Assessment of the modulation degrees of intensity-modulated radiation therapy plans

Background To evaluate the modulation indices (MIs) for predicting the plan delivery accuracies of intensity-modulated radiation therapy (IMRT) plans. Methods A total of 100 dynamic IMRT plans that used TrueBeam STx and 102 dynamic IMRT plans that used Trilogy were selected. For each plan, various MIs were calculated, which included the modulation complexity score (MCS), plan-averaged beam area (PA), plan-averaged beam irregularity (PI), plan-averaged beam modulation (PM), MI quantifying multi-leaf collimator (MLC) speeds (MIs), MI quantifying MLC acceleration (MIa), and MI quantifying MLC acceleration and segment aperture irregularity (MIc,IMRT). To determine plan delivery accuracy, global gamma passing rates, MLC errors of log files, and dose-volumetric parameter differences between original and log file-reconstructed IMRT plans were obtained. To assess the ability of each MI for predicting plan delivery accuracy, Spearmans rank correlation coefficients (rs) between MIs and plan delivery accuracy measures were calculated. Results PI showed moderately strong correlations with gamma passing rates in MapCHECK2 measurements of both TrueBeam STx and Trilogy (rs = − 0.591 with p <  0.001 and − 0.427 with p <  0.001 to with gamma criterion of 2%/2 mm, respectively). For ArcCHECK measurements, PI also showed moderately strong correlations with the gamma passing rates in the ArcCHECK measurements of TrueBeam STx and Trilogy (rs = − 0.545 with p <  0.001 and rs = − 0.581 with p <  0.001 with gamma criterion of 2%/2 mm, respectively). The PI showed the second strongest correlation with MLC errors in both TrueBeam STx and Trilogy (rs = 0.861 with p <  0.001 and rs = 0.767 with p <  0.001, respectively). In general, the PI showed moderately strong correlations with every plan delivery accuracy measure. Conclusions The PI showed moderately strong correlations with every plan delivery accuracy measure and therefore is a useful predictor of IMRT delivery accuracy.This work was supported by a National Research Foundation of Korea (NRF) grant from the Korea government (MSIP). (No.2017M2A2A7A02020639, No.2017M2A2A7A02020640, No.2017M2A2A7A02020641, No.2017M2A2A7A02020643)

The Viewing Machine

Technology in architecture. rhetoric of construction. often expresses an erotic search for knowledge. As Marco Frascari explains, Technology is the fertile factor for the architectural production of elegant meanings, it deals with both the construction- the logos of techne (elegant art)- and the construing- the techne of logos (rhetoric). 1 In this case technology translates from figures of thought into figures of site, and figures of making. It may be construed as a condition that attempts to answer the question: How does one begin? The curriculum developed for the Undergraduate Architecture Program at the University of Pennsylvania provides a place for the cultivation of technology through the demonstration of architectural strategies for making. This is explored through a constant variable. the interest in building: the delight in experimental construction 1s the adventure into the space of the unknown condition, between conception and execution. This adventure, into the constructional unknown, uses technology and the discipline of drawing as a poetic act. In this sense. technology is demonstrated along with cosmology as it reconciles the art of construing and constructing. One vehicle for this reconcifiation is through a process and product called the viewing machine taught during the first year of architecture. Most of the students. beginning the Bachelors of Arts in Architecture, are quite young and eager to explore the unknown. The studio meets for three hours, two days a week. The studio begins with an exercise in perspective and speculation

The Transient Thermal Disturbance in Surrounding Formation during Drilling Circulation

