Gonad shielding in pelvic radiography: modern optimised X-ray systems might allow its discontinuation

Efficacy of gonadal shielding in dose reduction for female pelvic radiography

This study aimed to evaluate the dose reduction using gonad shielding (GS) during pelvic imaging. Three types of pelvic images (radiography, magnetic resonance and computed tomography) were fused to elucidate the three-dimensional relationship between the position of ovaries and GS. To estimate the dose received by the ovaries, the off-axis dose at any given depth was measured under two different imaging conditions using thermoluminescence dosemeters and a polymethyl methacrylate phantom. The mean ovarian depth was 8.4 cm. The mean estimated ovarian dose without an additional filter was 0.36 mGy without GS and 0.14 mGy with GS. The mean estimated ovarian dose with an additional filter was 0.24 mGy without GS and 0.10 mGy with GS. The efficacy of ovarian dose reduction should be evaluated based on the achieved ovarian dose, considering the ovarian depth and use of additional filtration, rather than the ovarian protection rate of GS.

Radiographers' attitudes toward the use of lead contact shielding

INTRODUCTION

Lead contact shielding has been a crucial component of patient radiation protection since it was first introduced in the early 1900s. Concerns surrounding the hereditary effects of ionising radiation were a driver for using lead shielding. Recently the American Association of Physics in Medicine (AAPM) and the British Institute of Radiology (BIR) have published position papers that suggest that lead contact shielding is no longer needed due to reduced radiation doses for x-ray examinations. This work examines radiographers' opinions on these position papers.

METHODS

An online survey with quantitative and qualitative elements was designed to explore knowledge and attitudes toward the BIR and AAPM position papers. The population for this survey was all qualified radiographers.

RESULTS

The majority (59%) of participants are aware of the AAPM guidance, and 76% are aware of the BIR guidance. Given the changes in the gonad tissue weighting factor, 66% believed additional emphasis should be placed on protecting organs and tissues with higher tissue weighting factors. The vast majority (87%) believed lead shielding is not the primary dose reduction strategy, with 82% agreeing that lead shielding may interfere with the AEC.

CONCLUSION

This study identifies a perception that lead protection may still play a role in patient protection, particularly for children and pregnant patients. However, it is not considered the primary mechanism of protection. More specific guidance and information are needed to incorporate the guidance for radiographers into working practice, improving patient care.

IMPLICATIONS FOR PRACTICE

Lead shielding remains a tool for radiation protection in particular examinations, however, its role has diminished in clinical practice.

RECOMMENDATIONS

Additional research is required into the number of repeat x-rays associated with the use of lead shielding and the actual dose saving for shielding outside the field of view. Additional education and specific clarification on when to use and not use lead contact shielding is required.

Exploring radiographers' perceptions and knowledge about patient lead shielding: a cross-sectional study in Greece and Cyprus

The present study aimed to explore radiographers' knowledge, clinical practice and perceptions regarding the use of patient lead shielding in Greece and Cyprus. Qualitative data were analyzed using conceptual content analysis and through the classification of findings into themes and categories. A total of 216 valid responses were received. Most respondents reported not being aware of the patient shielding recommendations issued by the American Association of Physicists in Medicine (67%) or the guidance issued by the British Institute of Radiology (69%). Shielding-related training was generally not provided by radiography departments (74%). Most of them (85%) reported that they need specific guidance on lead shielding practices. Also, 82% of the respondents said that lead shielding should continue to be used outside the pelvic area when imaging pregnant patients. Pediatric patients are the most common patient category to which lead shielding was applied. Significant gaps in relevant training have been identified among radiographers in Greece and Cyprus, highlighting the need for new protocols and provision of adequate training on lead shielding practices. Radiography departments should invest in appropriate shielding equipment and adequately train their staff.

A retrospective evaluation of supine pelvic radiography image quality using centring points and anatomical axial rotation, including reliability of measurements (ARLEX-P STUDY)

INTRODUCTION

Pelvic radiographs are commonly used for the investigation of a variety of conditions. Comparison between examinations requires a consistent radiographic technique but variations in image quality and radiographic centring points are frequently reported in the literature. The aim of this study was to establish the amount of variation in the radiographic centring point (RCP) and pelvic axial rotation (PAR), with a secondary aim of reporting the reliability of such measures.

METHODS

Using a previously acquired imaging archive, 633 adult pelvis/hip radiographs were identified on a Picture Archiving and Communication System (PACS). Radiographs with bilateral prostheses, evidence of acute pelvic trauma, projections acquired on a stretcher/trolley and those demonstrating large discontinuity between the detector and X-ray field centre were excluded. To determine centring point variation (+ values denote superior variations) and axial rotation multiple measurements were obtained from each radiograph. A video was used to train five observers and each of these reviewed ten random cases to determine inter- and intra-rater reliability. One of the five observers then performed the measurements on all remaining radiographs.

