Journal of Biomedical Physics and Engineering最新文献

{"title":"Comparison of three Radiotherapy Techniques Volumetric Modulated Arc Therapy with Variable and Constant Dose Rate and Intensity-Modulated Radiotherapy for the Irradiation of Five Cancer Sites.","authors":"Varsha Raghunathji Gedam, Anirudh Pradhan","doi":"10.31661/jbpe.v0i0.2210-1549","DOIUrl":"10.31661/jbpe.v0i0.2210-1549","url":null,"abstract":"<p><strong>Background: </strong>Volumetric modulated arc therapy (VMAT) is mostly considered due to its superior tumor coverage and sparing of organs at risk (OAR) with shorter treatment delivery time.</p><p><strong>Objective: </strong>This study aimed to explore the feasibility and potential benefits of VMAT with a constant dose rate (CDR).</p><p><strong>Material and methods: </strong>In this analytical study, 75 cancer patients (15 from each cancer) were selected. Step and shoot intensity-modulated radiation therapy (S&S IMRT), CDR, and VDR VMAT (variable dose rate VMAT) plans were generated for each patient using the Monte Carlo algorithm on the Monaco treatment planning system for 6 MV photon energy. For dosimetric comparison, some variables were compared, including doses to the planning target volume (PTV), OAR, homogeneity index, conformity index (CI), treatment delivery time, and monitor units.</p><p><strong>Results: </strong>CI was higher in CDR and VDR VMAT plans compared to IMRT without any significant variation for PTV coverage V95 and PTV mean dose. In the sparing of OAR, no significant variation was found between CDR, VDR, and IMRT for the brain, head-neck, oesophagus, lung, and prostate. The treatment delivery time was reduced more, i.e., by up to 72-80% in the CDR VMAT technique compared to IMRT.</p><p><strong>Conclusion: </strong>CDR VMAT technique generates a clinically acceptable plan in terms of PTV coverage, dose conformity, and OAR sparing as IMRT and VDR VMAT in all five cancer sites.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 4","pages":"335-346"},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11336051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Twin Paradox: From Einstein's Theory to NASA's Twin Astronauts.","authors":"Seyed Mohammad Javad Mortazavi, Payman Rafiepour, Seyed Alireza Mortazavi, Lembit Sihver","doi":"10.31661/jbpe.v0i0.2307-1634","DOIUrl":"10.31661/jbpe.v0i0.2307-1634","url":null,"abstract":"","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 4","pages":"421-422"},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11336052/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and Evaluation of a Patellar Tendon-Bearing Brace with Off-Loading Mechanism on Tibia.","authors":"Vahid Chamani, Mahmood Bahramizahed, Mobina Khosravi, Akbar Biglarian, Gholamreza Ghorbani Amjad, Seyyed Mohammad Ebrahim Mousavi, Mokhtar Arazpour","doi":"10.31661/jbpe.v0i0.2403-1738","DOIUrl":"10.31661/jbpe.v0i0.2403-1738","url":null,"abstract":"<p><p>The current study aimed to design a patellar-tendon-bearing (PTB) brace capable of measuring and quantifying weight offloading on the tibia. The PTB brace was designed with off-loading mechanism on the tibia with features, including ankle joint, vertical sliding adaptor, vertical sliding piece, and upper connector of load cells to PTB brace. Also, the present study investigated the effect of brace on 20 healthy individuals under 8 different off-loading conditions, based on measuring the vertical distance between the calf shells and foot plate through a sliding adapter at 0.5, 1, 1.5, 2, 2.5, 3, and 3.5 cm. The Pedar device and load cells embedded in PTB brace were used to determine the extent of offloading and assess the reliability and validity of brace. Increasing the vertical distance between the calf shells and the footplate can lead to a greater amount of offloading. Accordingly, off-loading ranged from a minimum of 16.5% at 0 cm position to a maximum of 60.48% at 3.5 cm position of sliding adapter. Percentage values of tibia off-loading in 8 conditions were not significantly different in Padar devices and PTB brace. Therefore, PTB brace load cells, as a valid method, can measure off-loading levels. When fabricating a PTB brace, a monitoring system with load cells is essential to measure the amount of tibial offloading, leading to readjustment if limb slides down inside the brace. Additionally, a component is needed to correctly position limb in off-loading condition. In the current study, sliding adapter of brace can provide that capability.