Methodological approach to create an atlas using a commercial auto-contouring software.
CONCLUSION: A statistically significant improvement of auto-contours accuracy was obtained using our atlas and optimized workflow instead of the MIM Software pelvic atlas. PMID: 33236827 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 25, 2020 Category: Physics Authors: Casati M, Piffer S, Calusi S, Marrazzo L, Simontacchi G, Di Cataldo V, Greto D, Desideri I, Vernaleone M, Francolini G, Livi L, Pallotta S Tags: J Appl Clin Med Phys Source Type: research

Evaluation of deep learning-based auto-segmentation algorithms for delineating clinical target volume and organs at risk involving data for 125 cervical cancer patients.
CONCLUSION: The auto-segmentation model was as accurate as the medical resident but with much better efficiency in this study. Furthermore, the auto-segmentation approach offers additional perceivable advantages of being consistent and ever improving when compared with manual approaches. PMID: 33238060 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 25, 2020 Category: Physics Authors: Wang Z, Chang Y, Peng Z, Lv Y, Shi W, Wang F, Pei X, Xu XG Tags: J Appl Clin Med Phys Source Type: research

Three discipline collaborative radiation therapy (3DCRT) special debate: Peer review in radiation oncology is more effective today than 20 years ago.
PMID: 33232567 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 24, 2020 Category: Physics Authors: Ahmad A, Santanam L, Solanki AA, Padilla L, Vlashi E, Guerrieri P, Dominello MM, Burmeister J, Joiner MC Tags: J Appl Clin Med Phys Source Type: research

Effect of dental metal artifact conversion volume on dose distribution in head-and-neck volumetric-modulated arc therapy.
CONCLUSIONS: The results show that the artificial variability of manual artificial tooth metal artifact contouring has little effect on the dose distribution of VMAT. However, it should be noted that the dose distribution may change depending on the contouring method in cases where the overlap between PTV and metal artifact areas is large. PMID: 33226172 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 23, 2020 Category: Physics Authors: Kitagawa K, Ikushima H, Sasaki M, Furutani S, Kawanaka T, Kubo A, Tonoiso C, Kudoh T, Kano Y, Tsuzuki A Tags: J Appl Clin Med Phys Source Type: research

Evaluation of cine imaging during multileaf collimator and gantry motion for real-time magnetic resonance guided radiation therapy.
CONCLUSION: During MLC motion, cine images maintained adequate PIU, and the geometric distortion of points within 15.225 cm from isocenter was less than the 1 mm threshold necessary for real-time target tracking and gating. During gantry rotation, PIU was negatively affected by banding artifacts, and spatial integrity was only maintained within 10 cm from isocenter. Future work should investigate the effects imaging artifacts have on real-time target tracking during MRgRT. PMID: 33226709 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 23, 2020 Category: Physics Authors: Kielbasa JE, Meeks SL, Kelly P, Willoughby TR, Zeidan O, Shah AP Tags: J Appl Clin Med Phys Source Type: research

Monte Carlo simulation of 6-MV dynamic wave VMAT deliveries by Vero4DRT linear accelerator using EGSnrc moving sources.
Abstract The commissioning and benchmark of a Monte Carlo (MC) model of the 6-MV Brainlab-Mitsubishi Vero4DRT linear accelerator for the purpose of quality assurance of clinical dynamic wave arc (DWA) treatment plans is reported. Open-source MC applications based on EGSnrc particle transport codes are used to simulate the medical linear accelerator head components. Complex radiotherapy irradiations can be simulated in a single MC run using a shared library format combined with BEAMnrc "source20." Electron energy tuning is achieved by comparing measured vs simulated percentage depth doses (PDDs) for MLC-d...
Source: Journal of Applied Clinical Medical Physics - November 21, 2020 Category: Physics Authors: Rostamzadeh M, Ishihara Y, Nakamura M, Popescu IA, Mestrovic A, Gete E, Fedrigo R, Bergman AM Tags: J Appl Clin Med Phys Source Type: research

Characterization of radiotherapy component impact on MR imaging quality for an MRgRT system.
This study showed that gantry position can impact imaging isocenter, but spatial integrity errors were not dependent on gantry position, MLC field size, or treatment table power state. Significant isocenter variation, while reduced postupgrade, is cause for further investigation. PMID: 33211375 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 19, 2020 Category: Physics Authors: Lewis BC, Gu B, Klett R, Lotey R, Green OL, Kim T Tags: J Appl Clin Med Phys Source Type: research

