid with 3.0% statistical uncertainty (0.2 cm, 3.0%). Results: OSLD, film, the 0.1 cm, 0.2%, and 0.2 cm, 3.0% TPS ESE doses, underestimated skin doses measured by the MOSkin™ by as much as –75.3%, –7.0%, –24.7%, and –41.9%, respectively. Film results were most similar to MOSkin™ skin dose measurements. Conclusions: These results show that electron streams can deposit significant doses outside the primary field and that dosimeter choice and TPS calculation settings greatly influence the reported readings. Due to the steep dose gradient of the ESE, EBT3 film remains the choice for accurate skin dose assessment in this challenging environment. [ABSTRACT FROM AUTHOR]

The x-ray spectrum of a flash radiography source based on wire-shorted rod-pinch diode (RPD) is measured by an absorption spectrometer and calculated by the Geant4 Monte-Carlo code. The RPD is driven by a two-stage linear transformer driver (charging voltage ±45 kV per stage), which delivers ∼300 kA current within ∼200 ns on a short-circuit inductive load (∼30 nH). The spectrometer consists of LiF thermoluminescence dosimeters and metal filters of different materials and thicknesses, and the spectrum is reconstructed based on the Geant4 simulated dosimeter responses to various photon energies through different filters. The measured spectrum reaches an endpoint photon energy of ∼130 keV. The radiation characteristics of the RPD in the experiment are also modeled in Geant4 using measured voltage and current waveforms, and the results show an overestimation in photon number and endpoint energy (∼147 keV) compared to the measured spectrum, which indicates that during the bremsstrahlung process, the effective electron current is ∼27% of the total current, and the effective voltage is ∼12% lower than the directly reconstructed resistive voltage. A rough agreement is found between the spectra results and the non-relativistic Bethe–Heitler model with Sommerfeld correction; therefore, the analytic result can serve as an initial guess for spectrum reconstruction methods such as the perturbation method. [ABSTRACT FROM AUTHOR]

This study investigates the thermoluminescence (TL) emission spectra of various doped CaF2 materials after exposure to ionizing radiation. The understanding of the TL spectra of these single-doped materials, systematically produced under the same sintering conditions, contributes to the interpretation of complex TL spectra observed in naturally occurring fluorite crystals. The production of Ce3+, Tm3+, Tb3+, Dy3+, Er3+, Pr3+, Nd3+, and Yb3+ doped calcium fluoride was carried out using the combustion synthesis method. The emission spectrum lines could be ascribed to the RE transitions that occur when a trapped hole center recombines with a RE2+. Emissions range from the ultra-violet to the near-infrared. This study aids in tailoring new materials for specific applications and the matching of emitted light to specific filters and instrumentation used for detection. [ABSTRACT FROM AUTHOR]

Light exposure fundamentally influences human physiology and behavior, with light being the most important zeitgeber of the circadian system. Throughout the day, people are exposed to various scenes differing in light level, spectral composition and spatio-temporal properties. Personalized light exposure can be measured through wearable light loggers and dosimeters, including wrist-worn actimeters containing light sensors, yielding time series of an individual's light exposure. There is growing interest in relating light exposure patterns to health outcomes, requiring analytic techniques to summarize light exposure properties. Building on the previously published Python-based pyActigraphy module, here we introduce the module pyLight. This module allows users to extract light exposure data recordings from a wide range of devices. It also includes software tools to clean and filter the data, and to compute common metrics for quantifying and visualizing light exposure data. For this tutorial, we demonstrate the use of pyLight in one example dataset with the following processing steps: (1) loading, accessing and visual inspection of a publicly available dataset, (2) truncation, masking, filtering and binarization of the dataset, (3) calculation of summary metrics, including time above threshold (TAT) and mean light timing above threshold (MLiT). The pyLight module paves the way for open-source, large-scale automated analyses of light-exposure data. [ABSTRACT FROM AUTHOR]

