International Journal of Medical Physics, Clinical Engineering and Radiation Oncology最新文献

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Comparative Study of Dose Distribution Homogeneity between 3D-Brachytherapy and Intensity Modulated Radiation Therapy Techniques in Cervix Cancer Tumors 三维近距离放疗与调强放疗在宫颈癌治疗中的剂量分布均匀性比较研究
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-08-28 DOI: 10.4236/ijmpcero.2019.83015
Mostafa Elnagger, H. A. Motaweh, Kareman Zard
{"title":"Comparative Study of Dose Distribution Homogeneity between 3D-Brachytherapy and Intensity Modulated Radiation Therapy Techniques in Cervix Cancer Tumors","authors":"Mostafa Elnagger, H. A. Motaweh, Kareman Zard","doi":"10.4236/ijmpcero.2019.83015","DOIUrl":"https://doi.org/10.4236/ijmpcero.2019.83015","url":null,"abstract":"Aim: The purpose of this study was to compare the dosimetric results of the techniques (3D-Brachytherapy and intensity-modulated radiotherapy IMRT) in patients with locally advanced cervical carcinoma (LACC). Method: There are 15 patients with locally advanced cervical carcinoma (LACC), after the completion of external beam radiotherapy (EBRT) for the whole pelvic irradiation 45 Gy/25 fractions, followed by 3D-Brachytherapy 24 Gy per weekly fractions and 36 Gy of IMRT per 18 fractions. Coverage of targets volume and doses received by normal tissue were compared in two techniques. Method: 15 patients of LACC treated with 3D-Brachytherapy were selected for this study. IMRT plans were also created for all the patients. 3D-Brachytherapy and IMRT plans were compared on the basis of target volume coverage, dose to Organs at risk (OAR’s), homogeneity index (HI) and conformity index (CI). Results: The results showed that D90% of HRCTV in the 3D-Brachytherapy was covered more than D90% of PTV in the IMRT of prescribed dose, the D2CC and the V60Gy values of Bladder and rectum were significantly lower than in 3D-Brachytherapy. The HI and CI in 3D-Brachytherapy were found better than IMRT. Conclusion: 3D-Brachytherapy significantly reduced the irradiated volume of OAR’s and improved dose coverage in tumor volume compared to that by IMRT.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85103869","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
A Longitudinal Study of Clinical Benefits with Implementation of the Deep Inspiration Breath-Hold Technique in Post-Operative Radiotherapy for Left-Sided Breast Cancer 左侧乳腺癌术后放疗实施深吸气屏气技术临床获益的纵向研究
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-08-14 DOI: 10.4236/ijmpcero.2019.83014
C. Han, N. Vora, Sean X. Zhang, An Liu, J. Wong
{"title":"A Longitudinal Study of Clinical Benefits with Implementation of the Deep Inspiration Breath-Hold Technique in Post-Operative Radiotherapy for Left-Sided Breast Cancer","authors":"C. Han, N. Vora, Sean X. Zhang, An Liu, J. Wong","doi":"10.4236/ijmpcero.2019.83014","DOIUrl":"https://doi.org/10.4236/ijmpcero.2019.83014","url":null,"abstract":"Purpose/Objectives: We aimed to report clinical effects on critical organ dose \u0000and cardiac toxicity from implementation of the deep inspiration breath-hold \u0000(DIBH) technique in post-operative extern-beam radiotherapy of patients with \u0000left-sided breast cancer, using longitudinal clinical data. Materials/Methods: \u0000We retrieved three groups of patients who received post-operative radiotherapy \u0000of left-sided breast cancer in our institution in recent years: Groups A and \u0000B consist of patients whose treatment did not include internal mammary \u0000nodes (IMN) and who were treated with the free breathing technique and \u0000with the DIBH technique, respectively, and Group C consists of patients \u0000whose radiotherapy included internal mammary nodes with the DIBH technique. \u0000Dose parameters for the heart and left lung were retrieved from the \u0000treatment plans. Radiation-induced cardiac risks were estimated using existing \u0000risk models. Results: The average heart dose was 2.65 ± 0.98 Gy, 1.10 ± \u00000.29 Gy, and 1.26 ± 0.25 Gy in Groups A, B, and C, respectively. The average \u0000heart volumes