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Achieving Improved Construction Efficiency for Multi-Story Steel Concentrically Braced Frames
Akram Zain,Ali Imanpour,Robert G. Driver 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.2
Volumetric steel modules were proposed in this study to improve construction effi ciency of multi-story steel concentrically braced frames. Two types of modules, (1) gravity modules and (2) braced modules, which features the steel concentrically braced frame (CBF) system, are fi rst introduced. The proposed braced module consists of steel CBFs to carry lateral seismic or wind loads. The module assembly and construction sequence are then presented. The structural design of the modules is performed in accordance with the Canadian steel design standard. An analysis of the structural costs is then carried out on a prototype building consisting of the volumetric modules to evaluate the cost effi ciency of the system as compared to a conventional braced frame system. The gravity and lateral load-carrying capacities of a two-story CBF subassembly are fi nally examined under lateral seismic loads using continuum-based fi nite element analysis with emphasis on the inelastic response of braces. The results of the cost analysis confi rm the potential benefi ts off ered by volumetric gravity and braced modules to improving construction effi ciency of steel CBFs through off -site construction of the modules and on-site assembly. Furthermore, the results obtained from the structural response evolution of the CBF subassembly suggest an acceptable lateral load-carrying capacity and appreciable ductility capacity provided by braced modules.
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Chung, Joo-Hyun,Na, Kyoungsu,Kim, Il Han The Korean Society for Radiation Oncology 2018 Radiation Oncology Journal Vol.36 No.4
Purpose: To retrospectively analyze dosimetric parameters of volumetric-modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT) delivered to extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue in the stomach (gastric MALT lymphoma) to find out advantages of VMAT and conditions for definite benefits of VMAT. Materials and Methods: Fifty patients with stage I-II gastric MALT lymphoma received VMAT (n = 14) or 3D-CRT (n = 36) between December 2005 and April 2018. Twenty-seven patients were categorized according to whether the planning target volume (PTV) overlaps kidney(s). Dosimetric parameters were analyzed by dose-volume histogram. Results: Radiation dose to the liver was definitely lower with VMAT in terms of mean dose (p = 0.026) and V<sub>15</sub> (p = 0.008). The V<sub>15</sub> of the left kidney was lower with VMAT (p = 0.065). For those with PTV overlapping kidney(s), the left kidney V<sub>15</sub> was significantly lower with VMAT. Furthermore, the closer the distance between the PTV and kidneys, the less the left kidney V<sub>15</sub> with VMAT (p = 0.037). Delineation of kidney(s) by integrating all respiratory phases had no additional benefit. Conclusions: VMAT significantly increased monitor units, reduced treatment time and radiation dose to the liver and kidneys. The benefit of VMAT was definite in reducing the left kidney V<sub>15</sub>, especially in geometrically challenging conditions of overlap or close separation between PTV and kidney(s).
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정주현,나경수,김일한 대한방사선종양학회 2018 Radiation Oncology Journal Vol.36 No.4
Purpose: To retrospectively analyze dosimetric parameters of volumetric-modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT) delivered to extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue in the stomach (gastric MALT lymphoma) to find out advantages of VMAT and conditions for definite benefits of VMAT. Materials and Methods: Fifty patients with stage I-II gastric MALT lymphoma received VMAT (n = 14) or 3D-CRT (n = 36) between December 2005 and April 2018. Twenty-seven patients were categorized according to whether the planning target volume (PTV) overlaps kidney(s). Dosimetric parameters were analyzed by dose-volume histogram. Results: Radiation dose to the liver was definitely lower with VMAT in terms of mean dose (p = 0.026) and V15 (p = 0.008). The V15 of the left kidney was lower with VMAT (p = 0.065). For those with PTV overlapping kidney(s), the left kidney V15 was significantly lower with VMAT. Furthermore, the closer the distance between the PTV and kidneys, the less the left kidney V15 with VMAT (p = 0.037). Delineation of kidney(s) by integrating all respiratory phases had no additional benefit. Conclusions: VMAT significantly increased monitor units, reduced treatment time and radiation dose to the liver and kidneys. The benefit of VMAT was definite in reducing the left kidney V15, especially in geometrically challenging conditions of overlap or close separation between PTV and kidney(s).
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Christian Ostheimer,Patrick Hübsch,Martin Janich,Reinhard Gerlach,Dirk Vordermark 대한방사선종양학회 2016 Radiation Oncology Journal Vol.34 No.4
Purpose: Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensitymodulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). Materials and Methods: A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. Results: VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8%– 88.4% in coplanar, 77.5%–88.2% in non-coplanar IMRT and 82.8%–90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Conclusion: Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.
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Ostheimer, Christian,Hubsch, Patrick,Janich, Martin,Gerlach, Reinhard,Vordermark, Dirk The Korean Society for Radiation Oncology 2016 Radiation Oncology Journal Vol.34 No.4
Purpose: Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensity-modulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). Materials and Methods: A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. Results: VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8%-88.4% in coplanar, 77.5%-88.2% in non-coplanar IMRT and 82.8%-90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Conclusion: Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.