FMEA occurrence values for four failure modes occurring using look-up tables for dose calculations.
Abstract PURPOSE: For a number of different treatment types [such as Total Body Irradiation (TBI), etc.] most institutions utilize tables from commissioned databooks to perform the dose calculations. Each time one manually looks up data from a large table and then copies the numbers for a manual calculation, there is potential for errors. While a second check effectively mitigates the potential error from such calculations, information regarding the frequency and nature of such mistakes is important to develop protocols and workflows that avoid related errors. METHODS: Five years' worth of TBI calculations we...
Source: Journal of Applied Clinical Medical Physics - November 15, 2020 Category: Physics Authors: Nelson G, Paxton A, Kunz J, Huang J, Szegedi M, Sarkar V, Salter B Tags: J Appl Clin Med Phys Source Type: research

A phantom study to evaluate three different registration platform of 3D/3D, 2D/3D, and 3D surface match with 6D alignment for precise image-guided radiotherapy.
y SL Abstract PURPOSE: To evaluate two three-dimensional (3D)/3D registration platforms, one two-dimensional (2D)/3D registration method, and one 3D surface registration method (3DS). These three technologies are available to perform six-dimensional (6D) registrations for image-guided radiotherapy treatment. METHODS: Fiducial markers were asymmetrically placed on the surfaces of an anthropomorphic head phantom (n = 13) and a body phantom (n = 8), respectively. The point match (PM) solution to the six-dimensional (6D) transformation between the two image sets [planning computed tomography (...
Source: Journal of Applied Clinical Medical Physics - November 12, 2020 Category: Physics Authors: Kuo HC, Lovelock MM, Li G, Ballangrud Å, Wolthuis B, Della Biancia C, Hunt MA, Berry SL Tags: J Appl Clin Med Phys Source Type: research

Surface and build-up dose comparison between Elekta 6  MV flattening filter and flattening-filter-free beams using an advanced Markus ionization chamber and a solid water-equivalent phantom.
Surface and build-up dose comparison between Elekta 6 MV flattening filter and flattening-filter-free beams using an advanced Markus ionization chamber and a solid water-equivalent phantom. J Appl Clin Med Phys. 2020 Nov 12;: Authors: Imae T, Takenaka S, Watanabe Y, Aoki A, Matsuda K, Sasaki K, Saegusa S, Nawa K, Nakagawa K, Abe O Abstract Using a plane-parallel advanced Markus ionization chamber and a stack of water-equivalent solid phantom blocks, percentage surface and build-up doses of Elekta 6 MV flattening filter (FF) and flattening-filter-free (FFF) beams were measured as a function o...
Source: Journal of Applied Clinical Medical Physics - November 12, 2020 Category: Physics Authors: Imae T, Takenaka S, Watanabe Y, Aoki A, Matsuda K, Sasaki K, Saegusa S, Nawa K, Nakagawa K, Abe O Tags: J Appl Clin Med Phys Source Type: research

Monte Carlo simulations of EBT3 film dose deposition for percentage depth dose (PDD) curve evaluation.
CONCLUSIONS: PDD measurements with films should either be performed with film in perpendicular orientation to the beam axis or in parallel orientation with a ~ 2º tilt and no air gaps. PMID: 33155768 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 6, 2020 Category: Physics Authors: Robinson SM, Esplen N, Wells D, Bazalova-Carter M Tags: J Appl Clin Med Phys Source Type: research

Proton vs Hyperarc ™ radiosurgery: A planning comparison.
Proton vs Hyperarc™ radiosurgery: A planning comparison. J Appl Clin Med Phys. 2020 Nov 05;: Authors: Boczkowski A, Kelly P, Meeks SL, Erhart K, Bova FJ, Willoughby TR Abstract For many patients, stereotactic radiosurgery (SRS) offers a minimally invasive, curative option when surgical techniques are not possible. To date, the literature supporting the efficacy and safety of SRS treatment techniques uses photon beams. However, with the number of proton therapy facilities exponentially growing and the favorable physical properties of proton beam radiation therapy, there is an opportunity to devel...
Source: Journal of Applied Clinical Medical Physics - November 5, 2020 Category: Physics Authors: Boczkowski A, Kelly P, Meeks SL, Erhart K, Bova FJ, Willoughby TR Tags: J Appl Clin Med Phys Source Type: research