receiving at least 25 Gy were 7.10 ± 9.79 cc in Group A, 0.07 ± \u00000.22 cc in Group B, and 0.03 ± 0.08 cc in Group C. On average, the excessive \u0000risk of having ischemic heart disease was estimated to be 19.6%, 8.1%, and \u00009.3% in Groups A, B, and C, respectively. The mean left lung doses were 5.73 \u0000± 1.86 Gy, 5.93 ± 1.55 Gy, and 9.13 ± 1.57 Gy in Groups A, B, and C, respectively. Conclusion: Implementation of the DIBH technique significantly lowered \u0000heart dose and decreased the ischemic heart disease risk in patients receiving \u0000post-operative radiotherapy for left-sided breast cancer, without significant \u0000increase in left lung dose.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73528102","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
Level of Practical Skills in Personnel Dosimetry Monitoring and the Laboratory Experience with Different Types of TLD Readers 人员剂量监测的实践技能水平和不同类型TLD阅读器的实验室经验
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-08-14 DOI: 10.4236/IJMPCERO.2019.83013
H. K. Agyeman, B. Nyarko, S. Osae, F. Adeku, E. Darko, J. Amoako, J. Owusu-Banahene, S. Inkoom, B. Agyeman, P. Manteaw, E. Amoatey, G. O. Aseidu, P. Appiah, B. D. Bekoe, D. Charles
{"title":"Level of Practical Skills in Personnel Dosimetry Monitoring and the Laboratory Experience with Different Types of TLD Readers","authors":"H. K. Agyeman, B. Nyarko, S. Osae, F. Adeku, E. Darko, J. Amoako, J. Owusu-Banahene, S. Inkoom, B. Agyeman, P. Manteaw, E. Amoatey, G. O. Aseidu, P. Appiah, B. D. Bekoe, D. Charles","doi":"10.4236/IJMPCERO.2019.83013","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.83013","url":null,"abstract":"This study was carried out to analyze individual annual dose records of diagnostic radiology staff at forty-eight (48) different medical facilities in urban and rural Region of Ghana for the period of 2011-2015. The monitored dose data were extracted from the Radiation Protection Institute of the Ghana Atomic Energy Commission’s database called the Dose Management System (DMS). The doses of these OEWs analyzed, are divided into four subgroups namely; general radiographers, radiologists, computed tomography (CT) technologists, fluoroscopy technologists. The dose distribution, collective dose and mean annual dose were determined. A total of 1574 OEWs were monitored comprising of 56% radiographers, 15% radiologist, 21% computed tomography (CT) technologists and 8% fluoroscopy technologists. The average annual effective dose ranged from 0.36 to 1.70 mSv with radiographers receiving the largest. Fluoroscopy technologist recorded the least annual total collective effective dose value of 0.1 person-Sv. The study contributes to the existing works to promote a more comprehensive personal monitoring service for OEWs. Continued analysis of occupational doses should be an integral component of institutional radiation safety programs in Ghana.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75446684","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
Arteriovenous Malformation (AVM) Treated with Robotic Radiosurgery: Impact of Beam Reduction in 12 Gy Normal Brain Volume and It’s Clinical Implication 机器人放射治疗动静脉畸形:12 Gy正常脑容量减束的影响及其临床意义
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-08-14 DOI: 10.4236/IJMPCERO.2019.83012
D. Dutta, Sathiya Krishnamoorthy, G. Krishnan, H. Sudahar
{"title":"Arteriovenous Malformation (AVM) Treated with Robotic Radiosurgery: Impact of Beam Reduction in 12 Gy Normal Brain Volume and It’s Clinical Implication","authors":"D. Dutta, Sathiya Krishnamoorthy, G. Krishnan, H. Sudahar","doi":"10.4236/IJMPCERO.2019.83012","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.83012","url":null,"abstract":"Purpose: Dosimetric study to evaluate impact of “beam” reduction in AVM radiosurgery on normal brain dose parameters and it’s clinical implications. Materials and Methods: Five small volume AVMs (nidus volume 0.31 - 1.94 cc) planned for single fraction SRS with robotic radiosurgery system. Planning scans done with CT scan brain, CT & MR angiography, then nidus volume and organ at risk (OARs) were contoured. Planning was done with multiplan planning system. Plan evaluated as per Flickenger model parameters of 12 Gy nomal brain vol & marginal dose. 7.5 mm and 10 mm cons used, optimization done with seqential algorithm. 