Abstract:
:The purpose of this work is to prospectively assess the setup accuracy that can be achieved with a stereotactic body localizer (SBL) in immobilizing patients for stereotactic intensity-modulated radiotherapy (IMRT) for prostate cancer. By quantifying this important factor and target mobility in the SBL, we expect to provide a guideline for selecting planning target volume margins for stereotactic treatment planning. We analyzed data from 40 computed tomography (CT) studies (with slice thickness of 3 mm) involving 10 patients with prostate cancer. Each patient had four sets of CT scans during the course of radiotherapy. For the purpose of this study, all four sets of CT scans were obtained with the patients immobilized in a customized body pillow formed by vacuum suction. Unlike other immobilization devices, this system consists not only of a customized body pillow, but also of a fixation sheet used to suppress patient respiratory motion, a stereotactic body frame to provide stereotaxy, and a carbon fiber base board to which both the body cushion and the frame are affixed. We identified four bony landmarks and measured their coordinates in the stereotactic body frame on each set of CT scans. The displacements of the bony landmarks from their corresponding positions on the simulation scan (first CT scan) were analyzed in three dimensions in terms of overall, systematic, and random categories. The initial planned isocenter was also marked on the patients' skin with fiducials for each CT study. The distance from each bony landmark to the fiducial-based isocenter was measured and compared among the four sets of CT scans. The deviations in distances were also compared to those measured from the landmarks to the stereotactic frame center, in order to determine the effectiveness of the rigid body frame in positioning patients with prostate cancer. Target inter-fraction motion in this system was also studied for five patients by measuring the deviations in distances from the target geometric center to the bony landmarks. Our results showed that the overall setup accuracy had standard deviations (SDs) of 2.58 mm, 2.41 mm, and 3.51 mm in lateral (LAT), anterior-posterior(AP), and superior-inferior (SI) directions, respectively. The random component had SDs of 1.72 mm, 2.06 mm, and 2.79 mm, and the systematic component showed SDs of 0.92 mm, -0.27 mm, and 0.90 mm in these three directions. In terms of three-dimensional vector, the mean displacement over 116 measurements was 3.0 mm with an SD of 1.29 mm. Compared to the rigid reference, the skin-mark-based reference was less reliable for patient repositioning in terms of reproducing known bony landmark positions. The mean target mobility relative to the bony landmarks was 2.22 +/- 3.45 mm, 0.17 +/- 1.11 mm, and 0.11 +/- 2.69 mm in the AP, LAT, and SI directions, respectively. In conclusion, the body immobilization system has the ability to immobilize prostate cancer patients with satisfactory setup accuracy for fractionated extracranial stereotactic radiotherapy. A rigid frame system serves as a reliable alignment reference in terms of repositioning patients into the planning position, while skin-based reference showed larger deviations in repositioning patients.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Wang L,Jacob R,Chen L,Ma C,Movsas B,Feigenberg S,Konski Adoi
10.1120/jacmp.v5i2.1947keywords:
subject
Has Abstractpub_date
2004-04-01 00:00:00pages
18-28issue
2issn
1526-9914journal_volume
5pub_type
临床试验,杂志文章abstract::Remote afterloading devices used for high-dose-rate (HDR) brachytherapy may be supplied with different sources, and these sources typically have differing initial source strengths. In addition, the proposed frequency for source changes may also vary, depending upon the source type. Dosimetric parameters unique to each...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i6.4239
更新日期:2013-11-04 00:00:00
abstract::Continuous arterial spin labeling (CASL) is a technique for performing quantitative perfusion measurements without the need for exogenous contrast agent administration. This technique has seen limited use in the clinic due to problems of poor sensitivity and the potential for artifacts. In addition, CASL requires the ...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
doi:10.1120/jacmp.v6i1.2068
更新日期:2005-01-01 00:00:00
abstract::PET/CT imaging could improve delineation of rectal carcinoma gross tumor volume (GTV) and reduce interobserver variability. The objective of this work was to compare various functional volume delineation algorithms. We enrolled 31 consecutive patients with locally advanced rectal carcinoma. The FDG PET/CT and the high...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i5.4696
更新日期:2014-09-08 00:00:00
abstract::Routine constancy checks of electron energy are often time consuming because of the necessity to measure a dose at two depths. A technique is described that uses a double-wedge shaped phantom positioned on a Profiler diode array for measuring an electron energy constancy metric similar to R(50). The double-wedge elect...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v4i3.2516
更新日期:2003-07-01 00:00:00
