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 ...
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 underl...
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
