Single Option Research Articles

Option Pricing Based on Neural Stochastic Differential Equations

Firstly, based on the Black-Scholes stock price model, the neural stochastic differential equation (NSDE) model was established by parameterizing the asset return rate and volatility as a drift network and a diffusion network, respectively. Secondly, in the empirical analysis, the underlying asset as a single stock option was used as the research object, and real stock data was used for the network training and testing. The experimental results show that the NSDE model can overcome the defects of the constant assumption of the Black-Scholes model. Finally, for the case where the price of the underlying asset of the option was unobservable, we proposed that the price of any target option and the price of a known option could be constrained within the Wasserstein distance of their risk-neutral equivalent martingale measure, and theoretically proved the method.

Assessing investment priorities for inclusive agricultural transformation in Tanzania

AbstractMotivationPolicy‐makers dealing with conflicting development goals and constrained budgets must comprehend the relative cost effectiveness of agricultural and rural development initiatives.PurposeWe assess the impact of alternative interventions on development outcomes—economic growth, job creation, poverty reduction, and diet quality—to inform decision‐making and resource allocation in Tanzania's agriculture. We analyse trade‐offs among development objectives and explore budget reallocation to enhance the efficiency of public spending.Approach and methodsWe used a computable general equilibrium (CGE) model linked top‐down with microsimulation modules to simulate the impact of public investment options.FindingsNo single option emerges as the most effective across all development objectives. Investments in improved inputs and extension for horticulture and cash crops stand out for diet quality and employment creation. Livestock services show consistently high rankings across multiple objectives. Investments to boost cereals and root crops promote growth and reduce poverty but do little to increase employment and diet quality.Budget reallocation towards more cost‐effective interventions can significantly enhance the development effectiveness of Tanzania's agricultural expenditures and would substantially increase cumulative gross domestic product growth between 2019 and 2028.Policy implicationsPolicy‐makers can use the findings to design and prioritize agricultural interventions that better align with broader development objectives. Tanzania can achieve higher benefits and contribute to overall development goals by reallocating resources towards more cost‐effective expenditure options.

Is a single minimum wage policy viable option? Evidence from the impact of minimum wage on youth employment in Malaysia

The present study is aimed to identify an ideal mechanism to reduce negative effect of minimum wage on youth employment generation. Using available data from Department of Statistics, the study runs an annual panel regression at the state level based on fixed effect specification model. The finding demonstrates that the minimum wage has a negative effect on employment, particularly among youth. It implies that there is an excess of labour supply in the market at the current wage rate. As a result, the rate set is higher than equilibrium, signifying firm disadvantages. The negative effect is more prevalent if the single national minimum wage rate policy is applied to all states. Therefore, the national wage policy should be thoroughly examined. Instead, a regional wage rate should be explored as a potential solution for mitigating and preventing negative employment effects.

ThP4.10 - Outcomes of Transcystic Laparoscopic Common Bile Duct Exploration at the time of Laparoscopic Cholecystectomy in patients with small common bile duct diameter

Abstract Aim Laparoscopic Cholecystectomy with Laparoscopic Common Bile Duct Exploration (LC+LCBDE) is a single stage therapeutic option for management of choledocholithiasis. There have been limited publications regarding the feasibility of transcystic LCBDE in patients with small (≤8mm) common bile ducts (CBD). This study seeks to examine the outcomes for patients with small ducts who underwent LC+LCBDE via a transcystic approach in a district general hospital over a two-year period. Methods Prospectively collected data regarding all patients who underwent LC+LCBDE over a period from January 2022 to December 2023 was retrospectively reviewed. Data concerning indication for surgery, CBD diameter, length of stay, complication rate, and readmission rate were determined from Electronic Care Records. Data were analysed using Microsoft Excel. Results 50 patients were identified. CBD diameter (as measured at pre-operative Magnetic Resonance Cholangiopancreatography [MRCP]) ranged from 3.5mm to 8mm (average 6.25mm). One patient required conversion to open surgery due to difficulties with the LC element of the operation. Median postoperative length of stay was 1 day (range 0-8 days) and readmission rate was 6%. One patient experienced a complication beyond Clavien-Dindo Grade 2, this caused by a superficial wound infection requiring washout under general anaesthetic. One patient required subsequent Endoscopic Retrograde Cholangiopancreatography (ERCP) for management of retained CBD stones. Conclusions LC+LCBDE is a safe and effective management option for patients in the setting of choledocholithiasis with small common bile duct diameter. Small CBD should not necessarily be a deterrent to consideration of LCBDE as a therapeutic option in appropriately selected patients.

