A Patient-Specific correspondence model to track tumor location in thorax during radiation therapy.

Purpose: We present a patient-specific model to estimate tumor location in the thorax during radiation therapy using chest surface displacement as the surrogate signal.

Methods: Two types of data are used for model construction: Four-dimensional computed tomography (4D-CT) images of the patient and the displacement of two points on the patient's skin on the thoracic area. Principal component analysis is used to fit the correspondence model.

Comparison of visual and semi-automated kilovoltage cone beam CT image QA analysis.

Established kilovoltage cone-beam computed tomography (kV-CBCT) image quality assurance (QA) guidelines often rely on recommendations provided by the American Association of Physicists in Medicine (AAPM) task group (TG) reports with metrics that use visual analysis. This can result in measurement variations by different users, especially in visually subjective analyzes such as low contrast resolution. Consequently, there is a growing interest in more automated means of image QA analysis that can offer increased consistency, accuracy, and convenience.

A novel analytical method for computing dose from kilovoltage beams used in Image-Guided radiation therapy.

Purpose: A modified convolution/superposition algorithm is proposed to compute dose from the kilovoltage beams used in IGRT. The algorithm uses material-specific energy deposition kernels instead of water-energy deposition kernels.

Methods: Monte Carlo simulation was used to model the Elekta XVI unit and determine dose deposition characteristics of its kilovoltage beams.

Generation of material-specific energy deposition kernels for kilovoltage x-ray dose calculations.

Purpose: Dose calculation of kilovoltage x rays used in Image-Guided Radiotherapy has been investigated in recent years using various methods. Among these methods are model-based ones that suffer from inaccuracies in high-density materials and at interfaces when used in the kilovoltage energy range. The main reason for this is the use of water energy deposition kernels and simplifications employed such as density scaling in heterogeneous media.

First Multimodal, Three-Dimensional, Image-Guided Total Marrow Irradiation Model for Preclinical Bone Marrow Transplantation Studies.

Purpose: Total marrow irradiation (TMI) has significantly advanced radiation conditioning for hematopoietic cell transplantation in hematologic malignancies by reducing conditioning-induced toxicities and improving survival outcomes in relapsed/refractory patients. However, the relapse rate remains high, and the lack of a preclinical TMI model has hindered scientific advancements. To accelerate TMI translation to the clinic, we developed a TMI delivery system in preclinical models.

First clinical implementation of GammaTile permanent brain implants after FDA clearance.

Purpose: GammaTile cesium-131 (Cs) permanent brain implant has received Food and Drug Administration (FDA) clearance as a promising treatment for certain brain tumors. Our center was the first institution in the United States after FDA clearance to offer the clinical use of GammaTile brachytherapy outside of a clinical trial. The purpose of this work is to aid the medical physicist and radiation oncologist in implementing this collagen carrier tile brachytherapy (CTBT) program in their practice.

How low can you go? A CBCT dose reduction study.

Purpose: Cone beam computed tomography (CBCT) is often used for patient setup based solely on bony anatomy. The goal of this work was to evaluate whether CBCT dose can be lowered to the level of kV image pair doses when used for bony anatomy-based IGRT without compromising positioning accuracy.

Methods: An anthropomorphic phantom was CT scanned in the head, head and neck, chest, and pelvis regions and setup on the linear accelerator couch with the isocenter near the planned location.

Dry Needling for Hamstring Flexibility: A Single-Blind Randomized Controlled Trial.

Context: Hamstring muscle tightness is one of the most common problems in athletic and healthy people. Dry needling (DN) was found to be an effective approach for improving muscle flexibility, but there is no study to compare this approach with static stretching (SS) as a common technique for the increase of muscle length.

Objective: To compare the immediate effects of DN and SS on hamstring flexibility in healthy subjects with hamstring tightness.

Practice patterns and recommendations for pediatric image-guided radiotherapy: A Children's Oncology Group report.

This report by the Radiation Oncology Discipline of Children's Oncology Group (COG) describes the practice patterns of pediatric image-guided radiotherapy (IGRT) based on a member survey and provides practice recommendations accordingly. The survey comprised of 11 vignettes asking clinicians about their recommended treatment modalities, IGRT preferences, and frequency of in-room verification. Technical questions asked physicists about imaging protocols, dose reduction, setup correction, and adaptive therapy.

The MedRisk instrument for measuring patient satisfaction with physical therapy care: A validation of the Persian-language version.

: Valid and reliable tools are required to measure patient satisfaction with physical therapy care. The aim of this study was to translate the MedRisk instrument for measuring patient satisfaction with physical therapy care (MRPS) into Persian language and to evaluate its measurement properties.: A cross-sectional and prospective validation study design was adopted.

Responsiveness and longitudinal validity of the Persian version of COMI to physiotherapy in patients with non-specific chronic low back pain.

Background and aims The Core Outcome Measures Index (COMI) is a short, self-reported questionnaire for assessing important outcomes in patients with low back pain (LBP). The present study was conducted to explore the responsiveness and longitudinal validity of the Persian COMI (COMI-P) in patients with non-specific chronic LBP. Methods In this prospective cohort study of patients with non-specific chronic LBP receiving physiotherapy, patients completed a booklet containing the COMI-P, Persian Functional Rating Index (FRI-P), and a visual analogue scale (VAS) for pain before and after the end of ten-sessions of physiotherapy.

Two-dimensional dose reconstruction using scatter correction of portal images.

Context: Electronic portal imaging devices (EPIDs) could potentially be useful for patient setup verification and are also increasingly used for dosimetric verification. The accuracy of EPID for dose verification is dependent on the dose-response characteristics, and without a comprehensive evaluation of dose-response characteristics, EPIDs should not be used clinically.

