Abstract:
:We report our technique for hemibody skin electron irradiation with a custom-made plywood shield. The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six-pair dual field (Stanford technique) at an extended source-to-skin distance (SSD) of 377 cm, with the addition of a plywood shield placed at 50 cm from the patient. The shield is made of three layers of stan-dard 5/8'' thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable-height stand. Gafchromic EBT3 films were used in assessing the shield's transmission factor and the extent of the dose penumbra region for two different shield-phantom gaps. The shield transmission factor was found to be about 10%. The width of the penumbra (80%-to-20% dose falloff) was measured to be 12 cm for a 50 cm shield-phantom gap, and reduced slightly to 10 cm for a 35 cm shield-phantom gap. In vivo dosimetry of a real case confirmed the expected shielded area dose.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Rivers CI,AlDahlawi I,Wang IZ,Singh AK,Podgorsak MBdoi
10.1120/jacmp.v17i6.6367subject
Has Abstractpub_date
2016-11-08 00:00:00pages
276-282issue
6issn
1526-9914journal_volume
17pub_type
杂志文章abstract::The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i4.6218
更新日期:2016-07-08 00:00:00
abstract::Chest wall radiation therapy treatment delivery was monitored using a 5 mm thick radiochromic poly(vinyl alcohol) cryogel that also provided buildup material. The cryogels were used to detect positioning errors and measure the impact of shifts for a chest wall treatment that was delivered to a RANDO phantom. The phant...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6148
更新日期:2016-09-08 00:00:00
abstract::Independent treatment planning system (TPS) check with Mobius3D software, log files based quality assurance (QA) with MobiusFX, and phantom measurement-based QA with ArcCHECK were performed and cross verified for head-and-neck (17 patients), chest (16 patients), and abdominal (19 patients) cancer patients who underwen...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13036
更新日期:2020-10-01 00:00:00
abstract::Four-dimensional computerized tomography (4DCT) is required for stereotactic ablative body radiotherapy (SABR) of mobile targets to account for tumor motion during treatment planning and delivery. In this study, we report on the impact of an image review quality assurance process performed prior to treatment planning ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12825
更新日期:2020-03-01 00:00:00
abstract::Flattening filter-free (FFF) beams produce higher dose rates. Combined with compensator-based intensity modulated radiotherapy (IMRT) techniques, the dose delivery for each beam can be much shorter compared to the flattened beam MLC-based or flattened beam compensator-based IMRT. This 'snap shot' IMRT delivery is bene...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12018
更新日期:2017-01-01 00:00:00
abstract::Precise radiation therapy (RT) for abdominal lesions is complicated by respiratory motion and suboptimal soft tissue contrast in 4D CT. 4D MRI offers improved con-trast although long scan times and irregular breathing patterns can be limiting. To address this, visual biofeedback (VBF) was introduced into 4D MRI. Ten v...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i3.6017
更新日期:2016-05-08 00:00:00
abstract::The goal of this study was to investigate small field output factors (OFs) for flat-tening filter-free (FFF) beams on a dedicated stereotactic linear accelerator-based system. From this data, the collimator exchange effect was quantified, and detector-specific correction factors were generated. Output factors for 16 j...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i6.6433
更新日期:2016-11-08 00:00:00
abstract::The increasing popularity of intensity-modulated arc therapy (IMAT) treatments requires specifically designed linac quality assurance (QA) programs. Gantry angle is one of the parameters that has a major effect on the outcome of IMAT treatments since dose reconstruction for patient-specific QA relies on the gantry ang...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i6.3981
更新日期:2012-11-08 00:00:00
abstract::This study aimed to verify the accuracy of half-value layer (HVL) measured using the new copper pipe method with the CT ionization chamber while the X-ray tube is rotating and to compare it with the conventional nonrotating method and Monte Carlo simulation method based on the actual measurement and geometry of the ne...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12780
更新日期:2019-12-01 00:00:00
abstract::The GafChromic XR Type R film is a relatively new product for recording high radiation dose in interventional radiological procedures. Means of measuring the film response were studied in this investigation. Two handheld reflective-type densitometers of different models were compared in the range of 0-8 Gy. They were ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v4i4.2501
更新日期:2003-10-01 00:00:00
abstract::In Winston-Lutz (WL) tests, the isocenter of a linear accelerator (linac) is determined as the intersection of radiation central axes (CAX) from multiple gantry, collimator, and couch angles. It is well known that the CAX can wobble due to mechanical imperfections of the linac. Previous studies suggested that the wobb...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i1.5792
更新日期:2016-01-08 00:00:00
abstract::Highly attenuating radiation treatment couches are no longer useful in the present era of radiotherapy utilizing IMRT and IGRT. Carbon fibers couch tops with its high tensile strength and low density present a useful alternative. The objective of the current study was to quantify the attenuation of megavoltage photons...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i3.2979
更新日期:2009-06-02 00:00:00
abstract::The purpose of this study was to assess treatment margins in free-breathing irradiation of pancreatic cancer after bone alignment, and evaluate their impact on conformal radiotherapy. Fifteen patients with adenocarcinoma of the head of the pancreas underwent implantation of single fiducial marker. Intrafraction uncert...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i4.4152
更新日期:2013-07-08 00:00:00
abstract::The purpose of this study was to develop and validate cardiac computed tomog-raphy (CT) quantitative analysis software with a patient-specific, 17-segment myocardial model that uses electrocardiogram (ECG)-gated cardiac CT images to differentiate between normal controls and severe aortic stenosis (AS) patients. ECG-ga...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6237
更新日期:2016-09-08 00:00:00