Semiautomatic Exploration of Conceptual Design Spaces through Parametric Shape Variability and Additive Manufacturing

Design ideation activities that involve the manipulation of geometry rely heavily on manual input. For feasibility reasons, the generation of design alternatives must often be limited, particularly when these alternatives need to be prototyped and tested. This paper describes a conceptual design strategy that leverages variational three-dimensional geometry to automatically generate a large number of design alternatives from a template model and their corresponding physical prototypes for evaluation and testing. In our approach, 3D geometric variations are produced automatically from a single design concept modeled parametrically, which are then used to generate 3D-printable files. Our method is suitable for design scenarios where real-world testing is preferred over virtual simulation and requires designers to consider a concept idea as a family of solutions, instead of a single design option. Our strategy enables an effective exploration of conceptual design spaces in highly constrained situations and facilitates parallel prototyping, which is known to produce better results than serial prototyping. We demonstrate the feasibility and effectiveness of the proposed method through a case study that involves the design of an instrument for ophthalmic surgery for extracting an intraocular lens (IOL) from the eye. Using our approach, nine unique concept families comprising a total of 150 designs were rapidly and successfully prototyped and tested.

Bracing of children with pectus carinatum: A literature review

BACKGROUND: Conservative treatment of children with carinatum is currently an urgent and unresolved problem despite the wide range of techniques available. Conservative treatment stops the progression of deformation and reduces the degree of deformation or eliminates it. Methods of evaluating treatment results include clinical (photo–video assessment, questionnaire survey, and chest measurements) and instrumental diagnostics (radiography, computed tomography [CT], and 3D scanning); however, no method of correction and orthosis that would consider all the tasks of conservative treatment, method of evaluating conservative treatment, and uniform protocol have been established. AIM: This study aimed to analyze the literature containing information on the conservative treatment of patients with pectus carinatum. MATERIALS AND METHODS: The study presents the results of a search in PubMed, Cochrane, and eLibrary using combinations of operators and keywords. A total of 54 foreign and domestic sources were extracted, and the search was not limited retrospectively. RESULTS: Orthosis is effective and positively perceived by doctors and patients. The most modern designs in the treatment of carinatum included dynamic orthoses FMF-DCS and Braceworks (Calgary). Recent studies have reported a strong correlation between 3D scanning and CT to assess treatment outcomes. However, no single option for conservative correction of deformity allowed for achieving all treatment goals. The assessment of the effectiveness of orthosis using photos, videos, and questionnaire, and chest measurement is subjective. CONCLUSIONS: The disadvantages of prosthetics determine the need to develop a clear treatment algorithm, methodology, and objective assessment of treatment outcomes, requiring further research.

Patient Perspectives on the Prevalence and Burden of Intertriginous Psoriasis: Results from a National Survey of Adults with Psoriasis in the United States.

A survey was conducted by The Harris Poll on behalf of Arcutis Biotherapeutics in the USA to understand perspectives and burden of patients with psoriasis using prescription topical treatments for their disease. This manuscript presents results from the subset of patients with intertriginous psoriasis. The survey was conducted online October 21-November 24, 2021, among 507 US adults aged 18+years with psoriasis diagnosed by a healthcare provider and currently using prescription topical treatment. Participants with intertriginous psoriasis were patients with plaque psoriasis reporting symptoms in the armpit, groin, under breast, stomach fold, or between the buttocks. Of the 507 respondents, 320 (64%) reported symptoms in intertriginous areas at some point, typically between the buttocks (31%). Most patients with intertriginous psoriasis reported it made them feel embarrassed (80%), anxious (79%), or depressed (69%). In addition, 45% of these patients reported intertriginous psoriasis caused a negative impact on sexual anxiety or distress. Quality of life impact was reported as "very strong negative impact" in 16% of patients with groin involvement vs. 6% in patients with no groin involvement and 15% in women vs. 6% in men. Patients with intertriginous psoriasis reported that itch (61%), scaling (53%), redness (49%), and skin cracking (46%) related to intertriginous psoriasis had the greatest negative impact on quality of life. Most (86%) of these patients said they would be more adherent if a single treatment option could be used to treat all affected areas of their body. Psoriasis involvement in intertriginous areas over the course of disease is common and has a negative impact on these patients' quality of life, particularly emotional well-being and sexual health.

