Simultaneous optimization of multiple Planning Target Volumes (PTVs) of varying size and location in the cranium is a non‐trivial task. The rate of dose falloff around PTV structures is variable and depends on PTV characteristics such as the volume. The metric R50% is one parameter that can be used to quantify dose falloff achieved in a given treatment plan. An important treatment planning question

April 9–10th brought to Louisville, KY a flowering of my dogwood trees and some occasional violets pushing their way through my grass. Spring is a fertile season for new thinking, and I wish to share new ideas. Some discussions I have had with certain medical physicists over the past several days have been especially thought‐provoking and caused me to reflect on some of the character and substance

In the last two decades, incredible progress in various medical imaging modalities and sensing techniques have been made, leading to the proliferation of three‐dimensional (3D) imagery. Byproduct of such great progress is the production of huge volume of medical images and this big data place a burden on automatic image processing methods for diagnostic assistance processes. Moreover, large amount

A method for estimating peak skin dose (PSD) from CTDIvol has been published but not validated. The objective of this study was to validate this method during CT‐guided ablation procedures. Radiochromic film was calibrated and used to measure PSD. Sixty‐eight patients were enrolled in this study, and measured PSD were collected for 46 procedures. CTDIvol stratified by axial and helical scanning was

To evaluate the use of commercial‐grade strontium aluminate phosphorescent powder as a thermoluminescent (TL) dosimeter for clinical radiotherapy beams.

Volumetric‐modulated arc therapy (VMAT) requires highly accurate control of multileaf collimator (MLC) movement, rotation speed of linear accelerator gantry, and monitor units during irradiation. Pretreatment validation and monitoring of these factors during irradiation are necessary for appropriate VMAT treatment. Recently, a gantry mounted transmission detector “Delta4 Discover® (D4D)” was developed

To develop a simulation model for GammaMed Plus high dose rate 192Ir brachytherapy source in TOPAS Monte Carlo software and validate it by calculating the TG‐43 dosimetry parameters and comparing them with published data.

To investigate intrinsic sensitivity of an electronic portal imaging device (EPID) and the ArcCHECK detector and to use this in assessing their performance in detecting delivery variations for lung SBRT VMAT. The effect of detector spatial resolution and dose matrix interpolation on the gamma pass rate was also considered.

We describe the creation and characterization of a calibration CT mini‐lung‐phantom incorporating simulated airways and ground‐glass densities. Ten duplicate mini‐lung‐phantoms with Three‐Dimensional (3‐D) printed tubes simulating airways and gradated density polyurethane foam blocks were designed and built. Dimensional accuracy and CT numbers were measured using micro‐CT and clinical CT scanners.

1 INTRODUCTION Since the advent of the AAPM Medical Physics 3.0 Initiative, AAPM has been focused on how physicists can bring additional value to their respective organizations. This could be as simple as new approaches to QA procedures or as complex as expanding greatly beyond our traditional roles in the clinic. As recently highlighted in the Medical Physics Leadership Academy Journal Club, the Arbinger

The aim of this study was to verify the possibility of summing the dose distributions of combined radiotherapeutic treatment of cervical cancer using the extended Lucas‐Kanade algorithm for deformable image registration.

Virtual anatomic phantoms offer precise voxel mapping of the variation of anatomy with ground truth deformation vector fields (DVFs). Dice similarity coefficient (DSC) and mean distance to agreement (MDA) are the standard metrics for evaluating geometric contour congruence when testing deformable registration (DIR) algorithms. A HN virtual patient phantom data set was used for a kVCT‐kVCT automatic

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

Metal artifact reduction (MAR) methods are used to reduce artifacts from metals or metal components in computed tomography (CT). In radiotherapy (RT), CT is the most used imaging modality for planning, whose quality is often affected by metal artifacts. The aim of this study is to systematically review the impact of MAR methods on CT Hounsfield Unit values, contouring of regions of interest, and dose

Dose escalation is key for improved outcomes in intermediate‐risk prostate cancer, including unfavorable intermediate‐risk (UIR) cases. This educational report is designed to provide information about our quality high‐dose 125I seed implantation monotherapy technique in which a biologically effective dose (BED) ≧ 200 Gy is applied for treatment of intermediate‐risk prostate cancer. This protocol is

The purpose of this work was to estimate and compare breast and lung doses of chest CT scans using organ‐based tube current modulation (OBTCM) to those from conventional, attenuation‐based automatic tube current modulation (ATCM) across a range of patient sizes.

