AAPM medical physics practice guideline 10.a.: Scope of practice for clinical medical physics.
Abstract The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of r...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Clements J Tags: J Appl Clin Med Phys Source Type: research

A measurement of the attenuation of radiation from F-18 by a PET/MR scanner.
Abstract The attenuation of 511 keV photons by the structure of a PET/MR scanner was measured prior to energizing the magnet. The exposure rate from a source of fluorine-18 was measured in air and, with the source placed at the isocenter of the instrument, at various points outside of the scanner. In an arc from 45 to 135 degrees relative to the long axis of the scanner and at a distance of 1.5 m from the isocenter, the attenuation by the scanner is at least 5.6 half-value layers from the MR component alone and at least 6.6 half-value layers with the PET insert installed. This information could inform better desig...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Wendt RE, Ai HA, Meier JG, Lopez BP, Fahrenholtz SJ, Mawlawi OR Tags: J Appl Clin Med Phys Source Type: research

Cone-Beam CT image contrast and attenuation-map linearity improvement (CALI) for brain stereotactic radiosurgery procedures.
n M Abstract A Contrast and Attenuation-map Linearity Improvement (CALI) framework is proposed for cone-beam CT (CBCT) images used for brain stereotactic radiosurgery (SRS). The proposed framework is tailored to improve soft tissue contrast of a new point-of-care image-guided SRS system that employs a challenging half cone beam geometry, but can be readily reproduced on any CBCT platform. CALI includes a pre- and post-processing step. In pre-processing we apply a shading and beam hardening artifact correction to the projections, and in post-processing step we correct the dome/capping artifact on reconstructed imag...
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Hashemi S, Huynh C, Sahgal A, Song WY, Nordström H, Eriksson M, Mainprize JG, Lee Y, Ruschin M Tags: J Appl Clin Med Phys Source Type: research

An algorithm for automated modulation transfer function measurement using an edge of a PMMA phantom: Impact of field of view on spatial resolution of CT images.
CONCLUSION: An automated MTF method was successfully developed using an edge phantom, the PMMA phantom. The method is easy to implement in a clinical environment and is not influenced by user experience. PMID: 30338920 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Anam C, Fujibuchi T, Budi WS, Haryanto F, Dougherty G Tags: J Appl Clin Med Phys Source Type: research

Assessment of combined use of ArcCheck ® detector and portal dosimetry for delivery quality assurance of head and neck and prostate volumetric-modulated arc therapy.
CONCLUSION: The combined use of the two measurement processes did not statistically improve the detectability of technical errors compared to use of single process. PMID: 30338922 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Moliner G, Sorro L, Verstraet R, Daviau PA, Casas M, Piron B, Dubois K, Debrigode C, Barrau C, Bons F, Greffier J Tags: J Appl Clin Med Phys Source Type: research

Medical Physics 3.0, physics for every patient.
PMID: 30338923 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 19, 2018 Category: Physics Authors: Samei E, Mills MD Tags: J Appl Clin Med Phys Source Type: research

Small-spot intensity-modulated proton therapy and volumetric-modulated arc therapies for patients with locally advanced non-small-cell lung cancer: A dosimetric comparative study.
CONCLUSIONS: Small-spot IMPT improves cord, heart, and lung sparing compared to VMAT and achieves clinically acceptable plan robustness at least for the patients included in this study with motion amplitude less than 11 mm. Our study supports the usage of IMPT to treat some lung cancer patients. PMID: 30328674 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 17, 2018 Category: Physics Authors: Liu C, Sio TT, Deng W, Shan J, Daniels TB, Rule WG, Lara PR, Korte SM, Shen J, Ding X, Schild SE, Bues M, Liu W Tags: J Appl Clin Med Phys Source Type: research

A program to train medical physicists for direct patient care responsibilities.
CONCLUSIONS: The training program that we have developed incorporates an array of established education techniques and provides a comprehensive, accessible, means of improving medical physicists' patient communication skills. PMID: 30328675 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 17, 2018 Category: Physics Authors: Brown DW, Atwood T, Moore K, MacAulay R, Murphy J, Mundt A, Pawlicki T Tags: J Appl Clin Med Phys Source Type: research