The effect of the coronavirus disease 2019 pandemic on ophthalmologic practice from the egyptian population’s point of view

Aim The aim of this study is to understand the impact of COVID 19 on patients’ view of and willingness to seek ophthalmic services in Egypt. It analyzes if there were changes in their eye care habits and under which conditions they would seek advice or undergo elective procedures. Patients and methods It is a cross sectional observational study using a questionnaire that was sent online. The questionnaire included 29 questions. All questions were closed ended questions, provided with a list of optional answers (single answer or multiple answer options). Patients were divided according to age (below 60 years and 60 and above). A follow up survey was done 2 months later and included 13 questions to compare their answers with the initial questionnaire. Results This study included the responses of 596 participants, who answered our questionnaire fully and 198 participants answered the follow-up questionnaire. The vast majority of the participants claimed they would not visit an ophthalmologist during the pandemic, would not undergo any elective surgery and relied on social media for information. On follow- up, the participants were more willing to visit an eye doctor, continue routine follow-ups, took more safety precautions and relied more on medical sources for information. Conclusion Age, contact with vulnerable groups, presence of the chronic diseases and duration of the pandemic significantly affect the patients’ willingness to seek ophthalmic services. Changes in populations’ information and doctor practice are needed in this pandemic.

Roadmap of Graphite Moderator and Graphite-Matrix TRISO Fuel Management Options

Most high-temperature reactors use graphite as a moderator and structural material. This includes high-temperature gas-cooled reactors with helium cooling and TRi-structural ISOtropic (TRISO) fuel particles embedded in graphite, as well as fluoride salt–cooled high-temperature reactors with clean salt coolant and TRISO fuel particles embedded in graphite and thermal spectrum molten salt reactors with a graphite moderator and fuel dissolved in the salt. The largest volume radioactive waste stream from these reactors is the irradiated graphite. We describe herein a roadmap for management of these graphite wastes that contain radioactive 14C, tritium, and other radionuclides. There may be some graphite wastes with sufficiently low radioactivity levels that can be treated as nonradioactive waste and managed like other graphite waste. Management options for the graphite include (1) direct disposal, (2) recycled back to the reactor or other nuclear applications, and (3) oxidizing the graphite with release as an effluent or underground sequestration of the carbon dioxide. Cosequestration of this carbon dioxide with carbon dioxide from industrial, biological, and cement production processes can isotopically dilute the 14C before sequestration to eliminate the possibility of exceeding individual radiation exposure limits. We also describe options for processing graphite-matrix TRISO fuel, including separating the bulk graphite to reduce the volumes of used fuel for disposal or processing to recover fissile materials. The inventories of radioactive isotopes in different carbon wastes vary by many orders of magnitude; thus, there is no single economic option for the management of all graphite waste.

“Tear down this wall”. A theory of strategic communication that integrates both communication and organizational theory

PurposeThe term strategic communication has become firmly established in recent years. The emergence of the term was associated with the hope of finding a more fitting description for overlapping communication processes, since existing approaches can hardly fulfill these expectations. To date, the research has been dominated by communication-focused and, in particular, organization-focused approaches that show little interest in the alternative perspective. An integrating perspective can overcome the wall that exists between the communication level and the organizational level.Design/methodology/approachThe integrating communication and organizational theory framework is developed on the basis of Niklas Luhmann’s “Theory of Social Systems” (TSS), which can be attributed to the “Communication Constitutes Organization” (CCO) perspective. This perspective seems appropriate because its communication theory integrates the sender and addressee perspectives, and its extended organization theory can be used to describe in detail the organizational structures of strategic communication.FindingsThe communication theoretical framework states that one of the functions of strategic communication is to reduce complexity to a single follow-up option. From the sender’s perspective, strategic communication can be defined as an attempt to encourage acceptance of a follow-up option proposed out of self-interest. The organizational theory framework that both builds on this and is linked to it first shows the diversity of strategic organizational communications before explaining their formal and informal structures.Originality/valueThis paper is the first to offer a comprehensive framework that integrates concrete strategic communication activities as well as the (in)formal organizational structures that lead to their emergence. On the one hand, this enables a more differentiated description of all relevant aspects of communication theory (e.g. tonality, clarity vs. ambiguity and technical dissemination medium). On the other, the organizational theoretical framework offers a systematization that can be used to describe various formal and informal structures comparatively. Above all, this kind of inclusive, integrating framework is the prerequisite for research that relates the diverse concrete strategic communication activities to an organization’s formal and informal rules and thus understands them as (primarily) the result of organizational decisions.