20 Gy was prescribed to isodose with appropriate nidus coverage (>98%). Total beams of five plans were 85 - 250, monitor unit 17,259 - 24,602 MU. 12 Gy normal brain volume is 0.9 - 7.6 cc. Then beam reduction is done by reducing beams with minimum MU in steps of 50, 100, 150, 200, 250 MU and after beam reduction, re-optimization done. Prescription isodose was changed to keep the nidus coverage > 98%. Impacts of beam reduction on 12 Gy normal brain vol and conformity/homogeniety index were analyzed. Results: Optimal plans of five patients with 20 Gy prescribed to 88% - 90% isodose, nidus coverage more than 98%. In dosimetric parameters, mean CI was 1.36 - 1.51, nCI 1.41 - 1.51, HI 1.1 - 1.4 and mean 12 Gy normal brain volume 0.17, 1.44, 5.3, 5.5 and 7.6cc respectively. After beam reduction of less than 50 MU contribution (in case#1), prescibing at suitable isodose (85%) beam reduces to 79 and 12 Gy volume marginally increases to 26.4 cc. Beam reduction of less than 100 MU reduces to 53 - 92 beamlets. Reduction of beams with less than 150 MU contribution did not significantly change the 12Gy normal brain volume. However, reduction of beamlets with more than 200 MU, 250 MU, 300 MU, 450 MU and 550 MU significantly affects the 12 Gy normal brain volume. Prescription-isodose modified from 83% to 50% to have >98% coverage. CI and HI increased from 1.36 - 1.51 to 2.51 - 2.63 and 1.1 - 1.4 to 1.52 - 1.54 respectively. There was exponential increase in 12 Gy volume with reduction of beams with higher proportion in larger nidus. Conclusions: In robotic radiosurgery system, beam reduction even after re-optimization impairs the conformity index and increase 12 Gy normal brain volume, hence long-term toxicity. Optimal beam numbers are required for optimal plan generation.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76787512","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
A Comparative Study of Dosimetric Analysis of Three Different Sets of Five Fields and Seven Fields IMRT Plans for Prostate Cancer 前列腺癌五场、七场放射治疗方案剂量学分析的比较研究
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-08-14 DOI: 10.4236/ijmpcero.2019.83016
M. Zope, D. Patil, Angel Kuriakose, Aslam Rahman, V. Trivedi, S. Keshri
{"title":"A Comparative Study of Dosimetric Analysis of Three Different Sets of Five Fields and Seven Fields IMRT Plans for Prostate Cancer","authors":"M. Zope, D. Patil, Angel Kuriakose, Aslam Rahman, V. Trivedi, S. Keshri","doi":"10.4236/ijmpcero.2019.83016","DOIUrl":"https://doi.org/10.4236/ijmpcero.2019.83016","url":null,"abstract":"The advent of Intensity Modulated Radiation Therapy (IMRT) is rapidly \u0000changing the field of Radiation Oncology. IMRT has the potential to improve \u0000clinical implementation of highly conformal non-convex dose distributions. \u0000Nonetheless, a number of IMRT approaches including coplanar and noncoplanar \u0000beam techniques with 5 to 9 beams at different angles have been used in \u0000an effort to get the best dose distribution. The purpose of this study is to \u0000compare the dose to normal tissue and dose-limiting structures, conformity \u0000index, homogeneity index, number of monitor units required for the treatment \u0000of prostate cancer in 3 sets of five and seven beam IMRT plans and thus \u0000to select the best IMRT approach for patients with prostate cancer.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78945888","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
Treatment-Plan Comparison of Three Advanced Radiation Treatment Modalities for Fractionated Stereotactic Radiotherapy to the Head and Neck 头颈部分割立体定向放射治疗的三种先进放射治疗方式的治疗方案比较
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-05-27 DOI: 10.4236/IJMPCERO.2019.82010
He Wang, James Yang, Xiaodong Zhang, Jing Li, S. Frank, Zhongxiang Zhao, D. Luo, X. Zhu, Congjun Wang, S. Tung, A. Garden, D. Rosenthal, C. Fuller, G. Gunn, A. Ghia, J. Reddy, S. Raza, F. D. Monte, M. Chambers, P. Brown, S. Su, J. Phan
