Skin Dose Research Articles

Chest X-Ray ESD and ESAK Assessment in A Few Diagnostic Radiological Facilities in Delta State

Background: The utilization of X-rays in medical procedures has sparked apprehension regarding their potential adverse consequences, despite their undeniable advantages in the realms of diagnosis and therapy. The present study aimed to evaluate the levels of Entrance Skin Dose (ESD) and Entrance Skin Air Kerma (ESAK) associated with chest X-ray examinations conducted in diagnostic radiological facilities located within Delta State. The present study employed a standardized approach to describe the materials and methods used in the research. The dose assessment was performed on a sample of 700 patients who were 18 years of age or older. These patients were selected from 10 operational facilities located throughout the State. The findings of the study are as follows: The effective dose (ESD), ascertained through the utilization of patient anatomical data and exposure parameters, fell within the recommended reference dose limits of 1 mGy (National Nuclear Regulatory Agency) and 0.4 mGy (International Atomic Energy Agency) for the majority of healthcare facilities. Nevertheless, certain centers demonstrated elevated dose levels, which can be attributed to factors such as increased exposure rates, aging x-ray tubes, and inadequate technician competency. The effective dose values (ESD) exhibited a range of 0.018 to 1.671 mGy for males and 0.084 to 1.542 mGy for females. The range of Entrance Skin Air Kerma (ESAK) values for males was found to be between 0.019 and 0.085 mGy, while for females it ranged from 0.016 to 0.098 mGy. These values were observed to be within the recommended dose limits. In conclusion, this study emphasizes the significance of surveillance of radiation exposure and the implementation of quality assurance protocols in order to safeguard patient well-being and mitigate potential hazards linked to chest X-ray procedures conducted in diagnostic radiological establishments.

Establishment of local diagnostic reference levels for abdomen and chest radiographies in the region of Algarve, Portugal

PurposeTo assess doses variabilities in the same abdomen and chest RX exams for adults, to check the need for dose harmonization. To calculate Diagnostic Reference Levels (DRL), mandatory in the European Union, for the Algarve district in Portugal. Our results can be a valuable reference for the Portuguese official determination of DRLs, still in progress. MethodWe considered 4,936 abdomen and 41,320 chest radiographs of adults, covering 7 health centres and 35 radiographers in Algarve. Entrance skin dose (ESD) was calculated for each radiograph and the corresponding uncertainty estimated. Mean doses per centre and per technician, and their uncertainties, were calculated to access dose variabilities. DRLs, set at the 3rd quartile of the total ESD distribution, were determined for a standard patient and for intervals of body mass index (BMI) to study their correlation with patient anatomical variations. Standard quartile errors were estimated. ResultsOur results suggest significant dispersion in applied ESDs among different centres and radiographers. Estimates of DRLs also show small fluctuations across years and an important dependence on BMI intervals. For a standard patient, they are 8.7 ± 0.1 (abdomen) and 0.44 ± 0.01 (chest), while the European DRLs are, respectively, 5.1 and 0.2 (all in mGy). ConclusionsResults suggest that there is room for dose optimization and harmonization with European DRLs, urging a national dose survey and the establishment of official national DRLs. Official DRLs in intervals of BMI would be quite beneficial, to avoid unnecessary dose exposures.

Effect of different CTV shrinkage and skin flash margins on skin dose for left chest wall IMRT: A dosimetric study

