Conventional Planning Research Articles

A Pilot Study of Simulation-Free Hippocampal-Avoidance Whole Brain Radiotherapy Using Diagnostic MR-Based and Online Adaptive Planning

We aimed to demonstrate the clinical feasibility and safety of a simulation-free hippocampal avoidance whole brain radiotherapy (HA-WBRT) workflow in a Phase I clinical trial (NCT05096286). Feasibility was defined as successful completion of the simulation-free HA-WBRT workflow through treatment delivery in at last 70% of treated patients. Ten candidates for HA-WBRT were enrolled for treatment on a ring gantry CT-guided Linac with online adaptive capabilities. Structures were contoured on the diagnostic brain MRI, which was then registered to a separate head computed tomography (CT) of similar head shape, obtained from an atlas-based database. A HA-WBRT "pre-plan" was generated using the atlas-based CT (AB-CT) and the NRG-CC001 constraints. At first fraction, the AB-CT was used as the primary dataset and deformed to the patient's cone-beam CT (CBCT) for dose calculation. The brain, ventricles, and brainstem contours were matched through rigid translation and rotation to the corresponding anatomy on the CBCT to aid in alignment, given the differences in rotational head positioning from diagnostic MRI to CBCT setup. Lastly, the lens, optic nerves, and brain contours were manually edited based on CBCT visualization. Plans were then optimized, and the adaptive plan was chosen for treatment if the plan met all objectives. Workflow tasks were timed. In addition, conventional plans using patients' sim CTs were created for each patient for the purpose of prospective dosimetric comparison. The dosimetric parameters were compared for each patient between the delivered sim-free plan and the conventional sim CT plan using the sign test via statistical software, with p<.05 indicating significance. Median time from approved sim order to first fraction was 4 days (range: 2-7); median time in room (door-to-door) was 49 minutes (range: 35-70). All patients successfully completed all ten fractions and 90% of the simulation-free radiation plans met all NRG-CC001 constraints. For one patient, the sim-free plan at fraction one failed the planning target volume (PTV) coverage objective (coverage of 89%); this was deemed acceptable for delivery by the treating radiation oncologist. An offline replan was then performed to meet NRG-CC001 constraints and used for the subsequent nine fractions. There was no clinically meaningful difference in dosimetric constraints between the sim-free plan (calculated on AB-CT) and conventional CT sim plan. Statistically, the sim-free plans provided improved PTV coverage to higher doses compared to the conventional plans (Table). At a median follow-up of 43 days (range: 9 -280), the intracranial progression-free survival rate was 90%. Simulation-free HA-WBRT is feasible, results in plans that are dosimetrically comparable to conventional CT sim workflows and succeeds in decreasing time to initiation of HA-WBRT by at least 50%. Further studies with a larger cohort are warranted to optimize the workflow.

Commissioning and Initial Validation of Commercial Treatment Planning System for the Electron FLASH Research Extension

