Iranian Journal of Medical Physics最新文献_第2页

Commentary on “Assessment of Radiation-induced Secondary Cancer Risks in Breast Cancer Patients Treated with 3D Conformal Radiotherapy” “三维适形放射治疗癌症乳腺癌患者辐射诱发继发癌症风险评估”述评

Iranian Journal of Medical Physics Pub Date : 2021-09-03 DOI: 10.22038/IJMP.2021.59028.1989

H. Ghaznavi

{"title":"Commentary on “Assessment of Radiation-induced Secondary Cancer Risks in Breast Cancer Patients Treated with 3D Conformal Radiotherapy”","authors":"H. Ghaznavi","doi":"10.22038/IJMP.2021.59028.1989","DOIUrl":"https://doi.org/10.22038/IJMP.2021.59028.1989","url":null,"abstract":"Hassan Ali Nedaie et al., recently have published “Assessment of Radiation-induced Secondary Cancer Risks in Breast Cancer Patients Treated with 3D Conformal Radiotherapy” paper in Iranian journal of Medical Physics. The aim of this study was to evaluate the secondary cancer risk in organs at risk for breast cancer radiotherapy by the 3D-CRT technique. The authors used BEIR VII model for measuring of excess absolute risk (EAR) and excess relative risk(ERR). This model was basically used for organs that received low dose (below 1-2 Gy). Based on the same paper, it’s clear that organs like contralateral breast and ipsilateral lung, and heart received a high dose, about several Gy In Nedaie et al. paper, authors reported mean dose for thyroid, heart, contralateral breast and ipsilateral lung are ranged from 3.73 to 15.99, since BEIR VII model is not appropriate for high dose, hence, cancer risk estimation encounters an error. On the other hand, received dose for organs in field is inhomogeneously distributed, for changing inhomogeneously distributed dose to a homogeneous dose, the concept of organ equivalent dose (OED) has been applied. The OED was calculated using the Schneider paper, this model considered repair cells after radiotherapy, dose fractionation, dose–response curve, etc. Therefore, for estimating secondary cancer risk of organs in field that receive high dose, we should use OED model .","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41635966","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

Statistical process control in monitoring radiotherapy quality assurance program: An institutional experience 监测放射治疗质量保证计划中的统计过程控制:一个机构经验

Iranian Journal of Medical Physics Pub Date : 2021-08-29 DOI: 10.22038/IJMP.2021.55869.1931

R. Vysakh, R. Raman, P. Niyas, P. Aflah, M. Musthafa, M. Krishnan, C. Ranjith, P. Anjana

{"title":"Statistical process control in monitoring radiotherapy quality assurance program: An institutional experience","authors":"R. Vysakh, R. Raman, P. Niyas, P. Aflah, M. Musthafa, M. Krishnan, C. Ranjith, P. Anjana","doi":"10.22038/IJMP.2021.55869.1931","DOIUrl":"https://doi.org/10.22038/IJMP.2021.55869.1931","url":null,"abstract":"Introduction: Statistical process control (SPC) is a handy and powerful tool for monitoring quality assurance (QA) programs in radiotherapy. The potential reasons for an uncontrolled QA state monitored via SPC can be identified using the cause-and-effect diagram. This study explains the institutional experience in monitoring weekly output constancy of medical linear accelerator (Linac) and patient-specific quality assurance (PSQA) using SPC and cause-and-effect diagram. Material and methods: Prospective monitoring of output constancy has been demonstrated by the simultaneous usage of Shewhart’s I-MR charts and time-weighted control charts. Two hundred and forty-one PSQA results were retrospectively analysed in a combined γ and dose volume histogram (DVH) based analysis using control charts and process capability indices. A PSQA analysis method has been illustrated in which the site-specific action limits (AL) and control limits (CL) for γ and DVH based analysis were obtained using SPC. Results: The simultaneous use of different control charts indicated a systematic error in the output constancy of Linac as successive measurement points fell above the CL. The reason for failure in output constancy was found using a cause-and-effect diagram due to a faulty monitor ion chamber. The obtained AL and CL for γ and DVH based analysis were used to decide pass or fail criteria in PSQA. Among the analysed treatment plans, four Head and Neck (HN), two Central Nervous System (CNS), four Gastro-Intestinal (GI), and four Gastro Urinal (GU) plans failed the PSQA analysis. Cause-and-effect analysis of these failed treatment plans in PSQA pointed out six primary potential sources of errors in the results. Conclusions: SPC tools can be adopted among institutions for consistent and comparable QA programs. If the QA process monitored using SPC falls outside the CL, cause-and-effect diagrams can be used to extract all possible contributing factors that lead to such a process state.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43537542","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