{"title":"Treatment-Plan Comparison of Three Advanced Radiation Treatment Modalities for Fractionated Stereotactic Radiotherapy to the Head and Neck","authors":"He Wang, James Yang, Xiaodong Zhang, Jing Li, S. Frank, Zhongxiang Zhao, D. Luo, X. Zhu, Congjun Wang, S. Tung, A. Garden, D. Rosenthal, C. Fuller, G. Gunn, A. Ghia, J. Reddy, S. Raza, F. D. Monte, M. Chambers, P. Brown, S. Su, J. Phan","doi":"10.4236/IJMPCERO.2019.82010","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.82010","url":null,"abstract":"Purpose: Fractionated stereotactic radiosurgery (FSRS) can be given with at least three modalities: Gamma Knife, with the noninvasive frameless extend system (GKE); linear accelerator-based volumetric modulated arc therapy (VMAT); and intensity-modulated proton therapy (IMPT). We extracted treatment plans for patients who had received FSRS with GKE for recurrent skull base or intracranial tumors, created corresponding plans for VMAT and IMPT, and compared the quality of the three sets of plans. Methods and materials: Plans were extracted for 9 patients with recurrent malignant skull-base tumors (n = 6) or large intracranial tumors (n = 3) who had received FSRS with GKE (median dose 24 Gy in 3 fractions) in 2013 through 2015. Plans for VMAT were generated with a TrueBeam STx LINAC machine using 6-MV photons, and plans for IMPT were generated with multi-field optimization. The optimized VMAT and IMPT plans were normalized to achieve the best possible target coverage while meeting the same dose-volume constraints on organs at risk (OARs) as the GKE plans. Plans were evaluated on the basis of target coverage, conformity index, homogeneity index, gradient index, and treatment efficiency. Results: The median target volume was 10.2 cm3 (range 1.9 - 33.8 cm3). The VMAT and IMPT plans met all OAR constraints, and target coverage and conformity were comparable among all plans. VMAT and IMPT plans showed significantly better target uniformity and treatment delivery efficiency (P < 0.001). The gradient index and low-dose-bath were superior in the GKE plans (P < 0.001), indicating smaller irradiated volumes. When inverse planning was used, VMAT plans could achieve a similar or steeper dose drop-off at the target-OAR boundary than GKE plans. Conclusion: FSRS for skull base and large intracranial lesions delivered by VMAT and IMPT can achieve comparable target coverage, conformity, and sparing of critical structure as the GKE while providing superior target uniformity and treatment delivery efficiency. The GKE had superior high-dose gradients outside the target and thus better protected surrounding normal structures.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82053961","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
Characterization of the Long-Term Interaction between Intracellular Reactive Oxygen Species and Oxidative DNA Damage in Murine Lin-/Sca-1+ Cells Exposed to Ionizing Radiation 暴露于电离辐射的小鼠Lin-/Sca-1+细胞胞内活性氧与氧化性DNA损伤之间长期相互作用的表征
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-05-20 DOI: 10.4236/IJMPCERO.2019.82009
Junya Ishikawa, T. Morisaki
{"title":"Characterization of the Long-Term Interaction between Intracellular Reactive Oxygen Species and Oxidative DNA Damage in Murine Lin-/Sca-1+ Cells Exposed to Ionizing Radiation","authors":"Junya Ishikawa, T. Morisaki","doi":"10.4236/IJMPCERO.2019.82009","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.82009","url":null,"abstract":"Mutations in the Sfpi1 gene are essential for the development of radia-tion-induced acute myeloid leukemia. In this study, we investigated long-term interaction among immature hematopoietic cell number, intra-cellular reactive oxygen species contents, and oxidative DNA damage fre-quency after irradiation. Lin-/Sca-1+ cells were isolated from C3H/HeN mice on days 1 - 400 after 0 - 3 Gy total body irradiation. On days 1 - 7, the number of surviving cells decreased and reached a minimum; however, the number of cells gradually recovered