A clinical 3D/4D CBCT-based treatment dose monitoring system.
In conclusion, we have demonstrated the feasibility and effectiveness of a treatment dose verification system in our clinical setting. PMID: 30306710 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 10, 2018 Category: Physics Authors: Qin A, Gersten D, Liang J, Liu Q, Grill I, Guerrero T, Stevens C, Yan D Tags: J Appl Clin Med Phys Source Type: research

Electrometer offset current due to scattered radiation.
Abstract Relative dose measurements with small ionization chambers in combination with an electrometer placed in the treatment room ("internal electrometer") show a large dependence on the polarity used. While this was observed previously for percent depth dose curves (PDDs), the effect has not been understood or preventable. To investigate the polarity dependence of internal electrometers used in conjunction with a small-volume ionization chamber, we placed an internal electrometer at a distance of 1 m from the isocenter and exposed it to different amounts of scattered radiation by varying the fiel...
Source: Journal of Applied Clinical Medical Physics - October 9, 2018 Category: Physics Authors: Wegener S, Sauer OA Tags: J Appl Clin Med Phys Source Type: research

Occupational radiation exposure to nursing staff during cardiovascular fluoroscopic procedures: A review of the literature.
CONCLUSIONS: The review has highlighted a lack of published literature focussing on dose to nurses. There is a need for future research in this area to inform nursing staff of factors which may contribute to high occupational doses and of methods for minimizing the risk of exposure, particularly regarding the importance of utilizing radiation protective equipment. PMID: 30294978 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 8, 2018 Category: Physics Authors: Wilson-Stewart K, Shanahan M, Fontanarosa D, Davidson R Tags: J Appl Clin Med Phys Source Type: research

On the improvement of CBCT image quality for soft tissue-based SRS localization.
CONCLUSIONS: Our results indicate that optimization of the imaging protocol, and thereby an increase in the imaging dose, is warranted for improved soft-tissue visualization for intracranial SRS. PMID: 30294838 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 7, 2018 Category: Physics Authors: Mao W, Gardner SJ, Snyder KC, Wen NW, Zhong H, Li H, Jackson P, Shah M, Chetty IJ Tags: J Appl Clin Med Phys Source Type: research

Merging images with different central frequencies reduces banding artifacts in balanced steady-state free precession magnetic resonance cisternography.
CONCLUSIONS: The maximum magnitude merging of images with different central frequencies makes it possible to reduce banding artifacts on bSSFP images without the need for special pulse sequences and image processing programs. PMID: 30288917 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 5, 2018 Category: Physics Authors: Matsumoto K, Yokota H, Mukai H, Masuda Y, Uno T, Miyati T Tags: J Appl Clin Med Phys Source Type: research

GammaKnife versus VMAT radiosurgery plan quality for many brain metastases.
Abstract The purpose of this work was to compare dose distributions between two radiosurgery modalities, single-isocenter volumetric modulated arc therapy (VMAT), and GammaKnife Perfexion (GK), in the treatment of a large number (≥7) of brain metastases. Twelve patients with 103 brain metastases were analyzed. The median number of targets per patient was 8 (range: 7-14). GK plans were compared to noncoplanar VMAT plans using both 6-MV flattening filter-free (FFF) and 10-MV FFF modes. Parameters analyzed included radiation therapy oncology group conformity index (CI), 12, 6, and 3 Gy isodose volumes (V12&nb...
Source: Journal of Applied Clinical Medical Physics - October 4, 2018 Category: Physics Authors: Potrebko PS, Keller A, All S, Sejpal S, Pepe J, Saigal K, Kandula S, Sensakovic WF, Shridhar R, Poleszczuk J, Biagioli M Tags: J Appl Clin Med Phys Source Type: research