The metrological quality of a measurement is characterised by evaluating the uncertainty in the measurement. In this paper, uncertainty in personal dose measured using individual monitoring CaSO4:Dy-based thermoluminescence dosimeter badge is evaluated by application of the guide to the expression of uncertainty in measurement method. The present dose reporting quantity, whole body dose (WBD) and the proposed quantity, personal dose equivalent, H p(10) has been used as measurands. The influence of various input quantities on the measurement were analyzed through tests that conform to the requirements of the International Electrotechnical Commission IEC 62387. The study found that the expanded uncertainties for WBD and H p(10) measurements were 63.4% and 41.4%, respectively, corresponding to a 95% coverage probability for workplace fields covering a wide photon energy range (33–1250 keV). However, the uncertainty estimates were quite lower for the type of workplaces that are identified using the dose evaluation algorithm. The input quantities, namely, the response to a mixture of photon beam qualities and photon energy and angular dependence contribute the most to the total uncertainty. [ABSTRACT FROM AUTHOR]

This document is a news and product update from the Journal of Medical Engineering & Technology. It includes information about new products in the medical engineering field. One of the featured products is the IRP400 polisher from Zeeko, a company known for its computer-controlled optics polishing machines. Another product mentioned is the RadWatch dosimeter from Landauer, which is designed to measure low-level radiation exposure. The document also highlights the inomed RM system, a stereotactic system used in precise stereotactic surgery. [Extracted from the article]

Background: The newly available ZAP‐X stereotactic radiosurgical system is designed for the treatment of intracranial lesions, with several unique features that include a self‐shielding, gyroscopic gantry, wheel collimation, non‐orthogonal kV imaging, short source‐axis distance, and low‐energy megavoltage beam. Systematic characterization of its radiation as well as other properties is imperative to ensure its safe and effective clinical application. Purpose: To accurately determine the radiation output of the ZAP‐X with a special focus on the smaller diameter cones and an aim to provide useful recommendations on quantification of small field dosimetry. Methods: Six different types of detectors were used to measure relative output factors at field sizes ranging from 4 to 25 mm, including the PTW microSilicon and microdiamond diodes, Exradin W2 plastic scintillator, Exradin A16 and A1SL ionization chambers, and the alanine dosimeter. The 25 mm cone served as the reference field size. Absolute dose was determined with both TG‐51‐based dosimetry using a calibrated PTW Semiflex ion chamber and measurements using alanine dosimeters. Results: The average radiation output factors (maximum deviation from the average) measured with the microDiamond, microSilicon, and W2 detectors were: for the 4 mm cone, 0.741 (1.0%); for the 5 mm cone: 0.817 (1.0%); for the 7.5 mm cone: 0.908 (1.0%); for the 10 mm cone: 0.946 (0.4%); for the 12.5 mm cone: 0.964 (0.2%); for the 15 mm cone: 0.976 (0.1%); for the 20 mm cone: 0.990 (0.1%). For field sizes larger than 10 mm, the A1SL and A16 micro‐chambers also yielded consistent output factors within 1.5% of those obtained using the microSilicon, microdiamond, and W2 detectors. The absolute dose measurement obtained with alanine was within 1.2%, consistent with combined uncertainties, compared to the PTW Semiflex chamber for the 25 mm reference cone. Conclusion: For field sizes less than 10 mm, the microSilicon diode, microDiamond detector, and W2 scintillator are suitable devices for accurate small field dosimetry of the ZAP‐X system. For larger fields, the A1SL and A16 micro‐chambers can also be used. Furthermore, alanine dosimetry can be an accurate verification of reference and absolute dose typically measured with ion chambers. Use of multiple suitable detectors and uncertainty analyses were recommended for reliable determination of small field radiation outputs. [ABSTRACT FROM AUTHOR]