RESULTS

Following exclusions 380 radiographs were evaluated. The median (IQR) RCP deviation from the inter-acetabular line was +22 (+2 to +43) mm where both iliac crests were present and -29 (-45 to -12) mm where they were not. Eleven (3%) cases demonstrate RCP variation from the midline of greater than 25 mm (no bias towards the left or right side). The median (IQR) PAR was 0.0 (-1.5 to 1.4) degrees with greater variance in PAR for male participants (p = 0.004). Almost 60% of inter-rater ICC measurements were categorised as excellent, good or moderate.

CONCLUSION

Variations in RCP and PAR exist when evaluating a sample of routinely acquired pelvis radiographs. Some initial factors, such as sex and sub-examination type (full pelvis [XPEL] or low centred pelvis [XHIPB]) have been identified as having a statistical affect on variability. Further research and methods to standardise radiographic techniques is required and must be multidimensional in nature.

IMPLICATIONS FOR PRACTICE

Selection of radiographic technique, including RCP, appears to influence components of the pelvis radiograph. Given the increasing clinical requirements for pelvic radiography further standardisation alongside individual optimisation is warranted.

The effect of breast shielding outside the field of view on breast entrance surface dose in axial X-ray examinations: a phantom study

PURPOSE

The purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations.

METHODS

Using an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student's t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding.

RESULTS

A total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv (P = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant.

CONCLUSION

This study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols.

A Study of Radiation Protection Standards Compliance in Hospital Radiographic Departments in Iran

Background

The X-ray is a critical diagnostic and therapeutic tool with harmful effects. The International Commission on Radiological Protection (ICRP) has some recommendations regarding applying radiation protection principles.

Objective

This study aimed to determine the standards of the typical radiation protection in radiographic departments of hospitals in Iran.

Material and Methods

In this cross-sectional descriptive study, the usual radiation protection standards in places, such as the physical environment of the control and waiting rooms, radiographic devices, the physical space of the darkroom, and shielding facilities, were investigated using a checklist in Iran. A total of 84 hospitals in 51 cities throughout Iran were randomly selected, and the checklists were distributed to the radiation protection officers. In hospitals with multiple radiography rooms, the radiation protection officers were asked to complete the checklist about the room with the highest workload as a baseline to evaluate their facilities. Finally, the authors reviewed all checklists.

Results

In radiology departments in control and waiting rooms, the mean of radiation protection was 71.9%. Pregnancy and radiation warning signs and labels were present in 96.1% of the parameters, while gonad shielding protocols were not presented.

Conclusion

The principles of observed radiation protection were unsatisfactory, and it is recommended that surveillance be conducted at frequent intervals.

Exploring the implementation of evidence-based optimisation strategies: A qualitative study of the experience of diagnostic radiographers

INTRODUCTION

Radiographers are responsible for ensuring safe and effective use of ionising radiation. Through evidence-based practice (EBP), valuable optimisation strategies can be implemented to fulfil these responsibilities. This study aimed to explore radiographers' attitudes, perceptions, and experience of using evidence-based optimisation strategies.

METHODS

A Grounded Theory approach using in-depth interviews. UK-based radiographers were recruited. Discussions focused on (1) the role of evidence-based optimisation strategies in daily practice, (2) assistance in implementing evidence-based optimisation strategies, and (3) the role of EBP and optimisation strategies in the future. Interviews were transcribed verbatim and analysed using open and axial coding.

RESULTS

Participants (n = 13) stated that EBP is not frequently used to implement optimisation strategies. Participants relied on the knowledge taught in education settings and their professional skills to optimise in daily practice, alongside departmental protocols. Barriers identified as affecting the implementation of optimisation strategies related to reluctance to change, a lack of support from superiors, and a lack of resources to engage with EBP. Some participants expected the use of optimisation strategies to become unnecessary due to technology advancements.

CONCLUSION

The results indicate that effective operationalisation of EBP is not part of daily practice among radiographers to implement valuable optimisation strategies in daily practice.

IMPLICATIONS FOR PRACTICE

The potential barriers to implementing evidence-based optimisation strategies highlighted in this study suggest that improving access to resources and empowerment of individual radiographers is required to enable radiographers to implement optimisation strategies.