Laparoscopic resection rectopexy (RRP) combined with mesh sacrocolpopexy (SCP) for obstructed defecation syndrome with pelvic organ prolapse in an interdisciplinary approach.

Obstructive defecation syndrome (ODS) is frequently associated with pelvic organ prolapse (POP) and compromises the quality of life in affected patients. In cases conservative treatment fails surgical therapy is required. The video case study combines a laparoscopic resection rectopexy (RRP) with a mesh sacrocolpopexy (SCP) in an interdisciplinary surgical approach. In this video an 86-year-old woman with ODS and POP, suffering from a dolichocolon with rectal intussusception, an apical prolapse after total hysterectomy 1990, and occasional stress urinary incontinence underwent interdisciplinary laparoscopic surgery. A tubular anterior rectal and sigmoid resection with suture rectopexy as in a resection rectopexy (RRP) was combined with a sacrocolpopexy (SCP) using a synthetic mesh. Surgical outcome including postoperative morbidity, functional bowel evacuation, and POP reconstitution as in POP-Q score after surgery were documented. No intra- or postoperative complications occurred. At 6 months follow-up clinical outcomes for ODS, bowel dysfunction, and faecal control were improved. Anatomical outcome for POP and stress urinary incontinence symptoms were corrected. We report a promising interdisciplinary surgical approach as a single treatment option for the complex medical condition of women suffering from ODS and POP combining laparoscopic RRP with SCP. This surgical approach proved to be feasible, safe, and effective.

ОПЫТ ЛЕЧЕНИЯ ПАЦИЕНТОВ СО СВИЩАМИ ОБОДОЧНОЙ КИШКИ ДИВЕРТИКУЛЯРНОГО ПРОИСХОЖДЕНИЯ

Abstract. Introduction. In the 21st century, a massive increase was noted in the incidence of diverticular disease (DD) by more than 10 times with an increase in the frequency of its complications ranging from 5 to 25%. According to the literature, the colon fistulation frequency is 5-30%, over a half of such formations being colovesical fistulas. The problem of surgical approaches to the purulent-inflammatory complications of DD is far from being resolved. Despite the fact that diverticular disease is a benign pathology, inflammatory process often creates serious technical difficulties in surgery due to the violation of the anatomical relationship of the intestine with the surrounding organs, while surgeries often affect several organs with a high infection risk. Aim. Analysis of the results of the treatment of patients with diverticular colon fistulas in a specialized department of a multidisciplinary hospital. Materials and Methods. Treatment outcomes were analyzed retrospectively in 347 patients with diverticular colon disease complications for the period from 2013 to 2022. The study included 17 patients with diverticular fistulas: 14 (82.4%) patients with internal (intestinal-urinary (13) and intestinal-vaginal (1)) fistulas and 3 (17.6%) with external ones. Results and Discussion. The therapeutic and diagnostic algorithm for diverticular fistulas required a wide range of diagnostic methods and a multidisciplinary approach. Surgery remains the single treatment option for this pathology. The choice of the surgical procedure depended on the inflammatory process severity, its spread to the surrounding abdominal organs, and the largest diverticula accumulation in the gut. In the group of patients with intestinal-urinary fistulas, the resection was not limited to the removal of the colon segment only. In 9 (52.9%) cases, it was expanded to the anterior rectum resection due to the inflammation transition to its upper ampullary region. We are supporters of the one-stage surgical procedures with forming the primary anastomosis in patients with diverticular fistulas. We give preference to the Sigal-Ramazanov invagination anastomosis that allows avoiding the anastomosis due to creating a duplicate of the intestinal wall hiding the anastomosis zone. The paper identifies probable predictors of complicating diverticular disease with fistulation. Conclusions. Choosing the optimal treatment option for patients with diverticular disease complications is a difficult problem. It is better to operate on them in the coloproctology departments of multidisciplinary hospitals with the established good interaction among the members of a multidisciplinary team.