Use of a commercial ion chamber detector array for the measurement of high spatial-resolution photon beam profiles.
Abstract Linear accelerator (linac) commissioning and quality assurance measurements are time-consuming tasks that often require a water tank scanning system to acquire profile scans for full characterization of dosimetric beam properties. To increase efficiency, a method is demonstrated to acquire variable resolution, photon beam profile data using a commercially available ion chamber array (0.5 cm detector spacing). Field sizes of 2 × 2, 5 × 5, 10 × 10, and 15 × 15 cm2 were acquired at depths in solid water of dmax , 5 cm, and 10 ...
Source: Journal of Applied Clinical Medical Physics - October 4, 2018 Category: Physics Authors: Karimnia V, Belley MD, Rodgers R, Price M Tags: J Appl Clin Med Phys Source Type: research

Evaluation of offline adaptive planning techniques in image-guided brachytherapy of cervical cancer.
This study examines offline adaptive planning techniques that may reduce intrafraction uncertainties by shortening the time between the planning CT and treatment delivery. Eight patients who received EBRT followed by HDR boosts were retrospectively reviewed. A CT scan was obtained for each insertion. Four strategies were simulated: (A) plans based on the current treatment day CT; (B) plans based on the first fraction CT; (C) plans based on the CT from the immediately preceding fraction; (D) plans based on the closest anatomically matched previous CT, using all prior plans as a library. Strategies B, C, and D allow plans to...
Source: Journal of Applied Clinical Medical Physics - October 3, 2018 Category: Physics Authors: Liu H, Kinard J, Maurer J, Shang Q, Vanderstraeten C, Hayes L, Sintay B, Wiant D Tags: J Appl Clin Med Phys Source Type: research

A hybrid planning strategy for stereotactic body radiation therapy of early stage non-small-cell lung cancer.
Abstract Currently dynamic conformal arcs (DCA) and volumetric modulated arc therapy (VMAT) are two popular planning techniques to treat lung stereotactic body radiation therapy (SBRT) patients. Of the two, DCA has advantages in terms of multi-leaf collimator (MLC) motion, positioning error, and delivery efficiency. However, VMAT is often the choice when critical organ sparing becomes important. We developed a hybrid strategy to incorporate DCA component into VMAT planning, results were compared with DCA and VMAT plans. Four planning techniques were retrospectively simulated for 10 lung SBRT patients: DCA, Hybrid-...
Source: Journal of Applied Clinical Medical Physics - October 3, 2018 Category: Physics Authors: Liu H, Sintay B, Pearman K, Shang Q, Hayes L, Maurer J, Vanderstraeten C, Wiant D Tags: J Appl Clin Med Phys Source Type: research

A snapshot of medical physics practice patterns.
Abstract A large number of surveys have been sent to the medical physics community addressing many clinical topics for which the medical physicist is, or may be, responsible. Each survey provides an insight into clinical practice relevant to the medical physics community. The goal of this study was to create a summary of these surveys giving a snapshot of clinical practice patterns. Surveys used in this study were created using SurveyMonkey and distributed between February 6, 2013 and January 2, 2018 via the MEDPHYS and MEDDOS listserv groups. The format of the surveys included questions that were multiple choice ...
Source: Journal of Applied Clinical Medical Physics - October 1, 2018 Category: Physics Authors: Kisling KD, Ger RB, Netherton TJ, Cardenas CE, Owens CA, Anderson BM, Lee J, Rhee DJ, Edward SS, Gay SS, He Y, David SD, Yang J, Nitsch PL, Balter PA, Urbauer DL, Peterson CB, Court LE, Dube S Tags: J Appl Clin Med Phys Source Type: research

Clinical commissioning of a new patient positioning system, SyncTraX FX4, for intracranial stereotactic radiotherapy.
CONCLUSION: Our results demonstrate a competent performance of the SyncTraX FX4 system in terms of the localization accuracy for intracranial SRT. PMID: 30273444 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - October 1, 2018 Category: Physics Authors: Tanabe S, Umetsu O, Sasage T, Utsunomiya S, Kuwabara R, Kuribayashi T, Takatou H, Kawaguchi G, Aoyama H Tags: J Appl Clin Med Phys Source Type: research

