International Journal of Medical Physics, Clinical Engineering and Radiation Oncology最新文献_第6页

Investigation of Target Minimum and Maximum Dosimetric Criteria for the Evaluation of Standardized Radiotherapy Plan —Target Minimum and Maximum Evaluation 评价标准化放疗计划的目标最小和最大剂量学标准的研究——目标最小和最大评价

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2020-03-25 DOI: 10.4236/ijmpcero.2020.92005

J. Yu, H. Geng, Y. Gong, M. Machtay, H. Lukka, Z. Liao, Ying Xiao, W. Zou

{"title":"Investigation of Target Minimum and Maximum Dosimetric Criteria for the Evaluation of Standardized Radiotherapy Plan —Target Minimum and Maximum Evaluation","authors":"J. Yu, H. Geng, Y. Gong, M. Machtay, H. Lukka, Z. Liao, Ying Xiao, W. Zou","doi":"10.4236/ijmpcero.2020.92005","DOIUrl":"https://doi.org/10.4236/ijmpcero.2020.92005","url":null,"abstract":"Purpose: Standardization of tumor dosimetric coverage is essential for the evaluation of radiotherapy treatment plan quality. National clinical trials network RTOG protocols include tumor target dosimetric criteria that specify the prescription dose and minimum and maximum dose (Dmin and Dmax) coverages. This study investigated the impact of various minimum and maximum dose definitions using tumor control probability (TCP) models. Methods and Materials: Three disease sites (head and neck, lung, and prostate) were studied using target volume dosimetric criteria from the RTOG 0920, 1308, and 0938 protocols. Simulated target dose-volume histograms (DVHs) of Dmin and Dmax were modeled using the protocol specifications. Published TCP models for the three disease sites were applied to the DVH curves. The effects of various dose definitions on TCP were studied. Results: While the prescription dose coverage was maintained, a -3.7% TCP difference was observed for head and neck cancer when the target doses varied by 3.5% of the tumor volume from the point dose. For prostate and lung cancers, -3.3% and -2.2% TCP differences were observed, respectively. The TCPs for head and neck and prostate cancers were more negatively affected by deviations in the Dmin than the TCP for lung cancer. The lung TCP increased to a greater extent with a change in the Dmax compared with the head and neck and prostate TCPs. Conclusions: These results can be used to evaluate plan quality when the target dose only slightly deviates from the dosimetric criteria. When the overall target prescription dose coverage is maintained, the Dmax is recommended to be within 3% of the target volume: 98% (for head and neck and prostate) and 97% (for lung) of the target volume, satisfying the Dmin needed to maintain TCP variations at less than 2.1%. Using 0.03 cc instead of a point dose for Dmin and Dmax criteria minimally impacts TCPs.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82604472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The Effect of Absorbed Dose to Organs at Risk Following Craniospinal Irradiation Using Different Radiotherapy Techniques 不同放射治疗技术对颅脑损伤后器官吸收剂量的影响

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2020-03-25 DOI: 10.4236/ijmpcero.2020.92008

Hadeer Shahin, E. Attalla, H. S. Abou-Elenien, H. Elsayed, I. Bashter, Marwa A. Suliman

