Purpose: In 2021, the Canadian Organization of Medical Physicists (COMP) conducted its first equity, diversity, and inclusion Climate Survey. The membership's experiences of inclusion, belonging, professional opportunities, discrimination, microag-gressions, racism, and harassment in their professional lives are presented.Methods and Materials: The ethics-reviewed survey was distributed in English and French to full members of COMP. Partic-ipants responded to questions covering demographics and professional climate. Simple descriptive statistics were used to mea-sure frequency of responses. Data pertaining to impressions on the climate within the profession were compared using nonparametric statistical tests.Results: The survey was distributed to 649 eligible members; 243 (37%) responded, and 214 (33%) provided full response sets. From the full response sets, findings showed that in general, age, highest academic degree, and racial and ethnic distribution trends of medical physicists were comparable with previously collected data and/or the Canadian population. The experiences of respondents relating to harassment in the workplace and perception of climate are reported and provide a useful benchmark for future assessments of interventions or training programs. In the workplace, fewer women (58%) reported having professional opportunities compared with men (70%). The survey also found that 17% of respondents (most of whom were women) directly or indirectly experienced sexual harassment in the workplace within the past 5 years. Finding that 23% of survey respondents identified as having a disability is a valuable reminder that accommodations in the workplace are necessary for more than 1 in every 5 medical physicists working in clinics.Conclusions: This study provided insight into the diversity and experiences of medical physicists in Canada. The majority of respondents had positive perceptions about their professional environment. However, equity-lacking groups were identified, such as women, underrepresented minorities, Indigenous peoples, and people with visible and invisible disabilities. & COPY; 2023 Elsevier Inc. All rights reserved.

PurposeTo evaluate the impact of emerging conductor technology on RF coils. Performance and resulting image quality of thin or alternate conductors (eg, aluminum instead of copper) and thicknesses (9‐600 μm) are compared in terms of SNR.MethodsEight prototype RF coils (15 cm × 15 cm square loops) were constructed and bench‐tested to measure quality factor. The coils used 6‐mm‐wide conducting strips of either copper or aluminum of a few different thicknesses (copper: 17, 32, 35, 127, 600 μm; aluminum: 9, 13, 20, 127 μm) on acetate projector sheets for backing. Corresponding image SNR was measured at 0.48 tesla (20.56 MHz).ResultsThe coils spanned a range of unloaded quality factors from 89 to 390 and a fivefold range of losses. The image SNRs were consistent with the coils’ bench‐measured efficiencies (0.33‐0.73). Thin aluminum conductors (9 μm) led to the highest reduction in SNR (65% that of 127 μm copper). Thin copper (<32 μm) conductors lead to a much smaller decrease in SNR (approximately 10%) compared to 127 μm copper. No performance difference was observed between 127 μm thick copper and aluminum. The much thicker 600 μm copper bars only yield a 5% improvement in SNR.ConclusionEven at 0.48 tesla, copper RF coil conductors much thinner than those in conventional construction can be used while maintaining SNR greater than 50% that of thick copper. These emerging coil conductor technologies enable RF coil functionality that cannot be achieved otherwise.

PURPOSE:The RF coils for magnetic resonance image guided radiotherapy (MRIgRT) may be constructed using thin and/or low-density conductors, along with thinner enclosure materials. This work measures the surface dose increases for lightweight conductors and enclosure materials in a magnetic field parallel to a 6 MV photon beam. METHODS:Aluminum and copper foils (9-127 μm thick), as well as samples of polyimide (17 μm) and polyester (127 μm) films are positioned atop a polystyrene phantom. A parallel plate ion chamber embedded into the top of the phantom measures the surface dose in 6 MV photon beam. Measurements (% of dose at the depth of maximum dose) are performed with and without a parallel magnetic field (0.22T at magnet center). RESULTS:In the presence of a magnetic field, the unobstructed surface dose is higher (31.9%Dmax versus 22.2%Dmax). The surface dose is found to increase linearly with thickness for thin (<25 μm) copper (0.339%Dmax μm-1) and aluminum (0.116%Dmax μm-1) foils. In the presence of a magnetic field the slope is lower (copper: 0.16%Dmax μm-1, aluminum: 0.06%Dmax μm-1). The effect of in-beam foils is reduced due to partial shielding of the surface from contaminant electrons. Copper causes a surface dose increase ≈3 times higher than aluminum of the same thickness, consistent with their relative electron density. Polyester film (127μm) increases the surface dose (to 35% Dmax with field) about as much as a gown (36% Dmax with field), while the increase with polyimide film (17μm) is less than 1% above the open field dose. CONCLUSIONS:Thin copper and aluminum conductors increase surface dose by an amount comparable to a hospital gown. Similarly, enclosure materials made of thin polyester or polyimide film increase surface dose by only a few %Dmax in excess of an unobstructed beam. Based on measurements in this study, in-beam, surface RF coils are feasible for MRIgRT systems.

PURPOSE Close-fitting surface coils and arrays provide higher image signal-to-noise ratio (SNR) than volume coils. However, proximity to the skin can increase its radiation dose due to electrons ejected when a treatment beam travels through the coil. In this work we evaluate the performance of thin aluminum and copper conductors as a means to limit skin dose while maintaining acceptable SNR. MATERIALS & METHODS Surface dose was measured in polystyrene for a 6 MV photon beam (Varian Silhouette) using a parallel plate PTW Markus ion chamber, both with and without a 0.2 T magnetic field. Sheets of aluminum and copper of various thicknesses were placed at the beam entrance surface. The magnetic field was parallel to the beam and generated with two GMW electromagnets [1]. Surface dose measurements were normalized to maximum dose (Dmax), which is at a depth of 1.5 cm in the polystyrene phantom. Surface coils designed for a 0.5 T linac-MR system [2] were constructed from aluminum foils (9, 13 and 20 μm thickness), copper tape (32 μm), flexible PCB (18 μm and 35 μm), and copper sheet (125 μm). At the operating frequency of 20.56 MHz the penetration (skin) depths in aluminum and copper are 18 μm and 14 μm respectively. All coils were 15 × 15 cm2 square loops of 6-mm-wide strips with 12-cm-long connections to a board containing low-loss tuning and matching capacitors (Voltronics, ATC). Loaded and unloaded quality factors (Q) were measured by driving the matched coil and receiving with a small loop (S21 measurement on a network analyzer); efficiency is calculated as η = 1–Qloaded/Qunloaded, and SNR μ√η [3]. Coils were matched to 50 Ω, and Q measurements were corrected for loading at the coil port [4]. Coil SNR was measured by acquiring gradient echo images of a uniform phantom (Figure 1).