The physics of CT dosimetry: CTDI and beyond
Gurpreet SinghJournal of Medical Physics 2019 44(3):228-229 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Gurpreet Singh Source Type: research

Evaluation and validation of IBA I & #39;MatriXX array for patient-specific quality assurance of tomotherapy & #174;
N V. N Madhusudhana Sresty, A Krishnam Raju, B Nagarjuna Reddy, VC Sahithya, Yakub Mohmd, G Deleep Kumar, T Anil Kumar, Tasneem Rushdi, S Aparna, G Durga Prasad, Harjot Kaur BajwaJournal of Medical Physics 2019 44(3):222-227TomoTherapy® is a modern radiation treatment technique in which intensity-modulated radiation therapy (IMRT) is delivered in helical fashion. A two-dimensional (2D) array which has been existing for IMRT patient-specific quality assurance (PSQA) verifications for many years is I'MatriXX. Our objectives were to validate this I'MatriXX and to evaluate it for different patient sites and fracti...
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: N V. N Madhusudhana Sresty A Krishnam Raju B Nagarjuna Reddy VC Sahithya Yakub Mohmd G Deleep Kumar T Anil Kumar Tasneem Rushdi S Aparna G Durga Prasad Harjot Kaur Bajwa Source Type: research

Evaluation of healthy tissue dose at different regions between volumetric-modulated arc therapy and intensity-modulated radiation therapy plans in the treatment of various cancers
Conclusions: VMAT plan can reduce the risk of secondary malignancy while treating different sites of cancer. VMAT is the most appropriate technique than IMRT, especially in the treatment of large tumor volume. Special attention has to be given, especially while treating women and children. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Jayapalan Krishnan Suresh Rao Sanath Hegde Jayarama Shetty Source Type: research

Calibration of gafchromic EBT film using the Microtek ScanMaker 9800XL plus flatbed scanner with a modified one red-channel after three-channel method
Conclusion: The proposed technique allows the use of the three-channel method to calibrate film using a Microtek 9800XL+ scanner. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Liyun Chang Sheng-Yow Ho Hueisch-Jy Ding Shyh-An Yeh Pang-Yu Chen Source Type: research

A Model-based method for assessment of salivary gland and planning target volume dosimetry in volumetric-modulated arc therapy planning on head-and-neck cancer
This study examined the relationship of achievable mean dose and percent volumetric overlap of salivary gland with the planning target volume (PTV) in volumetric-modulated arc therapy (VMAT) plan in radiotherapy for a patient with head-and-neck cancer. The aim was to develop a model to predict the viability of planning objectives for both PTV coverage and organs-at-risk (OAR) sparing based on overlap volumes between PTVs and OARs, before the planning process. Forty patients with head-and-neck cancer were selected for this retrospective plan analysis. The patients were treated using 6 MV photons with 2-arc VMAT plan in pres...
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Honglai Zhang Yijian Cao Jeffrey Antone Adam C Riegel Maged Ghaly Louis Potters Abolghassem Jamshidi Source Type: research

A novel design of N-fiducial phantom for automatic ultrasound calibration
Conclusions: The results showed that our proposed method has a high efficiency to perform automatic feature extraction compared to conventional extraction performed by humans. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Maria Chatrasingh Jackrit Suthakorn Source Type: research

Correlation between biological effective dose and radiation-induced liver disease from hypofractionated radiotherapy
Conclusion: The strong correlations of the V10Gy and V15Gy PD-volume metrics as well as the V16.7Gy3(BED of V10Gy) to both classic and chronic RILD imply the appropriateness of the current 15Gy evaluation level for liver toxicity with hypo-fractionated treatments. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Angelo M Bergamo Kevin Kauweloa Gregory Gan Zheng Shi Janeen Daniels Richard Crownover Ganesh Narayanasamy Sotirios Stathakis Panayiotis Mavroidis Niko Papanikolaou Alonso Gutierrez Source Type: research