Impacts of Increasing Number of IMRT Beams on Heart’s Dose-Distribution in Left Breast Irradiation: Dosimetric Study 增加左乳IMRT束数对心脏剂量分布的影响:剂量学研究

Iranian Journal of Medical Physics Pub Date : 2021-08-18 DOI: 10.22038/IJMP.2021.57104.1959

Mohammad Shahanawaj Ansari, Mohammad Ziyauddin Khan, S. Sharma

{"title":"Impacts of Increasing Number of IMRT Beams on Heart’s Dose-Distribution in Left Breast Irradiation: Dosimetric Study","authors":"Mohammad Shahanawaj Ansari, Mohammad Ziyauddin Khan, S. Sharma","doi":"10.22038/IJMP.2021.57104.1959","DOIUrl":"https://doi.org/10.22038/IJMP.2021.57104.1959","url":null,"abstract":"Objectives: The main objective of this study was to assess the impacts of increasing number of IMRT beams on cardiac dose-distribution in left-sided breast irradiation so that we can reduce heart’s mean dose up to clinically acceptable level. Materials and Methods: For this study 107 female patients, diagnosed with left-sided breast cancer were selected retrospectively. In 107 patients, there were 52 patients of chest wall irradiation including supra-clavicular fossa, while 22 patients were of breast conserving surgery excluding supra-clavicular fossa and internal mammary lymph nodes, and 33 patients were of chest wall irradiation including internal mammary lymph nodes and supra-clavicular fossa. Exclusion criteria were previous history of left-sided breast radiation therapy, uncommon fractionated dose delivered in past, indication of palliative radiation therapy. Intensity modulated radiotherapy plans were generated using 7, 9 and11 beams for each patient and prescribed dose was 40.05 Gy in 15 fractions (2.67 Gy /fraction) for the targets.Results:Heart: V5Gy(cc): This was low-dose volume of our study in which 11-bIMRT technique yielded better result as compared to 9- and 7-bIMRT. Maximum and minimum values of V5 were found 539.60cc in 9-bIMRT and 141.32cc in 11-bIMRT techniques respectively. V25Gy(cc): The maximum value of V25Gy was found 41.73cc in 7-bIMRT technique, while the lowest value was 0.29cc in 11-bIMRT. The IMRT technique with 11 beams showed comparatively better result on this parameter as well as 3-5cc volume of V25Gy was spared. Mean dose (Gy): Maximum value of mean dose was found 8.51Gy in 7-bIMRT while it was 6.53Gy in 11-bIMRT technique. Conclusions: The study indicates that increasing number of IMRT beams reduces heart’s high-dose volume and improves quality of treatment plans. It is judicious to use 11-bIMRT technique in left-sided breast irradiation as it produces clinically acceptable mean heart dose.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48787133","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

Dosimetric Impact of Bladder Volumetric Changes During Helical Radiotherapy for Rectal Cancer 直肠癌症螺旋放射治疗过程中膀胱容积变化的剂量影响

Iranian Journal of Medical Physics Pub Date : 2021-08-18 DOI: 10.22038/IJMP.2021.57164.1961

