Identifying child maltreatment during virtual medical appointments through the COVID-19 pandemic: A physician-based survey.

Background: Throughout the COVID-19 pandemic there has been a documented decline in reports to child protective services, despite an increased incidence of child maltreatment. This is concerning for increasing missed cases. This study aims to examine if and how Canadian paediatricians are identifying maltreatment in virtual medical appointments. Methods: A survey was sent through the Canadian Paediatric Surveillance Program (CPSP) to 2770 practicing general and subspecialty paediatricians. Data was collected November 2021 to January 2022. Results: With a 34% (928/2770) response rate, 704 surveys were eligible for analysis. At least one case of child maltreatment was reported by 11% (78/700) of respondents following a virtual appointment. The number of cases reported was associated with years in medical practice (P = 0.026) but not with the volume (P = 0.735) or prior experience (P = 0.127) with virtual care, or perceived difficulty in identifying cases virtually (Cramer's V = 0.096). The most common factors triggering concern were the presence of social stressors, or a clear disclosure. The virtual physical exam was not contributory. Nearly one quarter (24%, 34/143) required a subsequent in-person appointment prior to reporting the case and 32% (207/648) reported concerns that a case had been identified late, or missed, following a virtual appointment. Some commented that clear harm resulted. Conclusions: Many barriers to detecting child maltreatment were identified by paediatricians who used virtual care. This survey reveals that virtual care may be an important factor in missed cases of child maltreatment and may present challenges to timely identification.

Adolescents' Cannabis Knowledge and Risk Perception: A Systematic Review.

To systematically review evidence evaluating cannabis-related knowledge and perception of risk in children and adolescents. We systematically searched Medline, PsycINFO, and EMBASE using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. 133 studies from around the world (including ages 10-18 yrs) met inclusion criteria, with 70% meeting grade 2C quality. Increased knowledge and perception of risk of cannabis frequently correlated with lower levels of current use and intent to use. Studies examining correlations over time generally demonstrated increased adolescent cannabis use and decreased perception of risk. Included prevention-based interventions often enhanced knowledge and/or perception of risk in adolescents exposed to the intervention. Studies exploring outcomes relating to legislative changes for recreational marijuana use demonstrated considerable heterogeneity regarding knowledge and perception of risk whereas studies that focused on medicinal marijuana legislative changes overwhelmingly demonstrated a decrease in perception of risk post legalization. Increased knowledge and perception of risk of cannabis in adolescents often correlate with lower levels of current use and intention to use in the future. Further study and implementation of public health and clinically-oriented strategies that seek to increase knowledge among youth about the potential health harms of cannabis use should continue and be prioritized.

Measurement of surface dose in an MR-Linac with optically stimulated luminescence dosimeters for IMRT beam geometries.

PURPOSE: This study aims to measure the surface dose on an anthropomorphic phantom for intensity-modulated radiation therapy (IMRT) plans treated in a 1.5 T magnetic resonance (MR)-Linac. Previous studies have used Monte Carlo programs to simulate surface dose and have recognized high surface dose as a potential limiting factor for the MR-Linac; however, to our knowledge surface dose measurement for clinical plans has not yet been published. Given the novelty of the MR-Linac, it is important to perform in vivo measurements of a potentially dose-limiting factor such as surface dose when moving forward for clinical use. METHODS: Optically stimulated luminescence dosimeters (OSLDs) were used on an anthropomorphic phantom. Intensity-modulated radiation therapy plans were generated to treat a near-surface breast tumor in the phantom. The tumor was treated with 2, 3, 5, 7, and 9 beam IMRT plans with a 1.5 T MR-Linac using a 7-MV photon beam. The plans were generated in a Monte Carlo treatment planning system (TPS) capable of modeling magnetic field effects. The surface dose was sampled in seven locations on the surface surrounding the planning target volume (PTV), and in two different OSLD configurations with the dosimeters measuring water equivalent depths of 0.16 and 0.64 mm. The TPS was used to estimate the doses at the OSLD locations. In addition, MR images were taken of a pork belly with and without an OSLD placed anteriorly placed to determine the effect of an OSLD on image fidelity. RESULTS: For the 3, 5, 7, and 9-beam configurations, surface doses were approximately half that of the prescription dose to the simulated tumor, although the magnitude of the skin dose relative to the prescription is certainly also dependent on individual patient anatomy. The general trend for both TPS and measurements was that the greater the number of beams, the lower the skin doses and dose readings; also, with increasing numbers of beams, doses at shallow depths become lower relative to deeper depths. The MR images showed that the presence of the OSLD did not induce clinically relevant geometric distortions or intensity differences. CONCLUSIONS: To our knowledge, this study is the first of its kind to experimentally measure the surface dose in an MR-Linac for IMRT plans. This study has explored the use of OSLDs to measure in vivo surface dose in a clinical setting. OSLDs may be used to measure skin dose clinically when there are concerns of skin radiation burns and near-surface toxicity. Optically stimulated luminescence dosimeters are promising devices for in vivo surface dosimetry in an MR-Linac.