abstract::Stereotactic body radiotherapy (SBRT) of lung tumors via the ring-mounted Halcyon Linac, a fast kilovoltage cone beam CT-guided treatment with coplanar geometry, a single energy 6MV flattening filter free (FFF) beam and volumetric modulated arc therapy (VMAT) is a fast, safe, and feasible treatment modality for select...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13146
更新日期:2020-12-20 00:00:00
abstract:BACKGROUND:We analyzed the clinical and imaging characteristics of patients with breast ductal carcinoma in situ with microinvasion (DCISM) and breast ductal carcinoma in situ (DCIS). METHODS:We analyzed the records of 40 patients diagnosed with DCISM and 61 patients with DCIS who were hospitalized at Shengjing Hospit...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13122
更新日期:2020-12-17 00:00:00
abstract:PURPOSE:The target detectability of cone beam computed tomography (CBCT) performed in image-guided radiation therapy (IGRT) was investigated to achieve sufficient image quality for patient positioning over a course of treatment session while maintaining radiation exposure from CBCT imaging as low as reasonably achievab...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12306
更新日期:2018-05-01 00:00:00
abstract:INTRODUCTION:This study aimed to investigate the feasibility of generating pseudo dual-energy CT (DECT) from one 120-kVp CT by using convolutional neural network (CNN) to derive additional information for quantitative image analysis through phantom study. METHODS:Dual-energy scans (80/140 kVp) and single-energy scans ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13148
更新日期:2020-10-14 00:00:00
abstract:PURPOSE:The aim of this study was to develop and assess the performance of supervised machine learning technique to classify magnetic resonance imaging (MRI) voxels as cancerous or noncancerous using noncontrast multiparametric MRI (mp-MRI), comprised of T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12992
更新日期:2020-10-01 00:00:00
abstract:OBJECTIVES:To evaluate the influence of MRI scanning parameters on texture analysis features. METHODS:Publicly available data from the Reference Image Database to Evaluate Therapy Response (RIDER) project sponsored by The Cancer Imaging Archive included MRIs on a phantom comprised of 18 25-mm doped, gel-filled tubes, ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12482
更新日期:2018-11-01 00:00:00
abstract::The purpose was to assess the variability in automated translational head/neck setup corrections computed from several different imaging modalities and rigid registration methods using patient anatomy. Shifts were calculated using three commercial and one in-house automated rigid registration methods for nine head/nec...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i1.3337
更新日期:2010-10-13 00:00:00
abstract:PURPOSE:Volumetric modulated arc therapy (VMAT) is gaining popularity for stereotactic treatment of lung lesions for medically inoperable patients. Due to multiple beamlets in delivery of highly modulated VMAT plans, there are dose delivery uncertainties associated with small-field dosimetry error and interplay effects...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12878
更新日期:2020-07-01 00:00:00
abstract::The purpose of this study was to describe our experience with 1.0T MR-SIM including characterization, quality assurance (QA) program, and features necessary for treatment planning. Staffing, safety, and patient screening procedures were developed. Utilization of an external laser positioning system (ELPS) and MR-compa...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i2.5201
更新日期:2015-03-08 00:00:00
abstract:PURPOSE:Beam matching occurs on all linacs to some degree and when two are more are matched to each other, patients are able to be transferred between machines. Quality assurance of plans can also be performed "distributively" on any of the matched linacs. The degree to which machines are matched and how this translate...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12567
更新日期:2019-04-01 00:00:00
abstract::Locally advanced non-small-cell lung cancer (NSCLC) is a common disease with a low overall survival even with aggressive treatments. Standard imaging (CT and PET/CT) provide no information about normal lung function. We therefore, sought to pilot HeMRI in patients with non-small-cell lung cancer before and after defin...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i2.3357
更新日期:2011-01-31 00:00:00
abstract::During volume-modulated arc therapies (VMAT), dosimetric errors are introduced by multiple open dynamic leaf gaps that are present in fixed diaphragm linear accelerators. The purpose of this work was to develop a methodology for adjusting the rounded leaf end modeling parameters to improve out-of-field dose agreement ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i6.6343
更新日期:2016-11-08 00:00:00
abstract::This work describes the use of 3D printing technology to create individualized boluses for patients treated with electron beam therapy for skin lesions of the eye canthi. It aimed to demonstrate the effectiveness of 3D-printed over manually fabricated paraffin boluses. The study involved 11 patients for whom the const...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12013
