Search

Stacked teacups inspired the idea that columnar assemblies of stacked bowl-shaped molecules may exhibit a unique dynamic behavior, unlike usual assemblies of planar disc- and rod-shaped molecules. On the basis of the molecular design concept for creating higher-order discotic liquid crystals, found in our group, we synthesized a sumanene derivative with octyloxycarbonyl side chains. This molecule forms an ordered hexagonal columnar mesophase, but unexpectedly, the columnar assembly is very soft, similar to sugar syrup. It displays, upon application of a shear force on solid substrates, a flexible bending motion with continuous angle variations of bowl-stacked columns while preserving the two-dimensional hexagonal order. In general, alignment control of higher-order liquid crystals is difficult to achieve due to their high viscosity. The present system that brings together higher structural order and mechanical softness will spark interest in bowl-shaped molecules as a component for developing higher-order liquid crystals with unique mechanical and stimuli-responsive properties.

Purpose: The questionnaire survey investigated whether "Explainer videos about radiation therapy (RT-Video)", "Treatment of breast cancer patients by female radiation therapists (F-RTT)" and "Treating male patients while wearing underwear in pelvic radiation therapy (M-RTT)" can improve patient's satisfaction., Methods: The RT-Video survey included questions regarding the impression of radiation therapy, improving its understanding, and anxiety reduction (102 patients received radiation therapy). Fifty-one breast cancer patients were asked whether they preferred an F-RTT treatment. Subsequently, the patients treated with F-RTT (41 patients) and M-RTT (50 patients) were surveyed about their treatment satisfaction on a five-point scale., Results: RT-Video improved the understanding of radiation therapy for 86 out of 102 patients (84%). In all, 68 out of 102 patients (68%) had a negative impression of radiotherapy; among them, watching the RT-Video reduced anxiety in 63% of patients. A total of 14 out of 51 breast cancer patients (28%) preferred the F-RTT treatment. The percentage of patients who received treatment satisfaction by F-RTT and M-RTT was 95% and 84%, respectively., Conclusion: RT-Video, F-RTT and M-RTT treatments improved patients' satisfaction.

Purpose: This study introduced an A-mode portable ultrasound bladder scanner, the Lilium® α-200 (here after Lilium; Lilium Otsuka, Kanagawa, Japan), for the treatment of prostate cancer patients with hypofractionated volumetric modulated arc therapy to improve the reproducibility of bladder volume (BV)., Materials and Methods: Thirty patients were advised to maintain full BV prior to computed tomography (CT) simulation and daily treatment. Among these, the BV of 15 patients was measured using Lilium until a BV of 80% in the simulation was achieved (with the Lilium group). Daily cone-beam CT (CBCT) was performed for treatment. The correlation between BV measured by CBCT and Lilium was assessed. The differences in the BV and dosimetric parameters of the bladder in the CBCT versus planning CT were compared between the groups with and without Lilium., Results: There was a significantly strong relationship (r = 0.796, p < 0.05) between the BVs measured using CBCT and Lilium. The relative BV ratios to simulation CT < 0.5 and > 2 were observed in 10.3% and 12.7%, respectively, of treatment sessions without Lilium group, while these ratios were 1% and 2.8%, respectively, in the Lilium group. The mean absolute difference in the range of V 30Gy to V 40Gy without Lilium sessions was significantly larger (p < 0.05) than that in the Lilium group., Conclusion: The use of the A-mode portable ultrasound bladder scanner significantly improved the reproducibility of the BV, resulting in few variations in the dosimetric parameters for the bladder., (© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