Vision badge is an eye lens dosimeter to measure H p(3). This study aimed to evaluate the basic characteristics of the Vision badge and its performance as an eye lens dosimeter for endoscopists by phantom study. Energy dependence was evaluated by changing the tube voltage to 50 kV (effective energy of 27.9 keV), 80 kV (32.2 keV), and 120 kV (38.7 keV). Dose linearity was evaluated by changing the number of irradiation to 1, 5, and 40 times, which corresponded to 0.53, 5.32, and 21.4 mGy. Batch uniformity was evaluated by calculating the coefficient of variation of H p(3) obtained from 10 Vision badges. Angular dependence was evaluated at 0° (perpendicular to the incident direction of x-rays), 30°, 60°, 75°, and 90°. The Vision badge and optically stimulated luminescence (OSL) dosimeter were attached to the inside of the radioprotective glasses, worn on the endoscopist phantom, and the H p(3) obtained from both dosimeters were compared. The H p(3) obtained from the Vision badge with 38.7 keV was 3.8% higher than that with 27.9 keV. The Vision badge showed excellent linearity (R 2 = 1.00) with the air kerma up to 21.4 mGy. The coefficient of variation of the H p(3) for 10 Vision badges was 3.47%. The relative dose of the Vision badge decreased as the angle increased up to 75°, but increased at 90°. The H p(3) obtained by the OSL dosimeter and the Vision badge were decreased as the endoscopist phantom was turned away from the patient phantom. The H p(3) that was obtained by the Vision badge was 35.5%–55.0% less than that obtained by the nanoDot. In conclusion, the Vision badge showed specific angular dependence due to its shape, but satisfactory basic properties were exhibited for all characteristics. In phantom study, the Vision badge showed generally similar trends with the OSL dosimeter. [ABSTRACT FROM AUTHOR]

This work describes the development of a reusable 2D detector based on radiochromic reaction for radiotherapy dosimetric measurements. It consists of a radiochromic gel dosimeter in a cuboidal plastic container, scanning with a flatbed scanner, and data processing using a dedicated software package. This tool is assessed using the example of the application of the coincidence test of radiation and mechanical isocenters for a medical accelerator. The following were examined: scanning repeatability and image homogeneity, the impact of image processing on data processing in coincidence tests, and irradiation conditions—monitor units per radiation beam and irradiation field are selected. Optimal conditions for carrying out the test are chosen: (i) the multi-leaf collimator gap should preferably be 5 mm for 2D star shot irradiation, (ii) it is recommended to apply ≥2500–≤5000 MU per beam to obtain a strong signal enabling easy data processing, (iii) Mean filter can be applied to the images to improve calculations. An approach to dosimeter reuse with the goal of reducing costs is presented; the number of reuses is related to the MUs per beam, which, in this study, is about 5–57 for 30,000–2500 MU per beam (four fields). The proposed reusable system was successfully applied to the coincidence tests, confirming its suitability as a new potential quality assurance tool in radiotherapy. [ABSTRACT FROM AUTHOR]

Accelerating electrons to achieve chemical and biological effects is a well-established competence of Fraunhofer FEP. Today, there is a large variety of low-energy electron beam applications with a broad range of absorbed doses, e.g. modification of plastics, plasma-chemical syntheses, pollutant removal in wastewaters and exhaust gases, sterilization of medical products, disinfection of seeds, biocompatible functionalization of implants and stimulation of biotechnological processes. This calls for reliable, sensitive, and flexible methods for dosimetry. Radiochromic films are suitable tools to measure electron dose distributions for the characterization and quality control of Fraunhofer FEP's irradiation facilities. Risø B3 radiochromic film from DTU Health Tech, the dosimeter of choice at FEP, reliably detects doses in the range of 10–100 kGy. However, with new upcoming applications, doses in the single-digit kGy range and even lower come to the fore. Hence, the palette of dosimeters at FEP must be extended. Gafchromic's HD-V2 film is a welcome complement and widens the accessible dose range down to 10 Gy. Using a UV-VIS spectrophotometer for read-out of the films and custom analysis algorithms further increase the sensitivity of the dosimetric setup. Additionally, dosimeters based on the optically stimulated luminescence (OSL) of beryllium oxide offer a wide dose range and high sensitivity. They were used to measure doses induced by secondary X-ray components to gain more information about a specific radiation field. The work gives an overview of the dosimetric toolbox at Fraunhofer FEP and the efforts to implement new methods of detection for low-dose applications and X-ray dosimetry. [ABSTRACT FROM AUTHOR]