In postmastectomy radiation therapy (PMRT), the adequate skin surface dose remains a problem. In this study, the effect of different CTV shrinkage and Skin flash margins on skin dose was investigated, and the accuracy of skin surface dose calculated by TPS for PMRT using thermoluminescent dosimeters (TLDs) was evaluated. Eighty-eight measurement points were determined on the Alderson Rando phantom. To determine the effects of shrinkage margin on skin dose, separate CTVs were generated for 2 mm, 3 mm and 5 mm shrinkage. The prescribed dose was 50 Gy to CTV with a daily fraction dose of 2 Gy. A total of 12 plans were created using four different skin flash thicknesses for each CTV shrinkage margin. After applying 0 mm, 10 mm, 15 mm and 20 mm skin flash thicknesses for each area of the 7F-IMRT treatment plan, the plans were recalculated, and the SF-0, SF-10, SF-15 and SF-20 plans were created, respectively. The increase in skin flash thickness in IMRT plans resulted in a significant increase in skin dose. There was a significant difference between TPS and TLD doses in all chest wall areas for SF-0, SF-10, and SF-15 (p < 0.05). However, there was no significant difference in all areas of the chest wall for SF-20 (p > 0.05). The shrinkage margin thickness of the CTV was found to be inversely proportional to the skin dose for all treatment plans. In tumors near the surface, bolus or skin flash techniques can get the skin adequately dosed. However, the skin flash technique has shown superiority in the application. In PMRT, it is recommended to keep the shrinkage margin as small as possible and use the skin flash thickness of 20 mm for the skin to receive a sufficient dose.

An investigation on protection properties of Tantalum (V) oxide reinforced glass screens on unexposed breast tissue for mammography examinations

IntroductionThe utilization of radiation shielding material positioned between the both breasts are crucial for the reduction of glandular dose and the safeguarding of the contralateral breast during mammographic procedures. This study proposes an alternative substance for shielding the contralateral breast from radiation exposure during mammography screening. MethodsIn this study, we present an analysis of the shielding effectiveness of transparent glass that has been doped with Tantalum (V) oxide encoded as BTZT6. The evaluation of this shielding material was conducted using the MCNPX code, specifically for the ipsilateral and contralateral breasts. The design of the left and right breast phantoms involved the creation of three-layer heterogeneous breast phantoms, consisting of varying proportions of glandular tissue (25%, 50%, and 75%). The design of BTZT6 and lead-acrylic shielding screens is implemented using the MCNPX code. The comparative analysis of dose outcomes is conducted to assess the protective efficacy of BTZT6 and lead-acrylic shielding screens. ResultsThe utilization of BTZT6 shielding material resulted in a reduction in both breast dose and skin dose exposure when compared to the lead-acrylic shield. ConclusionBased on the findings acquired, the utilization of BTZT6 shielding material screens during mammography procedures involving X-rays with energy levels ranging from 26 to 30 keV is associated with a decrease in radiation dose. Implications for practiceIt can be inferred that the utilization of BTZT6 demonstrates potential efficacy in mitigating excessive radiation exposure to the breasts and facilitating the quantification of glandular doses in mammography procedures.

Patient Dose Estimation in Computed Tomography-Guided Biopsy Procedures.

This study establishes typical Diagnostic Reference Levels (DRL) values and assesses patient doses in computed tomography (CT)-guided biopsy procedures. The Effective Dose (ED), Entrance Skin Dose (ESD), and Size-Specific Dose Estimate (SSDE) were calculated using the relevant literature-derived conversion factors. A retrospective analysis of 226 CT-guided biopsies across five categories (Iliac bone, liver, lung, mediastinum, and para-aortic lymph nodes) was conducted. Typical DRL values were computed as median distributions, following guidelines from the International Commission on Radiological Protection (ICRP) Publication 135. DRLs for helical mode CT acquisitions were set at 9.7 mGy for Iliac bone, 8.9 mGy for liver, 8.8 mGy for lung, 7.9 mGy for mediastinal mass, and 9 mGy for para-aortic lymph nodes biopsies. In contrast, DRLs for biopsy acquisitions were 7.3 mGy, 7.7 mGy, 5.6 mGy, 5.6 mGy, and 7.4 mGy, respectively. Median SSDE values varied from 7.6 mGy to 10 mGy for biopsy acquisitions and from 11.3 mGy to 12.6 mGy for helical scans. Median ED values ranged from 1.6 mSv to 5.7 mSv for biopsy scans and from 3.9 mSv to 9.3 mSv for helical scans. The study highlights the significance of using DRLs for optimizing CT-guided biopsy procedures, revealing notable variations in radiation exposure between helical scans covering entire anatomical regions and localized biopsy acquisitions.