The aim of this study was to investigate the feasibility of commissioning the 16 MeV electron FLASH beam in a commercial treatment planning system (TPS) for pre-clinical research purposes. The delivery system consisted of a new commercial solution for which a linear accelerator was modified into a FLASH Research Extension platform. Additionally, preliminary radiation biology results were highlighted to showcase the future use of this system. To commission a commercial electron Monte Carlo (MC) for dose calculation of a 16 MeV FLASH beam in the TPS, radiochromic film was used to measure the vendor-required beam data, e.g., profiles and percent depth dose (PDD) curves for cone sizes of 6 × 6 cm2, 10 × 10 cm2, and 15 × 15 cm2 as well as an in-air profile for a 40 × 40 cm2 open field (no cone). Once the electron MC beam model was generated, additional measurements were collected for validation and compared against the calculated dose from the TPS. A treatment planning comparison between the newly commissioned FLASH beam and the conventional electron beam was conducted. Specifically, the dose-volume histograms (DVHs) for target volumes and organs at risk were investigated for skin cancer cases previously treated with conventional electron beams. Lastly, the FLASH dose distribution predicted by the electron MC for an in vitro cell study setup was validated with radiochromic film measurements, and initial radiobiology tests were conducted using FLASH and conventional dose-rate electron beams. The electron MC calculated dose for the 16 MeV electron FLASH beam agreed with measured PDDs within 1% for all field sizes. The beam profile characteristics, such as penumbra, shape, and full width at half maximum, demonstrated good agreement with less than 0.5 mm difference between the TPS and measurements. There were noticeable differences in the profiles of large fields between the FLASH and conventional dose-rate beam models due to the more forward-peaked FLASH beam. For treatment planning, Regarding DVH, the FLASH dose-rate plan provided comparable plan quality to the conventional dose-rate plan, achieving adequate coverage for the target volumes and sparing the healthy organs and tissues. The electron MC dose prediction for the FLASH beam was also found to be in good agreement with the film measurements of the in vitro cell study setup. Furthermore, the FLASH beam was observed to be more effective with a 20 % increase in killing pancreatic cancer cells compared to the conventional dose rate. The study successfully incorporated the 16 MeV electron FLASH Research Extension into the commercial TPS using electron Monte Carlo for dose calculation. This will be valuable for pre-clinical cell and animal studies. This research also enables FLASH treatment planning studies, a key component for the future implementation of FLASH into clinical care. Further research is necessary to incorporate the radiation biology effect of FLASH into the treatment planning system.

A Prospective Study of Machine Learning-Assisted Radiotherapy Planning for Patients Receiving 54 Gy to the Brain

Radiotherapy (RT) planning is presently a semi-manual, iterative, labor-intensive process which may result in unnecessary variation in plan quality. To improve treatment plan quality and decrease RT planning time, we conducted a prospective, blinded study to compare machine learning-assisted planning with conventional manual planning for patients receiving 54 Gy in 30 fractions for a primary brain tumor. From January 31, 2022 to January 10, 2023, 40 patients receiving 54 Gy for primary CNS tumors were prospectively enrolled (median age 50 years, range 4-78 years). Patients underwent standard CT/MR simulation and target/OAR delineation by the treating radiation oncologist. Each patient had one ML plan and 1-2 manual RT plans created by different planners. The reviewing oncologist was blinded to planning method by removing optimization and IMRT/VMAT beam arrangement details from all plans, which were then rated based on clinical acceptability, target coverage, OAR sparing, conformity, and dose-fall off. One preferred plan was chosen and used for clinical treatment. A total of 115 plans for 40 patients were evaluated: 40 ML plans (35% of all plans), and 75 manual plans (65% of all plans; 5 and 35 patients had 1 and 2 manual plans created, respectively). ML plans required a mean planning time of 65 min as compared to 107 min for manual plans, with a mean time savings of 41 min per patient (paired t-test p = 0.002). 97% of ML plans (95% confidence interval [CI] 85-100) and 96% of manual plans (95% CI 87-99) were designated clinically acceptable by the treating radiation oncologist. While ML-assisted plans represented 35% of plans evaluated, they were chosen as preferred for clinical treatment in 43% of cases (17/40, 95% CI 29-58, p = 0.32). Median doses to the brain (10.8 Gy vs. 11.3 Gy, Wilcoxon rank-sum p = 0.012) and brain minus PTV (9.2 Gy vs 10.0 Gy, Wilcoxon rank-sum p = 0.009) were lower with ML planning versus manual planning, respectively. Doses to other structures, including hippocampi, cochlea, pituitary and hypothalamus were not statistically different. In this prospective study with blinded oncologist evaluation, ML-assisted RT planning for primary CNS tumors was faster than manual planning, and produced a very high rate of acceptable plans with similar or superior OAR sparing. Future work will be undertaken to iteratively refine the ML model using the preferred cases from this study.