In this study, we assessed how image quality depends on the angle of tilt of a flex tilt coil supporting device during an MRI examination. All measurements were performed with an American College of Radiology (ACR) MRI phantom using a flex tilt coil supporting device. All images were analyzed using an automatic assessment method following the ACR MRI accreditation guidance. Image quality was compared

Our study aimed to improve the dosimetry of post modified radical mastectomy intensity‐modulated radiotherapy (PMRM‐IMRT) for left‐sided breast cancer patients by tailoring and minimizing PTV expansion three‐dimensionally utilizing 4D CT combined with on‐board cone beam CT (CBCT).

1 INTRODUCTION Vendor‐provided commercialized equipment and software are well accepted in the medical physics profession, since they are designed to free up physicists’ time, improve workflow efficiency, and provide higher accuracy and precision. There have been clear lines dividing three parties, at least in the field of radiation oncology: patients, health care providers, and medical device suppliers

1 INTRODUCTION The American College of Radiology (ACR) computed tomography (CT) Dose Index Registry (DIR) has been extraordinarily successful, with dose indices collected for over 102 million CT examinations to date.1, 2 The CT DIR has provided an ongoing source of normative clinical data which has been the gold standard for national and international benchmarking.3 The largest existing normative dataset

This study examined the variation in the thyroid volume determined by the ellipsoid approximation method due to differences in the measured length or area of the cross‐sectional plane of CT images.

When planning and delivering radiotherapy, ideally bolus should be in direct contact with the skin surface. Varying air gaps between the skin surface and bolus material can result in discrepancies between the intended and delivered dose. This study assessed a three‐dimensional (3D) printed flexible bolus to determine whether it could improve conformity to the skin surface, reduce air gaps, and improve

Radiotherapy plays an important role in the treatment of lung cancer, and both coplanar beam arrangements (CBA) and noncoplanar beam arrangements (NCBA) are adopted in clinic practice. The aim of this study is to answer the question whether NCBA are dosimetrically superior to CBA.

The purpose of the in silico study was to compare free breathing volumetric modulated arc therapy (VMAT) to standard deep inspiration breath‐hold (DIBH) three‐dimensional conformal radiotherapy (3DCRT) and determine whether the former is a viable option for elderly patients with left‐sided early stage breast cancer. Data from 22 patients with early‐stage left breast carcinoma requiring breast‐only

Patient‐specific quality assurance (QA) is very important in radiotherapy, especially for patients with highly conformed treatment plans like VMAT plans. Traditional QA protocols for these plans are time‐consuming reducing considerably the time available for patient treatments. In this work, a new MC‐based secondary dose check software (SciMoCa) is evaluated and benchmarked against well‐established

Skin collimation provides a sharp penumbra for electron beams, while the effect of bremsstrahlung from shielding materials is a concern. This phantom study was conducted to evaluate the safety and efficacy of a real‐time variable shape rubber containing‐tungsten (STR) that can be placed on a patient’s skin.

Stereotactic ablative body radiotherapy (SABR) of primary kidney cancers is confounded by motion. There is a risk of interplay effect if the dose is delivered using volumetric modulated arc therapy (VMAT) and flattening filter‐free (FFF) dose rates due to target and linac motion. This study aims to provide an efficient way to generate plans with minimal aperture complexity.

To validate an MR‐compatible version of the ScandiDos Delta4 Phantom+ on a 0.35T MR guided linear accelerator (MR‐Linac) system and to determine the effect of plan complexity on the measurement results.

The performance of the AgilityTM multileaf collimator was investigated with a focus on dynamic, small fields for flattening filter free (FFF) beams.