Quantitative analysis of treatments using real-time image gated spot-scanning with synchrotron-based proton beam therapy system log data.
Abstract A synchrotron-based real-time image gated spot-scanning proton beam therapy (RGPT) system with inserted fiducial markers can irradiate a moving tumor with high accuracy. As gated treatments increase the beam delivery time, this study aimed to investigate the frequency of intra-field adjustments corresponding to the baseline shift or drift and the beam delivery efficiency of a synchrotron-based RGPT system. Data from 118 patients corresponding to 127 treatment plans and 2810 sessions between October 2016 and March 2019 were collected. We quantitatively analyzed the proton beam delivery time, the difference...
Source: Journal of Applied Clinical Medical Physics - November 5, 2020 Category: Physics Authors: Yoshimura T, Shimizu S, Hashimoto T, Nishioka K, Katoh N, Taguchi H, Yasuda K, Matsuura T, Takao S, Tamura M, Tanaka S, Ito YM, Matsuo Y, Tamura H, Horita K, Umegaki K, Shirato H Tags: J Appl Clin Med Phys Source Type: research

Secondary malignancy risk for patients with localized prostate cancer after intensity-modulated radiotherapy with and without flattening filter.
Abstract Men treated for localized prostate cancer by radiotherapy have often a remaining life span of 10 yr or more. Therefore, the risk for secondary malignancies should be taken into account. Plans for ten patients were evaluated which had been performed on an Oncentra® treatment planning system for a treatment with an Elekta Synergy™ linac with Agility™ head. The investigated techniques involved IMRT and VMTA with and without flattening filter. Different dose response models were applied for secondary carcinoma and sarcoma risk in the treated region and also in the periphery. As organs at ...
Source: Journal of Applied Clinical Medical Physics - November 4, 2020 Category: Physics Authors: Treutwein M, Loeschel R, Hipp M, Koelbl O, Dobler B Tags: J Appl Clin Med Phys Source Type: research

A retrospective analysis of setup and intrafraction positional variation in stereotactic radiotherapy treatments.
CONCLUSIONS: Our results indicate that since patient intrafraction motion is unrelated to couch rotation and treatment duration, intrafraction patient monitoring in 6 DoF is required to minimize intracranial SRS/SRT margins. PMID: 33140915 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 3, 2020 Category: Physics Authors: Barnes M, Yeo A, Thompson K, Phillips C, Kron T, Hardcastle N Tags: J Appl Clin Med Phys Source Type: research

Automated phantom analysis for gamma cameras and SPECT: A methodology for use in a clinical setting.
CONCLUSION: Our automated method for quantitative image analysis is consistent and shows increased precision and sensitivity when compared to standard visual methods. Thresholds correspond well with visual analysis and previous guidelines for observer visibility (e.g., Rose criterion), making our framework suitable for routine use in a nuclear medicine department. PMID: 33142050 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 3, 2020 Category: Physics Authors: Tazegul TE, Polemi AM, Snyder A, Snyder C, Collins PG Tags: J Appl Clin Med Phys Source Type: research

Contextual loss based artifact removal method on CBCT image.
CONCLUSIONS: Although the CBCT-CT image pairs are not completely matched at the pixel level, the method proposed in this paper can effectively correct the artifacts in the CBCT slices and improve the image quality. The average CT number of the regions of interest (including bones, skin) also exhibited a significant improvement. Furthermore, the proposed method can be applied to enhance the performance on such applications as dose estimation and segmentation. PMID: 33136307 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 2, 2020 Category: Physics Authors: Xie S, Liang Y, Yang T, Song Z Tags: J Appl Clin Med Phys Source Type: research

Development of an HDR-BT QA tool for source position verification.
CONCLUSIONS: Our new HDR-BT QA tool developed for comprehensive source position verification will be useful for cross checking actual source positions and planned source positions on the RTPS. PMID: 33136313 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - November 2, 2020 Category: Physics Authors: Kumazaki Y, Hirai R, Igari M, Kobayashi N, Okazaki S, Abe T, Tamaki T, Noda SE, Kato S Tags: J Appl Clin Med Phys Source Type: research

