Justification and optimization of radiation exposures: a new framework to aggregate arbitrary detriments and benefits

Childbirth as Fault Lines: Justifications in Physician-Patient Interactions About Postnatal Rehabilitation

Research on justifications has shown their significance in advice-giving, decision-making and children disputes. However, the majority of studies gloss over practical functions of justifications in patient-physician interactions as they are often expected and pursued by patients and in turn, are adopted by physicians to support their stance and authority. This study, through conversation analysis (CA), aims to explore a) what are pragmatic functions of justifications in patient-physician interaction? b) how and when do physicians unfold their justifications for treatment recommendations? c) how do physicians deal with different responses based on their epistemic and deontic domains?. A total of 32 video-recordings between postpartum women and physicians are collected and studied. Four pragmatic functions of justifications drawn upon by physicians are explored: justifications as face-saving, reassurance, risk discussion and clarification-seeking. Despite physicians' attempts to justify their positions as less challenged by patients, this is not the entire picture as they demonstrate their desire to resolve patients' concerns and coordinate their viewpoints to achieve the best practice that facilitates patients' well-being.

Establishment of national diagnostic reference levels for computed tomography procedures in Sri Lanka: first nationwide dose survey

The main purpose of this study was to establish for the first time national diagnostic reference levels (NDRLs) for common computed tomography (CT) procedures in Sri Lanka. Patient morphometric data, exposure parameters and dose data such as volume CT dose index (CTDIvol) and dose-length product (DLP) were collected from 5666 patients who underwent 22 types of procedure. The extreme dose values were filtered before analysis to ensure that the data come from standard size patients. The median of the dose distribution was calculated for each institution, and the third quartile value of the median distribution was considered as the NDRL. Based on the inclusion and exclusion criteria, data from 4592 patients and 17 procedure types were considered for establishment of a NDRL, covering 41% of the country's CT machines. The proposed NDRLs based on CTDIvoland DLP were: non-contrast-enhanced (NC) head, 82.2 mGy/1556 mGy cm; contrast-enhanced (CE) head, 82.2 mGy/1546 mGy cm; chest NC, 7.4 mGy/350 mGy cm; chest CE, 8.3 mGy/464 mGy cm; abdomen NC, 10.5 mGy/721 mGy cm; abdomen arterial (A) phase, 13.4 mGy/398 mGy cm; abdomen venous (V) phase, 10.8 mGy/460 mGy cm; abdomen delay (D) phase, 12.6 mGy/487 mGy cm; sinus NC, 30.2 mGy/452 mGy cm; lumbar spine NC, 24.1 mGy/1123 mGy cm; neck NC, 27.5 mGy/670 mGy cm; high-resolution CT of chest, 10.3 mGy/341 mGy cm; kidneys ureters and bladder NC, 19.4 mGy/929 mGy cm; chest to pelvis (CAP) NC, 10.8 mGy/801 mGy cm; CAP A, 10.4 mGy/384 mGy cm; CAP V, 10.5 mGy/534 mGy cm; CAP D, 16.8 mGy/652 mGy cm. Although the proposed NDRLs are comparable with those of other countries, the observed broad dose distributions between the CT machines within Sri Lanka indicate that dose optimisation strategies for the country should be implemented for most of the CT facilities.

OCCUPATIONAL DOSE ASSESSMENT FOR NUCLEAR MEDICINE AND RADIOTHERAPY TECHNOLOGISTS IN SAUDI ARABIA

This study estimated the occupational radiation dose received by nuclear medicine and radiotherapy technologists in Saudi Arabia. A retrospective analysis of personal dosemetry data of 1243 nuclear medicine and radiotherapy technologists from 28 medical centers across Saudi Arabia from 2015 to 2019 was conducted. Thermoluminescent dosemeters were employed to monitor the occupational radiation dose. For the study period, the average annual values for nuclear medicine and radiotherapy technologists were found to be 1.22 mSv (SD = 1.00 mSv) and 0.73 mSv (SD = 0.40 mSv) for Hp(10) and 1.23 mSv (SD = 1.07 mSv) and 0.72 mSv (SD = 0.41 mSv) for Hp(0.07), respectively. The work routines of nuclear medicine technologists cause them to be exposed to higher radiation doses than radiotherapy technologists. The occupational doses for all technologists were found to be below the annual dose limits, which indicates satisfactory working conditions in terms of radiation protection.

OCCUPATIONAL DOSES TO RADIOGRAPHY INTERNSHIP STUDENTS IN SAUDI ARABIA USING OPTICALLY STIMULATED LUMINESCENCE DOSIMETRY

This study aimed to estimate a baseline for the effective doses received by radiography internship students in Saudi Arabia. A retrospective study was conducted from 2015 to 2018 to discern the effective dose measurements for a total of 206 students using optically stimulated luminescence dosemeters. Readings were performed using the OSLR-250 Automatic Reader. Data analysis was carried out on 813 readouts. The annual mean effective dose averaged over a period of 4 y was found to be 0.55 mSv, with a standard deviation of 0.34 mSv and a range of 0.14-1.58 mSv. The results show that 92% ($\frac{190}{206}$) of the students received annual effective doses of <1 mSv. No annual dose record exceeded the limits recommended by authorities (20 mSv/y). The study concluded that the applied radiation protection measures along with education and training help create a safe work environment for radiography internship students.

Generalized approach for radiotherapy treatment planning by optimizing projected health outcome: preliminary results for prostate radiotherapy patients

Research in cancer care increasingly focuses on survivorship issues, e.g. managing disease- and treatment-related morbidity and mortality occurring during and after treatment. This necessitates innovative approaches that consider treatment side effects in addition to tumor cure. Current treatment-planning methods rely on constrained iterative optimization of dose distributions as a surrogate for health outcomes. The goal of this study was to develop a generally applicable method to directly optimize projected health outcomes. We developed an outcome-based objective function to guide selection of the number, angle, and relative fluence weight of photon and proton radiotherapy beams in a sample of ten prostate-cancer patients by optimizing the projected health outcome. We tested whether outcome-optimized radiotherapy (OORT) improved the projected longitudinal outcome compared to dose-optimized radiotherapy (DORT) first for a statistically significant majority of patients, then for each individual patient. We assessed whether the results were influenced by the selection of treatment modality, late-risk model, or host factors. The results of this study revealed that OORT was superior to DORT. Namely, OORT maintained or improved the projected health outcome of photon- and proton-therapy treatment plans for all ten patients compared to DORT. Furthermore, the results were qualitatively similar across three treatment modalities, six late-risk models, and 10 patients. The major finding of this work was that it is feasible to directly optimize the longitudinal (i.e. long- and short-term) health outcomes associated with the total (i.e. therapeutic and stray) absorbed dose in all of the tissues (i.e. healthy and diseased) in individual patients. This approach enables consideration of arbitrary treatment factors, host factors, health endpoints, and times of relevance to cancer survivorship. It also provides a simpler, more direct approach to realizing the full beneficial potential of cancer radiotherapy.