In recent years, the use of low-energy electrons in various ecological and biotechnological applications has become increasingly relevant. One important application is the treatment of wastewater, wherein highly reactive species produced by water irradiation are used to oxidize pollutants. Low-energy electron irradiation has several advantages, such as minimal demands on radiation protection and electron beam (EB) source dimensions. However, to play into the main advantages of this technology and keep it economically viable, it is necessary to keep the absorbed dose as low as possible. This calls for a liquid dosimeter with sensitivity in the single digit kGy range. An extract from natural Hibiscus sabdariffa (Roselle) has been reported to show a radiochromic effect in this dose range. In the present work, Roselle dosimeter solutions were closely investigated and optimized to characterize a new module for EB wastewater treatment. Upon EB irradiation, the dosimeter solution demonstrated a dose-dependent fading in color, making it useful in the 0.3–7.5 kGy dose range. [ABSTRACT FROM AUTHOR]

To evaluate if real-time dose visualisation during computed tomography (CT)-guided interventions leads to a reduction in radiation dose to participating radiologists. The individual radiation dose radiologists are exposed to during CT interventions was measured using dedicated dosimeters (RaySafe i2-system, Unfors RaySafe GmbH, Billdal, Sweden) worn over the usual radiation protective apron. Initially, only the total radiation dose was measured, without visualisation (control group). In the following study period, the radiation dose was shown to participants on a live screen in real-time (experimental group). In both groups, the dose was recorded in 1-second intervals. The results collected were evaluated by comparison using descriptive statistics and mixed-effect models. In particular, the variables experience, gender, role, and position during the intervention were analysed. In total, 517 measurements of 304 interventions (n= 249 with and n= 268 without live screen) performed by 29 radiologists acting as interventionalists or assistants were analysed. All CT-guided interventions were performed percutaneously, the majority of which (n= 280) were microwave ablations (MWA). Radiation doses in the group without visualisation were comparable with usual dose rates for the corresponding intervention type. The mean total radiation dose was reduced by 58.1% (11.6 versus 4.86 μSv) in the experimental group (p= 0.034). The highest reduction of 78.5% (15.55 versus 3.35 μSv) was observed in radiologists with the role of assistant (p= 0.002). Sub-analysis showed significant dose reduction (p< 0.0001) for the use of live screen in general; considering all variables, the role "assistant" alone had a statistically significant influence (p= 0.002). The real-time visualisation of active radiation dose during CT interventions leads to a relevant reduction in radiation dose to participating radiologists. • Real-time dose visualisation leads to dose reduction on participating radiologists. • Most significant dose reduction was seen in radiologists in the role of "assistant". • Interventionalist's experience influences active radiation dose during interventions. [ABSTRACT FROM AUTHOR]

Long-term internal exposure to radon and its progenies may lead to lung cancer. An experimental setup was arranged to assess the impact of temperature and humidity on the distribution of radon concentration in a walk-in type stability test chamber. Different temperature and humidity conditions were established between 15–35 °C and 45–85%, respectively. Passive measurement of radon concentration was carried out using pinhole dosimeters on a monthly basis. The average radon concentration was found to increase with an increase in temperature and decreases with an increase in humidity. The distribution of radon concentration was found to be highly affected by ventilation and air circulation patterns inside the chamber. [ABSTRACT FROM AUTHOR]

Three Closed Transfer Systems (CTS) were evaluated for their reduction of operator exposure to plant protection products during mixing and loading: the inverted extraction systems, easyFlow M and easyconnect, and the probe extraction system, GoatThroat®. Exposure data were generated for gloves, hands, head, inner and outer body dosimeters generated in 4 European countries for high rate (Sorbitol) and low rate (Xylitol) surrogate products used by 12 operators. Exposure values were compared with predicted data using the Agricultural Operator Exposure Model as a benchmark for open pour loading (used in the EFSA Guidance). The CTS types conformed with the ISO 21191 standard for CTS performance, and their potential to significantly reduce operator exposure was confirmed in this study. There was no statistical difference in potential (naked) or actual (one layer of clothing) operator exposure using both inverted CTS types; allowing these data to be pooled. The inverted CTS types resulted in higher mean protection (> 98% potential exposure and > 95% actual exposure) than GoatThroat® (> 80% potential exposure and > 95% actual exposure). These data can be used to derive reduction factors that could be used in the AOEM model for calculations involving mitigation e.g., 0.05 for inverted CTS since they reduced exposure by > 95% and 0.3 for probe extraction CTS types. All 3 CTS significantly reduced operator exposure to products during M&L. These and future CTS types which comply with ISO 21191 standards could be considered as mitigation devices. These findings will help to build confidence of farmers to use CTS routinely, resulting in safer pesticide handling. [ABSTRACT FROM AUTHOR]