Surface and near-surface dose measurements at beam entry and exit in a 1.5 T MR-Linac using optically stimulated luminescence dosimeters.

The objective of this study is to measure surface and near-surface dose at entry and exit surfaces in a 1.5 T MR-Linac (Elekta AB, Stockholm, Sweden) using optically stimulated luminescence dosimeters (OSLDs). OSLDs were expected to be useful for measuring surface dose in a strong magnetic field because they can be taped to undersides to measure exit dose, and their dose response have been shown to be reasonably insensitive to variations in beam angle, beam energy, and magnetic fields. The surface and near-surface dose at the entry and exit of a 20 cm thick solid water phantom was measured with OSLDs for 5 × 5, 10 × 10, and 22 × 22 cm2 field sizes. The solid water phantom was elevated off the couch top to produce an air gap of 3.7 cm so as to observe the electron return effect (ERE) near the beam exit surface. Measurement depths ranged from surface to 15 mm deep from entry and exit surfaces. The phantom dose distribution was also computed in the Monaco (Elekta AB, Stockholm, Sweden) Monte Carlo treatment planning system (TPS). For the 5 × 5, 10 × 10, and 22 × 22 cm2 field sizes the surface dose at depth 0 mm was extrapolated from OSLD measurements to be 10.9%, 12.0%, and 13.5%. The surface entry dose was found to be far less field size-dependent compared to a conventional linac, likely due to a lack of electronic contamination due to the strong magnetic field perpendicular to the beam. The ERE effect was observed in the measurements near the exit surface of the phantom, and was in close agreement with the TPS calculation.

Online Adaptive Radiation Therapy.

The current paradigm of radiation therapy has the treatment planned on a snapshot dataset of the patient's anatomy taken at the time of simulation. Throughout the course of treatment, this snapshot may vary from initial simulation. Although there is the ability to image patients within the treatment room with technologies such as cone beam computed tomography, the current state of the art is largely limited to rigid-body matching and not accounting for any geometric deformations in the patient's anatomy. A plan that was once attuned to the initial simulation can become suboptimal as the treatment progresses unless improved technologies are brought to bear. Adaptive radiation therapy (ART) is an evolving paradigm that seeks to address this deficiency by accounting for ongoing changes in the patient's anatomy and/or physiology during the course of treatment, affording an increasingly more accurate targeting of disease. ART relies on several components working in concert, namely in-room treatment image guidance, deformable image registration, automatic recontouring, plan evaluation and reoptimization, dose calculation, and quality assurance. Various studies have explored how a putative ART solution would improve the current state of the art of radiation therapy-some centers have even clinically implemented online adaptation. These explorations are reviewed here for a variety of sites.

Magnetic field dose effects on different radiation beam geometries for hypofractionated partial breast irradiation.

PURPOSE: Hypofractionated partial breast irradiation (HPBI) involves treatment to the breast tumor using high doses per fraction. Recent advances in MRI-Linac solutions have potential in being applied to HPBI due to gains in the soft tissue contrast of MRI; however, there are potentially deleterious effects of the magnetic field on the dose distribution. The purpose of this work is to determine the effects of the magnetic field on the dose distribution for HPBI tumors using a tangential beam arrangement (TAN), 5-beam intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). METHODS: Five patients who have received HPBI were selected with two patients having bilateral disease resulting in a total of two tumors in this study. Six planning configurations were created using a treatment planning system capable of modeling magnetic field dose effects: TAN, IMRT and VMAT beam geometries, each of these optimized with and without a transverse magnetic field of 1.5 T. RESULTS: The heart and lung doses were not statistically significant when comparing plan configurations. The magnetic field had a demonstrated effect on skin dose: for VMAT plans, the skin (defined to a depth of 3 mm) D1cc was elevated by +11% and the V30 by +146%; for IMRT plans, the skin D1cc was increased by +18% and the V30 by +149%. Increasing the number of beam angles (e.g., going from IMRT to VMAT) with the magnetic field on reduced the skin dose. CONCLUSION: The impact of a magnetic field on HPBI dose distributions was analyzed. The heart and lung doses had clinically negligible effects caused by the magnetic field. The magnetic field increases the skin dose; however, this can be mitigated by increasing the number of beam angles.