S. Karaca, Kadriye Ayşenur Arlı Karaçam

{"title":"Dosimetric Impact of Bladder Volumetric Changes During Helical Radiotherapy for Rectal Cancer","authors":"S. Karaca, Kadriye Ayşenur Arlı Karaçam","doi":"10.22038/IJMP.2021.57164.1961","DOIUrl":"https://doi.org/10.22038/IJMP.2021.57164.1961","url":null,"abstract":"Purpose: This study aims to investigate the dosimetric impact of bladder volumetric changes during helical radiotherapy (RT) for rectal cancer (RC).Methods: A total of 42 RC patients' helical RT treatment plans were analyzed. The bladder volumes were divided into 3 groups (Group1: V 200ml). Planning target volume(PTV), PTVboost, bladder, bowel, right, and left femoral head dose values were analyzed and compared between groups. Statistical analysis was done with a one-way ANOVA test in SPSS18.0 program. A value of p <0.05 was considered statistically significant.Results: The median age of the patients was 59 (range:22-87) and bladder volume ranged from 41.44ml-620.82ml. In the dosimetric data comparison of the patient groups with different bladder volumes, the D50 dose values of PTV and PTV boost volume was highest in Group 3 (p=0.039). No statistical significance was found between PTV and PTVboost’ doses of D98 and D2 and groups. The optimum PTV dose value was in Group2. Bowel doses were highest in Group 1. As the bladder volume increased, the Dmax, Dmean, V15%, and V30% values of the bowel doses decreased. There was a statistical significant relationship between bladder Dmax doses and groups (p = 0.024). Femoral heads doses increased in proportion to increasing bladder volume groups and these results were statistical significant for V5% and V30% (p <0.05).Conclusion: In our study, as the bladder volume increased, there was an inversely proportional decrease in the bowel doses and a directly proportional increase in the femoral head and bladder doses. Bladder volume values significantly affected values of the target and critical organs dose during helical RT for RC.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42669013","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

Evaluation of radioprotective efficacy of Drymaria cordata extract on whole-body radiation-induced haematological damage in mice 天竺葵提取物对小鼠全身辐射致血液学损伤的防护作用评价

Iranian Journal of Medical Physics Pub Date : 2021-07-31 DOI: 10.22038/IJMP.2021.56512.1946

I. Akomolafe, N. Chetty

{"title":"Evaluation of radioprotective efficacy of Drymaria cordata extract on whole-body radiation-induced haematological damage in mice","authors":"I. Akomolafe, N. Chetty","doi":"10.22038/IJMP.2021.56512.1946","DOIUrl":"https://doi.org/10.22038/IJMP.2021.56512.1946","url":null,"abstract":"Introduction: This study aimed to evaluate the radioprotective potential of Drymaria cordata (DC) extract on mice’s haematological parameters following exposure to X-rays radiation.Materials and Methods: Sixty female mice weighing 38-45g, 10-12 weeks old, were used for this study. The mice were divided into six different groups containing ten mice, sub-divided into irradiated and un-irradiated groups. The animals received 250mg/kg extract of DC by oral gavage for thirteen days in addition to feeding and water ad libitum. Mice were irradiated at the Radiotherapy and Oncology Department of Grey’s Hospital using a linear accelerator. Blood samples were collected at different time intervals for the haematology test with post-irradiation monitoring for 30 days. Results: Exposure of mice to 4Gy and 8Gy of X-ray radiation produced significant changes in the mice’s erythrocytes, haematocrit, leukocytes and platelets, in a dose and time-dependent manner compared with the control (CNT) group. The present study revealed a progressive decrease in all the haematological parameters until 30 days among the irradiated groups. However, animals treated with DC extract before irradiation and animals who received extract only exhibited a significant time-dependent increase in the studied haematological parameters compared to the animals in the CNT group. Furthermore, the pre-treatment of mice with the DC delayed the onset of mortality, thereby increasing mice's survival rate compared with the irradiated control. Conclusion: Our findings showed that DC is a potent natural radioprotective agent through its ability to reduce radiation-induced damage in mice’s haematopoietic system and increase the survival rate.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45505224","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