Estimation of dose and cancer risk to newborn from chest X-ray in South-South Nigeria: a call for protocol optimization

Background

The use of X-ray as a diagnostic tool for complication and anomaly in the neonatal patient has been helpful, but the effect of radiation on newborn stands to increase their cancer risk. This study aims to determine the mean, 50th percentile (quartile 2 (Q2)), and 75th percentile (quartile 3 (Q3)) entrance surface dose (ESD) from anteroposterior (AP) chest X-ray and to compare our findings with other relevant studies. The study used calibrated thermoluminescent dosimeters (TLDs), which was positioned on the central axis of the patient. The encapsulated TLD chips were held to the patients’ body using paper tape. The mean kilovoltage peak (kVp) and milliampere seconds (mAs) used was 56.63(52–60) and 5.7 (5–6.3). The mean background TLD counts were subtracted from the exposed TLD counts and a calibration factor was applied to determine ESD.

Results

The mean ESDs of the newborn between 1 and 7, 8 and 14, 15 and 21, and 22 and 28 days were 1.09 ± 0.43, 1.15 ± 0.50, 1.19 ± 0.45, and 1.32 ± 0.47 mGy respectively. A one-way ANOVA test shows that there were no differences in the mean doses for the 4 age groups (P = 0.597). The 50th percentile for the 4 age groups was 1.07, 1.26, 1.09, and 1.29 mGy respectively, and 75th percentile were 1.41, 1.55, 1.55, and 1.69 mGy respectively. The mean effective dose (ED) in this study was 0.74 mSv, and the estimated cancer risk was 20.7 × 10−6.

Conclusion

ESD was primarily affected by the film-focus distance (FFD) and the patient field size. The ESD at 75th percentile and ED in this study was higher compared to other national and international studies. The estimated cancer risk to a newborn was below the International Commission on Radiological Protection (ICRP) limit for fatal childhood cancer (2.8 × 10−2Sv−1).

Impact of Eye and Breast Shielding on Organ Doses During Cervical Spine Radiography: Design and Validation of MIRD Computational Phantom

Purpose: The study aimed to design and validate computational phantoms (MIRD) using the MCNPX code to assess the impact of shielding on organ doses. Method: To validate the optimized phantom, the obtained results were compared with experimental results. The validation of the optimized MIRD phantom was provided by using the results of a previous anthropomorphic phantom study. MIRD phantom was designed by considering the parameters used in the anthropomorphic phantom study. A test simulation was performed to compare the dose reduction percentages (%) between the experimental anthropomorphic phantom study and the MCNPX-MIRD phantom. The simulation was performed twice, with and without shielding materials, using the same number and locations of the detector. Results: The absorbed dose amounts were directly extracted from the required organ and tissue cell parts of output files. Dose reduction percentages between the simulation with shielding and simulation without shielding were compared. The highest dose reduction was noted in the thymus (95%) and breasts (88%). The obtained dose reduction percentages between the anthropomorphic phantom study and the MCNPX-MIRD phantom were highly consistent and correlated values with experimental anthropomorphic data. Both methods showed Relative Difference (%) ranges between 0.88 and 2.22. Moreover, the MCNPX-MIRD optimized phantom provides detailed dose analysis for target and non-target organs and can be used to assess the efficiency of shielding in radiological examination. Conclusion: Shielding breasts and eyes during cervical radiography reduced the radiation dose to many organs. The decision to not shield patients should be based on research evidence as this approach does not apply to all cases.

Bismuth Pelvic X-Ray Shielding Reduces Radiation Dose Exposure in Pediatric Radiography

BACKGROUND

Radiation using conventional X-ray is associated with exposure of radiosensitive organs and typically requires the use of protection. This study is aimed at evaluating the use of bismuth shielding for radiation protection in pediatric pelvic radiography. The effects of the anteroposterior and lateral bismuth shielding were verified by direct measurements at the anatomical position of the gonads.

METHODS

Radiation doses were measured using optically stimulated luminescence dosimeters (OSLD) and CIRS ATOM Dosimetry Verification Phantoms. Gonad radiographs were acquired using different shields of varying material (lead, bismuth) and thickness and were compared with radiographs obtained without shielding to examine the effects on image quality and optimal reduction of radiation dose. All images were evaluated separately by three pediatric orthopedic practitioners.

RESULTS

Results showed that conventional lead gonadal shielding reduces radiation doses by 67.45%, whereas dose reduction using one layer of bismuth shielding is 76.38%. The use of two layers of bismuth shielding reduces the dose by 84.01%. Using three and four layers of bismuth shielding reduces dose by 97.33% and 99.34%, respectively. Progressively lower radiation doses can be achieved by increasing the number of bismuth layers. Images obtained using both one and two layers of bismuth shielding provided adequate diagnostic information, but those obtained using three or four layers of bismuth shielding were inadequate for diagnosis.