{"title":"The Effect of Absorbed Dose to Organs at Risk Following Craniospinal Irradiation Using Different Radiotherapy Techniques","authors":"Hadeer Shahin, E. Attalla, H. S. Abou-Elenien, H. Elsayed, I. Bashter, Marwa A. Suliman","doi":"10.4236/ijmpcero.2020.92008","DOIUrl":"https://doi.org/10.4236/ijmpcero.2020.92008","url":null,"abstract":"Introduction: In medulloblastoma patients craniospinal irradiation is an important element the treatment. Our study aimed to evaluate the effect of absorbed dose to organs at risk using the hybrid intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) for craniospinal irradiation (CSI) in average risk medulloblastoma patients. Materials and Methods: In this study, thirteen medulloblastoma patients were included. The prescribed total dose to the planning target volume (PTV) was 23, 40 Gy in 13 fractions. Two radiotherapy techniques, three dimensional conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (IMRT) were used to treat these patients. The coverage of the Target was evaluated using the D mean, D95%, D2%, D98% and V95%. Other parameters were also compared such as Integral dose (ID), Homogeneity index (HI) and doses to the organs at risk (OARs). Results: There was no significant difference in the mean dose received by the PTV-Brain or the dose received by 95% and 98% of PTV volume using the two techniques. For PTV-Spine, the percentage volume receiving 95% of the total dose increased significantly in the hybrid IMRT technique compared to the conformal technique. So, hybrid IMRT plan achieved the best coverage for PTV spine. Lower dose for OAR was delivered by 3DCRT, except the heart and thyroid, hybrid IMRT achieved better sparing. All plans resulted in the same dose homogeneity index (DHI) for PTV-Brain. For PTV-Spine, hybrid IMRT technique achieved better dose homogeneity compared to 3DCRT technique (1.09 vs. 1.12; p > 0.05). Conclusions: hybrid IMRT technique can be realized on conformal technique because it achieved better dose coverage for the (PTV) and organ at risk (OAR). 3DCRT reduced mean dose to most OARS, except the heart and thyroid. Therefore, the hybrid IMRT technique may be a CSI treatment alternative to 3DCRT.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87981843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiple Scanning Effects in Radiochromic Film Dosimetry: A Method to Reduce the Increase of Optical Density 放射色膜剂量测定中的多重扫描效应:一种降低光密度增加的方法

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2020-02-26 DOI: 10.4236/ijmpcero.2020.91004

B. Ngono, A. Ebongue, D. Bongu, A. Sone, M. K. Njock

{"title":"Multiple Scanning Effects in Radiochromic Film Dosimetry: A Method to Reduce the Increase of Optical Density","authors":"B. Ngono, A. Ebongue, D. Bongu, A. Sone, M. K. Njock","doi":"10.4236/ijmpcero.2020.91004","DOIUrl":"https://doi.org/10.4236/ijmpcero.2020.91004","url":null,"abstract":"In this work, a method to reduce increase in optical density (OD) caused by multiple scanning in radiochromic film dosimetry in combination with a flatbed scanner is presented. Gafchromic EBT3 films are scanned with Epson Pro 1680 Expression scanner and time intervals of 15 minutes and 30 minutes are observed between consecutive scans to reduce the increase in temperature of the scanner. The maximum variations in OD after consecutive scans are calculated and compared to the values obtained for scans without interruption. For film irradiated to 3 Gy, a time interval of 15 minutes between two successive scans leads to a reduction of the OD increase of 56.2% compared to when films are scanned without interruption. Reductions of OD increase of 86.72% and 78.72% respectively for film irradiated to 1 Gy and 2 Gy are obtained when a time interval of 30 minutes is left between two successive scans. These results show that when time intervals are observed between consecutive scans, the increase in OD has significantly reduced. However, the method has the drawback of increasing the time needed to perform radiochromic film dosimetry.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74517843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Examination of the Run-Time Differences between the EGSnrc and the EGS5 Monte Carlo Codes EGSnrc和EGS5蒙特卡罗代码运行时差异的研究

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2020-01-03 DOI: 10.4236/ijmpcero.2020.91002