The Elekta Unity MR‐linac utilizes daily magnetic resonance imaging (MRI) for online plan adaptation. In the Unity workflow, adapt to position (ATP) and adapt to shape (ATS) treatment planning options are available which represent a virtual shift or full re‐plan with contour adjustments respectively. Both techniques generate a new intensity modulated radiation therapy (IMRT) treatment plan while the

Brainlab’s Elements Multiple Brain Mets SRS (MBMS) is a dedicated treatment planning system for single‐isocenter multi‐target (SIMT) cranial stereotactic radiosurgery (SRS) treatments. The purpose of this study is to present the commissioning experience of MBMS on an Elekta Versa HD.

To assess the dosimetric performance of an automated breast planning software.

To develop a method for automatically detecting needles from CT images, which can be used in image‐guided lung interstitial brachytherapy to assist needle placement assessment and dose distribution optimization.

The purpose of this study was to assess the quality of treatment planning using the PlanIQTM software and to investigate whether it is possible to improve the quality of treatment planning using the “Feasibility dose‐volume histogram (DVH)TM” implemented in the PlanIQTM software.

Transarterial radioembolization (TARE) effectively treats unresectable primary and metastatic liver tumors through intra‐arterial injection of Yttrium‐90 (90Y) beta particle emitting microspheres which implant around the tumor. Current dosimetry models are highly simplistic and there is a large need for an image‐based dosimetry post‐TARE, which would improve treatment safety and efficacy. Current post‐TARE

The Xstrahl 300 orthovoltage unit is designed to deliver kilovoltage radiation therapy using the appositional technique. However, it is not equipped with some typical linear accelerator features, such as mechanical distance indicator and crosshair projection, which are useful for facilitating equipment setup during various quality assurance (QA) and research activities. Therefore, we designed and constructed

This study aimed to evaluate the dosimetric properties of a newly developed thermoluminescent sheet‐type dosimeter (TLD‐sheet) for clinical proton beams.

The local building requirements to secure medical equipment in seismically active areas in the United States are based on recommendations of the American Society of Civil Engineers. In our institution we have recently acquired new linear accelerators, one of which had to be installed in an existing vault and one in a new vault. Since we are in a seismic active area, changes in the local code required

Studies have evaluated the viability of using open‐face masks as an immobilization technique to treat intracranial and head and neck cancers. This method offers less stress to the patient with comparable accuracy to closed‐face masks. Open‐face masks permit implementation of surface guided radiation therapy (SGRT) to assist in positioning and motion management. Research suggests that changes in patient

To synthesize a dual‐energy computed tomography (DECT) image from an equivalent kilovoltage computed tomography (kV‐CT) image using a deep convolutional adversarial network.

Patient‐Specific Quality Assurance (PSQA) measurement analysis depends on generating metrics representative of calculation and measurement agreement. Considering the heightened capability of discrete spot scanning protons to modulate individual dose voxels, a dose plane comparison approach that maintained all of the capabilities of the well‐established γ test, but that also provided a more intuitive

Due to the limited height of commercial prone breast boards, large or pendulous breasts may contact the base layer of the board during simulation and throughout the course of treatment. Our clinic has historically identified and marked this region of contact to ensure reproducible setup. However, this situation may result in unwanted hotspots where the breast rests atop the board due to electron scatter

Licon AL, Alexandrian A, Saenz D, Myers P, Rasmussen K, Stathakis S, Papanikolaou N, Kirby N. An open‐source tool to visualize potential cone collisions while planning SRS cases. J Appl Clin Med Phys. 2020;21:40–47. In the above‐mentioned article, the following acknowledgment section has been included. Ara Alexandrian was a recipient of a predoctoral fellowship from the Cancer Prevention & Research

Explore the feasibility of adopting failure modes and effects analysis (FMEA) for risk assessment of a high volume clinical service at a UK radiotherapy center. Compare hypothetical failure modes to locally reported incidents.

Hippocampal‐avoidance prophylactic cranial irradiation (HA‐PCI) offers potential neurocognitive benefits but raises technical challenges to treatment planning. This study aims to improve the conventional planning method using volumetric modulated arc therapy (VMAT) technique and investigate a better patient’s head positioning to achieve a high quality of HA‐PCI treatment plans.