Investigating the Effects of Brief Electrical Stimulation Duration on Sciatic Nerve Regeneration and Functional Recovery in a Rat Transection Model 研究短时间电刺激对大鼠坐骨神经再生和功能恢复的影响

Iranian Journal of Medical Physics Pub Date : 2021-07-19 DOI: 10.22038/IJMP.2021.57039.1958

N. Naghavi, Hosein Samaram, Sareh Naseri, M. B. Rasouli

{"title":"Investigating the Effects of Brief Electrical Stimulation Duration on Sciatic Nerve Regeneration and Functional Recovery in a Rat Transection Model","authors":"N. Naghavi, Hosein Samaram, Sareh Naseri, M. B. Rasouli","doi":"10.22038/IJMP.2021.57039.1958","DOIUrl":"https://doi.org/10.22038/IJMP.2021.57039.1958","url":null,"abstract":"Background. Periodic and brief electrical stimulations (ES) are used as therapeutic protocols to improve nerve regeneration and functional recovery in various nervous system disorders. Periodic ES is applied transcutaneously for several sessions post-surgery, but brief ES is applied directly to the nerve during the surgery. Brief ES has no negative effects on functional recovery but applying periodic ES may delay the recovery. Objective. In most research studies, brief ES has been applied for 1-hour, although in some studies shorter durations were used. In this research, to reduce the risk of infection and cost, brief ESs with different durations (1-hour and shorter durations) were studied in a comparative study. Methods. The right sciatic nerve of 24 adult male Wistar rats was transected and sutured to a silicone tube. Experimental groups stimulated by 10, 30, and 60 minutes ES (20Hz, 3V, 100µs). The hot plate test was done biweekly. At the end of the experimental period (12 weeks), the histomorphometric assessments were performed on the intra silicon tube segment of the regenerated nerve and its tibial branch.Results. Hot plate test results showed an increase in the regeneration speed in experimental groups; furthermore, the 60-min ES group had better outcomes in histomorphometric assessment than other groups that may be due to ES effect on the neuronal cell bodies.Conclusion. As the results indicate, the 60-min ES had a better outcome compared to other groups. Other specifics of a brief ES such as frequency, pulse width, and waveform (monophasic or biphasic) may be studied in future research.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42368983","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

Suitability Assessment of an Indigenous Heterogeneous Thoracic Phantom for Patient-Specific Quality Assurance in Radiotherapy. 自体异质胸椎假体在放射治疗患者特异性质量保证中的适用性评估。

Iranian Journal of Medical Physics Pub Date : 2021-06-29 DOI: 10.22038/IJMP.2021.52426.1862

V. Gangwar, A. K. Agarwal, O. Gurjar, L. Kumar, V. Mishra, S. Mishra

{"title":"Suitability Assessment of an Indigenous Heterogeneous Thoracic Phantom for Patient-Specific Quality Assurance in Radiotherapy.","authors":"V. Gangwar, A. K. Agarwal, O. Gurjar, L. Kumar, V. Mishra, S. Mishra","doi":"10.22038/IJMP.2021.52426.1862","DOIUrl":"https://doi.org/10.22038/IJMP.2021.52426.1862","url":null,"abstract":"Objective: Patient-specific quality assurance (PSQA) assumes a vital role in precise and accurate radiation delivery to cancer patients. Since the patient body comprises heterogeneous media, the present study aimed to fabricate a heterogeneous thoracic phantom for PSQA. Materials and Methods: Heterogeneous thoracic (HT) phantom was fabricated using rib cage made up of bone equivalent material, kail-wood to mimic lungs and wax to mimic the various body parts. The physical density of all these materials used in phantom fabrication was measured and compared with that of the corresponding part of the actual human thorax. One beam was planned on the computed tomography (CT) images of the phantom and actual patient thorax region. Dose distribution in both the plans was measured and analyzed. Results: The estimated densities of heart, lung, ribs, scapula, spine, and chest wall tissues were 0.804 ± 0.007, 0.186 ± 0.010, 1.796 ± 0.061, 2.017 ± 0.026, 2.106 ± 0.029 and 0.739 ± 0.028 respectively in case of HT phantom while 1.038 ± 0.010, 0.199 ± 0.031, 1.715 ± 0.040, 2.006 ± 0.019, 1.929 ± 0.065 and 0.816 ± 0.028 g/cc, respectively in case of actual human thorax region.The depths of isodose curves in HT phantom were also comparable to the isodose curve’s depths in real patient. The PSQA results were within ± 3% for flat beam (FB) and flattening filtered free beam (FFFB) of 6 megavolts (MV) energy.Conclusion: The density and the dose distribution pattern in the HT phantom were similar to that in the actual human thorax region. Thus, fabricated HT phantom can be utilized for radiation dosimetry in thoracic cancer patients. The materials used to develop HT phantom are easily available in the market at an affordable price and easy to craft.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46223314","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 New Automated Method for Microscopy Image Analysis: Curvelet Paradigm as a Framework for Sperm Detection 一种新的显微镜图像分析自动化方法:曲波范式作为精子检测的框架

