Adaptations to general surgery resident education in response to COVID-19.

BACKGROUND: The COVID-19 pandemic led to many new provincial public health measures to reallocate resources in response to an impending surge of cases. These necessary decisions had several downstream effects on general surgery training. We surveyed the actions taken by Canadian general surgery training programs in response to the COVID-19 pandemic. METHOD: A mixed-methods survey was sent to all general surgery program directors to assess various domains in surgical education and modifications made because of the pandemic. Responses were quantified as proportions or qualitative narratives describing those changes. RESULTS: Most programs (13/15) recalled residents from planned rotations and redistributed them to rotations considered as core required services, including acute care surgery, trauma surgery and intensive care. Many programs also restructured their acute care surgery models to allow for a group of "reserve" residents to replace trainees who became infected with SARS-CoV-2. In terms of clinical experience, there was a reduction in both clinical and operative exposure among trainees. The reduction in clinical exposure disproportionately affected junior residents, whose involvement in COVID-19 cases was restricted. Formal educational sessions were maintained, but delivered virtually. Many programs instituted a program of increased frequency of communication with trainees. CONCLUSION: Many programs embraced using virtual platforms for teaching. The demonstrated utility of virtual teaching may lead to rethinking how training programs deliver didactic teaching and expand teaching opportunities. However, many programs also perceived a decrease in clinical and procedural exposure, primarily affecting junior residents. More information is needed to quantify the deficit in learning incurred as a result of the pandemic as well as its long-term effects on resident competency.

Cumulative Effective Dose and Cancer Risk of Pediatric Population in Repetitive Whole-Body Scan Using Dual-Energy X-Ray Absorptiometry.

This study aims to quantitatively evaluate the cumulative effective dose and associated cancer risk of pediatric patients of US and Hong Kong population undergoing repetitive whole-body scans with dual-energy X-ray absorptiometry (DXA) during their diagnosis and follow-up periods. Organ-absorbed doses of pediatric patients undergoing DXA whole-body scan have been computer simulated using patient imaging parameters input to the Monte Carlo software PCXMC. Gender- and age-specific effective doses have been calculated with the simulated organ-absorbed doses using the ICRP-103 approach. The associated radiation-induced cancer risk, expressed as lifetime attributable cancer risk (LAR), has been estimated according to the method introduced in the Biological Effects of Ionizing Radiation VII report. Mathematical fitting for effective dose and for LAR, as a function of age at exposure, has been analytically obtained to quantitatively estimate the cumulated effective dose and LAR for pediatric patients of US and Hong Kong population with repetitive DXA whole-body scan during their follow-up period. The effective dose of a single DXA whole-body scan for patients exposed at the age between 5 and 18 years was calculated as 8.47-17.68 µSv. The corresponding LAR for US and Hong Kong population was between the range of 4.57 × 10-7 and 7.14 × 10-7. The cumulative effective dose of DXA whole-body scan for patients exposed annually at age between 5 and 18 years was calculated as 180 µSv for girls and 168 µSv for boys. The corresponding cumulative LAR for US and Hong Kong population was calculated as 3.77 × 10-6 to 5.48 × 10-6. Girls would be at a statistically significant higher cumulated cancer risk than boys under the same whole-body DXA protocol (p = 0.03). The probability of cumulative LAR for pediatric populations undergoing annual DXA whole-body scan is regarded as minimal. We demonstrate the use of computer simulation and analytic formulation to quantitatively obtain the cumulated effective dose and cancer risk at any age of exposure, which are useful information for medical personnel to track patient radiation dose and to alleviate patients' parents concern about radiation safety in repetitive whole-body scan using DXA.

Dressed for success? Silver impregnated nanocrystalline dressing for initial treatment of giant omphalocele.