Threshold in breast compression reduction for full-field digital mammography and digital breast tomosynthesis

IntroductionBreast compression is essential in mammography to improve image quality and reduce radiation dose. However, it can cause discomfort or even pain in women which could discourage them from attending future mammography examinations. Therefore, this study aims to explore the maximum reduction in breast compression in full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) that is achievable without impacting on image quality and dose. MethodsTen compression force (CF) levels (20N–110N, with 10N intervals) were assessed on Siemens MAMMOMAT Inspiration with Nuclear Associates 18–228 phantom. Imaging was carried out in craniocaudal projection using Automatic Exposure Control at 28 kVp with a Tungsten/Rhodium anode/filter combination, and at 50° sweep angle for DBT. Using ImageJ software, image quality of the acquired mammograms and central tomosynthesis slices were examined based on mass conspicuity (MC) and microcalcification conspicuity (MicroC). Entrance skin dose (ESD) and mean glandular dose (MGD) were recorded from Digital Imaging and Communication in Medicine image header. Linear regression was performed to examine the relationship between CF with ESD, MGD, MC and MicroC. Differences in image quality and radiation dose were assessed with one-way analysis of variance and Kruskal-Wallis H test. ResultsSignificant correlations were noted between CF with ESD and MicroC for FFDM and DBT, with DBT also demonstrating associations with MGD and MC. No significant differences were observed for ESD, MGD, MC and MicroC when CF was reduced to 40N and 80N in FFDM and DBT respectively. ConclusionThis study demonstrated that CF can be reduced as low as 40N and 80N in FFDM and DBT respectively, without significant impact on image quality and radiation dose. Implications for practiceReduced mammographic compression may reduce discomfort or pain in women, which may improve attendance rate in breast screening programmes. Findings from this study will provide reference for future work examining breast compression in mammography.

Assessment of organ doses, peak skin doses and effective doses in patients undergoing anterior cervical discectomy and fusion utilising VirtualDose-IR software.

In this study, the effect of patient- and procedure-related parameters on organ doses (ODs), peak skin dose (PSD) and effective dose (E) during anterior cervical discectomy and fusion (ACDF) was evaluated. Patient- and procedure-related parameters, as well as fluoroscopy time, kerma-area product (KAP), cumulative air-kerma (Kair) and incident Kair, were analysed for 50 ACDF procedures performed with a mobile C-arm. These parameters were inserted in VirtualDose-IR software implementing sex-specific and body mass index (BMI)-adjustable anthropomorphic phantoms to calculate OD, PSD and E. The BMI, gender and type of implants did not significantly affect KAP, incident Kair, PSD and E. However, the type of fusion significantly affected the E. The single fusions in C5/C6 resulted in significantly higher KAP, incident Kair and E than C4/C5 levels, while those performed in C6/C7 resulted in significantly higher E and PSD than C4/C5 levels. The thyroid, oesophagus and salivary glands received the largest doses in all groups studied. The BMI did not significantly affect ODs. The salivary glands absorbed significantly higher doses in males than females, while the extrathoracic region's dose significantly increased for multi- than single-level fusions. The fusions in C6/C7 resulted in significantly higher oesophagus and thyroid doses than C3/C4 and C4/C5 levels, as well as fusions performed in C5/C6 compared with C4/C5 levels. The data presented here could be used by the neurosurgeons as a comparator for future studies in optimising radiation protection during ACDF procedures in the operating theatre by keeping the ODs, PSD and E as low as reasonably practicable.