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Christian Ostheimer, Patrick Hübsch, Martin Janich, Reinhard Gerlach, Dirk Vordermark 대한방사선종양학회 2016 Radiation Oncology Journal Vol.34 No.4
Purpose: Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensitymodulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). Materials and Methods: A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. Results: VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8%-88.4% in coplanar, 77.5%-88.2% in non-coplanar IMRT and 82.8%-90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Conclusion: Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.
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송승호 ( Song Seung-ho ),권우빈 ( Kwon Woo-bin ),최진욱 ( Choi Jin-ouk ),조훈희 ( Cho Hun-hee ) 한국건축시공학회 2023 한국건축시공학회 학술발표대회 논문집 Vol.23 No.1
The construction industry’s lack of experience and expertise makes it difficult for projects to realize the full benefits of implementing modular construction. Such project performance-hindering elements are often labeled as modular challenges. The added requirement for the transportation of the finished volumetric module is one aspect of the ‘module transportation logistics,’ the under-researched modular challenge that can prevent projects from incurring maximum cost and productivity benefits. The typical module transportation phases include lifting, transporting, and offloading. From conducting a literature review, this paper aims to investigate the equipment commonly adopted to lift and offload the module and validate its economic efficiency by comparing it with the alternative lifting/offloading equipment used in the two case projects. The results showed that hydraulic jacks are an economic alternative to the crane for lifting/offloading the module. The increase in single-module projects with smaller budgets made crane usage economically undesirable, and this study suggested a viable option for a more economical alternative.
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Cho, Yeona,Cho, Yoon Jin,Chang, Won Suk,Kim, Jun Won,Choi, Won Hoon,Lee, Ik Jae BioMed Central 2019 Radiation oncology Vol.14 No.1
<P><B>Background</B></P><P>We evaluated the optimal radiotherapy (RT) plan for synchronous bilateral breast cancer (SBBC), especially treatment plans including the regional lymph node (LN) area.</P><P><B>Methods</B></P><P>This study was conducted using 15 patients with SBBC (5 with small breasts, 5 with large breasts, and 5 who underwent a left total mastectomy). The clinical target volume (CTV) was defined as the volume enveloping the bilateral whole breasts/chest wall and left regional LN area. We established the following plans: 1) volumetric-modulated arc therapy (VMAT)-the only plan using two pairs of partial arcs for the whole target volume, 2) VMAT using one partial arc for the left CTV followed by a 3D tangential technique for the right breast (primary hybrid plan), and 3) VMAT for the left CTV followed by a tangential technique using an automatically calculated prescription dose for the right breast, considering the background dose from the left breast VMAT plan (modified hybrid plan). The Tukey test and one-way analysis of variance were used to compare the target coverage and doses to organs at risk (OARs) of the three techniques.</P><P><B>Results</B></P><P>For target coverage, the VMAT-only and modified hybrid plans showed comparable target coverage in terms of D<SUB>mean</SUB> (50.33 Gy vs. 50.53 Gy, <I>p</I> = 0.106). The primary hybrid plan showed the largest distribution of the high-dose volume, with V<SUB>105%</SUB> of 25.69% and V<SUB>110%</SUB> of 6.37% for the planning target volume (PTV) (<I>p</I> < 0.001). For OARs including the lungs, heart, and left anterior descending artery, the percentages of volume at various doses (V<SUB>5Gy</SUB>, V<SUB>10Gy</SUB>, V<SUB>20Gy</SUB>, V<SUB>30Gy</SUB>) and D<SUB>mean</SUB> were significantly lower in both the primary and modified hybrid plans compared to those of the VMAT-only plan. These results were consistent in subgroup analyses of breast size and morphological variation.</P><P><B>Conclusions</B></P><P>The modified hybrid plan, using an automatically calculated prescription dose for the right breast and taking into consideration the background dose from the left breast VMAT plan, showed comparable target coverage to that of the VMAT-only plan, and was superior for saving OARs. However, considering that VMAT can be adjusted according to the physician’s intention, further evaluation is needed for developing a better plan.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1186/s13014-019-1257-5) contains supplementary material, which is available to authorized users.</P>
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식도암의 방사선치료에서 부분 각도에 의한 회전 치료를 이용한 조사체적의 감소