OBJECTIVE: The purpose of this study was to describe outcomes and resource utilization in patients treated with twice-weekly silver impregnated (SI) nanocrystalline dressings for initial non-operative management of giant omphalocele (GO). METHODS: A retrospective review of patients with GO treated with SI dressings was undertaken. Clinical parameters, cost, and complications were recorded. RESULTS: Five patients with GO were treated with SI dressings between 2014 and 2016. Clinical characteristic (mean ± SD) included gestational age 36 ± 4 weeks, birth weight 2.6 ± 0.63 kg, GO size 10.2 ± 4.7 cm, ventilator days 7.5 ± 8.7 d, days in NICU 41 ± 20 d, days to full feeds, 30 ± 15 d, and LOS 62 ± 41 d. The average in-hospital cost of SI dressings was $110 CAD/week. This is comparable to daily silver sulfadiazine dressings ($109CAD/week) which were used historically. All patients were discharged with once- or twice-weekly dressing changes. No ruptures occurred. There was one mortality secondary to pulmonary sepsis. CONCLUSIONS: For initial non-operative management of GO, twice weekly SI nanocrystalline dressings is safe and effective. Use of SI dressings results in decreased handling of infants, reduced physician and nursing resource utilization, and favourable outcomes. LEVEL OF EVIDENCE: IV (Retrospective Case Series).

Patient dosimetry for 90Y selective internal radiation treatment based on 90Y PET imaging.

Until recently, the radiation dose to patients undergoing the 90Y selective internal radiation treatment (SIRT) procedure is determined by applying the partition model to 99mTc MAA pretreatment scan. There can be great uncertainty in radiation dose calculated from this approach and we presented a method to compute the 3D dose distributions resulting from 90Y SIRT based on 90Y positron emission tomography (PET) imaging. Five 90Y SIRT treatments were retrospectively analyzed. After 90Y SIRT, patients had 90Y PET/CT imaging within 6 hours of the procedure. To obtain the 3D dose distribution of the patients, their respective 90Y PET images were convolved with a Monte Carlo generated voxel dose kernel. The sensitivity of the PET/CT scanner for 90Y was determined through phantom studies. The 3D dose distributions were then presented in DICOM RT dose format. By applying the linear quadratic model to the dose data, we derived the biologically effective dose and dose equivalent to 2 Gy/fraction delivery, taking into account the spatial and temporal dose rate variations specific for SIRT. Based on this data, we intend to infer tumor control probability and risk of radiation induced liver injury from SIRT by comparison with established dose limits. For the five cases, the mean dose to target ranged from 51.7 ± 28.6 Gy to 163 ± 53.7 Gy. Due to the inhomogeneous nature of the dose distribution, the GTVs were not covered adequately, leading to very low values of tumor control probability. The mean dose to the normal liver ranged from 21.4 ± 30.7 to 36.7 ± 25.9 Gy. According to QUANTEC recommendation, a patient with primary liver cancer and a patient with metastatic liver cancer has more than 5% risk of radiotherapy-induced liver disease (RILD).

Assessing the risk of inadvertent radiation exposure of pregnant patients during radiation therapy planning and treatment in British Columbia.

PURPOSE: To explore health care professionals' perceptions of, and experience with, the risk of inadvertent radiation exposure to pregnant patients in radiation therapy (RT) departments. METHODS AND MATERIALS: The survey was distributed to 342 health care professionals working in RT departments in British Columbia (BC), including radiation therapists, medical physicists, radiation oncologists, and radiation oncology residents. RESULTS: There were 119 responses, 65% of who were radiation therapists. Respondents' mean duration of experience was 13.9 years (range, 1-25), over which time the BC Cancer Agency has delivered at least one course of RT to an estimated 16,000 women under the age of 50. Of the responses, 11.6% indicated that they had ever, in their training or career, encountered a situation where RT was inadvertently given to a pregnant patient. Upon reviewing anonymous comments, at least 7 discrete incidents were described. Fifty-two percent of radiation oncologists never, or only occasionally, remembered to discuss the risk of RT in pregnancy; 53% did not believe there were signs posted in their cancer center warning patients or reminding staff of this risk. Furthermore, 61% did not know if there was any patient education material designed for this purpose. Establishment of a checklist to screen for potentially fertile females prior to RT was felt to be a useful intervention by 49% of respondents. CONCLUSIONS: There is a risk of RT exposure to pregnant patients. Procedures and policies to prevent inadvertent irradiation of pregnant patients appear to be inadequate in BC. Provincial policies should be introduced to help reduce the risk of inadvertent RT of pregnant patients.