Shlomi Caduri, I. Orion

{"title":"Examination of the Run-Time Differences between the EGSnrc and the EGS5 Monte Carlo Codes","authors":"Shlomi Caduri, I. Orion","doi":"10.4236/ijmpcero.2020.91002","DOIUrl":"https://doi.org/10.4236/ijmpcero.2020.91002","url":null,"abstract":"EGS5 Monte Carlo code is a general-purpose code for calculating photons and electrons transport for complex geometries in a wide range of energies. EGSnrc Monte Carlo code (BEAMnrc enclosed) was specially developed for medical physics usage, in particular for Linac modeling and dose calculations. Both EGS5 an EGSnrc were developed based on the former EGS4 code. For each of the codes, changes were made in the electron transport methods and in the geometrical utilities. Conformity between EGS5 calculation results and EGSnrc code results for Linac modelling was shown in recent work in our group. However, a large simulation run-time difference was found for the same conditions and statistical precision between these two codes. The EGS5 code took a longer period to obtain the same results compared to the EGSnrc code for Linac modelling. The electron transport in EGSnrc is based on the ESTEPE parameter, which is the maximum fractional energy loss per electron step. We investigated the ESTEPE parameter influence on the run-time and on the results accuracy. A set of variety simulations were performed using both codes in order to inspect the codes performance. We found that the EGSnrc run-time is strongly influenced by choosing different ESTEPE parameter values. While setting larger fractional energy losses per step, reduced simulation run-time was achieved. Hence, for optimal dose, one should define the optimal ESTEPE step-size parameter to achieve the desired dose results resolution. The use of the EGS5 code, based on the electron transport method improvements, is automatically adapted to the desired dose results quality without any user interference. Choosing the proper ESTEPE parameter for the use of EGSnrc for a given simulation resulted in similar run-time duration as with the use of EGS5. In conclusion, some cases that were tested in this study on the EGS5 and on the EGSnrc showed that the EGS5 is faster and more fluent to use between these two codes.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91443710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Usefulness of Diffusion Weighted and Contrast Enhanced Magnetic Resonance Imaging in Characterization of Inconclusive Ovarian Mass 弥散加权和增强磁共振成像在不确定卵巢肿块诊断中的应用

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2020-01-03 DOI: 10.4236/ijmpcero.2020.91003

Ghada Mohammed Abd El Razeq, M. A. Ahmed

{"title":"The Usefulness of Diffusion Weighted and Contrast Enhanced Magnetic Resonance Imaging in Characterization of Inconclusive Ovarian Mass","authors":"Ghada Mohammed Abd El Razeq, M. A. Ahmed","doi":"10.4236/ijmpcero.2020.91003","DOIUrl":"https://doi.org/10.4236/ijmpcero.2020.91003","url":null,"abstract":"Introduction: Ovarian cancer is the commonest reason for death in females due to gynecologic malignancy around the world. In contrast to other gynecologic tumours, the definitive diagnosis is accomplished days after of the index surgery by the histopathology. Preoperative assessment based on conventional MRI is not accurate. Information is expanding increasing about the ability of new MRI modalities to assess ovarian mass. Aim of the study: To assess the ability of dynamic contrast-enhanced MRI (DCE–MRI), and Diffusion-weighted image (DWI) to describe uncertain ovarian masses. Patients and Methods: This is a retrospective study. Patients were referred from radio-diagnosis department and gynecology department of Qena faculty of medicine hospitals, South Valley University. Patients had uncertain adnexal masses at ultrasound. Magnetic resonance examination was doneutilizing 1.5 Tesla machine. The protocol included T1WI, T2WI, T1WI following contrast, and DWI. Results: We included 44 patients with different forms of complex cystic and solid ovarian masses. The final pathology of the ovarian masses was 18 benign, 4 borderline, and 22 malignant. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for DWI were 100%, 94.4%, 96.3%, 100%, and 97.7% respectively. The performance of DWI was higher than the conventional MRI and DCE-MRI. Conclusion: DCE-MRI and DWI have accepted ability to recognize malignant ovarian mass.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88579047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Analyzing Planning Techniques for Whole Brain Radiotherapy 全脑放疗计划技术分析

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2020-01-01 DOI: 10.4236/ijmpcero.2020.91001