Virtual Injection Software Reduces Radiation Exposure and Procedural Time of Prostatic Artery Embolization Performed with Cone-Beam CT

PurposeTo evaluate the impact of virtual injection software (VIS) use during cone-beam computed tomography (CT)–guided prostatic artery embolization (PAE) on both patient radiation exposure and procedural time. Materials and MethodsThis institutional review board (IRB)–approved comparative retrospective study analyzed the treatment at a single institution of 131 consecutive patients from January 2020 to May 2022. Cone-beam CT was used with (Group 1, 77/131; 58.8%) or without VIS (Group 2, 54/131, 41.2%). Radiation exposure (number of digital subtraction angiography [DSA] procedures), dose area product (DAP), total air kerma (AK), peak skin dose (PSD), fluoroscopy time (FT), and procedure time (PT) were recorded. The influences of age, body mass index, radial access, and use of VIS were assessed. ResultsIn bivariate analysis, VIS use (Group 1) showed reduction in the number of DSA procedures (8.6 ± 3.7 vs 16.8 ± 4.3; P < .001), DAP (110.4 Gy·cm2 ± 46.8 vs 140.5 Gy·cm2 ± 61; P < .01), AK (642 mGy ± 451 vs 1,150 mGy ± 637; P = .01), PSD (358 mGy ± 251 vs 860 mGy ± 510; P = .001), FT (35.6 minutes ± 15.4 vs 46.6 minutes ± 20; P = .001), and PT (94.6 minutes ± 41.3 vs 115.2 minutes ± 39.6, P = .005) compared to those in Group 2. In multivariate analysis, AK, PSD, FT, and PT reductions were associated with VIS use (P < .001, P < .001, P = .001, and P = .006, respectively). ConclusionsThe use of VIS during PAE performed under cone-beam CT guidance led to significant reduction in patient radiation exposure and procedural time.

A novel approach to predict acute radiation dermatitis in patients with head and neck cancer using a model based on Bayesian probability

PurposeIn this study, we aimed to establish a method for predicting the probability of each acute radiation dermatitis (ARD) grade during the head and neck Volumetric Modulated Arc Therapy (VMAT) radiotherapy planning phase based on Bayesian probability. MethodsThe skin dose volume >50 Gy (V50), calculated using the treatment planning system, was used as a factor related to skin toxicity. The empirical distribution of each ARD grade relative to V50 was obtained from the ARD grades of 119 patients (55, 50, and 14 patients with G1, G2, and G3, respectively) determined by head and neck cancer specialists. Using Bayes’ theorem, the Bayesian probabilities of G1, G2, and G3 for each value of V50 were calculated with an empirical distribution. Conversely, V50 was obtained based on the Bayesian probabilities of G1, G2, and G3. ResultsThe empirical distribution for each graded patient group demonstrated a normal distribution. The method predicted ARD grades with 92.4 % accuracy and provided a V50 value for each grade. For example, using the graph, we could predict that V50 should be ≤24.5 cm3 to achieve G1 with 70 % probability. ConclusionsThe Bayesian probability-based ARD prediction method could predict the ARD grade at the treatment planning stage using limited patient diagnostic data that demonstrated a normal distribution. If the probability of an ARD grade is high, skin care can be initiated in advance. Furthermore, the V50 value during treatment planning can provide radiation oncologists with data for strategies to reduce ARD.

The effect of geometrical parameters of skin brachytherapy patch source on depth dose distribution using Monte Carlo simulation

Brachytherapy of superficial skin tumors using beta-emitting sources is a method that has been investigated by some researchers in both simulation and experimental studies with promising results. In the current study, the effect of geometrical parameters of some relevant radionuclides including Y-90, Re-188, P-32, and Ho-166 on the depth dose distribution in skin tissue has been investigated through Monte Carlo simulation.MCNPX Monte Carlo code was employed to model the above-mentioned patch sources in cylindrical format and then the effect of patch geometrical parameters including the source-to-skin distance (SSD), patch thickness, and patch diameter on depth dose distribution was assessed through modeling and calculation of the dose inside a cubic phantom mimicking the skin tissue.The obtained results demonstrated that increasing the SSD, patch thickness, and patch diameter (with the same activity) will reduce the depth dose distribution. Changing the SSD has a more significant effect on the dose gradient within the depth than other geometrical parameters. It was also observed that the effect of patch diameter on the skin-delivered dose gets less sensible as the patch size goes beyond the range of beta radiation inside tissue.Finally, it can be concluded that the patch source geometrical parameters can affect the depth dose distribution inside the skin tissue. This fact may be of concern regarding the delivery of a high radiation dose in a single treatment session. Therefore, variations of patch source geometrical parameters should be considered during the skin dose calculation plan.