Effect of MU-weighted multi-leaf collimator position error on dose distribution of SBRT radiotherapy in peripheral non-small cell lung cancer.
CONCLUSIONS: There was significant difference in dose sensitivity between MU-weighted and unweighted MLC position error of SBRT radiotherapy in peripheral NSCLC. MU is suggested to be included in the dosimetric evaluation of the MLC misalignments, since it is much closer to clinical radiotherapy. PMID: 33128499 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 31, 2020 Category: Physics Authors: Feng A, Chen H, Wang H, Gu H, Shao Y, Duan Y, Ying Y, Yue NJ, Xu Z Tags: J Appl Clin Med Phys Source Type: research

Calculating and estimating second cancer risk from breast radiotherapy using Monte Carlo code with internal body scatter for each out-of-field organ.
Abstract Out-of-field organs are not commonly designated as dose calculation targets during radiation therapy treatment planning, but they might entail risks of second cancer. Risk components include specific internal body scatter, which is a dominant source of out-of-field doses, and head leakage, which can be reduced by external shielding. Our simulation study quantifies out-of-field organ doses and estimates second cancer risks attributable to internal body scatter in whole-breast radiotherapy (WBRT) with or without additional regional nodal radiotherapy (RNRT), respectively, for right and left breast cancer us...
Source: Journal of Applied Clinical Medical Physics - October 30, 2020 Category: Physics Authors: Takata T, Shiraishi K, Kumagai S, Arai N, Kobayashi T, Oba H, Okamoto T, Kotoku J Tags: J Appl Clin Med Phys Source Type: research

Effect of protective glasses on radiation dose to eye lenses during whole breast irradiation.
This study aimed to investigate the amount of radiation exposure to eye lenses using optically stimulated luminescence dosimeters (OSLDs) and determine whether wearing special protective devices to protect the eyes, as an organ at risk, during whole breast irradiation, is necessary. METHODS: This experiment used OSLDs on water-equivalent phantom to measure the change in scattered radiation dose due to the difference of irradiation field while using 4- and 6-MV photons of TrueBeam linear accelerator. Using a total treatment dose of 50 Gy, a target was positioned to approximate the breast, and a plan was formulated...
Source: Journal of Applied Clinical Medical Physics - October 30, 2020 Category: Physics Authors: Nakamura T, Suzuki S, Kato K, Pongnapang N, Hayashi N, Kurokawa C, Kobayashi I, Negishi T, Matsunami T Tags: J Appl Clin Med Phys Source Type: research

Recommended dose voxel size and statistical uncertainty parameters for precision of Monte Carlo dose calculation in stereotactic radiotherapy.
Abstract Monte Carlo (MC)-based treatment planning requires a choice of dose voxel size (DVS) and statistical uncertainty (SU). These parameters effect both the precision of displayed dose distribution and time taken to complete a calculation. For efficient, accurate, and precise treatment planning in a clinical setting, optimal values should be selected. In this investigation, 30 volumetric modulated arc therapy (VMAT) stereotactic radiotherapy (SRT) treatment plans, 10 brain, 10 lung, and 10 spine were calculated in the Monaco 5.11.02 treatment planning system (TPS). Each plan was calculated with a DVS of 0.1 an...
Source: Journal of Applied Clinical Medical Physics - October 30, 2020 Category: Physics Authors: Goodall SK, Ebert MA Tags: J Appl Clin Med Phys Source Type: research

Technical note: Generation of a Cerenkov scatter function convolution kernel for a primary proton beam.
CONCLUSIONS: The CSF was obtained for a proton beam using the MCNP 6.2 code for a phantom constructed of light, medium, and dark stratified human skin, as well as for an optical phantom. The CSFs were then fit with a triple-Gaussian function. The coefficients can be used to generate a radially symmetric CSF, which can then be used to deconvolve a measured Cerenkov image to obtain the dose distribution. PMID: 33124752 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 30, 2020 Category: Physics Authors: Thompson SA Tags: J Appl Clin Med Phys Source Type: research

A study of the dosimetric impact of daily setup variations measured with cone-beam CT on three-dimensional conformal radiotherapy for early-stage breast cancer delivered in the prone position.
Abstract PURPOSE: To evaluate the dosimetric impact of daily positioning variations measured with cone-beam computed tomography (CBCT) on whole-breast radiotherapy patients treated in the prone position. METHODS: Daily CBCT was prospectively acquired for 30 consecutive patients positioned prone. Treatment for early-stage (≤II) breast cancer was prescribed with standard dose (50 Gy/25 fractions) or hypofractionation (42.56 Gy/16 fractions) for 13 and 17 patients, respectively. Systematic and random errors were calculated from the translational CBCT shifts and used to determine population-based set...
Source: Journal of Applied Clinical Medical Physics - October 30, 2020 Category: Physics Authors: Xiao A, Jutzy J, Hubert G, Edens M, Washington M, Hasan Y, Chmura SJ, Al-Hallaq HA Tags: J Appl Clin Med Phys Source Type: research