Optimal placement of inherent zeros in polynomial-based motion profiles for minimizing residual vibration and travel time under system uncertainties

Various industrial processes require motion profiles that determine machine movement over time for workpiece transfer, with the goal of minimizing transfer time to enhance productivity. However, pursuing the maximum speed can trigger excessive motion-induced vibration, which can reduce the manufacturing efficiency, accuracy and operational lifespan of the system. This study proposes a generalized motion profile optimization method that considers the strategic placement of inherent zeros within the motion profile: each inherent zero contributes to the reduction of residual vibration or optimization of arrival time. By offering freedom to the placement of zeros, four optimization options for polynomial-based motion profiles of each order are proposed, expanding on existing work that offered a single option. All proposed optimization options have closed-form solutions, making them easily applicable to industrial applications. The practical applicability of the suggested methodology is demonstrated through case studies and experiments.

Dynamics of backfill compressive strength obtained from enrichment tails for the circular waste management

At the current stage of development, the transition to a circular economy is a single option to achieve sustainable mining. Purpose was to identify a direction for mining tailings usage based on the circular waste management. The novelty of the author's approach lies in regulation of mechanical treatment of slag to optimize the backfill composition. The methodology involved a study of mining waste (slag) obtained from major (eight) metallurgical plants in Russia. For mathematical processing primary data, smoothing and deterministic three-dimensional interpolation methods were used. As a result, for the first time it has been established that the ultimate uniaxial compressive strength after mechanical treatment of slag increases by logarithmic laws. As the curing time increases from 10 days to 90 days (with the addition of Ca or Si) the strength increases by 21 % (7 % and 23 %). The possibility of completely replacing the traditional cement binder with metallurgical slag in the backfill composite has been proven. It has been established that the use of activation treatment (both mechanical and chemical) makes it possible to increase the strength characteristics of backfill samples after their curing. The principle of organizing mining production has been implemented, which provides for the use of intermediate products (blast furnace granulated slag), previously classified as technogenic waste, in a closed production cycle. The introduction of this principle will eliminate (minimize) the formation of man-made waste. The scientific merit of replacing traditional cement binder with technogenic waste (blast furnace granulated slag) allows implementation of circular economy in mining.

Advanced Levelized Cost Evaluation Method for Electric Vehicle Stations Concurrently Producing Electricity and Hydrogen

This study develops a new method to evaluate the economic viability of co-generation electric vehicle stations that concurrently generate electricity and hydrogen for charging battery electric vehicles and refueling hydrogen vehicles. The approach uniquely differentiates the costs associated with various energy outputs in co-generation stations and includes often-overlooked peripheral devices critical for accurate evaluation of the levelized cost of electricity (LCOE) and hydrogen (LCOH). The method was tested across three design configurations: two featuring single storage options (battery and fuel cell, respectively) and a third using hybrid storage employing both. Each configuration was modeled, simulated, and optimized using HOMER Pro 3.14.2 to determine the most optimal sizing solution. Then, based on the optimal sizing of each design, LCOE and LCOH were evaluated using the proposed method in this study. The analysis revealed that excluding often-overlooked peripheral devices could lead to a 27.7% error in LCOH evaluation, while the impact on LCOE was less than 1%. Among different configurations, the design with hybrid storage proved economically superior, achieving a total levelized cost of energy (TLCOE) for the entire system of USD 0.113/kWh, with the LCOE at USD 0.025/kWh and LCOH at USD 0.088/kWh (or USD 3.46/kg). Comparative analysis with state-of-the-art studies confirmed the accuracy of the proposed method. This study provides a more precise and holistic approach that can be leveraged for the feasibility analysis of electric vehicle stations globally, enhancing strategic decision-making in sustainable energy planning.