Evaluation of Plan Quality and Complexity for Automated Intracranial SBRT VMAT Treatment Plans

The purpose of this study was to evaluate the dosimetric quality and plan complexity of intracranial SBRT VMAT plans generated with an automated treatment planning system (TPS) compared to the standard conventional manually optimized VMAT plans. Ten clinical intracranial conventional SBRT VMAT plans manually generated using our standard TPS, (SE), were replanned using an automated VMAT radiosurgery TPS, Elements Cranial (EC). The plan target volume (PTV), OARs, prescription dose, fractionation, and beam arrangement remained constant between the corresponding plans from both systems. The PTV volume varied from 0.861cc to 40.022cc with prescription doses of 25Gy or 30Gy in 5 fractions. For each plan, PTV mean and max dose were recorded, as well as inverse Paddick conformity index (CI), gradient index (GI), and OAR mean and max doses. A Python script was used to calculate plan complexity metrics, including total MU, complexity metric, aperture irregularity metric, and modulation index total. Statistical significance of the comparisons was determined by performing a paired t-Test with α = 0.05. The results of plan quality and complexity metrics for each planning system are presented in Table 1. Dose conformality of the PTV showed no differences between plans generated with either planning system, with no statistical differences in the CI. The GI showed improvement for the automated plans, which appeared to be due to the system allowing higher PTV mean and max doses to achieve a sharper dose gradient from the target. There was a decrease in MU for the automated plans, which also correlated to statistically lower Complexity, Aperture Irregularity, and Modulation Index metrics. Differences in OAR mean and max doses between both systems were statistically insignificant. Clinically acceptable intracranial SBRT VMAT plans can be generated using an Automated TPS. Plan dosimetric quality with respect to PTV coverage and dose conformality, as well as OAR doses, were equivalent to manual plans. The automated plans were found to be less complex than manual plans, which may be related to the automated system allowing larger target dose inhomogeneity. While statistically significant differences were found between both systems, they may not be clinically relevant, and the differences could be related to the different planning techniques between systems.

Feasibility Study of Robust Treatment Planning in VMAT for Head and Neck Cancer

In general, patient positional uncertainty is considered by adding a geometrically expanded margin to clinical target volume (CTV) in photon radiation therapy. However, this method may not be suitable because image-guided radiotherapy is available. In intensity modulated proton beam therapy, robust treatment planning is currently common to take patient positional uncertainty into account in optimization rather than in margins. The purpose of this study is to assess the feasibility of clinical implementation of the method in volumetric modulated arc therapy (VMAT) for head and neck cancer. We quantitatively evaluated whether the plans with the robust optimization (Robust plans) can adequately cover CTV against patients' positional uncertainties and body shape change throughout a treatment course. Ten head and neck cancer patients were chosen, who were treated with PTV-based VMAT plans in our hospital between 2021.5-2022.4. RayStation V10A (RaySearch Laboratories, Stockholm, Sweden) was used for the robust optimization, which was applied to the CTVs with patient positional uncertainty of 5 mm in the 6-axis direction. Dose prescribed to the high- and low-risk CTVs were to 70 and 56 Gy in 35 fractions, respectively. To create the patients' CT images with residual set-up errors and body shape change at the treatment, pseudo simulation-CT images were created by deformable image registration with CBCT and simulation-CT. Dose distribution at the treatment was re-calculated by applying the plan to the pseudo simulation-CT images. The variation of D98 for the high-risk CTV from the time of treatment planning was evaluated on a weekly basis. For comparison, planning target volume (PTV) -based plans (5 mm margin circumference) were created and a similar evaluation was performed. D98 for the high-risk CTV varied between -3∼2% in the robust plan and between -5∼1% in the PTV-based plan during the treatment course. There was no significant difference in the amount of D98 variation between the two plans by t-test, except for one case with hypopharyngeal cancer. In this case, D98 for the high-risk CTV varied within ±1% with the PTV-based plan, whereas the value decreased up to 3% with the robust plan (p < 0.05). This case often had a residual setup error of approximately 5 mm at the sites related to the pitch rotation of head, suggesting that the dose distribution for the robust plan was affected by non-rigid positional errors. Patient weight loss during the treatment period was -3.5±2.4 kg, showing a weak correlation (r = -0.33) with the variation in D98 for the high-risk CTV. The robust treatment planning exhibits comparable CTV coverage to the conventional PTV-based planning against positional uncertainty and body shape change throughout a treatment period. In order to overcome set-up baseline shift by the non-rigid positional errors, re-planning should be recommended. Further planning studies will be conducted to promote clinical implementation of the method.