The quantification and potential impact of dark current on treatments with an MR-guided radiotherapy (MRgRT) system.
CONCLUSIONS: The dark current associated with new clinical treatment units should be considered prior to treatment delivery to ensure it will not lead to dosimetric inaccuracies. For the MRIdian linac system investigated in this work, the contribution from dark current remained relatively low, though users should be cognizant of the larger potential dosimetric contribution for plans with small doses per segment. PMID: 33119933 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 29, 2020 Category: Physics Authors: Shepard AJ, Mittauer KE, Bayouth JE, Yadav P Tags: J Appl Clin Med Phys Source Type: research

A simple dosimetric approach to spatially fractionated GRID radiation therapy using the multileaf collimator for treatment of breast cancers in the prone position.
Abstract The purpose of this study was to explore the treatment planning methods of spatially fractionated radiation therapy (SFRT), commonly referred to as GRID therapy, in the treatment of breast cancer patients using multileaf collimator (MLC) in the prone position. A total of 12 patients with either left or right breast cancer were retrospectively chosen. The computed tomography (CT) images taken for the whole breast external beam radiation therapy (WB-EBRT) were used for GRID therapy planning. Each GRID plan was made by using two portals and each portal had two fields with 1-cm aperture size. The dose prescri...
Source: Journal of Applied Clinical Medical Physics - October 29, 2020 Category: Physics Authors: Murphy NL, Philip R, Wozniak M, Lee BH, Donnelly ED, Zhang H Tags: J Appl Clin Med Phys Source Type: research

Effect of setup error in the single-isocenter technique on stereotactic radiosurgery for multiple brain metastases.
Abstract In conventional stereotactic radiosurgery (SRS), treatment of multiple brain metastases using multiple isocenters is time-consuming resulting in long dose delivery times for patients. A single-isocenter technique has been developed which enables the simultaneous irradiation of multiple targets at one isocenter. This technique requires accurate positioning of the patient to ensure optimal dose coverage. We evaluated the effect of six degrees of freedom (6DoF) setup errors in patient setups on SRS dose distributions for multiple brain metastases using a single-isocenter technique. We used simulated spherica...
Source: Journal of Applied Clinical Medical Physics - October 29, 2020 Category: Physics Authors: Nakano H, Tanabe S, Utsunomiya S, Yamada T, Sasamoto R, Nakano T, Saito H, Takizawa T, Sakai H, Ohta A, Abe E, Kaidu M, Aoyama H Tags: J Appl Clin Med Phys Source Type: research

Quantified VMAT plan complexity in relation to measurement-based quality assurance results.
This study investigated established VMAT complexity metrics as a means of predicting phantom-based measurement results for 93 treatments delivered on a TrueBeam linac, and 91 treatments delivered on two TrueBeam STx linacs. Complexity metrics investigated showed weak correlations to gamma passing rate, with the exception of the Modulation Complexity Score for VMAT, yielding moderate correlations. The Spearman's rho values for this metric were 0.502 (P 
Source: Journal of Applied Clinical Medical Physics - October 28, 2020 Category: Physics Authors: Nguyen M, Chan GH Tags: J Appl Clin Med Phys Source Type: research

On the optimization of bone SPECT/CT in terms of image quality and radiation dose.
CONCLUSIONS: In the study, we present a methodology that finds a compromise between diagnostic information and patient exposure during bone SPECT/CT procedures. PMID: 33111500 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 27, 2020 Category: Physics Authors: Tulik M, Tulik P, Kowalska T Tags: J Appl Clin Med Phys Source Type: research

Creating a treatment plan report should be mandated as a minimum standard practice for patient care and QA documentation.
PMID: 33103839 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 26, 2020 Category: Physics Authors: Xia P, Olch A, Rong Y Tags: J Appl Clin Med Phys Source Type: research

