This guideline has been prepared by the ACPSEM to provide a standardised quality assurance program to be used within General X-ray imaging environments. The guideline includes the responsibilities of various multidisciplinary team members within medical imaging facilities. It must be noted that the listed tests and testing frequencies are not intended to replace or become regulatory requirements. Implementing a quality assurance program as outlined in this position paper is there to ensure best practice for imaging facilities by providing a framework to establish and monitor correct equipment performance. The current document has been produced through an extensive review of current international practices and local experience within the Australasian healthcare environment. Due to the constant evolution of digital radiographic equipment, there is no current consensus in international quality assurance guidelines as they continue to be adapted and updated. This document describes the current state of the use of digital General X-ray equipment in the Australasian environment and provides recommendations of test procedures that may be best suited for the current medical imaging climate in Australasia. Due to the everchanging developments in the medical imaging environment and the ability of new technologies to perform more complex tasks it is believed that in the future this document will be further reviewed in the hopes of producing a more globally agreed upon standard quality assurance program. Any such adjustments that are deemed to be necessary to Version 1.0 of this document will be provided in electronic format on the ACPSEM website with a notification to all parties involved in the use of digital General X-ray equipment. This guideline does not provide detailed methodologies for all the quality control tests recommended as it is it is expected that the professionals implementing aspects of this quality assurance program have the working knowledge and access to appropriate resources to develop testing methodologies appropriate for their local imaging environment.

Digital breast tomosynthesis (DBT) is a main imaging modality for breast imaging. However, shielding calculations for DBT are commonly based on previous technology with softer beam spectra. In addition, shielding calculations often assume some patient attenuation is provided in locations to the posterior of the patient but without quantification of this attenuation. In this work, recent research in DBT shielding is validated by measuring scatter radiation in the vertical plane. It is also extended upon by measuring the scatter radiation in the horizontal plane and the effect of patient attenuation. These measurements are weighted by our local patient compressed breast thickness distribution to provide a simple scattering factor. Air kerma distributions are provided demonstrating the distribution of scatter radiation around the DBT system in the presence of patient body attenuation. The highest air kerma measured in any direction from a 4-view per patient screening tomosynthesis exam based on the local patient workload is 55 μGy at 1 m. This value can be used to conservatively treat the scatter radiation as an isotropic distribution for shielding assessments. This work is consistent with many recent publications, with the notable exception of the forward scattered peak which is smaller than previous studies. Under our locally encountered breast thickness distribution, the increased scatter radiation and consequent increased minimum shielding requirements is small in most cases. With 400 patients per week, the air kerma at 1 m is 22 mGy and, for a fully occupied public area 2 m away, this requires a gypsum plasterboard thickness of 18.0 mm which is 3.6 mm more than previous data suggests. Although the increase is minimal, standard manufacturing thicknesses of shielding material may not be automatically assumed to be sufficient and careful consideration of the scatter radiation is warranted.

Introduction Mammographic imaging can cause considerable stress and anxiety for some patients and may require someone to remain in the room during the procedure to provide both physical and emotional support. As such, these comforters and carers (C&C) are exposed to ionising radiation. Limited evidence is available stating the radiation dose received during a digital breast tomosynthesis (DBT) examination. This research aims to determine the optimal standing position for a C&C in the mammography room during a DBT mammogram that results in the lowest radiation dose, whilst providing high‐quality imaging, care and comfort to the patient. Methods A scatter detector was used to measure the dose at different standing positions of the carer relative to the patient during an examination. A polymethyl methacrylate (PMMA) phantom was also used to model the patient's breast and torso for further scatter dose measurements. Results The median air kerma for craniocaudal views posterior to the patient is 0.75 μGy compared with 10.1 μGy to either side. The median air kerma for mediolateral oblique views for posterolateral position is 0.41 μGy compared with 2.6 μGy anterolateral. No significant effect from breast density is noted from the dataset. Conclusion The optimal position for the C&C to stand is directly behind the patient in the craniocaudal position, and as far as possible posterolateral to the breast being imaged in the mediolateral oblique position. These two positions will result in the least radiation dose to the C&C.

Purpose: Candidates for liver transplantation (LT) with hepatocellular carcinoma (HCC) undergo a large number of diagnostic and interventional radiology procedures. A significant proportion of such procedures involve ionizing radiation with increased lifetime risk of cancer. The objective of our study was to review LT candidates with HCC to quantify ionizing radiation doses from different radiology procedures performed at a single transplant center.Method: We retrospectively reviewed 179 adult patients with HCC (median age 58.6 years [IQR, 55-62]; 155 [86.6%] males) who were accepted for LT between April 2010 and Dec 2018. Radiology procedures and radi-ation doses were retrieved and the total and median radiation effective dose in millisieverts (mSv) were calculated for different procedures. Exposure to ionizing radiation was categorized based on previously reported thresholds.Results: We assessed 9,986 radiology procedures for our cohort. Patients had a median effective dose prior to transplantation of 254 mSv (IQR, 130-421) with an annualized rate of 152 mSv (IQR, 92-266). Patient median dose increased to 316 mSv (IQR, 159-478) when including exposures post-LT within the study period. 85% of overall exposure was in the extremely high exposure category (>100 mSv). Interventional procedures repre-sented 13% of procedures with substantial radiation and contributed to 45% of radiation exposure while abdominal CTs represented 39% of total procedures and contributed to 45% of radiation exposure.Conclusions: Patients with HCC considered for LT undergo radiology procedures with significant cumulative radiation exposure. Attempts to reduce radiation exposure are suggested by minimizing unnecessary procedures and utilizing ones without ionizing radiation. Improving interventional techniques to reduce radiation doses is needed without compromising treatment delivery.

Magnetic Resonance Imaging linear-accelerator (MRI-linac) equipment has recently been introduced to multiple centres in Australia and New Zealand. MRI equipment creates hazards for staff, patients and others in the MR environment; these hazards must be well understood, and risks managed by a system of environmental controls, written procedures and a trained workforce. While MRI-linac hazards are similar to the diagnostic paradigm, the equipment, workforce and environment are sufficiently different that additional safety guidance is warranted. In 2019 the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) formed the Magnetic Resonance Imaging Linear-Accelerator Working Group (MRILWG) to support the safe clinical introduction and optimal use of MR-guided radiation therapy treatment units. This Position Paper is intended to provide safety guidance and education for Medical Physicists and others planning for and working with MRI-linac technology. This document summarises MRI-linac hazards and describes particular effects which arise from the combination of strong magnetic fields with an external radiation treatment beam. This document also provides guidance on safety governance and training, and recommends a system of hazard management tailored to the MRI-linac environment, ancillary equipment, and workforce.