Evaluation of the Entrance Surface Doses (ESD) for common diagnostic X-ray examinations

ObjectiveThe purpose of this study was to assess the Entrance Skin Dose (ESD) in patients undergoing multiple types of radiographic examinations across three hospitals in Saudi Arabia. MethodsThe patient ESD was estimated directly using optically stimulated luminesces (OSL) and indirectly using a survey meter and calculations for 100 adult patients undergoing common diagnostic X-ray examinations, including a posterior anterior chest, posterior anterior hand, anterior posterior foot, and anterior posterior knee examinations, in three hospitals in Saudi Arabia. Comparative analysis with national and international reference values was conducted. ResultsOur analyses revealed considerable heterogeneity in X-ray exposure parameters among the hospitals. The mean ESD values for the chest examination were 0.28 ± 0.13 mGy for the direct method and 0.19 ± 0.11 mGy for the indirect method. Hand examination using the direct method resulted in a mean ESD of 0.42 ± 0.15 mGy, while the indirect method yielded 0.23 ± 0.06 mGy. Remarkably, the ESD values in most cases exceeded national and international guidelines, with the knee examination ESD using the direct and indirect methods showing an alarming value of 1.54 ± 0.31 mGy and 1.18 ± 0.21 mGy, respectively. The correlation between direct ESD, indirect ESD showed a strong positive correlation exists between direct ESD and Indirect ESD (r = 0.8, p < 0.001). ConclusionThe study highlights the urgent need for standardized protocols and quality control measures across radiographic facilities in Saudi Arabia. The elevated ESD values signify a critical issue that requires immediate attention to minimize patient radiation exposure while maintaining diagnostic image quality. Quality control tests and adjustments in examination parameters are strongly advised.

Estimating the risk of cancer incidence and radiation-induced cancer death of children patients undergoing digital radiology X-ray examinations

BackgroundIt is generally accepted that children are more sensitive to radiation than adults and have a higher relative risk of cancer. The longer life expectancy after exposure increases the risk of developing radiation-associated malignancies. PurposeThis study aims to estimate the risk of cancer incidence and radiation-induced cancer death of children patients undergoing digital radiology X-ray examinations. Material and methodsIn this study, data were collected retrospectively from 15 radiography rooms in the major radiology centers in Mazandaran province (Iran). The information of 12 common digital radiography examinations including pelvis (in the anteroposterior projection (AP)), skull (in the two lateral projection (LAT) and posteroanterior projection (PA)), abdomen (AP), cervical vertebra (AP and LAT), chest (PA and LAT), lumbar vertebra (AP and LAT), thoracic vertebra (AP and LAT) examinations which was recorded from 10 to 15 years old patients. The Entrance Surface Air Kerma (ESAK), Entrance Skin Dose (ESD), and Organ Effective Dose (ED) were measured. Finally, the risk of cancer incidence and Risk of Exposure-Induced cancer Death (REID) values were estimated for these patients. ResultsIn total, 1800 (983 females and 817 males) patients (10–15 years old) were included in this study. Across all procedures, the lowest ED belonged to the skull (PA) examination (10.40 μSv), and the highest ED belonged to the AP abdominal imaging technique (378.46 μSv). The highest ESD was related to the lumbar spine (LAT) projection (3.62 ± 1.38 mGy) and the least to the cervical vertebra (AP) view (0.97 ± 0.21). It was also shown that the differences in cancer incidence and radiation-induced cancer death values in male and female patients were not statistically significant. ConclusionThe result showed that ESDs are influenced by various factors that affect patients' dose distributions, so through the optimization of imaging parameters, image quality can be increased and the patient dose reduced. These actions will necessarily decrease the risk of cancer incidence and radiation-induced mortality risk. Further studies are recommended to assess the workplace environment and practical training in radiology institutions, along with the quality control tests of radiology devices.