abstract::This paper investigates the accuracy of the two available calculation algorithms of the Oncentra MasterPlan three-dimensional treatment planning system (TPS)-- the pencil beam method and collapsed-cone convolution--in modeling the Varian enhanced dynamic wedge (EDW). Measurements were carried out for a dual high energ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i2.2867
更新日期:2009-04-22 00:00:00
abstract:PURPOSE:This study evaluates the feasibility of lung dose prediction based on target contour and patient anatomy for breast patients treated with proton therapy. METHODS:Fifty-two randomly selected patients were included in the cohort, who were treated to 50.4-66.4 Gy(RBE) to the left (36), right (15), or bilateral (1...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章,随机对照试验
doi:10.1002/acm2.12436
更新日期:2018-11-01 00:00:00
abstract::The design concept and dosimetric characteristics of a new applicator system for intraoperative radiation therapy (IORT) are presented in this work. A new hard-docking commercial system includes polymethylmethacrylate (PMMA) applicators with different diameters and applicator end angles and a set of secondary lead col...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v11i4.3244
更新日期:2010-07-19 00:00:00
abstract::Doses in Leksell GammaPlan (Elekta, Stockholm, Sweden) are calculated for each shot by summing the contribution from the 201 radiation beams emitted by the Gamma Knife (Elekta), weighted for attenuation in the tissue traversed. The patient's head is modeled based on 24 skull measurements, from which the depth to the c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v8i3.2377
更新日期:2007-07-17 00:00:00
abstract::Part II of this review article presents four case studies for which peak skin doses are calculated following the methods outlined in Part I of this review. The data available in the cases ranges from proprietary dose reports to fluoroscopy time and number of digital acquisition frames only. Flowcharts are provided for...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i1.3693
更新日期:2012-01-05 00:00:00
abstract::Endorectal balloons (ERBs) are routinely used in prostate proton radiation therapy to immobilize the prostate and spare the rectal wall. Rectal gas can distend the rectum and displace the prostate even in the presence of ERBs. The purpose of this work was to quantify the effects an ERB with a passive gas release condu...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i5.3945
更新日期:2012-09-06 00:00:00
abstract::While a few physicists have designed new plan check automation solutions for their clinics, fewer, if any, managed to adapt existing solutions. As complex and varied as the systems they check, these programs must gain the full confidence of those who would run them on countless patient plans. The present automation ef...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i4.4889
更新日期:2014-07-08 00:00:00
abstract::We have developed a method to improve the setup accuracy of a Varian Clinac 6/100 couch for delivering conformal arc therapy using a tertiary micro multileaf collimator (MLC) system. Several immobilization devices have been developed to improve the mechanical stability and isocenter alignment of the couch: turn-knob h...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v5i3.2026
更新日期:2004-07-01 00:00:00
abstract::Dental amalgams are a common source of artifacts in head and neck (HN) images. Commercial artifact reduction techniques have been offered, but are substantially ineffectual at reducing artifacts from dental amalgams, can produce additional artifacts, provide inaccurate HU information, or require extensive computation ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12922
更新日期:2020-08-01 00:00:00
abstract::We assessed interfraction positional variation in pancreatic tumors using daily breath-hold cone-beam computed tomography at end-exhalation (EE) with visual feedback (BH-CBCT). Eleven consecutive patients with pancreatic cancer who underwent BH intensity-modulated radiation therapy with visual feedback were enrolled. ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i2.5123
更新日期:2015-03-08 00:00:00
abstract::In this study, we compared the amount of lung tissue irradiated when respiratory gating was imposed during expiration with the amount of lung tissue irradiated when gating was imposed during inspiration. Our hypothesis was that the amount of lung tissue spared increased as inspiration increased. Computed tomography (C...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
doi:10.1120/jacmp.26.146
更新日期:2004-01-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The purpose of this study of pancreatic cancer patients treated with respiratory-guided stereotactic body radiotherapy (SBRT) on a standard linac was to investigate (a) the intrafractional relationship change (IRC) between a breathing signal and the tumor position, (b) the impact of IRC on the de...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12841
更新日期:2020-03-01 00:00:00
abstract::An inverse treatment planning (ITP) module on a commercial treatment planning system (TPS) (Helax AB, Uppsala, Sweden) is being used for an in-house clinical trial for treatment of nasopharyngeal cancer with contralateral parotid sparing. Intensity modulated radiation therapy (IMRT) fields are delivered by step and sh...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v3i2.2580
更新日期:2002-04-01 00:00:00
abstract::The control loop in the Varian DMLC system (V4.8) requires approximately 65 msec to monitor and halt the irradiation of a segment, causing an "overshoot" effect: the segment ends on a fractional monitor unit larger than that planned. As a result, the actual MU delivered may differ from that planned. In general, for st...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v2i3.2607
更新日期:2001-07-01 00:00:00
abstract::This study utilizes process control techniques to identify action limits for TomoTherapy couch positioning quality assurance tests. A test was introduced to monitor accuracy of the applied couch offset detection in the TomoTherapy Hi-Art treatment system using the TQA "Step-Wedge Helical" module and MVCT detector. Ind...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12136
更新日期:2017-09-01 00:00:00
abstract::True 3D CT dataset for treatment planning of an oversized patient is difficult to acquire due to the bore size and field of view (FOV) reconstruction. This project aims to provide a simple approach to reconstruct true CT data for oversize patients using CT scanner with limited FOV by acquiring double partial CT (left ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i2.3629
更新日期:2012-03-08 00:00:00