A PET CT uses x-rays and radionucleotide combined with a pharmaceutical to help reveal the metabolic or biochemical function of tissues or organs. It is an effective and highly sensitive way to detect a variety of conditions including cancer, heart disease and brain disorders. The length of the scanner and scan itself, in combination with the radiation dose can present challenges both the patient and staff. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the influence of different cone-beam computed tomography (CBCT) acquisition protocols on reducing the effective radiation dose while maintaining image quality. Materials and Methods: The effective dose emitted by a CBCT device was calculated using thermoluminescent dosimeters placed in a Rando Alderson phantom. Image quality was assessed by 3 experienced evaluators. The relationship between image quality and confidence was evaluated using the Fisher exact test, and the agreement among raters was assessed using the kappa test. Multiple linear regression analysis was performed to investigate whether the technical parameters could predict the effective dose. P-values<0.05 were considered to indicate statistical significance. Results: The optimized protocol (3 mA, 99 kVp, and 450 projection images) demonstrated good image quality and a lower effective dose for radiation-sensitive organs. Image quality and confidence had consistent values for all structures(P<0.05). Multiple linear regression analysis resulted in a statistically significant model. The milliamperage (b=0.504; t=3.406; P=0.027), kilovoltage peak (b=0.589; t=3.979; P=0.016) and number of projection images (b=0.557; t=3.762; P=0.020) were predictors of the effective dose. Conclusion: Optimized CBCT acquisition protocols can significantly reduce the effective radiation dose while maintaining acceptable image quality by adjusting the milliamperage and projection images. [ABSTRACT FROM AUTHOR]

Introduction: Radiation dose measurement is an essential part of radiotherapy to verify the correct delivery of doses to patients and ensure patient safety. Recent advancements in radiotherapy technology have highlighted the need for fast and precise dosimeters. Technologies like FLASH radiotherapy and magnetic‐resonance linear accelerators (MR‐LINAC) demand dosimeters that can meet their unique requirements. One promising solution is the plastic scintillator‐based dosimeter with high spatial resolution and real‐time dose output. This study explores the feasibility of using the LuSy dosimeter, an in‐house developed plastic scintillator dosimeter for dose verification across various radiotherapy techniques, including conformal radiotherapy (CRT), intensity‐modulated radiation therapy (IMRT), volumetric‐modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Materials and methods: A new dosimetry system, comprising a new plastic scintillator as the sensing material, was developed and characterized for radiotherapy beams. Treatment plans were created for conformal radiotherapy, IMRT, VMAT, and SRS and delivered to a phantom. LuSy dosimeter was used to measure the delivered dose for each plan on the surface of the phantom and inside the target volumes. Then, LuSy measurements were compared against an ionization chamber, MOSFET dosimeter, radiochromic films, and dose calculated using the treatment planning system (TPS). Results: For CRT, surface dose measurement by LuSy dosimeter showed a deviation of ‐5.5% and ‐5.4% for breast and abdomen treatment from the TPS, respectively. When measuring inside the target volume for IMRT, VMAT, and SRS, the LuSy dosimeter produced a mean deviation of ‐3.0% from the TPS. Surface dose measurement resulted in higher TPS discrepancies where the deviations for IMRT, VMAT, and SRS were ‐2.0%, ‐19.5%, and 16.1%, respectively. Conclusion: The LuSy dosimeter was feasible for measuring radiotherapy doses for various treatment techniques. Treatment delivery verification enables early error detection, allowing for safe treatment delivery for radiotherapy patients. [ABSTRACT FROM AUTHOR]