Study of dosimetric properties of flattened and unflattened megavoltage x ray beam on high Z implant materials.
CONCLUSION: The dosimetric properties of x ray photon beam were studied comprehensively in the presence of high Z material like stainless steel and titanium alloy using both flattened and UF beams to understand and incorporate the findings of various parameters in clinical condition due to the variation in energy spectrum from FF to UF x ray beam. PMID: 30267468 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 28, 2018 Category: Physics Authors: Rajamanickam T, Muthu S, Murugan P, Pathokonda M, Senthilnathan K, Arunai Nambi Raj N, Ramesh Babu P Tags: J Appl Clin Med Phys Source Type: research

Dosimetric effects of a repositioning head frame system and treatment planning system dose calculation accuracy.
Abstract This work aims to study the effect on surface dose and dose distribution caused by the Elekta Fraxion cranial immobilization system. The effect of Fraxion inclusion in Elekta Monaco treatment planning system and its calculation accuracy is also checked. To study the dose attenuation, a cylindrical phantom was located over the Elekta Fraxion with an IBA CC13 ionization chamber placed in the central insert at the linac isocenter. Dose measurements at multiple gantry angles were performed for three open fields, 10 × 10 cm, 5 × 5 cm and other smaller 2 × 2 cm. Measured doses were compared wi...
Source: Journal of Applied Clinical Medical Physics - September 25, 2018 Category: Physics Authors: Ferrer C, Huertas C, Plaza R, Aza Z, Corredoira E Tags: J Appl Clin Med Phys Source Type: research

Implementation and operation of incident learning across a newly-created health system.
CONCLUSIONS: We have developed an ILS that identifies issues related to the entire process of care delivery in radiation oncology, as evidenced by frequent and varied reported events. By identifying a broad spectrum of issues in a department, opportunities for improvement can be identified. PMID: 30225861 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 17, 2018 Category: Physics Authors: Schubert L, Petit J, Vinogradskiy Y, Peters R, Towery J, Stump B, Westerly D, Ridings J, Kneeland P, Liu A Tags: J Appl Clin Med Phys Source Type: research

Development of a dedicated phantom for multi-target single-isocentre stereotactic radiosurgery end to end testing.
CONCLUSION: A novel, versatile and cost-effective phantom for comprehensive E2E testing of MTSI SRS treatments was developed, incorporating multiple detector types and fiducial markers. The phantom is capable of quantifying the accuracy of each step in the MTSI SRS planning and treatment process. PMID: 30221462 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 16, 2018 Category: Physics Authors: Poder J, Brown R, Porter H, Gupta R, Ralston A Tags: J Appl Clin Med Phys Source Type: research

Partially ablative radiotherapy (PAR) for large mass tumors using simultaneous integrated boost: A dose-escalation feasibility study.
CONCLUSION: A modified SIB technique is dosimetrically feasible for large tumors, where doses higher than the tolerance dose of healthy tissues are necessary to increase the therapeutic gain. PMID: 30220111 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 15, 2018 Category: Physics Authors: Cilla S, Deodato F, Ianiro A, Macchia G, Picardi V, Buwenge M, Cammelli S, Zamagni A, Valentini V, Morganti AG Tags: J Appl Clin Med Phys Source Type: research

Using max standardized uptake value from positron emission tomography to assess tumor responses after lung stereotactic body radiotherapy for different prescriptions.
CONCLUSION: We demonstrated post max SUV read from PET/CT could efficiently and accurately assess tumor response after lung SBRT. Although SBRT with prescriptions resulting in a BED10  > 100 experienced favorable tumor responses for early staging cancer, escalation of BED10 to higher levels would be beneficial for lung cancer patients with later staging and larger volume tumors. PMID: 30216639 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 14, 2018 Category: Physics Authors: Ding M, Zollinger W, Ebeling R, Heard D, Posey R Tags: J Appl Clin Med Phys Source Type: research