Electronic portal imaging device-based three-dimensional volumetric dosimetry for intensity-modulated radiotherapy pretreatment quality assurance
Conclusion: The novel TPS-based heterogeneity correction can improve the 2D and 3D EPID-based back projection technique. Structures with large heterogeneities can also be handled using the proposed technique. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Manikandan Arjunan Sureka Chandra Sekaran Biplab Sarkar Saran Kumar Manavalan Source Type: research

Out-of-field dose calculation by a commercial treatment planning system and comparison by monte carlo simulation for varian TrueBeam & #174;
Conclusion: In this work, it was observed that the TPS underestimates doses beyond the edges of treatment fields for a clinical treatment executed on a TB machine. This indicates that the out-of-field dose from TPSs should only be used with a clear understanding of the inaccuracy of dose calculations beyond the edge of the field. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: NS Shine Raghukumar Paramu M Gopinath RC Jaon Bos PM Jayadevan Source Type: research

An experimental slope method for a more accurate measurement of relative radiation doses using radiographic and radiochromic films and its application to megavoltage small-field dosimetry
Conclusions: The authors have developed a novel and more accurate method for the relative dosimetry of photon and electron beams. This offers a unique method to determine PDD and ROF with a high spatial resolution in fields of steep dose gradient, especially in small fields. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 13, 2019 Category: Physics Authors: Raghavendra Holla D Khanna Bhaskaran K Pillai KV Jafar Ali PS Renil Mon CO Clinto Tharmarnadar Ganesh Source Type: research

Basic physics and radiation safety in nuclear medicine
Ajai Kumar ShuklaJournal of Medical Physics 2019 44(2):142-143 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Ajai Kumar Shukla Source Type: research

Clinical three-dimensional dosimetry in modern radiation therapy
Tharmarnadar GaneshJournal of Medical Physics 2019 44(2):139-141 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Tharmarnadar Ganesh Source Type: research

External beam radiotherapy with telecobalt machine: Tissue deficiency compensation in head-and-neck region and effect on skin reactions
Ramamoorthy Ravichandran, Bandana Barman, Gopal Datta, Ravi KannanJournal of Medical Physics 2019 44(2):135-138 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Ramamoorthy Ravichandran Bandana Barman Gopal Datta Ravi Kannan Source Type: research

Validation of the RapidArc delivery system using a volumetric phantom as per task group report 119 of the American association of physicists in medicine
Conclusion: Thus, the ArcCHECK can successfully be utilized for the validation of the RA delivery. The AXB has potential to perform dose calculations comparable to those of the AAA for RA plans in the homogeneous medium of the ArcCHECK phantom. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Lalit Kumar Girigesh Yadav Vimal Kishore Manindra Bhushan Munish Gairola Deepak Tripathi Source Type: research

Impact of silver nanoparticles on the ultraviolet radiation direct and bystander effects on TK6 cell line
Conclusions: Our findings showed the induced DNA damage in TK6 cell by AgNPs and UVC radiation and also were seen BSE. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Zohreh Eftekhari-Kenzerki Reza Fardid Abbas Behzad-Behbahani Source Type: research

Probing the effects of ionizing radiation on young & #39;s modulus of human erythrocytes cytoskeleton using atomic force microscopy
Conclusions: The elastic modulus of the erythrocytes could be an indicator of the adverse effect in the human blood generated by IR exposure through a radiotherapy treatment. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Ellas Spyratou Maria Dilvoi George Patatoukas Kalliopi Platoni Mersini Makropoulou Efstathios Petros Efstathopoulos Source Type: research

Multi-energy computed tomography breast imaging with Monte Carlo simulations: Contrast-to-noise-based image weighting
Conclusions: The new proposed CNR-based image weighting scheme is easy to implement and can be used for complicated phantoms with varying structures. A large increase in the CNR is seen with or without the use of iodine contrast. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: D & #233;te Van Eeden Freek C. P Du Plessis Source Type: research

Performance validation of in-house developed four-dimensional dynamic phantom
Conclusions: The mechanical and imaging performances of FDDP were found within the acceptable limits. Therefore, this phantom can be used for quality assurance of 4D imaging process in radiotherapy. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Rahul Kumar Chaudhary Rajesh Kumar SD Sharma Soumen Bera Vikram Mittal Sudesh Deshpande Source Type: research