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 4","pages":"407-414"},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11336054/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142037312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Lead-Free Materials for Radiation Shielding in Medical Settings: A Review.","authors":"Arash Safari, Payman Rafie, Shahram Taeb, Masoud Najafi, Seyed Mohammad Javad Mortazavi","doi":"10.31661/jbpe.v0i0.2404-1742","DOIUrl":"10.31661/jbpe.v0i0.2404-1742","url":null,"abstract":"<p><p>Radiation protection is an essential issue in diagnostic radiology to ensure the safety of patients, healthcare professionals, and the general public. Lead has traditionally been used as a shielding material due to its high atomic number, high density, and effectiveness in attenuating radiation. However, some concerns related to the long-term health effects of toxicity, environmental disease as well as heavy weight of lead have led to the search for alternative lead-free shielding materials. Leadfree multilayered polymer composites and non-lead nano-composite shields have been suggested as effective shielding materials to replace conventional lead-based and single metal shields. Using several elements with high density and atomic number, such as bismuth, barium, gadolinium, and tungsten, offer significant enhancements in the shielding ability of composites. This review focuses on the development and use of lead-free materials for radiation shielding in medical settings. It discusses the drawbacks of traditional lead shielding, such as toxicity, weight, and recycling challenges, and highlights the benefits of lead-free alternatives.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"229-244"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252547/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141725479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Critical Role of Radiation Protection in Modern Life.","authors":"James Welsh, Seyed Mohammad Javad Mortazavi, Lembit Sihver","doi":"10.31661/jbpe.v0i0.2405-1769","DOIUrl":"https://doi.org/10.31661/jbpe.v0i0.2405-1769","url":null,"abstract":"","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"211-212"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252546/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141724650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the Absorbed Dose Variations in the Thyroid Gland Exposed to Orthopantomography (OPG) while Swallowing: A Novel Approach to Radiation Protection.","authors":"Hassan Vafapour, Zaker Salehi PhD","doi":"10.31661/jbpe.v0i0.2305-1622","DOIUrl":"10.31661/jbpe.v0i0.2305-1622","url":null,"abstract":"<p><strong>Background: </strong>The reliance on specialized diagnostic techniques is on the rise across various medical fields, including dentistry. While orthopantomogram (OPG), offers many advantages in terms of dental diagnosis, it also poses potential risks to sensitive organs, notably the thyroid gland.</p><p><strong>Objective: </strong>This study aimed to evaluate the fluctuations in the absorbed dose within the thyroid gland during swallowing while undergoing an OPG procedure.</p><p><strong>Material and methods: </strong>In this computational simulation study, the BEAMnrc Monte Carlo code was employed to model an OPG machine, using 700 million particles across the energy range of 60-75 keV, which is standard for OPG procedures. The Monte Carlo (MC) model was cross-verified by comparing the derived spectra with those in the IPEM Report 78. A head and neck phantom was constructed using CT scan images with a slice thickness of 5 mm. This phantom underwent simulated beam exposure under two conditions: pre-swallow and post-swallow. Subsequently, the percentage depth dose was measured and contrasted across different depths.</p><p><strong>Results: </strong>After swallowing, there was an increase in the absorbed dose across all three regions of the thyroid (right, left, and center). Notably, regions near the hyoid bone exhibited a particularly significant increase in dose. In certain areas, the absorbed dose even tripled when compared to the pre-swallowing state.</p><p><strong>Conclusion: </strong>The findings indicate that during OPG imaging, swallowing can lead to an increased radiation dose to the thyroid gland. Given the thyroid's heightened sensitivity to radiation, such an increase in dosage is noteworthy.