until day 200. Intracellular reactive oxygen species contents significantly increased from day 1 to day 30. In addition, the frequency of oxidative DNA damage tended to increase from day 1 and day 30, and that at day 30 was significantly increased in the 3 Gy group compared with that in the control group. In contrast, decreased cell number, increased intracellular reactive oxygen species content, and decreased oxidative DNA damage frequency were observed on day 400. These results suggested that oxidative DNA damage was involved in intracellular reactive oxygen species generation induced by cell proliferation to compensate for cell death after irradiation.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83106707","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 Daily Tumor Motion by Measuring Fiducial Length on CBCT Images in Pancreatic Stereotactic Body Radiation Therapy 通过测量胰腺立体定向全身放射治疗中CBCT图像的基准长度来评估每日肿瘤运动
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-04-02 DOI: 10.4236/IJMPCERO.2019.82007
S. Jang, M. Hwang, R. Lalonde, D. Heron, M. Huq
{"title":"Evaluation of Daily Tumor Motion by Measuring Fiducial Length on CBCT Images in Pancreatic Stereotactic Body Radiation Therapy","authors":"S. Jang, M. Hwang, R. Lalonde, D. Heron, M. Huq","doi":"10.4236/IJMPCERO.2019.82007","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.82007","url":null,"abstract":"We investigated the feasibility of measuring daily fiducial length on cone-beam computed tomography (CBCT) images to assess the variation in daily tumor motion for pancreatic SBRT. Motion data for fifty pancreatic SBRT patients with fiducials were analyzed retrospectively to determine the tumor motion statistics. We also performed a phantom study which involved motion analysis of three gold fiducials placed around a solid target inside the Quasar Phantom as a function of variable tumor motion and breathing period. The end-exhalation CT-50 images were compared with the CBCT images acquired prior to treatment delivery on a TrueBeam STx linear accelerator. Sinusoidal tumor motion and patients’ breathing files acquired from a Varian-RPM system were used to simulate patients’ breathing patterns. The fiducial length was measured to determine its correlation with tumor motion. Patient tumor motions along the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions were found to be 0.7 ± 0.4 cm, 0.2 ± 0.3 cm, and 0.1 ± 0.2 cm, respectively. Average breathing period was 4.3 ± 0.8 seconds. For sinusoidal and patients’ breathing patterns, a significant correlation was observed between the fiducial length and tumor motions with R2 of 0.99. However, fiducial length was found to be independent of the variation in breathing periods. This work suggests that measuring the fiducial length on daily CBCT images could provide quantitative daily tumor motion for fiducial-based pancreatic SBRT. A timely decision to modify the motion management strategy could be made prior to daily treatment delivery.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89254782","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
Dosimetric Advantages of Volumetric Modulated Arc Therapy Based Coronal Arc Delivery Technique in Brain Stereotactic Radiosurgery: A Feasibility Study 脑立体定向放射外科中基于体积调制电弧治疗的冠状电弧输送技术的剂量学优势:可行性研究
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-03-26 DOI: 10.4236/IJMPCERO.2019.82008
G. Gill, R. Jakubovic, J. Baker, T. Button, Jenghwa Chang
{"title":"Dosimetric Advantages of Volumetric Modulated Arc Therapy Based Coronal Arc Delivery Technique in Brain Stereotactic Radiosurgery: A Feasibility Study","authors":"G. Gill, R. Jakubovic, J. Baker, T. Button, Jenghwa Chang","doi":"10.4236/IJMPCERO.2019.82008","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.82008","url":null,"abstract":"The feasibility of a volumetric modulated arc therapy (VMAT) based coronal arc (cARC) technique for treating a single brain metastasis or lesion proximal to the brainstem or optic chiasm was evaluated. Coplanar (CP) and non-coplanar (NCP) treatment plans to an anthropomorphic head/neck phantom