Aims: A scatter correction method is presented which is based on experimental data of a two-dimensional (2D) ion chamber array.

Effect of beam configuration with inaccurate or incomplete small field output factors on the accuracy of treatment planning dose calculation.

Purpose: To evaluate the effect of beam configuration with inaccurate or incomplete small field output factors on the accuracy of dose calculations in treatment planning systems.

Methods: Output factors were measured using various detectors and for a range of field sizes. Three types of treatment machines were configured in two treatment planning systems.

Multi-institutional evaluation of MVCT guided patient registration and dosimetric precision in total marrow irradiation: A global health initiative by the international consortium of total marrow irradiation.

Purpose: Total marrow irradiation (TMI) is a highly conformal treatment of the human skeleton structure requiring a high degree of precision and accuracy for treatment delivery. Although many centers worldwide initiated clinical studies using TMI, currently there is no standard for pretreatment patient setup. To this end, the accuracy of different patient setups was measured using pretreatment imaging.

Immediate Effects of Dry Needling as a Novel Strategy for Hamstring Flexibility: A Single-Blinded Clinical Pilot Study.

Context: There are numerous studies on the benefits of dry needling (DN) for pain relief. No studies exist examining the effects of DN on hamstring flexibility.

Objective: To determine the immediate effects of DN on hamstring flexibility in healthy subjects with shortened hamstrings.

Responsiveness of Minimal Clinically Important Change for the Persian Functional Rating Index in Patients with Chronic Low Back Pain.

Study Design: A prospective, within-group cohort study of 46 patients with chronic low-back pain (CLBP).

Purpose: To assess the responsiveness of the Persian Functional Rating Index (PFRI) and to determine the minimal clinically important change (MCIC) of the PFRI in a cohort of patients with CLBP.

Overview Of Literature: The FRI is an instrument for assessing pain and disability in patients with low-back pain.

Technical Note: Impact of region of interest size and location in Gafchromic film dosimetry.

Purpose: To evaluate dependence of measured dose on size and location of region of interest (ROI) in Gafchromic EBT3 film dosimetry.

Methods: Gafchromic EBT3 films were irradiated perpendicularly using the 6MV beam from a linear accelerator at 10 cm depth (100 cm SSD) of a 30 × 30 × 20 cm solid water phantom for a range of field sizes of 6 × 6 to 100 × 100 mm . ImageJ software was used for reading pieces of film.

Image guidance doses delivered during radiotherapy: Quantification, management, and reduction: Report of the AAPM Therapy Physics Committee Task Group 180.

Background: With radiotherapy having entered the era of image guidance, or image-guided radiation therapy (IGRT), imaging procedures are routinely performed for patient positioning and target localization. The imaging dose delivered may result in excessive dose to sensitive organs and potentially increase the chance of secondary cancers and, therefore, needs to be managed.

Aims: This task group was charged with: a) providing an overview on imaging dose, including megavoltage electronic portal imaging (MV EPI), kilovoltage digital radiography (kV DR), Tomotherapy MV-CT, megavoltage cone-beam CT (MV-CBCT) and kilovoltage cone-beam CT (kV-CBCT), and b) providing general guidelines for commissioning dose calculation methods and managing imaging dose to patients.

Early assessment of dosimetric and biological differences of total marrow irradiation versus total body irradiation in rodents.

Purpose: To develop a murine total marrow irradiation (TMI) model in comparison with the total body irradiation (TBI) model.

Materials And Methods: Myeloablative TMI and TBI were administered in mice using a custom jig, and the dosimetric differences between TBI and TMI were evaluated. The early effects of TBI/TMI on bone marrow (BM) and organs were evaluated using histology, FDG-PET, and cytokine production.

Evaluation of dose calculation accuracy of treatment planning systems at hip prosthesis interfaces.

There are an increasing number of radiation therapy patients with hip prosthesis. The common method of minimizing treatment planning inaccuracies is to avoid radiation beams to transit through the prosthesis. However, the beams often exit through them, especially when the patient has a double-prosthesis.

Implementation of full/half bowtie filter models in a commercial treatment planning system for kilovoltage cone-beam CT dose estimations.

The purpose of this study was to implement full/half bowtie filter models in a com-mercial treatment planning system (TPS) to calculate kilovoltage (kV) cone-beam CT (CBCT) doses of Varian On-Board Imager (OBI) kV X-ray imaging system. The full/half bowtie filter models were created as compensators in Pinnacle TPS using MATLAB software. The physical profiles of both bowtie filters were imported and hard-coded in the MATLAB system.

Dose response characteristics of a novel CCD camera-based electronic portal imaging device comparison with OCTAVIUS detector.

Aim: Dosimetric properties of a CCD camera-based Electronic Portal Imaging Device (EPID) for clinical dosimetric application have been evaluated. Characteristics obtained by EPID also compared with commercial 2D array of ion chambers.

Materials And Methods: Portal images acquired in dosimetry mode then exported raw fluence or uncorrected images were investigated.

Imaging dose from cone beam computed tomography in radiation therapy.

Imaging dose in radiation therapy has traditionally been ignored due to its low magnitude and frequency in comparison to therapeutic dose used to treat patients. The advent of modern, volumetric, imaging modalities, often as an integral part of linear accelerators, has facilitated the implementation of image-guided radiation therapy (IGRT), which is often accomplished by daily imaging of patients. Daily imaging results in additional dose delivered to patient that warrants new attention be given to imaging dose.