Novel Postoperative Hypofractionated Accelerated Radiation Dose-Painting Approach for Soft Tissue Sarcoma

Background: Hypofractionated radiotherapy (RT) offers benefits in the treatment of soft tissue sarcomas (STS), including exploitation of the lower α/β, patient convenience, and cost. This study evaluates the acute toxicity of a hypofractionated accelerated RT dose-painting (HARD) approach for postoperative treatment of STS. Materials and Methods: This is a retrospective review of 53 consecutive patients with STS who underwent resection followed by postoperative RT. Standard postoperative RT dosing for R0/R1/gross disease with sequential boost (50Gy + 14/16/20Gy in 32-35 fractions) were replaced with dose-painting, which adapts dose based on risk of disease burden, to 50.4 and 63/64.4/70 Gy in 28 fractions, respectively. The first 10 patients were re-planned with a sequential boost RT approach and dosimetric indices were compared. Time-to-event outcomes, including local control (LC), regional control (RC), distant control (DC), and overall survival (OS), were estimated with Kaplan-Meier (KM) analysis. Results: Median follow up was 25.2 months. Most patients had high grade (59%) STS of the extremity (63%) who underwent resection with either R1 (40%) or close (36%) margins. Four patients experienced grade 3 acute dermatitis which resolved by the 3-month follow up visit. The 2-year LC, RC, DC, and OS were 100%, 92%, 68%, and 86%, respectively. Compared to the sequential boost plan, HARD had a significantly lower field size (total V50Gy) (p=0.002), bone V50 (p=0.031), and maximum skin dose (p=0.008). Overall treatment time was decreased by 4-7 fractions, which translated to a decrease in estimated average treatment cost of $3,056 (range: $2,51-$4,335, p<0.001). Conclusions: In addition to benefits in cost, convenience, and improved biological effect in STS, hypofractionated accelerated RT dose-painting (HARD) regimen offers a safe treatment approach with dosimetric advantages compared to conventional sequential boost, which may translate to improved long-term toxicity.

Quantitative radiomics approach to assess acute radiation dermatitis in breast cancer patients.

We applied a radiomics approach to skin surface images to objectively assess acute radiation dermatitis in patients undergoing radiotherapy for breast cancer. A prospective cohort study of 20 patients was conducted. Skin surface images in normal, polarized, and ultraviolet (UV) modes were acquired using a skin analysis device before starting radiotherapy ('Before RT'), approximately 7 days after the first treatment ('RT D7'), on 'RT D14', and approximately 10 days after the radiotherapy ended ('After RT D10'). Eighteen types of radiomic feature ratios were calculated based on the values acquired 'Before RT'. We measured skin doses in ipsilateral breasts using optically stimulated luminescent dosimeters on the first day of radiotherapy. Clinical evaluation of acute radiation dermatitis was performed using the Radiation Therapy Oncology Group scoring criteria on 'RT D14' and 'After RT D10'. Several statistical analysis methods were used in this study to test the performance of radiomic features as indicators of radiodermatitis evaluation. As the skin was damaged by radiation, the energy for normal mode and sum variance for polarized and UV modes decreased significantly for ipsilateral breasts, whereas contralateral breasts exhibited a smaller decrease with statistical significance. The radiomic feature ratios at 'RT D7' had strong correlations to skin doses and those at 'RT D14' and 'after RT D10' with statistical significance. The energy for normal mode and sum variance for polarized and UV modes demonstrated the potential to evaluate and predict acute radiation, which assists in its appropriate management.