Clinical evaluation of a two-dimensional liquid-filled ion chamber detector array for verification of high modulation small fields in radiotherapy
Conclusions: The Octavius 1000 SRS is a dosimetrically accurate device to perform quality assurance checks in SBRT treatments. The broad range of measurements performed in this study quantified the dosimetric accuracy of Octavius 1000 SRS detector in the clinical setup of the small fields in radiotherapy. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Miljenko Markovic Ganesh Narayanasamy Sotirios Stathakis Panayiotis Mavroidis Ines-Ana Jurkovic Daniel Saenz Niko Papanikolaou Source Type: research

Dosimetric effect of rotational setup errors in single-isocenter volumetric-modulated arc therapy of multiple brain metastases
Conclusion: Our results indicate that correcting rotational uncertainties is critical in single-isocenter, multi-target SRS. For rotational deviations, radial distance of the target from isocenter along the respective axis has a strong influence on target coverage. For rotational setup deviation at a given radial distance larger targets tend to have lesser geometric miss compared to smaller targets. Mathematical model for spherical targets can be used to estimate V95 for given rotational errors. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Kasirajan Tamil Selvan Ganesan Padma Murugesan Kesavan Revathy N Arunai Nambi Raj K Senthilnathan P Ramesh Babu Source Type: research

Investigation of internal target volumes using device and deviceless four-dimensional respiratory monitoring systems for moving targets in four-dimensional computed tomography acquisition
Conclusion: The results showed that the DL method is an effective way of image sorting in 4D acquisition for smaller target excursion. When the target motion exceeds 3 mm in A-P and L-R directions with S-I more than 10 mm, DB method is the choice due to its accuracy in reproducing the absolute target volume. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - June 11, 2019 Category: Physics Authors: Raghavendra Holla D Khanna Shubhangi Barsing Bhaskaran K Pillai Tharmarnadar Ganesh Source Type: research

Study on measurement of environmental radioactivity and assessment of radiological hazards in Kashmir Valley
Gopiraj AnnamalaiJournal of Medical Physics 2019 44(1):70-70 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Gopiraj Annamalai Source Type: research

Fabrication and characterization of a three-dimensional positive-ion detector and its applications
Kulandaivel MuthuveluJournal of Medical Physics 2019 44(1):68-69 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Kulandaivel Muthuvelu Source Type: research

Determination of optimal clinical target volume to planning target volume margins for conformal radiotherapy planning using image guidance system in rectal cancer in prone position
Conclusions: Image guidance is an effective method to evaluate patient setup errors. Good quality immobilization devices and stringent patient setup policies can help to reduce PTV margins further. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Shashank Bansal Mouchumee Bhattacharyya Apurba Kumar Kalita Moirangthem Nara Singh Rubu Sunku Partha Pratim Medhi Ghritashee Bora Source Type: research

Radiation shielding for helical tomotherapy vault design
Conclusions: A typical helical tomotherapy vault design is proposed based on the calculated shielding thicknesses of protective barriers. Further, it is also concluded that tomotherapy machine can be installed in a vault designed for 6 MV conventional linear accelerator with minor modification. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Amanjot Kaur PN Pawaskar G Sahani Source Type: research

Development of a method to determine electron density and effective atomic number of high atomic number solid materials using dual-energy computed tomography
Conclusions: DECT can be used as an effective tool for determining the effective atomic number and electron density of high atomic number substance. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Avinav Bharati Susama Rani Mandal Arun Kumar Gupta Amlesh Seth Raju Sharma Ashu S Bhalla Chandan J Das S Chatterjee Pratik Kumar Source Type: research