New Advantage in Stereotactic Treatment of Lung and Pancreatic Cancer. Performance of Ultra-High Energy Electron (VHEE) Therapy Adjuvanted to the FLASH Effect: Clinical Implications and Treatment Plans Analysis

Very High-Energy Electron (VHEE) beams delivered at ultra-high dose rates and hence profiting from the FLASH effect, may be a viable alternative to conventional treatment plans for the treatment of deep-seated tumors. Experimental data support the evidence of a considerable normal tissue sparing effect when treatments are delivered with dose rates much larger (100 times or more) compared to the conventional ones. Lung cancer and pancreatic cancer are considered the two biggest cancer killers. We urgently need more research in these areas, more awareness that support improvement in treatment strategies. To evaluate the potential of FLASH VHEE irradiation in these two clinical situations, we investigated the achievable sparing of healthy tissues and critical dose-limiting structures, with the goal of performing a higher dose prescription. The study on the potential of VHEE for the stereotactic treatment of pancreatic and lung lesions was carried out on two clinical cases treated with Volumetric Modulated Arc Therapy (VMAT) techniques at University Hospital Campus Bio-Medico of Rome. The Planning Target Volume (PTV) was identified and the constraints on the Organs at Risk (OAR) and details on the irradiation approach were defined. The VHEE plan was designed to optimize the dose delivery to best activate the modelled FLASH effect based on the current experimental knowledge. In particular the impact on a dose threshold to activate the effect was studied. The VHEE treatment plan was based on an accurate Monte Carlo simulation of the electrons interactions and the results achievable with different FLASH effect models were studied. The simulation allowed the estimation of dose maps, which were used as input to an optimization algorithm that modified the fluence of each beam to meet treatment prescriptions in terms of dose to PTV. At the end the VHEE DVH plans were compared to VMAT plans. The results demonstrated that FLASH therapy with VHEE beams of 70-130 MeV, could represent a promising alternative to standard radiotherapy allowing a comparable sparing of the healthy tissues. In the case of pancreatic cancer, the Dose Volume Histograms (DVH) showed how such a technique can be effective in sparing the duodenum. In case of lung cancers, the result showed how pulmonary tissue sparing can lead to a substantial reduction of pulmonary toxicity in comparison with the VMAT technique. In the case of pancreatic cancer and assuming a non-negligible contribution from the FLASH effect, the DVH showed how the duodenum healthy tissue sparing could allow a higher dose to be prescribed at the target while keeping the constraints respected, improving the therapeutic ratio. In the case of lung cancer, the advantages of the technique are additionally increased by the significant benefit that could be related to the treatment delivery time reduction (<1s) and to the corresponding advantage coming from a reduced organ movement that translates in a lower risk of lung toxicity.

Dosimetric and radiobiological comparison between conventional and hypofractionated breast treatment plans using the Halcyon system.

The objective of this research is to compare the efficacy of conventional and hypofractionated radiotherapy treatment plans for breast cancer patients, with a specific focus on the unique features of the Halcyon system. The study collected and analyzed dose volume histogram (DVH) data for two groups of treatment plans implemented using the Halcyon system. The first group consisted of 19 patients who received conventional fractionated (CF) treatment with a total dose of 50 Gy in 25 fractions, while the second group comprised 9 patients who received hypofractionated (HF) treatment with a total dose of 42.56 Gy in 16 fractions. The DVH data was used to calculate various parameters, including tumor control probability (TCP), normal tissue complication probability (NTCP), and equivalent uniform dose (EUD), using radiobiological models. The results indicated that the CF plan resulted in higher TCP but lower NTCP for the lungs compared to the HF plan. The EUD for the HF plan was approximately 49 Gy (114% of its total dose) while that for the CF plan was around 53 Gy (107% of its total dose). The analysis suggests that while the CF plan is better at controlling tumors, it is not as effective as the HF plan in minimizing side effects. Additionally, it is suggested that there may be an optimal configuration for the HF plan that can provide the same or higher EUD than the CF plan.