To evaluate dosimetric properties of intensity‐modulated proton therapy (IMPT) for simulated treatment planning in patients with atrial fibrillation (AF) targeting left atrial‐pulmonary vein junction (LA‐PVJ), in comparison with volumetric‐modulated arc therapy (VMAT) and helical tomotherapy (TOMO).

This work of fiction is part of a case series by the Medical Physics Leadership Academy (MPLA) demonstrating the use of case studies as an educational method for the development of professionalism, leadership, and communication skills within the medical physics community 1 A facilitator's or self‐study guide is available. Please contact the MPLA Cases Subcommittee (https://www.aapm.org/org/structure/default

The aim of the study was to estimate and to compare effective doses in the elbow region resulting from four different x‐ray imaging modalities. Absorbed organ doses were measured using 11 metal oxide field effect transistor (MOSFET) dosimeters that were placed in a custom‐made anthropomorphic elbow RANDO phantom. Examinations were performed using Shimadzu FH‐21 HR radiography device, Siemens Sensation

The objective of this study was to investigate the dosimetric impact of range uncertainty in a large cohort of patients receiving passive scatter proton therapy.

To evaluate the accuracy of surface‐guided radiotherapy (SGRT) in cranial patient setup by direct comparison between optical surface imaging (OSI) and cone‐beam computed tomography (CBCT), before applying SGRT‐only setup for conventional radiotherapy of brain and nasopharynx cancer.

Two‐dimensional (2D) IMRT QA has been widely performed in Radiation Oncology clinic. However, concerns regarding its sensitivity in detecting delivery errors and its clinical meaning have been raised in publications. In this study, a robust methodology of three‐dimensional (3D) IMRT QA using fiducial registration and structure‐mapping was proposed to acquire organ‐specific dose information.

The purpose of this study was to gauge the experiences of applicants and program directors (PDs) in the Medical Physics (MedPhys) Match (MPM) and to determine the most important characteristics and factors that influence decision‐making for applicants and programs when screening, interviewing, and ranking in the MPM. Opinions were also solicited from applicants and PDs on the status of medical physics

The purpose of this study was to evaluate the performance of three common deformable image registration (DIR) packages across algorithms and institutions.

Radixact Synchrony corrects for target motion during treatment by adjusting the jaw and MLC positions in real time. As the jaws move off axis, Synchrony attempts to adjust for a loss in output due to the un‐flattened 6 MV beam by increasing the jaw aperture width. The purpose of this work was to assess the impact of the variable‐width aperture on delivered dose using measurements and simulations.

This study aimed to evaluate and compare different system calibration methods from a large cohort of systems to establish a commissioning procedure for surface‐guided frameless cranial stereotactic radiosurgery (SRS) with intrafractional motion monitoring and gating. Using optical surface imaging (OSI) to guide non‐coplanar SRS treatments, the determination of OSI couch‐angle dependency, baseline drift

To investigate the impact of computed tomography (CT) image acquisition and reconstruction parameters, including slice thickness, pixel size, and dose, on automatic contouring algorithms.

The performance of three digital detectors was measured at two exposure index (EI) levels in terms of the effect on features at the borderline of detectability. The null hypothesis was that there would be no statistically significant difference in the CNR of marginally visible features of a baseline‐ (2.2 µGy) and reduced dose (1.4 µGy) images. The experiment used three digital detectors and a phantom

1 Introduction The Coronavirus 2019 (COVID‐19) pandemic has severely impacted healthcare systems by putting a massive strain on emergency, intensive care, internal medicine departments, and caregivers. Outpatient care, including radiation oncology, has also been disrupted, forcing departments to modify operations so that patients can continue to obtain treatment in the safest and most effective manner

A novel, breast‐specific stereotactic radiotherapy device has been developed for delivery of highly conformal, accelerated partial breast irradiation. This device employs a unique, vacuum‐assisted, breast cup immobilization system that applies a gentle, negative pressure to the target breast with the patient in the prone position. A device‐specific patient loader is utilized for simulation scanning

The aim of this study is to evaluate the characteristics of the dosimetry and the skin dose of interstitial brachytherapy by the use of the free‐hand implantation technique toward the treatment of early breast cancer.