The injecting drilling mud is typically at the ambient temperature, relatively much colder than the deep formation, inducing a cooling effect in the formation. Although the cooled formation temperature gradually returns to its original temperature after drilling circulation, the recovery speed is slow due to low thermal diffusivity. Considering that any well tests begin in a short period after drilling ends, temperature recovery is not fully achieved before the tests. It means that the measured temperature of producing fluid is not that of the actual formation, significantly impairing the robustness of the subsequent thermal applications. Furthermore, there has been no quantified concept of thermal disturbance in the formation and its analysis. In this work, a proposed numerical transient heat transfer model computes the radial temperature in the drill pipe, annulus, and formation. The concept of quantifying thermal disturbance, named thermally disturbed radius (TDR), indicates how long the thermal disturbance occurs radially in the formation. The TDR increases with the more significant temperature difference between circulating fluid and formation. Thus, the TDR appears to be the largest at the bottom-hole depth. In the sensitivity of TDR of various operational parameters, circulation time (i.e., drilling time) is the most influential factor. Meanwhile, the other parameters do not significantly affect TDR: circulation rate, injecting mud temperature, and mud density. The sensitivity analysis concludes that as long as the operators control the drilling time, the uncertainty of the measured temperature after drilling can be manageable without limiting any other operational parameters

Fully automated image quality evaluation on patient CT: Multi-vendor and multireconstruction study

© 2022 Chun et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.While the recent advancements of computed tomography (CT) technology have contributed in reducing radiation dose and image noise, an objective evaluation of image quality in patient scans has not yet been established. In this study, we present a patientspecific CT image quality evaluation method that includes fully automated measurements of noise level, structure sharpness, and alteration of structure. This study used the CT images of 120 patients from four different CT scanners reconstructed with three types of algorithm: filtered back projection (FBP), vendor-specific iterative reconstruction (IR), and a vendor-agnostic deep learning model (DLM, ClariCT.AI, ClariPi Inc.). The structure coherence feature (SCF) was used to divide an image into the homogeneous (RH) and structure edge (RS) regions, which in turn were used to localize the regions of interests (ROIs) for subsequent analysis of image quality indices. The noise level was calculated by averaging the standard deviations from five randomly selected ROIs on RH, and the mean SCFs on RS was used to estimate the structure sharpness. The structure alteration was defined by the standard deviation ratio between RS and RH on the subtraction image between FBP and IR or DLM, in which lower structure alterations indicate successful noise reduction without degradation of structure details. The estimated structure sharpness showed a high correlation of 0.793 with manually measured edge slopes. Compared to FBP, IR and DLM showed 34.38% and 51.30% noise reduction, 2.87% and 0.59% lower structure sharpness, and 2.20% and -12.03% structure alteration, respectively, on an average. DLM showed statistically superior performance to IR in all three image quality metrics. This study is expected to contribute to enhance the CT protocol optimization process by allowing a high throughput and quantitative image quality evaluation during the introduction or adjustment of lowerdose CT protocol into routine practice.Y

The establishment of two shrines for successive Ryukyu kings and introduction of the Sho-boku(Zhao-Mu) order in the reign of the second Sho dynasty

Tai-byo (an ancestral shrine) was erected for the second royal line of the Sho dynasty. Sen-o-byo(the shrine for old kings) was dedicated to successive kings who came from several dynasties in Ryukyu Islands. In the Chinese-style system, Tai-byo (Tai miao) refers to a shrine of the House of a ruler where the spirit tablets of the ancestors are placed on both sides of the founder’s tablet,with successive generations placed on alternate sides. According to the Sho-boku(Zhao-Mu) order,the tablets of the father and the son should not to be placed on the same side (Sho or boku) of the altar. This paper examines the changes in the positions of the shrines and the placement of the tablets to understand the national significance of the two Ryukyu shrines from the late 17th century to the early 18th century. It is noteworthy that the Sho-boku order was adopted gradually based on the system peculiar to the Ryukyuans and has transformed into a system unique to East Asia. In Tai-byo, as the founder of the second royal line of the Sho dynasty, Sho Yen's enduring position of honor had been established, while in Sen-o-byo, as the first king of the Ryukyu, Shun Ten’s tablet was located at the center of the altar. At the same time, even if the king’s legitimate son (seshi) had not become the successor, his tablet was placed on the Sho or boku side of the shrines. Thus, the Chinese order was applied in the two shrines to appeal to the predominance and legitimacy of the second Sho dynasty

Novel circulatory connection from the acupoint Zhong Wan(CV12) to pancreas

Objectives : Demonstrating a novel circulatory path from the acupoint(CV12) to the pancreas. Method : Alcian blue(1% solution, 20μl, pH 7.4) was injected into the acupoint(CV12). Two hours later the surfaces of internal organs were observed by using a stereomicroscope. Results : Alcian blue arrived and colored the omental fat band(OFB) on the pancreas. The OFB connected the head and tail of the pancreas, the pancreas and the spleen, and the pancreas and the stomach. Conclusion : The existence of a novel circulatory path from the acupoint CV12 to the pancreas and its OFB was demonstrated

Dosimetric characteristics of a reusable 3D radiochromic dosimetry material.