S. Quoc, Q. Vinh, Cuong Bui Xuan, T. Van, Truong Vu

{"title":"Analyzing Planning Techniques for Whole Brain Radiotherapy","authors":"S. Quoc, Q. Vinh, Cuong Bui Xuan, T. Van, Truong Vu","doi":"10.4236/ijmpcero.2020.91001","DOIUrl":"https://doi.org/10.4236/ijmpcero.2020.91001","url":null,"abstract":"Aims: This study compares data between the Field in Field planning and Wedge planning techniques to figure out which technique has better dose coverage and distribution for PTV, and, if using FiF technique for whole brain treatment, how many beams will have better plan. Methods: 56 patients, who need to radiate whole brain with 30 Gy/10 fractions, have been selected for this study. Four plans have been made for each patient (FiF1—one subfield per field plan, FiF2—two subfields per field plan, FiF3—three subfields per field plan, and a Wedge plan). Results: The results of Field in Field plans including Compare dose distribution on the transverse CT slice, plan evaluation using DVH, number MU of plan, Dmax, HI, HTCI, DmaxPTV, DmeanPTV. Volume of PTV with the dose over 105% prescribed dose, dose of organ at risk, and Quality Assurance (QA) plan, are better than those of Wedge plan. Conclusions: Plans using Field in Field technique has better coverage, is more homogeneous in dose distribution than plan using Wedge technique. When using Field in Field technique for whole brain radiotherapy, using three subfields per field has better result than two subfields per field and one subfield per field.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88537570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Evaluation of Delivery Analysis to Detect Intrafractional Motion during Tomotherapy 放射分析在断层治疗中检测病灶内运动的评价

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-11-14 DOI: 10.4236/ijmpcero.2019.84020

K. Tarutani, M. Tanooka, K. Sano, Okada Wataru, Masayuki Fujiwara, K. Yamakado

{"title":"Evaluation of Delivery Analysis to Detect Intrafractional Motion during Tomotherapy","authors":"K. Tarutani, M. Tanooka, K. Sano, Okada Wataru, Masayuki Fujiwara, K. Yamakado","doi":"10.4236/ijmpcero.2019.84020","DOIUrl":"https://doi.org/10.4236/ijmpcero.2019.84020","url":null,"abstract":"The purpose of this study was to investigate the ability of a management system (Delivery Analysis: DA) to detect intrafractional motion during intensity-modulated radiation therapy (IMRT) in tomotherapy mode. Tomotherapy has made it possible to manage internal movements during treatment using software DA, which quantifies using the information of the passing dose obtained during the radiation treatment of patients. First, three treatment plans for the test were created (lumbar spine, prostate, and femur). Second, a pelvis phantom was moved in the X, Y, and Z directions, and a sinogram was acquired. The magnitudes of the movements were 3 mm, 5 mm, and 10 mm, respectively. Finally, the ability of DA to detect the motion was evaluated by comparing the sinogram obtained by moving the phantom with a reference sinogram obtained without movement. The sensitivity of DA could be detected with a shift amount of 3 mm (gamma analysis tolerance 0.3 mm/0.3%). The average gamma analysis of each direction at 0.3 mm/0.3% tolerance at each treatment site was 96.1% for the prostate, 93.5% for the lumbar spine, and 94.4% for the femur. Additionally, the average gamma pass rate results for the pelvic phantom in the X, Y, Z directions for a 10 mm shift were 96.2%, 96.3%, and 95.9%, respectively. DA is a powerful tool with high detection sensitivity and ability to detect body movement during treatment.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80460130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison between Predicted and Measured X-Ray Output in Some Conventional Radiography Units 一些常规x射线照相设备预测与测量x射线输出的比较

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-10-09 DOI: 10.4236/IJMPCERO.2019.84018

Calvin Didier Njiki, Yolande Huguette Ebele Yigbedeck, Joseph Eric Martial Ndjaka Manyol, Thierry Ndzana Ndah

引用次数: 1

Verification of Dosimetric and Positional Accuracy of Dynamic Tumor Tracking Intensity Modulated Radiation Therapy 动态肿瘤追踪调强放射治疗剂量学和位置准确性的验证

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-09-16 DOI: 10.4236/ijmpcero.2019.84019