Moving green infrastructure planning from theory to practice in sub-Saharan African cities requires collaborative operationalization

Researchers increasingly consider the systematic integration of green infrastructure (GI) concepts in urban planning as an essential approach to tackle significant current and future challenges. Cities in sub-Saharan Africa (SSA) face rapid urbanization, unregulated land-use practices, and poor enforcement of policies. These cities struggle to address the depletion and degradation of existing GI that increases their vulnerability to climatic hazards that threaten ecosystem integrity, and compromise human health. This paper draws on a review of policy documents, semi-structured interviews with metro officials, and cross-sector focus group discussions to explore ways to operationalize GI spatial planning and design on the ground. Through a case study of the City of Tshwane Metropolitan Municipality, South Africa, which takes a public-private co-development approach, we investigate the uptake of GI planning principles, the challenges, and local proposals for GI applications. In conjunction with the literature, we discuss the alternatives at hand. The local policy documents reflected many planning principles anchored in the Global North literature. Together with public and private partners, we co-developed four locally informed GI objectives: environmental protection, safety, joint ownership, and collaborative governance. We co-identified local planning principles and three strategies for operationalizing GI planning, including working with conventional planning, greater flexibility and creativity, and cross-sectoral collaboration. The findings suggest that collaborative strategies that allow greater access and the active, diverse use of GI could provide much-required cross-sectoral care and management. The real challenge is the establishment of such participatory partnerships as mechanisms to consolidate diverse priorities and co-develop technical and financial alternatives.

Pencil Beam Scanning Bragg Peak FLASH Technique for Ultra-High Dose Rate Intensity-Modulated Proton Therapy in Early-Stage Breast Cancer Treatment.

Bragg peak FLASH-RT can deliver highly conformal treatment and potentially offer improved normal tissue protection for radiotherapy patients. This study focused on developing ultra-high dose rate (≥40 Gy × RBE/s) intensity-modulated proton therapy (IMPT) for hypofractionated treatment of early-stage breast cancer. A novel tracking technique was developed to enable pencil beaming scanning (PBS) of single-energy protons to adapt the Bragg peak (BP) to the target distally. Standard-of-care PBS treatment plans of consecutively treated early-stage breast cancer patients using multiple energy layers were reoptimized using this technique, and dose metrics were compared between single-energy layer BP FLASH and conventional IMPT plans. FLASH dose rate coverage by volume (V40Gy/s) was also evaluated for the FLASH sparing effect. Distal tracking can precisely stop BP at the target distal edge. All plans (n = 10) achieved conformal IMPT-like dose distributions under clinical machine parameters. No statistically significant differences were observed in any dose metrics for heart, ipsilateral lung, most ipsilateral breast, and CTV metrics (p > 0.05 for all). Conventional plans yielded slightly superior target and skin dose uniformities with 4.5% and 12.9% lower dose maxes, respectively. FLASH-RT plans reached 46.7% and 61.9% average-dose rate FLASH coverage for tissues receiving more than 1 and 5 Gy plan dose total under the 250 minimum MU condition. Bragg peak FLASH-RT techniques achieved comparable plan quality to conventional IMPT while reaching adequate dose rate ratios, demonstrating the feasibility of early-stage breast cancer clinical applications.

Perencanaan Ulang Struktur Portal Utama Gedung PT. Ferron Par Pharmaceuticals Cikarang Integrasi BIM (Building Information Modelling)

In development construction projects, the digitalization of excellent and mature construction planning is needed to obtain efficient and effective construction results and through the implementation of BIM integrated Structural Planning and Analysis(Building Information Modelling) expected in building planning PT. Ferron Pharmaceuticals Cikarang can minimize the occurrence of errors. The purpose of this final project is to re-design the building of PT. Ferron Pharmaceuticals Cikarang by integrating conventional planning methods into a based planning method BIM (Building Information Modelling) for efficiency structure and project visualitation on the project. The process used is quantitative descriptive by conducting a literature study to understand the basics of planning a high-rise building structure, then proceeding with integration based on SAP2000. The result of this paper is an earthquake-resistant structural design with the Sway Frame with modelling 3D that can be applied to tall buildings with high levels of security, reliability and earthquake resistance. The Finding of this re-design is the high efficiency of this structure in reducing earthquake resistance and can be used as a reference for planning earthquake resisitant buildings in the future.

