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 uncertainties were assessed on simulation four-dimensional computed tomography (4D CT) by calculating maximal intrafraction fiducial excursion (MIFE). In the first ten patients, after bony alignment, the position of the fiducial was identified on weekly acquired megavolt cone-beam CT (MV-CBCT). The interfraction residual uncertainties were estimated by measuring the fiducial displacements with respect to the position in the first session. Patient mean (pM) and patient standard deviation (pSD) of fiducial displacement, mean (μM) and standard deviation (μSD) of pM, and root-mean-square of pSD (σ(res)) were calculated. In the other five patients, MIFE was added to the residual component to obtain personalized margin. In these patients, conformal kidney sparing (CONKISS) irradiation was planned prescribing 54/45 Gy to PTV1/PTV2. The organ-at-risk limits were set according to current NCCN recommendation. No morbidity related to the fiducial marker implantation was recorded. In the first ten patients, along right-left, anterior-posterior, and inferior-superior directions, MIFE was variable (mean ± std = 0.24 ± 0.13 cm, 0.31 ± 0.14 cm, 0.83 ± 0.35 cm, respectively) and was at most 0.51, 0.53, and 1.56 cm, respectively. Along the same directions, μM were 0.09, -0.05, -0.05 cm, μSD were 0.30, 0.17, 0.33 cm, and σ(res) were 0.35, 0.26, and 0.30 cm, respectively. MIFE was not correlated with pM and pSD. In the five additional patients, it was possible to satisfy recommended dose limits, with the exception of slightly higher doses to small bowel. After bony alignment, the margins for target expansion can be obtained by adding personalized MIFE to the residual interfraction term. Using these margins, conformal free-breathing irradiation is a reliable option for the treatment of pancreatic cancer.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Solla I,Zucca S,Possanzini M,Piras S,Pusceddu C,Porru S,Meleddu G,Farace Pdoi
10.1120/jacmp.v14i4.4152subject
Has Abstractpub_date
2013-07-08 00:00:00pages
4152issue
4issn
1526-9914journal_volume
14pub_type
杂志文章abstract::This study details the generation, verification, and implementation of a treatment planning system (TPS) couch top model for patient support system used in conjunction with a dedicated stereotactic linear accelerator. Couch top model was created within the TPS using CT simulation images of the kVue Calpyso-compatible ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i4.5441
更新日期:2015-07-08 00:00:00
abstract::A custom-made computer program, SWIMRT, to construct "multileaf collimator (MLC) machine" file for intensity-modulated radiotherapy (IMRT) fluence maps was developed using MATLAB and the sliding window algorithm. The user can either import a fluence map with a graphical file format created by an external treatment-pla...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v7i2.2231
更新日期:2006-05-25 00:00:00
abstract::The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth-dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small fi...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i1.3267
更新日期:2010-10-04 00:00:00
abstract::The purpose of this study was to develop and evaluate a noninvasive method to assess rotation time in modern commercial computed tomography (CT) systems. The rotation time was measured at a selected nominal rotation time (400 ms) utilizing two types of solid-state detectors: the RTI's CT Dose Profiler (CTDP) and Unfor...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i1.4517
更新日期:2014-01-06 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::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::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: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::A patient with a cardiac ventricular assist device (VAD) with computer-controlled driver presented to our department for radiation therapy. The treatment plan was 4500 cGy to the rectum over 25 fractions with 15MV photon beams. All beams avoided the pump and leads. The response to electromagnetic interference (EMI) wa...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v9i4.2851
更新日期:2008-10-29 00:00:00
abstract::The management of a pregnant patient in radiation oncology is an infrequent event requiring careful consideration by both the physician and physicist. The aim of this manuscript was to highlight treatment planning techniques and detail measurements of fetal dose for a pregnant patient recently requiring treatment for ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12262
更新日期:2018-09-01 00:00:00
abstract::A new method of generating wedge-shaped dose distributions through dynamic multileaf collimator dose delivery rather than computer-controlled jaw motion is presented. The method starts with the calculation of a wedge-shaped beam profile for the desired wedge angle. The resultant wedge beam profile is then passed to th...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v6i3.2060