Objective. To evaluate the reduction in energy dependence and aging effect of the lithium salt of pentacosa−10,−12-diynoic acid (LiPCDA) films with additives including aluminum oxide (Al2O3), propyl gallate (PG), and disodium ethylenediaminetetracetate (EDTA). Approach. LiPCDA films exhibited energy dependence on kilovoltage (kV) and megavoltage (MV) photon energies and experienced deterioration over time. Evaluations were conducted with added Al2O3 and antioxidants to mitigate these issues, and films were produced with and without Al2O3 to assess energy dependence. The films were irradiated at doses of 0, 3, 6, and 12 cGy at photon energies of 75 kV, 105 kV, 6 MV, 10 MV, and 15 MV. For the energy range of 75 kV to 15 MV, the mean and standard deviation (std) were calculated and compared for the values normalized to the net optical density (netOD) at 6 MV, corresponding to identical dose levels. To evaluate the aging effect, PG and disodium EDTA were incorporated into the films: sample C with 1% PG, sample D with 2% PG, sample E with 0.62% disodium EDTA added to sample D, and sample F with 1.23% disodium EDTA added to sample D. Main results. Films containing Al2O3 demonstrated a maximum 15.8% increase in mean normalized values and a 15.1% reduction in std, reflecting a greater netOD reduction at kV than MV energies, which indicates less energy dependence in these films. When the OD of sample 1–4 depending on the addition of PG and disodium EDTA, was observed for 20 weeks, the transmission mode decreased by 8.7%, 8.3%, 29.3%, and 27.3%, respectively, while the reflection mode was 5.4%, 3.0%, 37.0%, and 34.5%, respectively. Significance. Al2O3 effectively reduced the voltage and MV energy dependence. PG was more effective than disodium EDTA in preventing the deterioration of film performance owing to the aging effect. [ABSTRACT FROM AUTHOR]

Background/Objectives: To evaluate radiation exposure in standard interventional radiology procedures using a twin robotic X-ray system compared to a state-of-the-art conventional angiography system. Methods: Standard interventional radiology procedures (port implantation, SIRT, and pelvic angiography) were simulated using an anthropomorphic Alderson RANDO phantom (Alderson Research Laboratories Inc. Stamford, CT, USA) on an above-the-table twin robotic X-ray scanner (Multitom Rax, Siemens Healthineers, Forchheim, Germany) and a conventional below-the-table angiography system (Artis Zeego, Siemens Healthineers, Forchheim, Germany). The phantom's radiation exposure (representing the potential patient on the procedure table) was measured with thermoluminescent dosimeters. Height-dependent dose curves were generated for examiners and radiation technologists in representative positions using a RaySafe X2 system (RaySafe, Billdal, Sweden). Results: For all scenarios, the device-specific dose distribution differs depending on the imaging chain, with specific advantages and disadvantages. Radiation exposure for the patient is significantly increased when using the Multitom Rax for pelvic angiography compared to the Artis Zeego, which is evident in the dose progression through the phantom's body as well as in the organ-related radiation exposure. In line with these findings, there is an increased radiation exposure for the performing proceduralist, especially at eye level, which can be significantly minimized by using protective equipment (p < 0.001). Conclusions: In this study, the state-of-the-art conventional below-the-table angiography system is associated with lower radiation dose exposures for both the patient and the interventional radiology physician compared to an above-the-table twin robotic X-ray system for pelvic angiographies. However, in other clinical scenarios (port implantation or SIRT), both devices are suitable options with acceptable radiation exposure. [ABSTRACT FROM AUTHOR]

In the mining industry, dumper operators are exposed to combined noise and vibration, leading to discomfort. Dumpers are heavy earth-moving machines that are used for carrying bulky material in mining industries. Dumper operators are exposed to physical hazards such as vibration, noise, heat, and humidity, throughout their lifetime of work. Fifty-four dumper operators working in mines were selected for this study. Noise was measured as per the guidelines of the Directorate General Mining Safety, India, and whole-body vibration was measured as per the guidelines of ISO 2631-1::1997. Noise Pro DLX, Type 2 noise dosimeters were used for the measurement of personal noise exposure while SV-106 six channels vibration meters were used for whole body vibration (WBV) exposure measurement. Discomfort was calculated using the regression equation developed by Huang and Griffin (2014). The total discomfort level of mine operators was about 192. A predictive equation was derived by using a regression model to determine the contribution of individual variables causing discomfort. It was observed that for every unit increase in noise (LAeq), discomfort increased by 10.20 units, a one-unit increase in vibration (A (8)) led to a 51.7-unit increase in discomfort, while an increase of one unit of exposure time increased the discomfort level by 5.24 units. [ABSTRACT FROM AUTHOR]