Purpose: To compare the intrafractional motion error (IME) during stereotactic irradiation (STI) in patients with brain metastases immobilized using open- (Encompass) and full-face (DSPS) clamshell-style immobilization devices., Methods: Encompass (38 patients) and DSPS (38 patients) were used for patient immobilization, and HyperArc plans with three to four non-coplanar beams were generated to deliver 25 to 35 Gy in three to five fractions. Cone-beam computed tomography (CBCT) was performed on patients before and after the treatment. Moreover, the difference in patient position between the two CBCT images was considered as the IME. The margins to compensate for IME were calculated using the van Herk margin formula., Results: For Encompass, the mean values of IME in the translational setup were 0.1, 0.2, and 0.0 mm in the anterior-posterior, superior-inferior, and left-right directions, respectively, and the mean values of IME about rotational axes were -0.1, 0.0, and 0.0° for the Pitch, Roll, and Yaw rotations, respectively. For DSPS, the mean values of IME in the translational setup were 0.2, 0.2, and 0.0 mm in the anterior-posterior, superior-inferior, and left-right directions, respectively, and the mean values of IME about rotational axes were -0.1, -0.1, and 0.0° for the Pitch, Roll, and Yaw rotations, respectively. No statistically significant difference was observed between the IME of the two immobilization systems except in the anterior-posterior direction (p = 0.02). Moreover, no statistically significant correlation was observed between three-dimensional IME and treatment time. The margin compensation for IME was less than 1 mm for both immobilization devices., Conclusions: The IME during STI using open- and full-face clamshell-style immobilization devices is approximately equal considering the adequate accuracy in patient positioning., (© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

The 2011 Tohoku earthquake and tsunami in Japan was an extraordinarily stressful incident that caused harmful psychological reactions, such as posttraumatic stress disorder (PTSD), among affected individuals. However, a proportion of exposed individuals experienced posttraumatic growth (PTG), characterized by a noticeable degree of personal strength, spirituality, life appreciation, perception of new possibilities in life, and enhanced relationships with others. Some researchers have argued that these positive reactions may be an illusory change related to coping with traumatic events. We examined trajectory patterns related to PTG Inventory (PTGI) subscales to elucidate the existence of both real and illusory growth regarding quality of life (QoL), utilizing group-based trajectory models. Three online questionnaires were distributed at 6 months (N = 2,554; M age = 47.04 years, SD = 12.62), 12 months (N = 887; M age = 48.11 years, SD = 12.43), and 42 months (N = 560; M age = 48.86 years, SD = 12.25) postdisaster. Participants responded to items related to demographic characteristics, disaster experiences, posttraumatic stress symptoms, PTG, and QoL. Three main PTG trajectories emerged, characterized by growth, no growth, and illusory growth, with QoL as a time invariant covariate. Compared with the growth trajectory, the odds ratios (ORs) for no growth ranged from 2.27 to 5.04; for illusory growth, the ORs ranged from 2.09 to 4.67. To our knowledge, this was the first study to report growth trajectories related to PTGI subscales and their underlying differences in psychological mechanisms and processes following the 2011 Tohoku earthquake and tsunami., (© 2020 The Authors. Journal of Traumatic Stress published by Wiley Periodicals LLC on behalf of International Society for Traumatic Stress Studies.)

Background/aim: To assess the impact of the width of multileaf collimator (MLC) on dose distributions on HyperArc fractionated stereotactic irradiation for multiple (5-10) brain metastases., Patients and Methods: Twenty-one HyperArc (HA) plans were generated using the high definition (HD) MLC (2.5 mm) to deliver 30-35 Gy in 3-5 fractions (HA-HD). The HyperArc plans using Millennium (ML) MLC (5 mm) were retrospectively generated (HA-ML) using the same planning parameters with HA-HD. Dosimetric parameters between the planning target volume (PTV) and organs at risk (OARs) were compared., Results: The conformity index was significantly higher (p<0.0001) in the HA-HD plans (0.95±0.04) than that in the HA-ML plans (0.92±0.06). The HA-HD provided significantly lower (p<0.0001) gradient index (5.6±2.5) than HA-ML (6.2±3.5). For the brainstem and retina (right), a statistically significant difference (p<0.05) was observed between the HA-HD (12.8±10.9 and 2.8±1.7 Gy, for brainstem and retina, respectively) and HA-ML (13.6±11.1 and 3.0±1.8 Gy) plans. For the brain tissue, the HA-HD plans statistically significantly reduced dosimetric parameters (p<0.0001) in all evaluated dose range (V 6Gy -V 28Gy )., Conclusion: The narrower MLC provided significantly higher conformity, steeper dose gradient, and better normal tissue sparing., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: This study investigated the intra-fractional motion (IM) of patients immobilized using the QFix Encompass Immobilization System during HyperArc (HA) treatment., Method: HA treatment was performed on 89 patients immobilized using the Encompass. The IM during treatment (including megavoltage (MV) registration) was analyzed for six degrees of freedom including three axes of translation (anterior-posterior, superior-inferior (SI) and left-right (LR)) and three axes of rotation (pitch, roll, and yaw). Then, the no corrected IM (IM NC ) was retrospectively simulated (excluding MV registration) in three directions (SI, LR, and yaw). Finally, the correlation between the treatment time and the IM of the 3D vector was assessed., Results: The average IM in terms of the absolute displacement were 0.3 mm (SI), 0.3 mm (LR) and 0.2° (yaw) for Stereotactic radiosurgery (SRS), and 0.3 mm (SI), 0.2 mm (LR), and 0.2° (yaw) for stereotactic radiotherapy (SRT). The absolute maximum values of IM were <1 mm along the SI and LR axes and <1° along the yaw axis. The absolute maximum displacements for IM NC were >1 mm along the SI and LR axes and >1° along the yaw axis. In the correlation between the treatment time and the IM, the r-values were -0.025 and 0.027 for SRS and SRT respectively, along the axes of translation. For the axes of rotation, the r-values were 0.012 and 0.206 for SRS and SRT, respectively., Conclusion: Encompass provided patient immobilization with adequate accuracy during HA treatment. The absolute maximum displacement IM was less than IM NC along the translational/rotational axes, and no statistically significant relationship between the treatment time and the IM was observed., (© 2021 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of American Association of Physicists in Medicine.)