Pulmonary perfusion by chest digital dynamic radiography: Comparison between breath-holding and deep-breathing acquisition.
We examined the feasibility of a breath-holding protocol and compared it with the deep-breathing protocol to reduce respiratory artifacts. MATERIALS AND METHODS: A total of 42 consecutive patients with respiratory diseases (32 males; age, 68.6 ± 12.3 yr), including 21 patients with chronic obstructive pulmonary disease, underwent chest DDR through the breath-holding protocol and the deep-breathing protocol. Imaging success rate and exposure to radiation were compared. The correlation rate of temporal changes in each pixel value between the lung fields and left cardiac ventricles was analyzed. ...
Source: Journal of Applied Clinical Medical Physics - October 26, 2020 Category: Physics Authors: Yamamoto S, Hasebe T, Tomita K, Kamei S, Matsumoto T, Imai Y, Takahashi G, Kondo Y, Ito Y, Sakamaki F Tags: J Appl Clin Med Phys Source Type: research

Interplay effects in highly modulated stereotactic body radiation therapy lung cases treated with volumetric modulated arc therapy.
CONCLUSIONS: As expected, respiratory motion effects are most evident for large amplitude respirations, complex fields, and small field margins. However, under all tested conditions target coverage was maintained. PMID: 33104297 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 26, 2020 Category: Physics Authors: Fernandez DJ, Sick JT, Fontenot JD Tags: J Appl Clin Med Phys Source Type: research

Commissioning and clinical implementation of the first commercial independent Monte Carlo 3D dose calculation to replace CyberKnife M6 ™ patient-specific QA measurements.
CONCLUSION: The first commercially available MC 3D dose IDC was successfully commissioned and validated for the CyberKnife and replaced all routine patient-specific QA measurements in our clinic. PMID: 33103343 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 25, 2020 Category: Physics Authors: Milder MTW, Alber M, Söhn M, Hoogeman MS Tags: J Appl Clin Med Phys Source Type: research

Portal dosimetry scripting application programming interface (PDSAPI) for Winston-Lutz test employing ceramic balls.
CONCLUSIONS: Winston-Lutz PDSAPI delivers similar accuracy as two commercial applications for WL test. This new application can save time spent transferring data and has the potential to implement daily WL test with reasonable test time. It also provides the data storage capability, and enables easy access to imaging and shift data. PMID: 33098369 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 24, 2020 Category: Physics Authors: Hao Y, Schmidt MC, Wu Y, Knutson NC Tags: J Appl Clin Med Phys Source Type: research

Gantry angle dependent beam control optimization of a traveling wave linear accelerator to improve VMAT delivery.
CONCLUSION: This study shows an improved linac stability using improved lookup tables. Resulting in a lower number of interruptions, preventing down-time, and a lower risk of intrafraction motion due to longer treatment times. PMID: 33094890 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 23, 2020 Category: Physics Authors: van Appeldoorn AA, Kok JGM, Wolthaus JWH Tags: J Appl Clin Med Phys Source Type: research

Surface guided imaging during stereotactic radiosurgery with automated delivery.
CONCLUSIONS: Surface image guidance is a viable alternative to scheduled mid-treatment imaging for monitoring intrafraction motion during stereotactic radiosurgery with automated delivery. PMID: 33095971 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 23, 2020 Category: Physics Authors: Covington EL, Stanley DN, Fiveash JB, Thomas EM, Marcrom SR, Bredel M, Willey CD, Riley KO, Popple RA Tags: J Appl Clin Med Phys Source Type: research

Error sensitivity of a log file analysis tool compared with a helical diode array dosimeter for VMAT delivery quality assurance.
CONCLUSION: The results of this study clearly show that log file analysis is an excellent complement to phantom-based delivery QA of VMAT plans. We recommend a 1.5%/1.5 mm/Global criteria for log file-based gamma calculations. Log file analysis was implemented successfully in our clinical routine for VMAT delivery QA. PMID: 33095978 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 23, 2020 Category: Physics Authors: Szeverinski P, Kowatsch M, Künzler T, Meinschad M, Clemens P, DeVries AF Tags: J Appl Clin Med Phys Source Type: research

Effect of contrast dose on diagnostic performance in DCE-MR breast imaging.
Abstract OBJECTIVE: To assess the diagnostic performance of breast magnetic resonance (MR) imaging as a function of gadolinium contrast dose using a retrospective reader study. MATERIAL AND METHODS: IRB approval was obtained prior to the start of this study and was HIPAA compliant. One-hundred and fifty MR breast examinations were included that were acquired between January 2001 and December 2006. Seventy-five patients received contrast doses (gadopentetate dimeglumine) by weight of 0.10 mmol/kg and 75 patients were imaged using fixed volumes of 20 ml. The images were assessed by two radiologists wi...
Source: Journal of Applied Clinical Medical Physics - October 22, 2020 Category: Physics Authors: Le TT, McDonald ES, Isaac G, Rosen MA, Dougherty L Tags: J Appl Clin Med Phys Source Type: research