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"267-274"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141724624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Reexamination of Peto's Paradox: Insights Gained from Human Adaptation to Varied Levels of Ionizing and Non-ionizing Radiation.","authors":"Seyed Mohammad Javad Mortazavi, Omid Zare, Leyla Ghasemi, Parmis Taghizadeh, Parsa Faghani, Maryam Arshadi, Seyed Ali Reza Mortazavi, Lembit Sihver","doi":"10.31661/jbpe.v0i0.2402-1729","DOIUrl":"10.31661/jbpe.v0i0.2402-1729","url":null,"abstract":"<p><p>Humans have generally evolved some adaptations to protect against UV and different levels of background ionizing radiation. Similarly, elephants and whales have evolved adaptations to protect against cancer, such as multiple copies of the tumor suppressor gene p53, due to their large size and long lifespan. The difference in cancer protection strategies between humans and elephants/whales depends on genetics, lifestyle, environmental exposures, and evolutionary pressures. In this paper, we discuss how the differences in evolutionary adaptations between humans and elephants could explain why elephants have evolved a protective mechanism against cancer, whereas humans have not. Humans living in regions with high levels of background radiation, e.g. in Ramsar, Iran where exposure rates exceed those on the surface of Mars, seem to have developed some kind of protection against the ionizing radiation. However, humans in general have not developed cancer-fighting adaptations, so they instead rely on medical technologies and interventions. The difference in cancer protection strategies between humans and elephants/whales depends on genetics, lifestyle, environmental exposures, and evolutionary pressures. In this paper, we discuss how the differences in evolutionary adaptations between humans and elephants could explain why elephants have evolved a protective mechanism against cancer, whereas humans have not. Studying elephant adaptations may provide insights into new cancer prevention and treatment strategies for humans, but further research is required to fully understand the evolutionary disparities.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"309-314"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252545/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141724623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the Radioactive Waste Produced per Patient by Radiopharmaceutical Sources and Measuring the Radioactive Contamination of Surfaces and Staff at the Bushehr Nuclear Medicine Department.","authors":"Zahra Mohamadi Baghmolaei, Reza Fardid, Masoud Haghani, Gholamhassan Haddadi, Mohammad Abdolahi, Mohammad Ghaderian","doi":"10.31661/jbpe.v0i0.2209-1535","DOIUrl":"10.31661/jbpe.v0i0.2209-1535","url":null,"abstract":"<p><strong>Background: </strong>Nuclear medicine is an integral and developing field in diagnosing and treating diseases. Monitoring individuals' protection and radiation contamination in the workplace is vital for preserving working environments.</p><p><strong>Objective: </strong>This study aimed to monitor the nuclear medicine department's personnel, environment, and wastes to determine the level of occupational radiation and environmental pollution in Bushehr's nuclear medicine department.</p><p><strong>Material and methods: </strong>In this cross-sectional study, the initial activity of each radioisotope, radiopharmaceutical, and radioactive waste was measured using a \"well counter\" daily for three months. Three irradiators' absorbed doses were measured using a direct reading dosimeter. The contamination was determined using an indirect wipe test method on various surfaces. A Geiger Müller dosimeter was employed to examine personnel's hands, clothing, and footwear.</p><p><strong>Results: </strong>The highest activity was observed in technetium waste (1118.31 mCi). Every irradiator received a lower absorption dose than the International Commission on Radiological Protection (ICRP) standard threshold. The majority of contamination was associated with the exercise test room (0.04 Bq/cm²) and its work surface (0.013 Bq/cm²), which were both below the threshold (0.5 Bq/cm²). Staff monitoring indicated that two nurses (10 and 11 individuals) had the highest contamination rate (23.7%).</p><p><strong>Conclusion: </strong>Daily assessment of the type, activity, and method of radiopharmaceutical administration to the patient is advantageous for waste management. Surface contamination monitoring can significantly contribute to the estimation of the level of radiation pollution in the environment.