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RISS 인기검색어
- 검색키워드
- 저자 : Mohammad Mahfujur Rahman (검색결과 6 건)
- 무료
- 기관 내 무료
- 유료
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Daily Based Quality Assurance of Volumetric Modulated Arc Therapy for the Full Session of Treatment
Mohammad Mahfujur Rahman,Chan Hyeong Kim,SeongHoon Kim 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.7
Volumetric modulated arc therapy (VMAT) with highly complex advanced delivering technique, is widely practiced in radiation therapy and requires a quality assurance for treatment plan at least once a treatment session. In this study we collected six VMAT patients with different treatment sites. The VMAT plans and their quality assurance (QA) plans were performed on a daily basis before treatment for their full period of treatment. We tried to evaluate the accuracy of their delivering through analyses of first mechanical error of multileaf collimator (MLC) movement and second dosimetric error of beam delivery. We used a MATLAB program and portal dosimetry to estimate a maximum root mean square (RMS) error from dynalog files for mechanical analysis and a gamma index from portal dosimetry for dosimetric analysis, respectively. We introduced newly in this study a representative VMAT QA to be used to perform a routine VMAT QA. The daily variation of maximum error RMSs for all treatment sites were all below maximum 0:3503 0:0002 mm for treatment plans and QA plans and they all showed the gamma pass rate of more than 98%. Mean of inter difference between treatment and QA plans stayed below 0.04 mm, showing that QA deliveries agree well with treatment deliveries. The Linac used kept a good performance within the tolerances in American Association of Physicists in Medicine (AAPM) TG142 guideline for the period of research. We suggest that the representative VMAT QA can be a good surrogate for real VMAT plan and \whole time" plan QA for a patient selected randomly at least once a year be performed to confirm the long-term stability of Linac performance.
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Plan-Class Specific Reference Quality Assurance for Volumetric Modulated Arc Therapy
Rahman, Mohammad Mahfujur,Kim, Chan Hyeong,Kim, Seonghoon The Korean Association for Radiation Protection 2019 방사선방어학회지 Vol.44 No.1
Background: There have been much efforts to develop the proper and realistic machine Quality Assurance (QA) reflecting on real Volumetric Modulated Arc Therapy (VMAT) plan. In this work we propose and test a special VMAT plan of plan-class specific (pcsr) QA, as a machine QA so that it might be a good solution to supplement weak point of present machine QA to make it more realistic for VMAT treatment. Materials and Methods: We divided human body into 5 treatment sites: brain, head and neck, chest, abdomen, and pelvis. One plan for each treatment site was selected from real VMAT cases and contours were mapped into the computational human phantom where the same plan as real VMAT plan was created and called plan-class specific reference (pcsr) QA plan. We delivered this pcsr QA plan on a daily basis over the full research period and tracked how much MLC movement and dosimetric error occurred in regular delivery. Several real patients under treatments were also tracked to test the usefulness of pcsr QA through comparisons between them. We used dynalog file viewer (DFV) and Dynalog file to analyze position and speed of individual MLC leaf. The gamma pass rate from portal dosimetry for different gamma criteria was analyzed to evaluate analyze dosimetric accuracy. Results and Discussion: The maxRMS of MLC position error for all plans were all within the tolerance limit of < 0.35 cm and the positional variation of maxPEs for both pcsr and real plans were observed very stable over the research session. Daily variations of maxRMS of MLC speed error and gamma pass rate for real VMAT plans were observed very comparable to those in their pcsr plans in good acceptable fluctuation. Conclusion: We believe that the newly proposed pcsr QA would be useful and helpful to predict the mid-term quality of real VMAT treatment delivery.
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Mid-Term Performance of Clinical LINAC in Volumetric Modulated Arc Therapy
Rahman, Mohammad Mahfujur,Kim, Chan Hyeong,Kim, Seonghoon The Korean Association for Radiation Protection 2019 방사선방어학회지 Vol.44 No.1
Background: The mid-term performance of clinical linear accelerator (LINAC) during volumetric modulated arc therapy (VMAT) treatment period is not performed in clinical practice and usually replaced with one-time plan quality assurance (QA). In this research we aim to monitor daily reproducibility of VMAT delivery from tracking individual leaf movement error and dosimetric error to evaluate the mid-term quality of the machine used. Materials and Methods: First, multileaf collimator (MLC) information was imported into MATLAB program to determine which of the MLC leaves in the leaf bank had the maximum RMS position error (maxRMS). We estimated where the maximum positional errors (maxPE) of the chosen leaf occur along its path length and tracked its daily variations over the entire treatment period. Secondly, picture information of dosimetric error from portal dosimetry was imported into MATLAB where representative high gamma index region (HGR) was determined as HGR with length of > 1 cm and their centers were daily tracked. Results and Discussion: The maxPEs in the brain and tongue cases were distributed broader than in other cases, but all data were found located within ${\pm}0.5mm$. From first day to last day all of five cases show the similar visual pattern of HGRs and Centers of the longest HGRs remained within ${\pm}1mm$ of that in first day. These findings prove excellent mid-term performance of the LINAC used in VMAT treatments over a full course of treatment. Conclusion: Tracking the daily location changes of leaf movement and dosimetric error can be a good indicator of predicting the daily quality like stability and reproducibility of beam delivering in VMAT treatment.
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The Effect of Foreign Direct Investment on Public Health: Empirical Evidence from Bangladesh
Fahimul Kader SIDDIQUE,K. B. M. Rajibul HASAN,Shanjida CHOWDHURY,Mahfujur RAHMAN,Tahsin Sharmila RAISA,Nurul Mohammad ZAYED 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4
Health is an outset of psychological, social, financial, and physical state. Several macroeconomic factors are entangled with health and mortality. Infant mortality and life expectancy are two keyguard on demographic research context on last few decades. On the other hand, foreign inflows play an unprecedent role for raising economic circulation and providing more opportunities to build a better society. The study aims to investigate the relationship between foreign direct investment (FDI), economic growth, and Bangladesh’s health. This study employs time-series data from 1980 to 2018. Results show, with Auto-regressive Distribute Lag (ARDL) model, that there is significant cointegration among variables. Foreign investment and economic output relate significantly and positively to health. On the contrary, education is quasi-linked with a different sign-on different model. For model validation, pitfalls of time-series multicollinearity, heteroscedasiticy, and autocorrelation are not present. Also, CUSUM and CUSUMSQ tests are validating the model as stable and fit for future prediction. Medical assessment and education need more attention from the government as well as the private sector. FDI can play a catalyst role for improving the health sector, raising opportunity in educating and creating a better lifestyle. In order to optimize foreign investment, the government should implement necessary reforms and policies.
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