Phantom-based feasibility studies on phase-contrast mammography at Indian synchrotron facility indus-2
Conclusion: It was observed in case of all the phantoms and test samples that EEI and EE/N values are relatively higher for images taken in the phase mode. The absorbed dose to air at imaging plane was found to be 75.59 mGy and 28.9 mGy for 12 and 16 keV SR energies, respectively. However, these dose values can be optimized by reducing the image acquisition time without compromising the image quality when clinical samples are imaged. This work demonstrates the feasibility of XPCI in mammography using 12 and 16 keV SR X-ray beams. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Reena Sharma SD Sharma PS Sarkar B Singh AK Agrawal D Datta Source Type: research

Effective dose display system in gastric cancer X-ray screening
Conclusions: “Effective dose display system” was constructed to display effective dose immediately after gastric cancer X-ray screening. This system is on the way to be reformed by improving the regression equation on larger data. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Kenyu Yamamoto Naoko Fujiwara Masahiko Kiyama Yoshihiro Takeda Tadao Kuwano Toshizo Katsuda Masami Azuma Toshinori Ito Source Type: research

Evaluation of nanoDot optically stimulated luminescence dosimeter for cone-shaped small-field dosimetry of cyberknife stereotactic radiosurgery unit: A monte carlo simulation and dosimetric verification study
Conclusion: Its low reliable readings for cones smaller than 15 mm should be considered before its in vivo applications of Cyberknife system. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Fadil Akyol Neslihan Sarigul Mete Yeginer Yagiz Yedekci Haluk Utku Source Type: research

Extraction of retinal blood vessels on fundus images by kirsch & #39;s template and Fuzzy C-Means
Conclusion: The results show that this approach is a suitable alternative technique for the supervised method and it is support for similar fundus images dataset. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: T Jemima Jebaseeli C Anand Deva Durai J Dinesh Peter Source Type: research

Validation of three-dimensional electronic portal imaging device-based PerFRACTION & #8482; software for patient-specific quality assurance
Conclusions: PerFRACTIONTM appears reliable and valid under experimental conditions in air and with phantoms. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: A Aziz Sait Jason Figueredo Glenn W Jones Kai Jones Thomas McGowan Jeff Kapatoes Ramani Ramaseshan Source Type: research

Pretreatment dose verification in volumetric modulated arc therapy using liquid ionization chamber
Conclusions: The measured dose values by the two dosimeters and TPS calculated dose at a given point were found comparable suggesting that the LIC could be a good choice of dosimeter for pretreatment dose verification in VMAT. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Nitin R Kakade Rajesh Kumar Sunil Dutt Sharma Vikram Mittal D Datta Source Type: research

Dosimetric comparison of four volumetric-modulated arc therapy beam arrangements utilized for hippocampal-sparing whole-brain radiation therapy
Conclusions: Overall, beam setup 3 was considered to be the best. It is worth mentioning that, apart from our results, the election of one of these beam arrangements might be dependent on the amount of patient workload at a specific institution. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - March 11, 2019 Category: Physics Authors: Alejandro Prado Ana Isabel Milan & #233;s Eduardo Cabello Ra & #250;l D & #237;az Alejandro Ferrando Gustavo Pozo Mario Leonor Marta Manzano Source Type: research

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Pratik KumarJournal of Medical Physics 2018 43(4):277-279 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Pratik Kumar Source Type: research

Determination and analysis of film reject rate at eight selected governmental diagnostic X-ray facilities in Tigray Region, Northern Ethiopian
Conclusions: Rejected films were found to have been caused by numerous factors including incorrect exposure, poor technical judgment, patient motion, and improper film processing. Hence, strategies need to be developed within medical imaging departments to improve the situation. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Messele Yisak Arbese T Demissie Abebe B Abraha Mesele Source Type: research

Verification of treatment planning algorithms using optically stimulated luminescent dosimeters in a breast phantom
Zhenia Gopalakrishnan, Raghuram K Nair, P Raghukumar, Sharika V Menon, Saju BhasiJournal of Medical Physics 2018 43(4):264-269Aim: The aim of this study is to measure and compare the surface dose of treated breast and contralateral breast with the treatment planning system (TPS) calculated dose using calibrated optically stimulated luminescent dosimeter (OSLD) in an indigenous wax breast phantom. Materials and Methods: Three-dimensional conformal plans were generated in eclipse TPS v. 13 to treat the left breast of a wax phantom for a prescribed dose of 200 cGy. The plans were calculated using anisotropic analytical algori...
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Zhenia Gopalakrishnan Raghuram K Nair P Raghukumar Sharika V Menon Saju Bhasi Source Type: research