Detectors assessment for stereotactic radiosurgery with cones.
ano B Abstract The purpose of this work is to assess eight detectors performance for output factor (OF), percent depth dose (PDD), and beam profiles in a 6-MV Clinac stereotactic radiosurgery mode for cone irradiation using Monte Carlo simulation as reference. Cones with diameters comprised between 30 and 4 mm have been studied. The evaluated detectors were ionization chambers: pinpoint and pinpoint 3D, diodes: SRS, P and E, Edge, MicroDiamond and EBT3 radiochromic films. The results showed that pinpoints underestimate OF up to -2.3% for cone diameters ≥10 mm and down to -12% for smaller cones. Both n...
Source: Journal of Applied Clinical Medical Physics - September 14, 2018 Category: Physics Authors: Garnier N, Amblard R, Villeneuve R, Haykal R, Ortholan C, Colin P, Gérard A, Belhomme S, Mady F, Benabdesselam M, Serrano B Tags: J Appl Clin Med Phys Source Type: research

Impact of a novel exponential weighted 4DCT reconstruction  algorithm.
CONCLUSION: Exponential weighted 4DCT offers potential for reducing image blur (i.e., improving image sharpness) in 4DCT with a tendency to reduce artifacts. Future work will involve evaluating the impact on treatment planning including delineation ability and dose calculation. PMID: 30207053 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 11, 2018 Category: Physics Authors: Morris ED, Kim JP, Klahr P, Glide-Hurst CK Tags: J Appl Clin Med Phys Source Type: research

The dosimetric effect of electron density overrides in 3DCRT Lung SBRT for a range of lung tumor dimensions.
This study investigated the effect on plan quality and accuracy when overriding treatment volume electron density values. The QUASAR phantom with modified cork cylindrical inserts, each containing a simulated spherical tumor of 15-mm, 22-mm, or 30-mm diameter, was used to simulate lung tumor motion. Using Monaco 5.1 treatment planning software, two standard plans (50% central phase (50%) and average intensity projection (AIP)) were compared to eight electron density overridden plans that focused on different target volumes (internal target volume (ITV), planning target volume (PTV), and a hybrid plan (HPTV)). The target vo...
Source: Journal of Applied Clinical Medical Physics - September 10, 2018 Category: Physics Authors: Healy GEA, Marsh SH, Cousins AT Tags: J Appl Clin Med Phys Source Type: research

Regarding the parallel opposed editorial about: 3D printing technology will eventually eliminate the need of purchasing commercial phantoms for clinical medical physics QA procedures.
PMID: 30187997 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - September 6, 2018 Category: Physics Authors: Treutwein M Tags: J Appl Clin Med Phys Source Type: research

Equivalency of beam scan data collection using a 1D tank and  automated couch movements to traditional 3D tank measurements.
Equivalency of beam scan data collection using a 1D tank and automated couch movements to traditional 3D tank measurements. J Appl Clin Med Phys. 2018 Sep 06;: Authors: Knutson NC, Schmidt MC, Belley MD, Nguyen N, Price M, Mutic S, Sajo E, Li HH Abstract This work shows the feasibility of collecting linear accelerator beam data using just a 1-D water tank and automated couch movements with the goal to maximize the cost effectiveness in resource-limited clinical settings. Two commissioning datasets were acquired: (a) using a standard of practice 3D water tank scanning system (3DS) and (b) using a ...
Source: Journal of Applied Clinical Medical Physics - September 6, 2018 Category: Physics Authors: Knutson NC, Schmidt MC, Belley MD, Nguyen N, Price M, Mutic S, Sajo E, Li HH Tags: J Appl Clin Med Phys Source Type: research

Evaluation of the truebeam machine performance check (MPC): OBI X-ray tube alignment procedure.
This study evaluated the new procedure against conventional methods and examined the clinical significance of X-ray tube misalignment. Long term stability and short term repeatability of MPC tube alignment was assessed as well as sensitivity of the method to setup error. Standard quality assurance tests expected to be sensitive to tube misalignment were performed before and after tube alignment. These tests included: IsoCal verification; MPC kV imager offset; Winston-Lutz: kV imaging to treatment/radiation isocenter coincidence; CBCT image QA using the Catphan phantom; and OBI image geometric accuracy and center pixel alig...
Source: Journal of Applied Clinical Medical Physics - September 3, 2018 Category: Physics Authors: Barnes MP, Pomare D, Menk FW, Moraro B, Greer PB Tags: J Appl Clin Med Phys Source Type: research