EVALUASI DOSE-AREA PRODUCT DAN WAKTU FLUOROSKOPI SEBAGAI METRIK DOSIS PADA AUDIT DOSIS PROSEDUR FLUOROSKOPI INTERVENSIONAL: STUDI MULTISENTER

This study aims to evaluate conventional dose metrics, namely Dose-Area Product (DAP) and fluoroscopy time, commonly used in interventional fluoroscopy procedure dose audits, by comparing them to a dose metric that more closely represents the dose at the patient's skin, namely Entrance Surface Dose (ESD). The research was conducted by first calculating the ESD using AndroidTM-based software from a previous study (Mulia et al., 2020) with retrospective data from 2 (two) hospitals (20 patients each) that utilized the Philips Allura XPer FD20 interventional fluoroscopy system. The results showed that DAP and fluoroscopy time did not exhibit a linear correlation with the skin dose represented by ESD, with R2 values of 0.11 for Hospital A and 0.79 for Hospital B. Consequently, the DAP and fluoroscopy time dose metrics were deemed insufficient in representing the actual skin dose received by the patients. This study recommends medical physicists also include ESD calculations and utilize them in radiation dose audits as supplementary data to monitor patient deterministic effects directly. Keywords: skin dose, kerma, DAP, dose, interventional

Evaluation of the contamination droplet model used for the assessment of skin dose during the manipulation of radiopharmaceuticals

The manipulation of radiopharmaceuticals in nuclear medicine can result in the droplet contamination of operators resulting in the accumulation of a significant skin dose. Current methods to estimate this skin dose often utilise a 50 μl cylindrical droplet model, which can lead to unrealistically high estimated skin doses for some radiopharmaceuticals. By conducting experiments to measure the volume of real droplets arising from simulating the manipulation of radiopharmaceuticals, this work found that 50 μl is an overestimation of a realistic contamination droplet. For almost all radiopharmaceuticals considered in this work, incorporating a smaller droplet volume into skin dose simulations resulted in higher estimates of skin dose rate per unit of activity, which, when combined with appropriate activity concentrations and droplet volumes, resulted in lower skin doses for contamination droplet incidents. The results presented in this work challenge the 50 μl contamination droplet volume and highlight the importance of having an accurate model when estimating the skin dose for contamination scenarios.

The Effectiveness of Liquid Organic Fertilizer Banana Peel Kepok and Onion Peel to Plant Growth Ciplukan (Physalis Angulata L.)

Ciplukan (Physalis angulata L.) is a medicinal plant that grows wild in tropical climates that has many properties to cure various degenerative diseases. This plant is relatively rare because it is often considered a weed. Banana peels and shallots can be used as liquid organic fertilizer (POC). Liquid organic fertilizer has the advantage that the nutrients contained are more quickly and easily absorbed by plant roots. The purpose of this study was to determine the growth of ciplukan (Physalis angulata L.) plants through the provision of various doses of liquid organic fertilizer kepok banana peel and shallot skin and determine the best dose of liquid organic fertilizer in affecting the growth of ciplukan (Physalis angulata L.) plants. The method used in this research is an experiment consisting of independent variables, namely liquid organic fertilizer of kepok banana peel and shallot skin and the dependent variable is the growth of ciplukan plants (Physalis angulata L.). The sample used in this study was the Ciplukan plant (Physalis angulata L.). Sampling using group randomized design (RAK) technique. This experimental method uses 5 treatments and each treatment is repeated as many as 5 repetitions, thus there are 25 experimental units of ciplukan (Physalis angulata L.) plant samples with concentrations of 0 ml, 15 ml, 25 ml, 35 ml, and 45 ml with the observation parameters measured are plant height, stem diameter, number of leaves, and leaf width. The results showed that liquid organic fertilizer of kepok banana peel and shallot skin had an effect on the growth of ciplukan (Physalis angulata L.) plants. The concentration of 35 ml/polybag gives a better effect on plant height, stem diameter, and leaf width in ciplukan (Physalis angulata L.) plants compared to the control treatment and other treatments.