Imaging and dosimetric study on direct flat-panel detector-based digital mammography system
Conclusion: Under AEC mode, FOM values for the 4.5 cm thick BARC polymethyl methacrylate (PMMA) phantom were found to be 15.02, 15.88, and 19.82 at Mo/Mo, Mo/Rh, and W/Rh target/filter (T/F), respectively. Under OPDOSE mode, FOM values were found to 65.32, 11.80, and 1.14 for the BARC PMMA phantom thickness of 2, 4.5, and 8 cm, respectively. Under OPDOSE mode, the calculated MGD values for three Computerized Imaging Reference Systems slab phantoms having total thickness of 7 cm were observed to be 3.03, 2.32, and 1.75 mGy with glandular/adipose tissue compositions of 70/30, 50/50, and 30/70, respectively, whereas for the 2...
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Reena Sharma SD Sharma PS Sarkar D Datta Source Type: research

Dosimetric characterization of an intensity-modulated X-ray brachytherapy system
Conclusions: Dose distribution variance should be considered in beam modulation for clinical application. Dynamic movement of the pseudo-target is feasible and remains as a subject for future research. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Sung-Woo Lee Evgeny Sozontov Emil Strumban Fang-Fang Yin Source Type: research

Dosimetry effects caused by unilateral and bilateral hip prostheses: A monte carlo case study in megavoltage photon radiotherapy for computed tomography data without metal artifacts
Conclusions: The novel technique used enabled the complete exclusion of metal artifacts in the CT dataset. High-energy plans with more oblique beams can help minimize dose attenuation through HPs. Shadowing and interface effects are density dependent and greatest for SS316L, while UHMWPE poses negligible dose perturbation. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Courage Mahuvava Frederik Carl Phillipus Du Plessis Source Type: research

Comparison of interfractional setup reproducibility between two types of patient immobilization devices in image-guided radiation therapy for prostate cancer
Conclusion: It can be concluded that the settling of the vacuum fixation was caused by air leakage in the latter-half treatment, and the immobilization device type has no effect on the treatment-position reproducibility in IGRT. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Shoki Inui Yoshihiro Ueda Shingo Ohira Masaru Isono Akira Masaoka Seiya Murata Yuya Nitta Tsukasa Karino Masayoshi Miyazaki Teruki Teshima Source Type: research

Experimental assessment of proton dose calculation accuracy in small-field delivery using a mevion S250 proton therapy system
Conclusions: Eclipse TPS generates acceptable target coverage for small targets with carefully arranged multiple beams despite relatively large dose discrepancy for each beam. Surface doses higher than Eclipse calculations can be mitigated with multiple beams. When using EBT3 film, the quenching effect should be considered. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Kyle D DePew Salahuddin Ahmad Hosang Jin Source Type: research

Evaluation of plan quality metrics in stereotactic radiosurgery/radiotherapy in the treatment plans of arteriovenous malformations
Conclusions: The analysis shows that RTOG indices and EFOD would suffice for routine clinical radiosurgical treatment plan evaluation if a dose distribution is available for visual inspection. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: Sharika Venugopal Menon Raghukumar Paramu Saju Bhasi Raghuram Kesavan Nair Source Type: research

Study to compare the effect of different registration methods on patient setup uncertainties in cone-beam computed tomography during volumetric modulated arc therapy for breast cancer patients
Conclusion: For breast VMAT plan delivery, all three registration methods show insignificant variation in patient setup error. One can use any of the three registration methods for patient setup verification. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - December 7, 2018 Category: Physics Authors: P Mohandass D Khanna T Manoj Kumar T Thiyagaraj C Saravanan Narendra Kumar Bhalla Abhishek Puri Source Type: research