In June, 2019, Japan submitted its mid-century strategy to the United Nations Framework Convention on Climate Change and pledged 80% emissions cuts by 2050. The strategy has not gone through a systematic analysis, however. The present study, Stanford Energy Modeling Forum (EMF) 35 Japan Model Intercomparison project (JMIP), employs five energy-economic and integrated assessment models to evaluate the nationally determined contribution and mid-century strategy of Japan. EMF 35 JMIP conducts a suite of sensitivity analyses on dimensions including emissions constraints, technology availability, and demand projections. The results confirm that Japan needs to deploy all of its mitigation strategies at a substantial scale, including energy efficiency, electricity decarbonization, and end-use electrification. Moreover, they suggest that with the absence of structural changes in the economy, heavy industries will be one of the hardest to decarbonize. Partitioning of the sum of squares based on a two-way analysis of variance (ANOVA) reconfirms that mitigation strategies, such as energy efficiency and electrification, are fairly robust across models and scenarios, but that the cost metrics are uncertain. There is a wide gap of policy strength and breadth between the current policy instruments and those suggested by the models. Japan should strengthen its climate action in all aspects of society and economy to achieve its long-term target., Supplementary Information: The online version contains supplementary material available at 10.1007/s11625-021-00913-2., (© The Author(s) 2021.)

To compare the effect of a contrast-enhanced (CE) agent on volumetric-modulated arc therapy plans based on four types of images-virtual monochromatic images (VMIs) captured at 70 and 140 keV (namely VMI 70 and VMI 140 , respectively), water density image (WDI), and virtual non-contrast image (VNC) generated using a dual-energy computed tomography (DECT) system. A tissue characterization phantom and a multi-energy phantom were scanned, and VMI 70 , VMI 140 , WDI, and VNC were retrospectively reconstructed. For each image, a lookup table (LUT) was created. For 13 patients with nasopharyngeal cancer, non-CE and CE scans were performed, and volumetric-modulated arc therapy plans were generated on the basis of non-CE VMI 70 . Subsequently, the doses were re-calculated using the four types of DECT images and their corresponding LUTs. The maximum differences in the physical density estimation were 21.3, 5.2, -3.9, and 0.5% for VMI 70 , VMI 140 , WDI, and VNC, respectively. Compared with VMI 70 , the WDI approach significantly reduced (p < 0.05) the dosimetric difference due to the CE agent for the planning target volume (PTV) (D 50% ), whereas the difference was significantly increased for D 1% . Except for PTV (D 1% ), the differences were significantly lower (p < 0.05) in the treatment plans based on VMI 140 and VNC than that based on VMI 70 . For the VNC, the mean difference was less than 0.2% for all dosimetric parameters for the PTV. For patients with NPC, treatment plans based on the VNC derived from CE scan showed the best agreement with those based on the non-CE VMI 70 . Ideally, the effect of CE agent on dose distribution does not appear in treatment planning procedures., (Copyright © 2021 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.)