Framework for the quantitative assessment of adaptive radiation therapy protocols.
CONCLUSIONS: These results indicate that centers should establish ground truth replan criteria to assess current standard of practice ART protocols. In addition, more effective replan flags may be tested and identified according to the proposed framework. Such improvements in ART flagging may contribute to better clinical resource allocation and patient outcome. PMID: 30160025 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 29, 2018 Category: Physics Authors: Weppler S, Quon H, Banerjee R, Schinkel C, Smith W Tags: J Appl Clin Med Phys Source Type: research

Contour-based lung dose prediction for breast proton therapy.
CONCLUSION: A contour-based model was established to predict dose to ipsilateral lung in breast treatment. Clinically relevant accuracy was demonstrated. This model facilitates dose prediction before treatment planning. It could serve as a guide toward realistic clinical goals in the planning stage. PMID: 30141230 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 23, 2018 Category: Physics Authors: Zeng C, Sine K, Mah D Tags: J Appl Clin Med Phys Source Type: research

Second cancer risk after radiation therapy of ependymoma using the flattening filter free irradiation mode of a linear accelerator.
Abstract Pediatric patients suffering from ependymoma are usually treated with cranial or craniospinal three-dimensional (3D) conformal radiotherapy (3DCRT). Intensity-modulated techniques spare dose to the surrounding tissue, but the risk for second malignancies may be increased due to the increase in low-dose volume. The aim of this study is to investigate if the flattening filter free (FFF) mode allows reducing the risk for second malignancies compared to the mode with flattening filter (FF) for intensity-modulated techniques and to 3DCRT. A reduction of the risk would be advantageous for treating pediatric epe...
Source: Journal of Applied Clinical Medical Physics - August 19, 2018 Category: Physics Authors: Alvarez Moret J, Obermeier T, Pohl F, Loeschel R, Koelbl O, Dobler B Tags: J Appl Clin Med Phys Source Type: research

Comparison of semiautomated tangential VMAT with 3DCRT for breast or chest wall and regional nodes.
Abstract Radiotherapy to the breast after surgery sometimes requires adjoining nodes to be included in the treatment volume. In these cases, the traditional approach has been a complex 3-Dimensional Conformal Radiotherapy (3DCRT) beam arrangement which can result in significant dose heterogeneity at the beam junctions. A Volumetric Modulated Arc Therapy (VMAT) beam arrangement has previously been proposed for breast cases, where the chest wall/breast is treated with a limited angle (partial arc) tangential VMAT technique (Virén et al. [2015] Radiat Oncol. 10:79). In our study, this approach is extended...
Source: Journal of Applied Clinical Medical Physics - August 19, 2018 Category: Physics Authors: Byrne M, Archibald-Heeren B, Hu Y, Fong A, Chong L, Teh A Tags: J Appl Clin Med Phys Source Type: research

Parallel/Opposed Editorial: DMP/residency programs are more sustainable than MPAs for the future of the medical physics profession.
PMID: 30117259 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 17, 2018 Category: Physics Authors: Shi C, Parker BC, Rong Y Tags: J Appl Clin Med Phys Source Type: research

Medical physics 3.0 versus 1.0: A case study in digital radiography quality control.
CONCLUSIONS: MP1.0 tests failed to detect substandard system performance, but MP3.0 methods determined the root cause of the problem. MP3.0 exploits the wealth of data with more sensitive performance indicators. Data analytics are powerful tools whose proper application could facilitate early intervention in degraded system performance. PMID: 30117273 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 17, 2018 Category: Physics Authors: Carver DE, Willis CE, Stauduhar PJ, Nishino TK, Wells JR, Samei E Tags: J Appl Clin Med Phys Source Type: research