Quantitative analysis of MRI-guided radiotherapy treatment process time for tumor real-time gating efficiency.
CONCLUSION: The use of BHI gating technique can increase the treatment process time significantly. BHI technique could be not always an adequate delivery technique to optimize the treatment process time. Further gating techniques should be considered to improve the use of MRgRT. PMID: 33089954 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 22, 2020 Category: Physics Authors: Placidi L, Cusumano D, Boldrini L, Votta C, Pollutri V, Antonelli MV, Chiloiro G, Romano A, De Luca V, Catucci F, Indovina L, Valentini V Tags: J Appl Clin Med Phys Source Type: research

The effect of designing a rotational planning target volume on sparing pharyngeal constrictor muscles in patients with oropharyngeal cancer.
CONCLUSION: This new rotational PTV causes significant reduction of the overlap volume between PCMs and PTVs in order to spare the PCMs compared to isotropic expanded PTV. PMID: 33078521 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2020 Category: Physics Authors: Arbab M, Ai H, Bartlett G, Dawson B, Langer M Tags: J Appl Clin Med Phys Source Type: research

Feasibility study of using Stereotactic Field Diode for field output factors measurement and evaluating three new detectors for small field relative dosimetry of 6 and 10  MV photon beams.
This study assesses the feasibility of using stereotactic field diode (SFD) as an alternate to gaf chromic films for field output factor (FF) measurement and further evaluating three new detectors for small field dosimetry. Varian 21EX linear accelerator was used to generate 6 and 10 MV beams of nominal square fields ranging from 0.5 × 0.5 cm2 to 10 × 10 cm2 . One passive (EBT3 films) and five active detectors including IBA RAZOR diode(RD), SFD, RAZOR nanochamber (RNC), pinpoint chamber (PTW31023), and semiflex chamber (PTW31010) were employed. FFs were measured using films an...
Source: Journal of Applied Clinical Medical Physics - October 19, 2020 Category: Physics Authors: Gul A, Fukuda S, Mizuno H, Taku N, Kakakhel MB, Mirza SM Tags: J Appl Clin Med Phys Source Type: research

CBCT image quality QA: Establishing a quantitative program.
Abstract PURPOSE: Routine quality assurance (QA) of cone-beam computed tomography (CBCT) scans used for image-guided radiotherapy is prescribed by the American Association of Physicists in Medicine Task Group (TG)-142 report. For CBCT image quality, TG-142 recommends using clinically established baseline values as QA tolerances. This work examined how image quality parameters vary both across machines of the same model and across different CBCT techniques. Additionally, this work investigated how image quality values are affected by imager recalibration and repeated exposures during routine QA. METHODS: Cone-...
Source: Journal of Applied Clinical Medical Physics - October 19, 2020 Category: Physics Authors: Taneja S, Barbee DL, Rea AJ, Malin M Tags: J Appl Clin Med Phys Source Type: research

Patient-specific quality assurance using machine log files analysis for stereotactic body radiation therapy (SBRT).
Abstract An in-house trajectory log analysis program (LOGQA) was developed to evaluate the delivery accuracy of volumetric-modulated arc therapy (VMAT) for stereotactic body radiation therapy (SBRT). Methods have been established in LOGQA to provide analysis on dose indices, gantry angles, and multi-leaf collimator (MLC) positions. Between March 2019 and May 2020, 120 VMAT SBRT plans of various treatment sites using flattening filter-free (FFF) mode were evaluated using both LOGQA and phantom measurements. Gantry angles, dose indices, and MLC positions were extracted from log and compared with each plan. Integrate...
Source: Journal of Applied Clinical Medical Physics - October 19, 2020 Category: Physics Authors: Chow VUY, Kan MWK, Chan ATC Tags: J Appl Clin Med Phys Source Type: research