Iranian Journal of Medical Physics Pub Date : 2021-06-11 DOI: 10.22038/IJMP.2021.55758.1924

P. Taheri, S. V. Shojaedini

{"title":"A New Automated Method for Microscopy Image Analysis: Curvelet Paradigm as a Framework for Sperm Detection","authors":"P. Taheri, S. V. Shojaedini","doi":"10.22038/IJMP.2021.55758.1924","DOIUrl":"https://doi.org/10.22038/IJMP.2021.55758.1924","url":null,"abstract":"Analyzing sperm behavior in semen microscopy images is a modern approach for infertility treatment. distinguishing low contrast sperms from other parts of semen specimen is the major bottleneck of this technique. Machine vision approaches are fitting solutions for detection of sperms but they are challenging. In this article a new method is introduced which utilizes nonlinear mapping in curvelet framework to detect sperms in microscopy images. The proposed method may detect sperms despite of their poor contrasts and vague distribution, thanks to its better sparse representation and more directionality feature than existing approaches. Furthermore, adapting the parameters of the nonlinear mapping due to curvelet components is effective for reinforcement weak ridges as well as better compatibility with different microscopy images. The obtained results show the proposed method achieves the detection rate minimally 4 and maximally 17 percent better than its alternatives, in presence of zero false detection. Furthermore, it is shown that better detection of sperms by proposed method not only does not lead to extract more false objects but also may improve false positive rate by extent of [3-33] percent compared to other examined algorithms.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43765075","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

Radiation Dose And Image Quality In Various Examinations And Imaging Modes Of Dentomaxillofacial Cone Beam Computed Tomography 牙颌面锥束计算机断层扫描不同检查和成像方式的辐射剂量和图像质量

Iranian Journal of Medical Physics Pub Date : 2021-06-03 DOI: 10.22038/IJMP.2021.56040.1932