Perencanaan Ulang Struktur Portal Utama Gedung PT. Ferron Par Pharmaceuticals Cikarang Integrasi BIM (Building Information Modelling)

In development construction projects, the digitalization of excellent and mature construction planning is needed to obtain efficient and effective construction results and through the implementation of BIM integrated Structural Planning and Analysis(Building Information Modelling) expected in building planning PT. Ferron Pharmaceuticals Cikarang can minimize the occurrence of errors. The purpose of this final project is to re-design the building of PT. Ferron Pharmaceuticals Cikarang by integrating conventional planning methods into a based planning method BIM (Building Information Modelling) for efficiency structure and project visualitation on the project. The process used is quantitative descriptive by conducting a literature study to understand the basics of planning a high-rise building structure, then proceeding with integration based on SAP2000. The result of this paper is an earthquake-resistant structural design with the Sway Frame with modelling 3D that can be applied to tall buildings with high levels of security, reliability and earthquake resistance. The Finding of this re-design is the high efficiency of this structure in reducing earthquake resistance and can be used as a reference for planning earthquake resisitant buildings in the future.

Is a Novel Fluoroscopic Intraoperative Reference System Superior to Conventional Management for Distal Radius Fracture Reduction? A Propensity-matched Comparative Study.

Is a Novel Fluoroscopic Intraoperative Reference System Superior to Conventional Management for Distal Radius Fracture Reduction? A Propensity-matched Comparative Study.

Effects of Short Wave Diathermy Therapy in Patients with Adhesive Capsulitis of Shoulder (ACS)

There are varieties of management option for Adhesive capsulitis of shoulder (ACS) also known as Periarthrosis and in general population commonly known as Frozen Shoulder. Short Wave Diathermy (SWD) is one of the important therapeutic option for frozen sholder. The aim of the study is to determine effectiveness of SWD in order to improve the pain and range of motion in Adhesive Capsulitis. A total 56 subjects were selected for this non-randomized controlled trial in the Department of Physical Medicine and Rehabilitation, Chattogram Medical College Hospital with adhesive capsulitis in a period of 6 months. The subject were divided into two intervention groups; group-A with conventional treatment plan with SWD and group-B with conventional treatment only. Tool used for assessment were Visual Analogue Scale (VAS) to measure pain with Tenderness Grading (TG) and Shoulder Pain and Disability Index Score (SPADI). The analysis was done to measure the difference of effectiveness of both interventions by independent t-test with SPSS-20. Among 56 patients regarding analysis of sex in both groups male and female were matched (p&gt;0.05) and male - female ratio was 1.66: 1. Considering socioeconomic status, poor was 21.4%, middle class was 44.6% and rich was 33.9%. Among all patients 35.7% were housewives, 16.1% were service holder, farmers were 12.5%, businessmen were 16.2% and laborers were 3.6%. In total patients, 48.2% had right shoulder involvement, 50.0% had left side involvement and one patient had both sided disease. There were 92.7% patients who had localized pain and only 7.3% had radiation. Majority of the experienced pain in the evening was 56.4% and rest had pain at night was 43.6%. About half of the patients in both groups had constant and intermittent type of pain 47.5% and 45.5% respectively other types were sharp and dull. Significant difference between Group A and Group B was found at week 2, week 4 and week 6 follow-up (p&lt;0.05) whereas initial follow-up was non-significant in VAS analysis (p&gt;0.05). Significant difference between Group A and Group B was found at week 2, week 4 and week 6 follow-up (p&lt;0.05) regarding change of tenderness grading in Group A, then Group B patients. Significant difference between Group A and Group B was found at week 2, week 4 and week 6 follow-up (p&lt;0.05) regarding SPADI. When SWD is combined with conventional management of adhesive capsulitis it gives better reduction in pain and disability. Conventional treatment plan with SED is more effective in the management of pain and reduce disabilities in patients with ACS. Bangladesh Med J. 2021 Sept; 51(1): 1-7

Research on the trajectory tracking of a curved road in an active lane change scenario based on model predictive control algorithm