Technical Note: Extended field-of-view (FOV) MRI distortion determination through multi-positional phantom imaging.
v D Abstract Comprehensive characterization of geometric distortions for MRI simulators and MRI-guided treatment delivery systems is typically performed with large phantoms that are costly and unwieldy to handle. Here we propose an easily implementable methodology for MR distortion determination of the entire imaging space of the scanner through the use of a compact commercially available distortion phantom. The MagphanRT phantom was scanned at several locations within a MR scanner. From each scan, an approximate location of the phantom was determined from a subset of the fiducial spheres. The fiducial displacemen...
Source: Journal of Applied Clinical Medical Physics - October 19, 2020 Category: Physics Authors: Schüler E, Mallozzi R, Levy J, Hristov D Tags: J Appl Clin Med Phys Source Type: research

Fabrication of a pediatric torso phantom with multiple tissues represented using a dual nozzle thermoplastic 3D printer.
CONCLUSION: Patient-specific anthropomorphic phantoms can be 3D printed and assembled in sections for imaging and dosimetry applications. Such phantoms will be useful for dose verification purposes when commercial phantoms are unavailable for purchase in the specific anatomies of interest. PMID: 33073922 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2020 Category: Physics Authors: Mille MM, Griffin KT, Maass-Moreno R, Lee C Tags: J Appl Clin Med Phys Source Type: research

Impact of setup errors on multi-isocenter volumetric modulated arc therapy for craniospinal irradiation.
In conclusion, the dosimetric verification with intentionally introduced setup errors demonstrated that positional errors within 3 mm have a little impact for VMAT CSI, although setup errors should be minimized. Relying on the inverse optimization of VMAT to smooth the dose distribution in the junction areas is feasible for CSI. PMID: 33070426 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 18, 2020 Category: Physics Authors: Zhou Y, Ai Y, Han C, Zheng X, Yi J, Xie C, Jin X Tags: J Appl Clin Med Phys Source Type: research

Dosimetric and mechanical equivalency of Varian TrueBeam linear accelerators.
CONCLUSIONS: High level of equivalency, beyond clinically accepted criteria, of TrueBeam linacs could be achieved which reduced dose delivery systematic errors and increased confidence in interchanging patients among linacs. PMID: 33070456 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 18, 2020 Category: Physics Authors: Ghazal M, Södergren L, Westermark M, Söderström J, Pommer T Tags: J Appl Clin Med Phys Source Type: research

Incorporating sensitive cardiac substructure sparing into radiation therapy planning.
CONCLUSIONS: By introducing 0.35T MRIs acquired on an MR-linac to verify cardiac substructure segmentations for CT-based treatment planning, an opportunity was presented for more effective sparing with limited increase in plan complexity. Validation in a larger cohort with appropriate margins offers potential to reduce radiation-related cardiotoxicities. PMID: 33073454 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 18, 2020 Category: Physics Authors: Morris ED, Aldridge K, Ghanem AI, Zhu S, Glide-Hurst CK Tags: J Appl Clin Med Phys Source Type: research

Validation of the preconfigured Varian Ethos Acuros XB Beam Model for treatment planning dose calculations: A dosimetric study.
In this study, we comprehensively validated the accuracy of the Ethos AXB model by comparing it against the Halcyon AXB model, the Halcyon Anisotropic Analytical Algorithm (AAA) model, and measurements acquired on an Ethos linac. Results indicated that the Ethos AXB model demonstrated a comparable if not superior dosimetric accuracy to the Halcyon AXB model in basic and complex calculations, and at the same time its dosimetric accuracy in modulated and heterogeneous plans was better than that of the Halcyon AAA model. Despite the fact that the same algorithm was utilized, the Ethos AXB model and the Halcyon AXB model still...
Source: Journal of Applied Clinical Medical Physics - October 17, 2020 Category: Physics Authors: Hu Y, Byrne M, Archibald-Heeren B, Collett N, Liu G, Aland T Tags: J Appl Clin Med Phys Source Type: research

A feasibility study to estimate optimal rigid-body registration using combinatorial rigid registration optimization (CORRO).
CONCLUSIONS: We have developed a methodology called CORRO that allows us to estimate optimal alignment for rigid-registration of clinical image pairs using a large set landmark point. The results for the rigid-body registration have been shown to be comparable to results from commercially available algorithms for all six cases. CORRO can serve as an excellent tool that can be used to test and validate rigid registration algorithms. PMID: 33068076 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 17, 2020 Category: Physics Authors: Yorke AA, Solis D, Guerrero T Tags: J Appl Clin Med Phys Source Type: research