Review of the book entitled & #8220;Cancer, Radiation Therapy, and the Market & #8221; by Ms. Barbara Bridgman
Deepak Dattatray DeshpandeJournal of Medical Physics 2018 43(3):204-206 (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Deepak Dattatray Deshpande Source Type: research

Assessment of diagnostic reference level in radiography of neonatal chest anteroposterior examination: A hospital-based study
Jibon Sharma, Jogesh Sarma, Sushant AgarwalJournal of Medical Physics 2018 43(3):200-203Radiological imaging is an important modality of today's overall practicum. Imaging can begin as early as the 1st day of life. Neonates are 3–4 times more sensitive to radiation than adults. The purpose of the work was to assess the diagnostic reference level (DRL), the radiation organ dose, and effective organ dose for both sexes from chest anteroposterior radiograph, which is the most common radiographic examination performed at the Neonatal Intensive Care Unit (NICU). The entrance air kerma was measured using a solid-state ...
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Jibon Sharma Jogesh Sarma Sushant Agarwal Source Type: research

Monte Carlo simulation on the imaging contrast enhancement in nanoparticle-enhanced radiotherapy
This study focused on the imaging in radiotherapy by finding the relationship between the imaging contrast ratio and appropriate gold, iodine, iron oxide, silver, and platinum nanoparticle concentrations; the relationship between the imaging contrast ratio and different beam energies for the different nanoparticle concentrations; the relationship between the contrast ratio and various beam energies for gold nanoparticles; and the relationship between the contrast ratio and different thicknesses of the incident layer of the phantom including variety of gold nanoparticles (GNPs) concentration. Monte Carlo simulation was used...
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Ferdos Albayedh James C. L. Chow Source Type: research

Optimization of variance reduction techniques used in EGSnrc Monte Carlo Codes
The objective of this work was to determine the optimal combination of VRTs that increases the simulation speed and the efficiency of simulation, without compromising its accuracy. Selection of VRTs was performed using EGSnrc MC User codes, such as cavity and egs_chamber, for simulating various ion chamber geometries using 6 MV photon beams and 1.25 MeV60Co photon beams. The results show that the combination of XCSE and RR yields the highest efficiency for ion-chamber dose calculations inside a 30 cm × 30 cm × 30 cm water phantom. Hence, properly selecting a different VRT without altering the underlying physics i...
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Sangeetha Shanmugasundaram Sureka Chandrasekaran Source Type: research

A pilot study on the comparison between planning target volume-based intensity-modulated proton therapy plans and robustly optimized intensity-modulated proton therapy plans
The objective of this work is to compare the planning target volume (PTV)-based intensity-modulated proton therapy (IMPT) plans with robustly optimized IMPT plans using the robust optimization tools available in Pinnacle Treatment Planning System. We performed the study in five cases of different anatomic sites (brain, head and neck, lung, pancreas, and prostate). Pinnacle IMPT nonclinical version was used for IMPT planning. Two types of IMPT plans were created for each case. One is PTV-based conventionally optimized IMPT plan and the other is robustly optimized plan considering setup uncertainties. For the PTV-based plans...
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Bojarajan Perumal Harikrishna Etti Sundaresan Ranganathan Vaitheeswaran Source Type: research

Dosimetry of 175Ytterbium-poly (amidoamine) therapy for humans & #39; organs
Conclusion: The results showed that 175Yb-PAMAM nano-radiopharmaceutical has potential of application for liver and lung tumors. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Navideh Aghaei-Amirkhizi Sodeh Sadjadi Leila Moghaddam-Banaem Mitra Athari-Allaf Fariba Johari-Deha Source Type: research

Incidence of suboptimal applicator placement and the resulting dosimetric impact in image-based intracavitary brachytherapy
Conclusion: In order to achieve better local control and to decrease doses to OAR, it is important to perform a technically accurate applicator placement. A cost-effective, real-time image guidance modality like ultrasound is recommended for all insertions to ensure optimal applicator insertion. (Source: Journal of Medical Physics)
Source: Journal of Medical Physics - September 26, 2018 Category: Physics Authors: Ramya Rangarajan Source Type: research