Patient preference and acceptability of self-sampling for cervical screening in colposcopy clinic attenders: A cross-sectional semi-structured survey.

Low vaginal self-sampling has been pioneered as an important development to improve uptake of cervical screening globally. Limited research is available in specific patient groups in the UK exploring views around self-sampling to detect high-risk human papillomavirus (hrHPV) DNA. Therefore, we explored patient views to support development of a novel point-of-care self-sampling cervical cancer screening device, by undertaking a cross-sectional semi-structured questionnaire survey to explore preferences, acceptability, barriers and facilitators around self-sampling. Patients attending a colposcopy clinic, 25-64 years old, were invited to participate after having carried out a low vaginal self-sample using a regular flocked swab. Participants self-completed an anonymous 12-point questionnaire. Quantitative data were analysed in MS Excel and Graphpad Prism, and qualitative data with Nvivo. We recruited 274 patients with a questionnaire response rate of 76%. Acceptability of self-sampling was high (95%, n = 187/197; Cronbachs-α = 0.778). Participants were asked their choice of future screening method: a) low vaginal self-sampling, b) healthcare professional collected vaginal swab, c) cervical brush sample with healthcare professional speculum examination, or d) no preference. Preferences were: a) 37% (n = 74/198), b) 19% (n = 37/198); c) 9% (n = 17/198), and d) 35% (n = 70/198), showing no single option as a strong preference. Key motivators were: Test simplicity (90%, n = 170/190), speed (81%, n = 153/190) and less pain (65%, n = 123/190). Barriers included lack of confidence taking the sample (53%, n = 10/19), resulting in preference for a healthcare professional sample (47%, n = 9/19). Whilst self-sampling showed high acceptability, lack of strong preference for screening method may reflect that respondents attending colposcopy are already engaged with screening and have differing perception of cervical cancer risk. This group appear less likely to 'switch' to self-sampling, and it may be better targeted within primary and community care, focusing on under-screened populations. Any shift in this paradigm in the UK requires comprehensive education and support for patients and providers.

Unmet need for and impact of adopting immunobiological drugs for moderate to severe plaque psoriasis in a pediatric population.

Therefore, this study aimed to evaluate the impact of secukinumab and ustekinumab against moderate-to-severe plaque psoriasis in a Brazilian pediatric population with access to public healthcare. A survey of immunobiological treatments registered for use against pediatric psoriasis at the National Health Surveillance Agency was conducted. These treatments were compared to the list available in the same treatment category in the public health system through the Clinical Protocol and Therapeutic Guidelines for psoriasis. A quantitative analysis of the data of patients treated with immunobiological drugs the previous year in accordance with the Clinical Protocol and Therapeutic Guidelines was performed using data available in the DATASUS portal. The public budget impact scenarios analyzed were comparable to the investment already planned for acquiring the only available drug option. The incorporation of two therapeutic options in the Clinical Protocol and Therapeutic Guidelines list for moderate-to-severe pediatric psoriasis was feasible in a horizon of 5 years compared to the investment into the single option available to pediatric patients. These findings can facilitate the local analysis of budgetary impact and discussions on the feasibility of this therapeutic incorporation at the state level. Incorporation of secukinumab and ustekinumab was economically feasible. These drugs are options for those who do not respond to or have contraindications to etanercept.

Diagnosis of acute pulmonary embolism: when photon-counting-detector CT replaces energy-integrating-detector CT in daily routine.