The immobilization of patients with a bite block (BB) carries the risk of interpersonal infection, particularly in the context of pandemics such as COVID-19. Here, we compared the intra-fractional patient setup error (intra-SE) with and without a BB during fractionated intracranial stereotactic irradiation (STI). Fifteen patients with brain metastases were immobilized using a BB without a medical mask, while 15 patients were immobilized without using a BB and with a medical mask. The intra-SEs in six directions (anterior-posterior (AP), superior-inferior (SI), left-right (LR), pitch, roll, and yaw) were calculated by using cone-beam computed tomography images acquired before and after the treatments. We analyzed a total of 53 and 67 treatment sessions for the with- and without-BB groups, respectively. A comparable absolute mean translational and rotational intra-SE was observed (P > 0.05) in the AP (0.19 vs 0.23 mm with- and without-BB, respectively), SI (0.30 vs 0.29 mm), LR (0.20 vs 0.29 mm), pitch (0.18 vs 0.27°), roll (0.23 vs 0.23°) and yaw (0.27 vs 22°) directions. The resultant planning target volume (PTV) margin to compensate for intra-SE was <1 mm. No statistically significant correlation was observed between the intra-SE and treatment times. A PTV margin of <1 mm was achieved even when patients were immobilized without a BB during STI dose delivery., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Virtual monochromatic images (VMIs) at a lower energy level can improve image quality but the computed tomography (CT) number of iodine contained in the contrast-enhanced agent is dramatically increased. We assessed the effect of the use of contrast-enhanced agent on the dose distributions in volumetric modulated arc therapy (VMAT) planning for head and neck cancer (HNC). Based on the VMIs at 40 keV (VMI 40keV ), 60 keV(VMI 60keV ), and 77 keV (VMI 77keV ) of a tissue characterization phantom, lookup tables (LUTs) were created. VMAT plans were generated for 15 HNC patients based on contrast-enhanced- (CE-) VMIs at 40-, 60-, and 77 keV using the corresponding LUTs, and the doses were recalculated based on the noncontrast-enhanced- (nCE-) VMIs. For all structures, the difference in CT numbers owing to the contrast-enhanced agent was prominent as the energy level of the VMI decreased, and the mean differences in CT number between CE- and nCE-VMI was the largest for the clinical target volume (CTV) (125.3, 55.9, and 33.1 HU for VMI 40keV , VMI 60keV , and VMI 77keV, respectively). The mean difference of the dosimetric parameters (D 99% , D 50% , D 1% , D mean , and D 0.1cc ) for CTV and OARs was <1% in the treatment plans based on all VMIs. The maximum difference was observed for CTV in VMI 40keV (2.4%), VMI 60keV (1.9%), and VMI 77keV (1.5%) plans. The effect of the contrast-enhanced agent was larger in the VMAT plans based on the VMI at a lower energy level for HNC patients. This effect is not desirable in a treatment planning procedure., (© 2019 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.)

Purpose: Though virtual monochromatic images (VMIs) at low energy levels can improve image quality, the measured Hounsfield unit (HU) values can be inaccurate. We assessed the dosimetric error due to inaccurate HU estimation in volumetric modulated arc therapy (VMAT) planning., Methods: Based on the VMIs at 50 keV (VMI 50keV ), 77 keV (VMI 77keV ) and single-energy CT (SECT) image for a phantom with different sizes, lookup tables (LUT L and LUT S ) were created. Using an anthropomorphic phantom (head and spine regions), VMAT plans were generated based on VMI 50keV , VMI 77keV and SECT using the corresponding LUT L , and then, the doses were re-calculated using LUT S . For clinical cases, 30 VMAT plans (prostate, brain, and spine cases) were generated based on VMI 50keV and VMI 77keV ., Results: In the anthropomorphic phantom study, the difference in the dosimetric parameters for planning target volume (PTV) in the VMAT plan based on the VMI 77keV was smallest (within 0.1 Gy) among three types of treatment planning approach. In clinical cases, in general, the differences of the 3-dimensional gamma passing rate and dosimetric parameters in the treatment plans based on the VMI 50keV were larger than those in the VMI 77keV . Especially for brain cases, the difference for PTV was more prominent when AXB was used (the maximum difference was 0.5 Gy) than AAA., Conclusions: The dosimetric error due to the inaccurate HU estimation was larger in the VMIs at low energy levels. This may be clinically insignificant, but should be avoided in the VMAT treatment planning., (Copyright © 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)