To investigate the dosimetric characteristics of PRESAGEREU dosimeters.Commercially available PRESAGEREU dosimeters (size of 10 mm × 10 mm × 45 mm) were divided into two groups, with one of the groups placed at room temperature of 22°C (RT group) and another group placed at low temperature of 10°C (LT group). A total of 3 dosimeters (set of dosimeters) were irradiated at a time, with doses of 1 Gy, 2 Gy, 4 Gy, 8 Gy, 12 Gy, 16 Gy, and 20 Gy, at a nominal dose rate of 400 MU/min at temperature of 22°C. The dosimeters were irradiated three additional times by delivering the same doses as those during the initial irradiations (4 irradiation cycles). Optical density (OD) was assessed using optical CT scanning.Considering both linearity and sensitivity of the OD curves, R2 above 0.95 and sensitivity above 0.04 ΔOD/Gy were observed at the 1st irradiation (reading time ≤ 6 h) and 2nd irradiation (reading time = 0.5 h) for the RT group. For the LT group, those values were observed at the 1st irradiation (reading time ≤ 2 h), and the 3rd and 4th irradiations (both reading times = 0.5 h). Considering the reproducibility of signals in response to the same dose, dosimeters in the RT group showed average deviations among dosimeters less than 5% (the 1st and 2nd irradiations at the reading time of 0.5 h), while for dosimeters in the LT group showed average deviations among dosimeters less than 6% (the 3rd and 4th irradiations at the reading time of 0.5 h). For the rest, the OD curves were not linear, sensitivities of the dosimeters were lower than 0.04 ΔOD/Gy, and OD deviations at the same dose were larger than 6%.At room temperature, PRESAGEREU dosimeters could be used for dose measurement only for up to two dose measurement sessions. At low temperatures, usage of PRESAGEREU dosimeters for dose measurement seems to be possible from the 3rd irradiation. When reusing PRESAGEREU dosimeters, the OD curve should be re-defined for every measurement session because the shape of this curve depends on the irradiation history

Quantitative radiomics approach to assess acute radiation dermatitis in breast cancer patients.

PurposeWe applied a radiomics approach to skin surface images to objectively assess acute radiation dermatitis in patients undergoing radiotherapy for breast cancer.MethodsA prospective cohort study of 20 patients was conducted. Skin surface images in normal, polarized, and ultraviolet (UV) modes were acquired using a skin analysis device before starting radiotherapy ('Before RT'), approximately 7 days after the first treatment ('RT D7'), on 'RT D14', and approximately 10 days after the radiotherapy ended ('After RT D10'). Eighteen types of radiomic feature ratios were calculated based on the values acquired 'Before RT'. We measured skin doses in ipsilateral breasts using optically stimulated luminescent dosimeters on the first day of radiotherapy. Clinical evaluation of acute radiation dermatitis was performed using the Radiation Therapy Oncology Group scoring criteria on 'RT D14' and 'After RT D10'. Several statistical analysis methods were used in this study to test the performance of radiomic features as indicators of radiodermatitis evaluation.ResultsAs the skin was damaged by radiation, the energy for normal mode and sum variance for polarized and UV modes decreased significantly for ipsilateral breasts, whereas contralateral breasts exhibited a smaller decrease with statistical significance. The radiomic feature ratios at 'RT D7' had strong correlations to skin doses and those at 'RT D14' and 'after RT D10' with statistical significance.ConclusionsThe energy for normal mode and sum variance for polarized and UV modes demonstrated the potential to evaluate and predict acute radiation, which assists in its appropriate management