In this paper, a control method for trajectory planning and tracking of an intelligent vehicle is proposed. In terms of trajectory planning, a trajectory planning method for curved lane changes is designed based on conventional lane change trajectory planning and considering the adaptive correction of road curvature. In addition, curve trajectory tracking control strategy based on model predictive control is designed. Model predictive control is suitable for multi-input and multi-output nonlinear models, and it has the advantage of considering model constraints. This type of control makes the model output more in line with vehicle dynamics characteristics and improves the trajectory tracking accuracy. Finally, the simulation shows that the method proposed in this paper can generate a reasonable curved lane-changing trajectory, and under the consideration of the vehicle dynamics constraints, the MPC algorithm is used to effectively follow the expected trajectory, so that the vehicle can change lanes smoothly.

Security-constrained Transmission Expansion Planning with N-k Security Criterion and Transient Stability

The integration of large-scale wind power into the power system is a global trend in response to climate change, however, the intermittent nature of wind power presents new challenges for planners. Conventional transmission expansion planning (TEP) methods, which only consider N-1 static security, may not ensure the security of multiple contingencies and transient stability in a large-scale wind power integration scenario. Incorporating N-k-based static constraints and dynamic constraints, such as differential-algebraic-equations-(DAEs)-based transient stability constraints, into TEP can result in a heavy computational burden and render the TEP model intractable. This paper proposes a tractable mathematical model (S&DSTEP) for joint consideration of static and dynamic security in TEP with wind power. The uncertain wind power generation is captured through selected scenarios and the model is divided into a TEP master problem and multiple sub-problems for evaluating static security and transient stability. Static security is determined by the use of fault chain theory (FCT), avoiding the need for enumerating all N-k contingencies, thus reducing the computational burden. Transient stability is analyzed through the use of stabilizing cuts generated from the extended equal-area criteria (EEAC) rather than dynamic constraints expressed as DAEs. The proposed model is verified on the modified New England 39-bus system and IEEE 118-bus system, demonstrating its ability to consider transient stability while being more computationally efficient compared to the robust method that directly incorporates all contingency scenarios.

The Power of Radical Place-Making Practices: Lessons Learned from ufaFabrik in Berlin

This article investigates ufaFabrik’s practice within Berlin’s urban context, which emerged from an occupation of an abandoned site and evolved into a long-term experiment in radical place-making. Through this case study analysis, it explores the role of radical place-making in shaping urban policy, focusing on the dimensions of decision, place and policy. Drawing on an expanded conceptualisation of place-making that embraces a radical perspective, the study is based on a Ph.D. programme and on extensive field research. ufaFabrik has given place-making a political meaning, challenging conventional urban planning in relation to ‘undecided’ spaces. This paradigm of place-making represents grassroots activism and insurgent action and it can catalyse both local and urban transformations. Through a critical analysis of the limits and possibilities of radical place-making practice, the article argues that the ufaFabrik offers valuable insights into the potential of participatory and community-led approaches to reshape urban spaces and promote more inclusive and sustainable forms of urban governance. The study highlights how the re-politicisation of urban issues emerges from conflict and challenges established power dynamics. It highlights the interconnection between ‘place’ and ‘making’, weaving experiential and generative elements into the urban discourse, highlighting its transformative potential and reconfiguration of decision-making dynamics.

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve.

Due to the wide variety of morphology, size, and dynamics, selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation (PPVI). This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional (3D)-printed models for planning PPVI with the Venus P-valve. Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University. 3D model bench testing altered treatment strategy in all patients (100%). One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly. In the remaining 14 patients, valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery. In four patients, it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract (RVOT) ( n = 2) or risk of compression coronary artery ( n = 2). Concerning sizing, we found that an oversize of 2-5 mm suffices. Anchoring of the valve was dictated by the flaring of the in- and outflow portion in the pulmonary artery. PPVI was successful in all 14 patients (absence of valve migration, no coronary compression, and none-to-mild residual pulmonary regurgitation [PR]). The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group (36 [2] vs. 32 [4], Z = -3.77, P <0.001). In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique, as 2-5 mm sufficed.

Per-fraction planning to enhance optimization degrees of freedom compared to the conventional single-plan approach.