Investigating a novel split-filter dual-energy CT technique for improving pancreas tumor visibility for radiation therapy.
Abstract PURPOSE: Tumor delineation using conventional CT images can be a challenge for pancreatic adenocarcinoma where contrast between the tumor and surrounding healthy tissue is low. This work investigates the ability of a split-filter dual-energy CT (DECT) system to improve pancreatic tumor contrast and contrast-to-noise ratio (CNR) for radiation therapy treatment planning. MATERIALS AND METHODS: Multiphasic scans of 20 pancreatic tumors were acquired using a split-filter DECT technique with iodinated contrast medium, OMNIPAQUETM . Analysis was performed on the pancreatic and portal venous phases for seve...
Source: Journal of Applied Clinical Medical Physics - August 17, 2018 Category: Physics Authors: Di Maso LD, Huang J, Bassetti MF, DeWerd LA, Miller JR Tags: J Appl Clin Med Phys Source Type: research

Evaluation of automatic contour propagation in T2-weighted 4DMRI for normal-tissue motion assessment using internal organ-at-risk volume (IRV).
Abstract PURPOSE: The purpose of this study was to evaluate the quality of automatically propagated contours of organs at risk (OARs) based on respiratory-correlated navigator-triggered four-dimensional magnetic resonance imaging (RC-4DMRI) for calculation of internal organ-at-risk volume (IRV) to account for intra-fractional OAR motion. METHODS AND MATERIALS: T2-weighted RC-4DMRI images were of 10 volunteers acquired and reconstructed using an internal navigator-echo surrogate and concurrent external bellows under an IRB-approved protocol. Four major OARs (lungs, heart, liver, and stomach) were delineated in...
Source: Journal of Applied Clinical Medical Physics - August 15, 2018 Category: Physics Authors: Zhang J, Markova S, Garcia A, Huang K, Nie X, Choi W, Lu W, Wu A, Rimner A, Li G Tags: J Appl Clin Med Phys Source Type: research

A hybrid volumetric dose verification method for single-isocenter multiple-target cranial SRS.
Abstract A commercial semi-empirical volumetric dose verification system (PerFraction [PF], Sun Nuclear Corp.) extracts multi-leaf collimator positions from the electronic portal imaging device movies collected during a pre-treatment run, while the rest of the delivered control point information is harvested from the accelerator log files. This combination is used to reconstruct dose on a patient CT dataset with a fast superposition/convolution algorithm. The method was validated for single-isocenter multi-target SRS VMAT treatments against absolute radiochromic film measurements in a cylindrical phantom. The targ...
Source: Journal of Applied Clinical Medical Physics - August 15, 2018 Category: Physics Authors: Ahmed S, Kapatoes J, Zhang G, Moros EG, Feygelman V Tags: J Appl Clin Med Phys Source Type: research

Evaluation of the combined use of two different respiratory monitoring systems for 4D CT simulation and gated treatment.
CONCLUSIONS: Combined use of one system for 4D CT simulation and the other for gated treatment should be avoided as the resultant gating window would not fully match with each other due to the remarkable discrepancy in breathing traces acquired by the two different surrogate systems. PMID: 30105770 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 13, 2018 Category: Physics Authors: Liu J, Lin T, Fan J, Chen L, Price R, Ma CC Tags: J Appl Clin Med Phys Source Type: research

Who owns your data? Part III challenges to academic freedom.
PMID: 30105777 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 13, 2018 Category: Physics Authors: Mills MD Tags: J Appl Clin Med Phys Source Type: research

Investigation of a source model for a new electronic brachytherapy tandem by film measurement.
CONCLUSIONS: We quantified the agreement between the measured and provided anisotropy factors for a new Xoft Axxent 0-degree titanium tandem. Radiochromic film response at low kV energy was also investigated. Our results showed that vendor-supplied TG-43 values were appropriate for clinical use at majority of the angles. A rigorous quality assurance method for new electronic brachytherapy sources and applicators, along with complete knowledge of all dosimetric measuring tools, should be implemented for all parts of the verification and commissioning process. PMID: 30105891 [PubMed - as supplied by publisher] (Source: ...
Source: Journal of Applied Clinical Medical Physics - August 13, 2018 Category: Physics Authors: Martin E, Sowards K, Wang B Tags: J Appl Clin Med Phys Source Type: research