Assessment of the effectiveness of Saba shielding with the composition of Cu–Bi in neck CT imaging: a phantom and patient study

The use of computed tomography (CT) is a very well-established medical diagnostic imaging modality, however, the high radiation dose due to this imaging method is a major concern. Therefore, dose reduction methods are necessary, especially for superficial radiosensitive organs like the thyroid. The aim of this study is to construct and assess a CT shield with composition of 90% Cu and 10% Bi (Saba shield) with regard to dose reduction and image quality. The efficiency of the constructed shields for dose reduction was assessed by measuring entrance skin dose (ESD), using thermoluminescence dosimeters placed on an anthropomorphic phantom. Image quality was assessed quantitatively based on image noise and CT number accuracy by drawing regions of interest on CT images of the anthropomorphic phantom. Image quality was further investigated qualitatively in a patient study. Application of the Saba shield and 100% Bi shield with the thickness of one thickness (1T) reduced ESD by 50.2% and 51.7%, respectively, and using a three-fold thickness reduced ESD by 64.6% and 65.1%, respectively. Saba shield with thickness of 1T had no significant change in image noise in the anterior part, and image noise and mean CT number in the posterior part (P > 0.05). The statistical analysis performed did not find any meaningful difference between the study and control groups in image quality assessment of the patient study (P > 0.05). The 1T Saba shield reduced thyroid dose efficiently during neck CT imaging without causing unwanted effects on image quality.

Simulation of Hp(0,07) beta and photon response of a BeOSL finger ring dosemeter.

Simulation of a dosemeter's energy and angular response lowers development cost and time. To support development of a new beta sensitive dosemeter we simulate both the dosemeter and the skin dose in a rod phantom as there are no fluence to dose conversion coefficients in the ICRU Report 47 for electrons. Published spectra for BSS2, N-Series and S-Cs and S-Co were used to define sources, with CAD models used to define the simulation geometry. Simulation tools were validated with experimental beta and photon responses available for the BeOSL photon ring. The developed toolchain was then used to simulate several iterations of a beta sensitive detector element inside a beta ring holder, with the goal to minimise the need for repeated prototype fabrication and characterisation. Simulation results for the final design were compared to measurements on 3D printed prototypes with all radiation qualities, except 90Sr/90Y 0°, falling within measurement uncertainty.

Assessment of Radiation Dose and Phantom Skin Dose in Transarterial Chemoembolization in a Single Center with 2 Digital Subtraction Angiography Units

Objectives: This study aimed to assess and compare the radiation dose and phantom skin dose in transarterial chemoembolization (TACE) of two digital subtraction angiography (DSA) units (unit A: Philips Allura Xper FD20, unit B: Artis zee biplane)Material and Methods: The dose area product (DAP), reference air kerma (RAK), number of images (NI) and fluoroscopy time (FT) of 240 cases (120 cases/DSA unit) were retrospectively reviewed and collected. To assess skin dose, 28 nanoDot optically stimulated luminescence dosimeters (OSLDs) were placed on the phantom’s back and the TACE procedure was performed with 2 DSA units.Results: The median DAP, RAK, NI, and FT of unit A were 200.49 Gy·cm2, 379.84 mGy, 115 images, and 9.04 minutes, while for unit B were 109.74 Gy·cm2, 276.55 mGy, 121 images, and 10.19 minutes, respectively. Significant differences were observed in DAP, RAK, and FT. The RAK of all patients was less than 2 Gy. The phantom skin dose obtained from unit B was significantly lower than that of unit A in all positions. The peak skin doses of the phantom studies from both units were 973.15 and 658.66 mGy, respectively.Conclusion: The median DAP of the unit A DSA was higher than the national diagnostic reference levels (DRLs). The TACE procedure from both units is safe from skin reaction. To benefit patients, the planning of a dose optimization process of unit A DSA and management of TACE cases using the existing DSA machine must be considered.