更新日期:2017-01-01 00:00:00
abstract:PURPOSE:The purpose of this study was to introduce a new algorithm for automated measurement of the modulation transfer function (MTF) using an edge of a readily available phantom and to evaluate the effect of reconstruction filter and field of view (FOV) on the spatial resolution in the CT images. METHODS:Our automat...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12476
更新日期:2018-11-01 00:00:00
abstract::Increasingly, the advent of multislice CT scanners, volume CT scanners, and total body spiral acquisition modes has led to the use of Multi Planar Reconstruction and 3D datasets. In considering 3D resolution properties of a CT system it is important to note that both the in-plane (x,y) and z-axis (slice thickness) inf...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6294
更新日期:2016-09-08 00:00:00
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 of the phantom depth for field sizes ranging from 2 × 2 to 10 × ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13094
更新日期:2020-12-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Along with the increasing demand for high-quality radiotherapy and the growing number of high-precision radiotherapy devices, precise radiotherapy workflow management and accurate time evaluation of the entire radiotherapy process are crucial to providing appropriate, timely treatment for cancer ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12959
更新日期:2020-09-01 00:00:00
abstract::The aim of this study was to assess the performance of a gantry-mounted detector system and a couch set detector system using a systematic multileaf collimator positional error manually introduced for volumetric-modulated arc therapy. Four head and neck and esophagus VMAT plans were evaluated by measurement using an e...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i3.4495
更新日期:2014-05-08 00:00:00
abstract::This study evaluated unexpected dosimetric errors caused by machine control accuracy, patient setup errors, and patient weight changes/internal organ deformations. Trajectory log files for 13 gynecologic plans with seven- or nine-beam dynamic multileaf collimator (MLC) intensity-modulated radiation therapy (IMRT), and...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13163
更新日期:2021-01-10 00:00:00
abstract::The purpose of this study is to describe the comprehensive commissioning process and initial clinical experience of the Mevion S250 proton therapy system, a gantry-mounted, single-room proton therapy platform clinically implemented in the S. Lee Kling Proton Therapy Center at Barnes-Jewish Hospital in St. Louis, MO, U...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i2.5868
更新日期:2016-03-08 00:00:00
abstract::A new calculation algorithm has been developed for independently verifying doses calculated by the TomoTherapy Hi.Art treatment planning system (TPS). The algorithm is designed to confirm the dose to a point in a high dose, low dose-gradient region. Patient data used by the algorithm include the radiological depth to ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i1.2772
更新日期:2009-02-05 00:00:00
abstract::Breast treatments are becoming increasingly complex as the use of modulated and partial breast therapies becomes more prevalent. These methods are predicated on accurate and precise positioning for treatment. However, the ability to quantify intrafraction motion has been limited by the excessive dose that would result...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i6.4957
更新日期:2014-11-08 00:00:00
abstract::To estimate the lung tumor position from multiple anatomical features on four-dimensional computed tomography (4D-CT) data sets using single regression analysis (SRA) and multiple regression analysis (MRA) approach and evaluate an impact of the approach on internal target volume (ITV) for stereotactic body radiotherap...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12121
更新日期:2017-09-01 00:00:00
abstract:OBJECT:The purpose of this study was to compare two methods of stereotactic localization in Gamma Knife treatment planning: cone beam computed tomography (CBCT) or fiducial. While the fiducial method is the traditional method of localization, CBCT is now available for use with the Gamma Knife Icon. This study seeks to ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12745
更新日期:2019-11-01 00:00:00
abstract:PURPOSE:To provide insight into the types of questions asked to medical physicists by patients during one-on-one physicist-patient consults at one institution. MATERIALS AND METHODS:Medical physicists trained in patient communication techniques met with patients to provide an overview of the treatment planning and del...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12942
更新日期:2020-08-01 00:00:00
abstract:PURPOSE:Previous studies suggest that within radiation oncology, medical physicists (MP) experience high workloads. Little is known about how MPs use social support (SS) in times of stress. METHODS:In collaboration with the Workgroup on Prevention of Medical Error, the American Association of Physicists in Medicine ad...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12675
更新日期:2019-09-01 00:00:00