&#xD;In conventional radiotherapy, a single treatment plan is generated pre-treatment, and delivered in daily fractions. In this study, we propose to generate different treatment plans for all fractions ('Per-fraction' planning) to reduce cumulative OAR doses. Per-fraction planning was compared to the 'Conventional' single-plan approach for non-coplanar 4x9.5 Gy prostate SBRT.&#xD;&#xD;Approach:&#xD;An in-house application for fully automated, non-coplanar multi-criterial treatment planning with integrated beam angle and fluence optimization was used for plan generations. For the Conventional approach, a single 12-beam non-coplanar IMRT plan with individualized beam angles was generated for each of the 20 included patients. In Per-fraction planning, four fraction plans were generated for each patient. For each fraction, a different set of patient-specific 12-beam configurations could be automatically selected. Per-fraction plans were sequentially generated by adding dose to already generated fraction plan(s). For each fraction, the cumulative- and fraction dose were simultaneously optimized, allowing some minor constraint violations in fraction doses, but not in cumulative.&#xD;&#xD;Main results:&#xD;In the Per-fraction approach, on average 32.9 ± 3.1 [29;39] unique beams per patient were used. PTV doses in the separate Per-fraction plans were acceptable and highly similar to those in Conventional plans, while also fulfilling all OAR hard constraints. When comparing total cumulative doses, Per-fraction planning showed improved bladder sparing for all patients with reductions in Dmean of 22.6% (p=0.0001) and in D1cc of 2.0% (p=0.0001), reductions in patient volumes receiving 30% and 50% of the prescribed dose of 54.7% and 6.3%, respectively, and a 3.1% lower rectum Dmean (p=0.007). Rectum D1cc was 4.1 % higher (p=0.0001) and Urethra dose was similar. &#xD;&#xD;Significance:&#xD;In this proof-of-concept paper, Per-fraction planning resulted in several dose improvements in healthy tissues compared to the Conventional single-plan approach, for similar PTV dose. By keeping the number of beams per fraction the same as in Conventional planning, reported dosimetric improvements could be obtained without increase in fraction durations. Further research is needed to explore the full potential of the Per-fraction planning approach.&#xD.

Augmented and Virtual Reality for Preoperative Trauma Planning, Focusing on Orbital Reconstructions: A Systematic Review.

This systematic review summarizes recent literature on the use of extended reality, including augmented reality (AR), mixed reality (MR), and virtual reality (VR), in preoperative planning for orbital fractures. A systematic search was conducted in PubMed, Embase, Web of Science and Cochrane on 6 April 2023. The included studies compared extended reality with conventional planning techniques, focusing on computer-aided surgical simulation based on Computed Tomography data, patient-specific implants (PSIs), fracture reconstruction of the orbital complex, and the use of extended reality. Outcomes analyzed were technical accuracy, planning time, operative time, complications, total cost, and educational benefits. A total of 6381 articles were identified. Four articles discussed the educational use of VR, while one clinical prospective study examined AR for assisting orbital fracture management. AR was demonstrated to ameliorate the accuracy and precision of the incision and enable the better identification of deep anatomical tissues in real time. Consequently, intraoperative imaging enhancement helps to guide the orientation of the orbital reconstruction plate and better visualize the precise positioning and fixation of the PSI of the fractured orbital walls. However, the technical accuracy of 2-3 mm should be considered. VR-based educational tools provided better visualization and understanding of craniofacial trauma compared to conventional 2- or 3-dimensional images.

Socioeconomic Development: The Role of Impact Investments and CPEC

This paper investigates the modes of impact investing to overcome the socioeconomic challenges of Pakistan. A descriptive analysis of different social indicators for the period 2006 to 2017 is conducted which includes health, education, tourism, vocational training, agriculture, and access to water. Each socioeconomic indicator is examined as a possible mode of impact investment. This study reports that a better alignment of impact investing in the second phase of the China-Pakistan Economic Corridor (CPEC) will offer maximum development. The study recommends the most efficient and effective ways to achieve the greater goal of a prosperous Pakistan. The author strongly recommends the policymakers of CPEC to focus on impact investing along with conventional investment plans to combat the socioeconomic challenges in Pakistan.