황철환(Chulhwan Hwang),김성후(Seong Hu Kim),구재흥(Jae Heung Koo),손종기(Jong Ki So) 한국방사선학회 2018 한국방사선학회 논문지 Vol.12 No.5
세기변조방사선치료와 입체적세기조절회전치료 시 조사체적과 선량 퍼짐 현상을 줄이기 위한 방법으로 조사 각도를 제한하는 부분 각도에 의한 회전치료 기능을 적용하여 표적체적과 주변 정상장기의 선량에 대해 입체조형방사선치료와 비교 분석하였다. 치료계획에 따른 표적체적의 선량분포는 통계적으로 유의한 차이를 확인할 수 없었으며, 폐의 5 Gy(V5) 체적에서 입체조형방사선치료 56.53%, 세기변조방사선치료 52. 03%, 입체적세기조절회전치료 47.84%를 나타내어 유의한 차이를 나타내었다(CRT-IMRT p=0.035, CRT-VMAT p<0. 001, IMRT-VMAT p<0.001). 10 Gy 체적(V10)에서는 입체조형방사선치료 35.12%, 세기변조방사선치료 34.04%, 입체적세기조절회전치료 33.28%를 보여, 입체조형방사선치료와 세기변조방사선치료(p=0.018), 입체적세기 조절회전치료(p=0.035)에서 유의한 차이를 나타내었으나 20 Gy 체적(V20)에서는 유의한 선량 차이를 확인할 수 없었다. 심장의 평균선량과 20 Gy 체적은 치료계획에 따라 유의한 차이를 확인할 수 없었으나, 30, 40 Gy 체적은 입체적세기조절회전치료에서 37.16%, 22.46%를 나타내어 입체조형방사선치료와 비교에서 유의한 차이(p=0.028)를 보였다. 이와 같이 조사체적 감소에 따른 폐의 저 선량 체적(V5, V10)의 감소를 확인할 수 있었으며, 세기변조방사선치료와 입체적세기조절회전치료 시 조사 각도를 일부 제한함으로써 표적체적의 선량분포는 동일하게 유지함과 동시에 조사체적을 줄일 수 있었다. 이로 인해 폐의 선량 퍼짐 현상의 감소로부터 폐의 독성을 낮추는데 기여할 수 있을 것으로 사료된다. In this study, plans to apply 3D conformal radiotherapy, intensity modulated radiotherapy, and volumetric intensity modulated arc radiotherapy to esophageal cancer radiotherapy were compared. In particular, arc therapy was applied to reduce irradiated volume and spread of low-dose during intensity modulated radiation therapy and volumetric intensity modulated arc radiotherapy by limiting part of irradiated angle, in order to compare target doses and dose for surrounding normal tissues of the two methods and those of 3D conformal radiotherapy. No significant difference in target dose was found among the three methods. The 5 Gy volume(V5) of the lung showed 56.53% of conformal radiotherapy, 52.03% of intensity modulated radiotherapy, and 47.84% of volumetric modulated arc therapy(CRT-IMRT p=0.035, CRT-VMAT p<0.001, IMRT-VMAT p<0.001). The 10 Gy volume(V10) showed a significant difference in conformal radiotherapy 35.12%, intensity modulated radiotherapy 34.04%, and volumetric modulated arc radiotherapy 33.28%, showing significant difference in intensity modulated radiotherapy(p=0.018), volumetric modulated arc therapy(p=0.035), no significant difference in dose was found at 20 Gy volume. The mean dose and 20 Gy volume of the heart were not significantly different according to the treatment plan, but the 30 and 40 Gy volumes were 37.16% and 22.46% in the volumetric modulated arc radiotherapy, showing significant differences(p=0.028) in comparison with conformal radiotherapy. It is believed that, by limiting part of the irradiated angle during intensity modulated radiotherapy and volumetric intensity modulated arc radiotherapy, the irradiated volume and, thereby, the 5-10 Gy area and toxicity of the lung can be reduced while maintaining dose distribution of the target dose.
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Volumetric modulated arc therapy for carotid sparing in the management of early glottic cancer
Kim, Young Suk,Lee, Jaegi,Park, Jong In,Sung, Wonmo,Lee, Sol Min,Kim, Gwi Eon The Korean Society for Radiation Oncology 2016 Radiation Oncology Journal Vol.34 No.1
Purpose: Radiotherapy of the neck is known to cause carotid artery stenosis. We compared the carotid artery dose received between volumetric modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (IMRT) plans in patients with early glottic cancer. Materials and Methods: Twenty-one early glottic cancer patients who previously underwent definitive radiotherapy were selected for this study. For each patient, double arc VMAT, 8-field IMRT, 3-dimensional conformal radiotherapy (3DCRT), and lateral parallel-opposed photon field radiotherapy (LPRT) plans were created. The 3DCRT plan was generated using lateral parallel-opposed photon fields plus an anterior photon field. VMAT and IMRT treatment plan optimization was performed under standardized conditions to obtain adequate target volume coverage and spare the carotid artery. Dose-volume specifications for the VMAT, IMRT, 3DCRT, and LPRT plans were calculated with radiotherapy planning system. Monitor units (MUs) and delivery time were measured to evaluate treatment efficiency. Results: Target volume coverage and homogeneity results were comparable between VMAT and IMRT; however, VMAT was superior to IMRT for carotid artery dose sparing. The mean dose to the carotid arteries in double arc VMAT was reduced by 6.8% compared to fixed-field IMRT (p < 0.001). The MUs for VMAT and IMRT were not significantly different (p = 0.089). VMAT allowed an approximately two-fold reduction in treatment delivery time in comparison to IMRT (3 to 5 minutes vs. 5 to 10 minutes). Conclusion: VMAT resulted in a lower carotid artery dose compared to conventional fixed-field IMRT, and maintained good target coverage in patients with early glottic cancer.
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