M. Toossi, Navid Zafari Ghadim, Elham Dolat, H. Azimian, M. S. Moghadam

{"title":"Radiation Dose And Image Quality In Various Examinations And Imaging Modes Of Dentomaxillofacial Cone Beam Computed Tomography","authors":"M. Toossi, Navid Zafari Ghadim, Elham Dolat, H. Azimian, M. S. Moghadam","doi":"10.22038/IJMP.2021.56040.1932","DOIUrl":"https://doi.org/10.22038/IJMP.2021.56040.1932","url":null,"abstract":"AbstractIntroduction:Cone-beam computed tomography is used for specialized imaging of dental and maxillofacial structures. CBCTs capabilities and facilities for dental and maxillofacial imaging have resulted in their increasing clinical use. Although the dose of CBCT tests is low, its widespread use increases the cumulative dose. This study was conducted to evaluate head and neck effective dose and image quality in different organs for various exposure techniques in CBCT imaging.Materials and Methods:This study was performed on various CBCT imaging examinations. Head and neck parts of anthropomorphic male Rando® Alderson Phantom and thermoluminescent dosimeters were used for organ dosimetry. Contrast to noise ratio and signal to noise ratio were evaluated for image quality assessments. For this purpose, the region of the tooth and soft tissue images were randomly used as the basis. Results: Mean effective dose for face and paranasal sinuses imaging in three modes ( standard, low-dose, ultra-low dose), temporomandibular imaging in two modes(standard & low dose), and dental imaging in implant and endo imaging modes was equal to 382.17, 193.97, 79.96, 262.6, 135.67, 53.93, 682.83, 335.75, 184.18, and 234.57 μSv, respectively. Signal -to -noise ratio (SNR) for the above-mentioned procedures was equal to 6.04, 5.73, 3.71, 6.3, 6.00, 4.08, 14.2, 12.3, 7.51, and 6.97, respectively.Conclusion: The present study showed, when low dose and ultra-low-dose modes are chosen, the patient's dose will be severely reduced in most CBCT procedures. Contrast-to-noise ratio (CNR) and SNR will diminish too, but they are sufficient for some diagnostic purposes.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43727928","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

Dosimetric Efficacy of Voluntary Deep Inspiration Breath-Hold in the Radiotherapy of Left Breast Cancer Patients Using the UK START Trial 自愿深吸气屏气在英国START试验左乳腺癌患者放疗中的剂量学疗效

Iranian Journal of Medical Physics Pub Date : 2021-05-23 DOI: 10.22038/IJMP.2021.55746.1926

A. Hafez, Dina M Abdelaziz, M. Khalil, M. Nagdy

{"title":"Dosimetric Efficacy of Voluntary Deep Inspiration Breath-Hold in the Radiotherapy of Left Breast Cancer Patients Using the UK START Trial","authors":"A. Hafez, Dina M Abdelaziz, M. Khalil, M. Nagdy","doi":"10.22038/IJMP.2021.55746.1926","DOIUrl":"https://doi.org/10.22038/IJMP.2021.55746.1926","url":null,"abstract":"Introduction: Deep inspiration breath-hold (DIBH) technique is widely administered to left breast cancer (LBC) patients to reduce the radiation dose to the cardiopulmonary structures. The UK standardization of breast cancer radiotherapy (UK START) dose prescription was found comparable to the conventional schedule. The current study compared voluntary DIBH and free-breathing (FB) methods in the cardiopulmonary radiation doses of LBC patients with supraclavicular irradiation treated with the UK START trial. Materials and Methods: A computed tomography (CT) scan was acquired for a group of 50 LBC patients in DIBH and FB and a radiotherapy plan was created on each scan. The dose-volume histogram (DVH) parameters of the heart and lung were analyzed against their relevant first clinical acceptance criteria using one-sample t-test. Additionally, we assessed the correlation between the ipsilateral lung volume expansion and the cardiopulmonary dosimetric benefits. Results: The DIBH technique significantly reduced the cardiopulmonary doses compared with the FB method (p < 0.001). Furthermore, the mean difference between the mean heart dose (MHD) and its first acceptance criterion was -62.6 cGy (p < 0.001), and the volume of the heart and lung received at least 16 Gy (Heart V16Gy and lung V16Gy, respectively) was lower than their first acceptance criteria by -0.63% and -2.18% (p < 0.001), respectively. In contrast, the first acceptance criteria of the cardiopulmonary dosimetric parameters were not accomplished with the FB method. In addition, the difference in MHD and heart V20Gy between DIBH and FB plans showed a moderate correlation with ipsilateral lung volume expansion (r = 0.51 and 0.5, respectively). Conclusion: The DIBH technique should be served to all locally advanced LBC patients, and the ipsilateral lung volume expansion could be a predictor for the cardiac-sparing radiotherapy in LBC.","PeriodicalId":14613,"journal":{"name":"Iranian Journal of Medical Physics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48675507","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