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"245-254"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252552/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141724625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of Ionizing Radiation-Induced Apoptosis by Taurine in Human Peripheral Blood Lymphocytes: Flow Cytometry-based Quantification.","authors":"Shahab Faraji, Mohsen Rajaeinejad, Hamed Bagheri, Mohammad Afshar Ardalan, Hossein Moutabian, Faramarz Ehsani, Mohammad Pourarjmand, Samira Sadat Mirshafieyan, Farshid Alazamani, Susan Cheraghi","doi":"10.31661/jbpe.v0i0.2308-1655","DOIUrl":"10.31661/jbpe.v0i0.2308-1655","url":null,"abstract":"<p><strong>Background: </strong>Radiotherapy, a highly effective method of radiation-based treating cancers, can reduce the size of tumors and affect healthy tissues. Radiation-induced lymphopenia as a side effect of radiation therapy can reduce the effectiveness of the treatment.</p><p><strong>Objective: </strong>This study aimed to examine how taurine can protect peripheral blood lymphocytes from radiation-based apoptosis.</p><p><strong>Material and methods: </strong>In this experimental study, the effects of the taurine on lymphocytes were studied, and blood samples were divided into three groups: a negative control group that was not treated, a positive control group that was treated with cysteine (100 μg/ml), and a group that was treated with taurine (100 µg. mL^-1) in three different doses (4, 8 & 12 Gy) before irradiation. The percentage of apoptotic and necrotic lymphocytes was measured using flow cytometry 48 and 72 hours after the irradiation, respectively.</p><p><strong>Results: </strong>According to the groups treated with taurine, the number of lymphocytes undergoing apoptosis was lower and higher compared to the negative and positive control groups, respectively. The decrease in this value was more pronounced 48 hours after radiation compared to 72 hours. Furthermore, there was a slight increase in the number of apoptotic lymphocytes with increasing radiation dose.</p><p><strong>Conclusion: </strong>Taurine effectively protects human peripheral blood lymphocytes from radiation-based apoptosis.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"287-298"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252553/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141724648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Critical Look at Heavy Ion Beam Irradiation for Vaccine Development.","authors":"Payman Rafiepour, Seyed Mohammad Javad Mortazavi, Lembit Sihver","doi":"10.31661/jbpe.v0i0.2405-1765","DOIUrl":"10.31661/jbpe.v0i0.2405-1765","url":null,"abstract":"<p><p>Recent studies offer valuable insights into viral inactivation for vaccine development. Schulze et al. have demonstrated the potential of heavy ion beam irradiation to create effective vaccines, which is particularly relevant in the context of airborne pandemics. Notably, the success in immunizing mice via intranasal administration with the inactivated influenza virus is encouraging, especially given the genetic similarities between influenza and SARS-CoV-2. However, the study raises important considerations. While heavy ion treatment shows advantages, there are concerns about viral inactivation completeness and the potential for surviving viruses, albeit at extremely low levels. Prolonged irradiation times and the risk of selective pressure leading to the evolution of resistant variants are highlighted. Biosafety concerns regarding accidental lab escape of resistant strains are crucial, emphasizing the need for caution during experiments. Moreover, limitations in Monte Carlo simulations of virus irradiation are discussed, pointing out the need for more comprehensive studies to assess the impact of secondary particles on virus inactivation under realistic irradiation conditions. Given these considerations, while the study presents a promising approach for vaccine development, further research is essential to address potential drawbacks and optimize the method for safe and effective application.</p>","PeriodicalId":38035,"journal":{"name":"Journal of Biomedical Physics and Engineering","volume":"14 3","pages":"315-318"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11252548/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141724622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}