scanned head-first supine were compared to a cARC plan with the phantom rotated vertically. A set of planning target volumes (PTVs) were contoured centrally between the brainstem and optic chiasm (“Ant PTVs”) and posterior to brainstem (“Post PTVs”). Dosimetric indices such as conformity index (C.I.), gradient measure (G.M.), and dose volume histograms (DVHs) were compared for CP, NCP and cARC techniques. The TG101 guidelines for organs-at-risk (OARs), and 95% of PTV receiving at least 100% of the prescription dose (D95 = 100%) were used as plan objectives. Reductions in D50 and D30 to the brainstem of 85.1% ± 3.9% and 87.6% ± 3.2%, respectively were seen for “Post PTVs”, and 51.1% ± 17.8% and 85.6% ± 6.0% respectively for “Ant PTVs” using cARC versus CP (p ≤ 0.01). For chiasm, reductions of D50 and D30 were 61.7% ± 3.2% and 44.2% ± 8.9% for “Ant PTVs”, by 69.3% ± 8.0% and 74.3% ± 8.2% for “Post PTVs” (p ≤ 0.01). Comparing cARC to NCP led to similar dosimetric improvements. The conformity index (C.I.) was measured to be 1.101 ± 0.038, 1.088 ± 0.054, and 1.060 ± 0.040 for cARC, CP and NCP respectively (p ≤ 0.01). The overall GM in cm was 0.581 ± 0.097, 0.708 ± 0.064, and 0.476 ± 0.050 for cARC, CP and NCP respectively (p ≤ 0.01). The mean distance gradient fall-off (in cm) was 0.249 ± 0.038 (cARC), 0.749 ± 0.107 (CP), and 0.621 ± 0.068 (NCP) at the center slice in anterior-posterior direction of the target volume (p ≤ 0.01). The objective of this study is to compare the dosimetric indices of cARC with CP and NCP techniques. In conclusion, cARC can provide improved dosimetry as compared to CP and NCP for lesion proximal to the brainstem or optic chiasm.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77360436","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
Dosimetric Comparison of Integral Radiation Dose: Anisotropic Analytical Algorithm and Acuros XB in Breast Radiotherapy 乳腺放疗中积分辐射剂量的剂量学比较:各向异性分析算法和Acuros XB
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology Pub Date : 2019-03-26 DOI: 10.4236/IJMPCERO.2019.82006
A. Çakır, Z. Akgun
{"title":"Dosimetric Comparison of Integral Radiation Dose: Anisotropic Analytical Algorithm and Acuros XB in Breast Radiotherapy","authors":"A. Çakır, Z. Akgun","doi":"10.4236/IJMPCERO.2019.82006","DOIUrl":"https://doi.org/10.4236/IJMPCERO.2019.82006","url":null,"abstract":"The impact of the difference between Anisotropic Analytical Algorithm (AAA) and Acuros XB (AXB) in breast radiotherapy is not clearly due to different uses and further research is required to explain this effect. The aim of this study is to investigate the contribution of calculation differences between AAA and AXB to the integral radiation dose (ID) on critical organs. Seven field intensity modulated radiotherapy (IMRT) plans were generated using with AAA and AXB algorithms for twenty patients with early stage left breast cancer after breast conserving surgery. Volumetric and dosimetric differences, as well as, the Dmean, V5, V20 doses of the left and right-sided lung, the Dmean, V10, V20, V30 doses of heart and the Dmean, V5, V10 doses of the contralateral breast were investigated. The mean dose (Dmean), V5, V20 doses of the left-sided lung, the Dmean, V5, V10 doses of right-sided lung, the Dmean, V10, V20, V30 doses of heart and the Dmean, V5, V10 doses of the contralateral breast were found to be significantly higher with AAA. In this research integral dose was also higher in the AAA recalculated plan and the AXB plan with the average dose as follows left lung 2%, heart 2%, contralateral breast 8%, contralateral lung 4% respectively. Our study revealed that the calculation differences between Acuros XB (AXB) and Anisotropic Analytical Algorithm (AAA) in breast radiotherapy caused serious differences on the stored integral doses on critical organs. In addition, AXB plans showed significantly dosimetric improvements in multiple dosimetric parameters.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79769712","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: 2
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