To compare the diagnostic approach of acute pulmonary embolism (PE) with photon-counting-detector CT (PCD-CT) and energy-integrating-detector CT (EID-CT). Two cohorts underwent CT angiographic examinations with EID-CT (Group 1; n = 158) and PCD-CT (Group 2; n = 172), (b) with two options in Group 1, dual energy (Group 1a) or single energy (Group 1b) and a single option in Group 2 (spectral imaging with single source). In Group 2, all patients benefited from spectral imaging, only accessible to 105 patients (66.5%) in Group 1, with a mean acquisition time significantly shorter (0.9 ± 0.1 s vs 4.0 ± 0 .3 s; p < 0.001) and mean values of CTDIvol and DLP reduced by 46.3% and 47.7%, respectively. Comparing the quality of 70 keV (Group 2) and averaged (Group 1a) images: (a) the mean attenuation within pulmonary arteries did not differ (p = 0.13); (b) the image noise was significantly higher (p < 0.001) in Group 2 with no difference in subjective image noise (p = 0.29); and (c) 89% of examinations were devoid of artifacts in Group 2 vs 28.6% in Group 1a. The percentage of diagnostic examinations was 95.2% (100/105; Group 1a), 100% (53/53; Group 1b), and 95.3% (164/172; Group 2). There were 4.8% (5/105; Group 1a) and 4.7% (8/172; Group 2) of non-diagnostic examinations, mainly due to the suboptimal quality of vascular opacification with the restoration of a diagnostic image quality on low-energy images. Compared to EID-CT, morphology and perfusion imaging were available in all patients scanned with PCD-CT, with the radiation dose reduced by 48%. PCD-CT enables scanning patients with the advantages of both spectral imaging, including high-quality morphologic imaging and lung perfusion for all patients, and fast scanning-a combination that is not simultaneously accessible with EID-CT while reducing the radiation dose by almost 50%.

Deep learning-based optimization of field geometry for total marrow irradiation delivered with volumetric modulated arc therapy.

Total marrow (lymphoid) irradiation (TMI/TMLI) is a radiotherapy treatment used to selectively target the bone marrow and lymph nodes in conditioning regimens for allogeneic hematopoietic stem cell transplantation. A complex field geometry is needed to cover the large planning target volume (PTV) of TMI/TMLI with volumetric modulated arc therapy (VMAT). Five isocenters and ten overlapping fields are needed for the upper body, while, for patients with large anatomical conformation, two specific isocenters are placed on the arms. The creation of a field geometry is clinically challenging and is performed by a medical physicist (MP) specialized in TMI/TMLI. To develop convolutional neural networks (CNNs) for automatically generating the field geometry of TMI/TMLI. The dataset comprised 117 patients treated with TMI/TMLI between 2011 and 2023 at our Institute. The CNN input image consisted of three channels, obtained by projecting along the sagittal plane: (1) average CT pixel intensity within the PTV; (2) PTV mask; (3) brain, lungs, liver, bowel, and bladder masks. This "averaged" frontal view combined the information analyzed by the MP when setting the field geometry in the treatment planning system (TPS). Two CNNs were trained to predict the isocenters coordinates and jaws apertures for patients with (CNN-1) and without (CNN-2) isocenters on the arms. Local optimization methods were used to refine the models output based on the anatomy of the patient. Model evaluation was performed on a test set of 15 patients in two ways: (1) by computing the root mean squared error (RMSE) between the CNN output and ground truth; (2) with a qualitative assessment of manual and generated field geometries-scale: 1=not adequate, 4=adequate-carried out in blind mode by three MPs with different expertise in TMI/TMLI. The Wilcoxon signed-rank test was used to evaluate the independence of the given scores between manual and generated configurations (p<0.05 significant). The average and standard deviation values of RMSE for CNN-1 and CNN-2 before/after local optimization were 15±2/13±3mm and 16±2/18±4mm, respectively. The CNNs were integrated into a planning automation software for TMI/TMLI such that the MPs could analyze in detail the proposed field geometries directly in the TPS. The selection of the CNN model to create the field geometry was based on the PTV width to approximate the decision process of an experienced MP and provide a single option of field configuration. We found no significant differences between the manual and generated field geometries for any MP, with median values of 4versus 4 (p=0.92), 3versus 3 (p=0.78), 4versus 3 (p=0.48), respectively. Starting from October 2023, the generated field geometry has been introduced in our clinical practice for prospective patients. The generated field geometries were clinically acceptable and adequate, even for an MP with high level of expertise in TMI/TMLI. Incorporating the knowledge of the MPs into the development cycle was crucial for optimizing the models, especially in this scenario with limited data.

A model‐free approximation for barrier options in a general stochastic volatility framework

AbstractFor a general stochastic volatility framework with correlation between the spot price and the instantaneous volatility, an analytical approximation for single barrier options with continuous monitoring is given. The approximation is expressed only in terms of market observable implied volatilities and prices. As such the approximation is independent of the specific form and number of parameters of the skew‐generating stochastic volatility model.