Insights Gained From a Re-analysis of Five Improvement Cases in Healthcare Integrating System Dynamics Into Action Research

Background Healthcare is complex with multi-professional staff and a variety of patient care pathways. Time pressure and minimal margins for errors, as well as tension between hierarchical power and the power of the professions, make it challenging to implement new policies or procedures. This paper explores five improvement cases in healthcare integrating system dynamics (SD) into action research (AR), aiming to identify methodological aspects of how this integration supported multi-professional groups to discover workable solutions to work-related challenges. Methods This re-analysis was conducted by a multi-disciplinary research group using an iterative abductive approach applying qualitative analysis to structure and understand the empirical material. Frameworks for consultancy assignments/client projects were used to identify case project stages (workflow steps) and socio-analytical questions were used to bridge between the AR and SD perspectives. Results All studied cases began with an extensive AR-inspired inventory of problems/objectives and ended with an SDfacilitated experimental phase where mutually agreed solutions were tested in silico. Time was primarily divided between facilitated group discussions during meetings and modelling work between meetings. Work principles ensured that the voice of each participant was heard, inspired engagement, interaction, and exploratory mutual learning activities. There was an overall pattern of two major divergent and convergent phases, as each group moved towards a mutually developed point of reference for their problem/objective and solution, a case-specific multi-professional knowledge repository. Conclusion By integrating SD into AR, more favourable outcomes for the client organization may be achieved than when applying either approach in isolation. We found that SD provided a platform that facilitated experiential learning in the AR process. The identified results were calibrated to local needs and circumstances, and compared to traditional top-down implementation for change processes, improved the likelihood of sustained actualisation.publishedVersio

Insights gained from a systematic reanalysis of a successful model-facilitated change process in health care

Health care is a complex system with multiprofessional staff and multiple patient care pathways. Time pressure and minimal margins for error make it challenging to implement new policies or procedures, no matter how desirable. Changes in health care also requires the participation of the staff. System dynamics (SD) simulations can lead to shared systems understanding and allows for the development and testing of new scenarios in silico before implementing solutions. However, research shows that the actual implementation rate of simulations is low. This paper presents a reanalysis of a successful change project in health care combining SD principles with basic action research (AR) premises. The analysis was done by a multidisciplinary research group using qualitative methodology and identifies that a fruitful combination of AR inquiry and SD modelling potentially can improve implementation rates.publishedVersio

Intensity-modulated radiotherapy of nasopharyngeal carcinoma: a comparative treatment planning study of photons and protons

<p>Abstract</p> <p>Background</p> <p>The aim of this treatment planning study was to investigate the potential advantages of intensity-modulated (IM) proton therapy (IMPT) compared with IM photon therapy (IMRT) in nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>Eight NPC patients were chosen. The dose prescriptions in cobalt Gray equivalent (Gy_E) for gross tumor volumes of the primary tumor (GTV-T), planning target volumes of GTV-T and metastatic (PTV-TN) and elective (PTV-N) lymph node stations were 72.6 Gy_E, 66 Gy_E, and 52.8 Gy_E, respectively. For each patient, nine coplanar fields IMRT with step-and-shoot technique and 3D spot-scanned three coplanar fields IMPT plans were prepared. Both modalities were planned in 33 fractions to be delivered with a simultaneous integrated boost technique. All plans were prepared and optimized by using the research version of the inverse treatment planning system KonRad (DKFZ, Heidelberg).</p> <p>Results</p> <p>Both treatment techniques were equal in terms of averaged mean dose to target volumes. IMPT plans significantly improved the tumor coverage and conformation (<it>P </it>< 0.05) and they reduced the averaged mean dose to several organs at risk (OARs) by a factor of 2–3. The low-to-medium dose volumes (0.33–13.2 Gy_E) were more than doubled by IMRT plans.</p> <p>Conclusion</p> <p>In radiotherapy of NPC patients, three-field IMPT has greater potential than nine-field IMRT with respect to tumor coverage and reduction of the integral dose to OARs and non-specific normal tissues. The practicality of IMPT in NPC deserves further exploration when this technique becomes available on wider clinical scale.</p

Overview of JET results for optimising ITER operation

The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle (α) physics in the coming D–T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER

Potential biological markers of tumour response to radiation therapy in head and neck cancers

The rationale behind studying biological markers of tumour response to radiation therapy in head and neck cancers is to increase the individualisation of radiation therapy. This should ultimately lead to improvements in local control and survival and reduced morbidity. An evaluation was made of the theoretical and practical value of using low-dose rate irradiation to increase the resolution of clonogenic assays for radiosensitivity testing. In tumour cell lines low-dose rate irradiation improved discrimination between tumour radioresponsiveness groups. However, low-dose rate irradiation of primary human tumours followed by soft-agar clonogenic assay was impractical because it reduced the success rate for obtaining radiosensitivity data.One hundred and forty specimens of malignant head and neck tumours of different histology types were assessed for ability to grow in vitro (colony forming efficiency, CFE) and inherent tumour radiosensitivity (surviving fraction at 2 Gy, SF2) using a clonogenic soft-agar assay. The success rate for growing colonies was 74% (104/140) with a median CFE = 0.031%. SF2 was obtained for 88/140 patients (63%) with a median SF2 = 0.43. A comparison was made of SF2 values for different primary human tumour types. This showed that head and neck- (p = 0.03), cervix- (p = 0.02) and colorectal carcinomas (p = 0.003) were significantly more radioresistant than lymphomas. The relationships between proliferation, TP53 and SF2 were evaluated. No correlations were seen between SF2 and any of the parameters analysed. The study demonstrated the feasibility of obtaining parallel measurements of different biological markers in a large number of patients with head and neck cancers.A study was made of SF2 in relation to the immunohistochemical expression levels of the individual components (Ku (p70/p80) and DNA-PKcs) of the DNA double strand break repair enzyme, DNA-PK. No significant relationship was found between SF2 and the expression levels of Ku (p70/p80) or DNA-PKcs for patients with head and neck cancers.Finally, the relationship between SF2 and treatment outcome was prospectively studied in 84 patients with malignant head and neck cancers. SF2 was found to be a significant prognostic factor for local control (p = 0.036)