M. Sueoka, A. Sawada, H. Tanabe, Y. Okada, S. Taniuchi, N. Okuuchi, M. Tanooka, M. Kokubo, K. Yamakado

{"title":"Verification of Dosimetric and Positional Accuracy of Dynamic Tumor Tracking Intensity Modulated Radiation Therapy","authors":"M. Sueoka, A. Sawada, H. Tanabe, Y. Okada, S. Taniuchi, N. Okuuchi, M. Tanooka, M. Kokubo, K. Yamakado","doi":"10.4236/ijmpcero.2019.84019","DOIUrl":"https://doi.org/10.4236/ijmpcero.2019.84019","url":null,"abstract":"Purpose: We performed both, dosimetric and positional accuracy verification of \u0000dynamic tumor tracking (DTT) intensity modulated radiation therapy (IMRT), with \u0000the Vero4DRT system using a moving phantom (QUASAR respiratory motion platform; \u0000QUASAR phantom) and system log files. Methods: The QUASAR phantom was placed on a treatment couch. Measurement of the \u0000point dose and dose distribution was performed for conventional IMRT, with the \u0000QUASAR phantom static and moving; for DTT IMRT, this was performed with the \u0000phantom moving for pyramid shaped, prostate, paranasal sinus, and pancreas \u0000targets. The QUASAR phantom was driven by a sinusoidal signal in the \u0000superior-inferior direction. Furthermore, predicted positional errors induced \u0000by the Vero4DRT system and mechanical positional errors of the gimbal head, \u0000were calculated using the system log files. Results and Conclusion: For DTT IMRT, the dose at the evaluation point was within 3% compared \u0000with the verification plan, and the dose distribution in the passing rates of γ \u0000was 97.9%, with the criteria of 3% dose and 3 mm distance to agreement. The \u0000position error calculated from the log files was within 2 mm, suggesting the \u0000feasibility of employing DTT IMRT with high accuracy using the Vero4DRT system.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77178113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Periodic Measurements of Passive Proton Beam Width Using Radiochromic Film in Fixed Gantry System 用放射性致色膜周期性测量固定龙门系统中的被动质子束宽度

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-09-16 DOI: 10.4236/ijmpcero.2019.84017

T. Shimozato, K. Yasui, Hireto Kinou, Fumiaki Komatsu

{"title":"Periodic Measurements of Passive Proton Beam Width Using Radiochromic Film in Fixed Gantry System","authors":"T. Shimozato, K. Yasui, Hireto Kinou, Fumiaki Komatsu","doi":"10.4236/ijmpcero.2019.84017","DOIUrl":"https://doi.org/10.4236/ijmpcero.2019.84017","url":null,"abstract":"Background and Aim: Irradiation methods such as double scattering method \u0000and spot scanning method have been used in proton beam treatment devices. \u0000In the scattering method, a ridge filter or a range modulation wheel is used to \u0000create a spread-out Bragg peak, but the distribution at the patient position \u0000may change due to positional deviation of the incident beam. Therefore, assessment \u0000of the incident position of the beam is very important even in the \u0000scattering method. To investigate the width and distribution of the proton \u0000beam before entering the RMW, a radiochromic film was installed at the outlet \u0000of the transport pipe and the entrance of the profile-monitoring detector. Methods: In this study, the distributions of the beam at the exit of the transport \u0000pipe and the entrance of the monitor detector were measured using \u0000films. The beam width was measured from the full width at half maximum of \u0000the profile obtained from the distribution. Measurements were conducted \u0000every month for 10 months. Results: Beams of widths ranging from 1.82 to \u00002.30 mm in the horizontal direction and 4.25 to 5.33 mm in the vertical direction \u0000were outputted from the exit of the transport pipe. Beams of widths \u0000ranging from 2.16 to 2.67 mm in the horizontal direction and 4.06 to 5.31 \u0000mm in the vertical direction were outputted from the entrance of the monitor \u0000detector. The maximum width fluctuation for 10 months was 0.55 mm in the \u0000horizontal direction and 1.26 mm in the vertical direction at the entrance of \u0000the monitor detector. Conclusions: The distribution was obtained before the \u0000proton beam was scattered by the scatterer, and then we propose a method to \u0000periodically measure and monitor the changes in the beam distributions \u0000every month.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90398159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0