CONCLUSIONS

Bismuth shielding reduces radiation dose exposure providing appropriate protection for children undergoing pelvic radiography. The bismuth shielding material is lighter than lead, making pediatric patients more comfortable and less apt to move, thereby avoiding repeat radiography.

APQS consensus regarding patient shielding during routine radiographic imaging

Shielding, particularly of the gonads, has been a routine part of diagnostic radiographic imaging for many years. However, recent thinking suggests that such shielding may offer little benefit, and in some cases may actually cause harm, e.g. by obscuring anatomy or paradoxically increasing patient radiation dose secondary to the need for repeat imaging. This thinking has led many institutions in the West to abandon routine shielding. However, in Asia, shielding is still commonplace. It was felt that the Asia-Pacific Forum on Quality and Safety in Medical Imaging (APQS) was an ideal place to discuss the merits of shielding and deliver a pan-Asian consensus. The APQS is an annual meeting that convenes radiation safety and imaging quality experts from all of the major Asian regions. During the 2020 APQS meeting, radiation safety experts from each region discussed their opinions of shielding during a dedicated session. These experts' views were mostly in line with the views of Western radiologists. However, important country specific and cultural factors were noted by each of the experts. A pan-Asian consensus was issued by the forum. It is hoped that this consensus will guide the development of future shielding policies throughout Asia.

Use of out-of-field contact shielding on patients in medical imaging: A review of current guidelines, recommendations and legislative documents

The use of patient contact-shielding has become a topic of intensive scientific debate. While it has been common practice during the last decades, some studies have questioned the efficiency of using such shielding while others have highlighted the inconsistencies in its application. The objective of this work is to review current recommendations and legislative documents on the use of out-of-field shielding in X-ray imaging, including those from national authorities and from international and national organisations and professional bodies. The review, performed within the framework of the activities of EURADOS Working Group 12, covers available recommendations on use of contact shielding in adult, pregnant and paediatric patients in general radiography, fluoroscopy, computed tomography, mammography and dental radiology. It includes a comprehensive search of 83 documents from 32 countries and 6 international organisations over the last 39 years. In general, using shielding is recommended only under two conditions: if it does not compromise the diagnostic task and the performance of the procedure and/or if it reassures the patient and comforters that they are appropriately protected against potentially harmful effects of radiation. There are very few specific regulatory requirements to use shielding in a particular imaging modality, although they may consider use of shielding either as part of good radiological practice or as requirements for availability of protective or ancillary tools, without further specification of their use. There is a wide variety of positions among documents that recommend out-of-field shielding, those that do not recommend it and those that are not specific. Therefore, evidence-based consensus is still needed to ensure best and consistent practice.

Achievable dose reductions with gonadal shielding for children and adults during abdominal/pelvic radiographic examinations: A Monte Carlo simulation

PURPOSE

Recently, medical professionals have reconsidered the practice of routine gonadal shielding for radiographic examinations. The objective of this study was to evaluate the gonadal dose reduction achievable with gonadal shields in the primary beam during abdominal/pelvic radiographic examinations under ideal and non-ideal shielding placement.

METHODS

CT scans of CIRS anthropomorphic phantoms were used to perform voxelized Monte Carlo simulations of the photon transport during abdominal/pelvic radiographic examinations with standard filtration and 0.1 mm Cu + 1 mm Al added filtration to estimate gonadal doses for an adult, 5 yr old, and newborn phantom with and without gonadal shields. The reduction in dose when the shields were not placed at the ideal locations was also evaluated. The ratio of the number of scattered-to-primary photons (SPR) across the anteroposterior (AP) dimension of the phantoms was also reported.

RESULTS

The simulated dose reduction with ideal shielding placement for the testes and ovaries ranged from 80% to 90% and 55% to 70% respectively. For children, a misalignment of the shield to the gonad of 4 cm reduced the measured dose reduction to the gonads to <10%. For adults, this effect did not occur until the misalignment increased to ~6 cm. Effects of dose reduction with and without the gonadal shields properly placed were similar for standard filtration and added filtration. SPR at the level of the testes was consistently <1 for all phantoms. SPR for ovaries was ~1.5 for the adult and 5-yr old, and ~1 for the newborn phantom.

CONCLUSION

Dose reduction with ideal alignment of the simulated gonadal shield to the gonads in this study was greater for the testes than the ovaries; both reductions were substantial. However, the dose reductions were greatly reduced (to <10%) for both sexes with misalignment of the gonads to the shields by 4 cm for children and 6 cm for adults.