Compression Treatment of Breast Edema : A Randomized Controlled Pilot Study

Background: Patients treated for breast cancer with breast conserving surgery and radiotherapy (RT) often complain about swelling, heaviness, and pain in the treated breast. This pilot study was undertaken to examine if compression therapy was effective as an early treatment to reduce breast edema and symptoms assessed by Visual Analogue Scale (VAS). Methods and Results: Fifty-six breast cancer-treated women with breast edema, diagnosed by the measurement of tissue water content by tissue dielectric constant (TDC) technique 3 months post-RT, were randomized to either an intervention group, wearing a sports bra of compression type, or a control group, wearing a standard bra daily for 9 months when tissue water content in breast, upper arm, and lateral thorax of the operated side, and symptoms assessed by VAS were evaluated. No differences were found between the groups at start or end of study concerning tissue water content or VAS. However, within both groups, a significant reduction in tissue water content and experience of heaviness was found. Conclusion: Breast edema as well as experience of heaviness in the affected breast found at 3 months post-RT decreased after 9 months independent of whether a sports bra of compression type or a standard bra was used

Structure delineation in the presence of metal – A comparative phantom study using single and dual-energy computed tomography with and without metal artefact reduction

Background and purpose: Metal artefacts in computed tomography (CT) images impairs structure delineation. These artefacts can potentially be reduced with dual-energy CT (DECT) with or without using metal artefact reduction (MAR). The purpose was to investigate how structure delineation in DECT with or without MAR and single-energy CT (SECT) images were affected by metals. Materials and methods: A phantom with known irregular structures was developed. Reference structures were determined from a low-noise scan without metal. Bilateral hip prostheses were simulated with steel or titanium inserts. The phantom was scanned with SECT and fast-kV switching DECT with optional MAR. Four radiation oncologists delineated the structures in two phantom set-ups. Delineated structures were evaluated with Dice similarity coefficient (DSC) and Hausdorff distance relative to the reference structures. Results: With titanium inserts, more structures were detected for non-MAR DECT compared to SECT while the same or less were detected with steel inserts. MAR improved delineation in DECT images. For steel inserts, three structures in the region of artefacts, were delineated by at least two oncologists with MAR-DECT compared to none with non-MAR DECT or SECT. The highest values of DSC for MAR-DECT were 0.69, 0.81 and 0.77 for those structures. Conclusions: Delineation was improved with non-MAR DECT compared to SECT, especially for titanium inserts. A larger improvement was seen with the use of MAR for both steel and titanium inserts. The improvement was dependent on the location of the structure relative to the inserts, and the structure contrast relative to the background. Keywords: Radiotherapy, Treatment planning, Computed tomography, Delineation uncertainty, Dual-energy computed tomography, Metal artefact reductio

The risk of radiation-induced neurocognitive impairment and the impact of sparing the hippocampus during pediatric proton cranial irradiation

Background and purpose: Hippocampus is a central component for neurocognitive function and memory. We investigated the predicted risk of neurocognitive impairment of craniospinal irradiation (CSI) and the deliverability and effects of hippocampal sparing. The risk estimates were derived from published NTCP models. Specifically, we leveraged the estimated benefit of reduced neurocognitive impairment with the risk of reduced tumor control. Material and methods: For this dose planning study, a total of 504 hippocampal sparing intensity modulated proton therapy (HS-IMPT) plans were generated for 24 pediatric patients whom had previously received CSI. Plans were evaluated with respect to target coverage and homogeneity index to target volumes, maximum and mean dose to OARs. Paired t-tests were used to compare hippocampal mean doses and normal tissue complication probability estimates. Results: The median mean dose to the hippocampus could be reduced from 31.3 GyRBE to 7.3 GyRBE (p <.001), though 20% of these plans were not considered clinically acceptable as they failed one or more acceptance criterion. Reducing the median mean hippocampus dose to 10.6 GyRBE was possible with all plans considered as clinically acceptable treatment plans. By sparing the hippocampus to the lowest dose level, the risk estimation of neurocognitive impairment could be reduced from 89.6%, 62.1% and 51.1% to 41.0% (p <.001), 20.1% (p <.001) and 29.9% (p <.001) for task efficiency, organization and memory, respectively. Estimated tumor control probability was not adversely affected by HS-IMPT, ranging from 78.5 to 80.5% for all plans. Conclusions: We present estimates of potential clinical benefit in terms of neurocognitive impairment and demonstrate the possibility of considerably reducing neurocognitive adverse effects, minimally compromising target coverage locally using HS-IMPT