Energy-dependent OAR sparing and dose conformity for total marrow irradiation of obese patients.
CONCLUSIONS: Use of a higher energy 10 MV beam provided similar dose to target while achieving increased OAR and normal tissue sparing for the patients reviewed in this study. PMID: 30099836 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 11, 2018 Category: Physics Authors: Cherpak AJ, Monajemi T, Chytyk-Praznik K, Mulroy L Tags: J Appl Clin Med Phys Source Type: research

A quantitative assessment of the consequences of allowing dose heterogeneity in prostate radiation therapy planning.
This study systematically investigates the consequences of PTV dose uniformity that results from the application or removal of an upper dose constraint (UDC) in the inverse planning process for prostate VMAT treatments. OAR sparing, target coverage, hotspots, and plan complexity were compared between prostate VMAT plans with and without the PTV UDC optimized using the progressive resolution optimizer (PRO, Varian Medical Systems, Palo Alto, CA). Removing the PTV UDC, the median D1cc reached 144.6% for the CTV and the PTV, and an average increase of 3.2% TCP was demonstrated, while CTV and PTV coverage evaluated by D99% was...
Source: Journal of Applied Clinical Medical Physics - August 11, 2018 Category: Physics Authors: Sun L, Smith W, Ghose A, Kirkby C Tags: J Appl Clin Med Phys Source Type: research

Performance characteristics quality assurance considerations for displays used in interventional radiology cardiac catheterization facilities.
CONCLUSION: This work provides much needed data for the characterization of the performance of the large format displays used in IR and CC laboratory suites. These data may be used as a point of comparison when implementing a display QA program. PMID: 30091189 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 9, 2018 Category: Physics Authors: Silosky MS, Marsh RM Tags: J Appl Clin Med Phys Source Type: research

Online daily assessment of dose change in head and neck radiotherapy without dose-recalculation.
CONCLUSION: Using the DIR between the planning CT and daily CBCT can flag cases for plan adaptation before every fraction while not requiring a new re-planning CT scan and dose recalculation. PMID: 30084159 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 7, 2018 Category: Physics Authors: Vickress JR, Battista J, Barnett R, Yartsev S Tags: J Appl Clin Med Phys Source Type: research

A method to predict patient-specific table coordinates for quality assurance in external beam radiation therapy.
CONCLUSIONS: With proper indexing, table coordinates can be predicted with reasonable accuracy. The data suggest an action of level of 2 cm with certain exceptions for specific immobilization devices and directions. PMID: 30085393 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 7, 2018 Category: Physics Authors: Saenz DL, Astorga NR, Kirby N, Fakhreddine M, Rasmussen K, Stathakis S, Papanikolaou N Tags: J Appl Clin Med Phys Source Type: research

Dosimetric comparison of pencil beam and Monte Carlo algorithms in conformal lung radiotherapy.
CONCLUSIONS: A comparison of the dose data acquired in this study reveals that the MC algorithm calculations are closer to the 60 Gy prescribed dose for PTV, while the difference between the PB and MC algorithms was found to be non-significant. Because of the major difference arising from the dose calculation techniques by TPS that was observed in the MLD with significant medium heterogeneity, we recommend the use of the MC algorithm in such heterogeneous sites. PMID: 30079474 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 5, 2018 Category: Physics Authors: Elcim Y, Dirican B, Yavas O Tags: J Appl Clin Med Phys Source Type: research

Quality assurance tests for the Gamma Knife ® Icon™ image guidance system.
CONCLUSIONS: The manufacturer-required QA checks together with additional user-defined checks are an important combination for a robust quality assurance program ensuring the safe use of Gamma Knife® Icon™'s image guidance and motion management features. PMID: 30076672 [PubMed - as supplied by publisher] (Source: Journal of Applied Clinical Medical Physics)
Source: Journal of Applied Clinical Medical Physics - August 3, 2018 Category: Physics Authors: AlDahlawi I, Prasad D, Podgorsak MB Tags: J Appl Clin Med Phys Source Type: research