更新日期:2005-07-01 00:00:00
abstract::Magnetic resonance imaging (MRI) is regularly used for stereotactic imaging of Gamma Knife (GK) radiosurgery patients for GK treatment planning. MRI-induced thermal injuries have occurred and been reported for GK patients with attached metallic headframes. Depending on the specific MR imaging and headframe conditions,...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i4.3613
更新日期:2012-07-05 00:00:00
abstract::The purpose of this study was to demonstrate that Monte Carlo treatment planning systems require tissue characterization (density and composition) as a function of CT number. A discrete set of tissue classes with a specific composition is introduced. In the current work we demonstrate that, for megavoltage photon radi...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i5.5586
更新日期:2015-09-08 00:00:00
abstract:PURPOSE:The goal of this study was to find the optimal combination of collimator, photopeak and scatter correction for 177 Lutetium (177 Lu) SPECT/CT imaging. METHODS:Three experiments [sphere-to-background ratios (SBR) 50:1, 10:1, and 2:1] were performed with the NEMA Image Quality phantom filled with 177 Lu-trichlor...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12991
更新日期:2020-09-01 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::A Histogram Analysis in Radiation Therapy (HART) program was primarily developed to increase the efficiency and accuracy of dose-volume histogram (DVH) analysis of large quantities of patient data in radiation therapy research. The program was written in MATLAB to analyze patient plans exported from the treatment plan...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:
更新日期:2010-01-28 00:00:00
abstract::We describe a method for independently verifying the dose distributions from pre- and post-implant brachytherapy source distributions. Monte Carlo calculations have been performed to characterize the three-dimensional dose distribution in water phantom from a low-energy brachytherapy source. The calculations are perfo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v4i1.2543
更新日期:2003-01-01 00:00:00
abstract::Measurement of cumulative dose ƒ(0,150) with a small ionization chamber within standard polymethyl methacrylate (PMMA) CT head and body phantoms, 150 mm in length, is a possible practical method for cone-beam computed tomography (CBCT) dosimetry. This differs from evaluating cumulative dose under scatter equilibrium c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i6.5793
更新日期:2015-11-08 00:00:00
abstract::Beam quality correction kQQo (r), which reflects the absorbed energy dependence of the detector, is calculated for solid state detector materials diamond, LiF, Li2B4O7 and Al2O3 for the 137Cs RTR brachytherapy source using the Monte Carlo-based EGSnrc code system. The study also includes calculation of detector-specif...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i1.4445
更新日期:2014-01-06 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
abstract::The monochromatic images acquired by Gemstone spectral imaging (GSI) mode on the GE CT750 HD theoretically determines the computed tomography (CT) number more accurately than that of conventional scanner. Using the former, the CT number is calculated from (synthesized) monoenergetic X-ray data. We reasoned that the mo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i5.4335
更新日期:2013-09-06 00:00:00
abstract::The purpose of this study is to find the uncertainties in the reconstruction of MR compatible ring-tandem intracavitary applicators of high-dose rate image-based brachytherapy treatment planning using rigid registration of 3D MR and CT image fusion. Tandem and ring reconstruction in MR image based brachytherapy planni...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i2.4206
更新日期:2014-03-06 00:00:00
abstract::This study evaluated the extent of improvement in dose predication accuracy achieved by the Fast Monte Carlo algorithm (MC) compared to the Ray Tracing algorithm (RAT) in stereotactic body radiotherapy (SBRT) of non-small cell lung cancer (NSCLC), and how their differences were influenced by the tumor site and size. T...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i5.4280
更新日期:2013-09-06 00:00:00
abstract::External beam radiation therapy (RT) is often offered to breast cancer patients after surgical mastectomy followed by breast reconstruction with silicone implants. In some cases, the RT is administered while the patient is still implanted with a temporary tissue expander including a high-density metallic port, which i...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i2.3295
更新日期:2011-01-19 00:00:00
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 ply...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i6.6367
更新日期:2016-11-08 00:00:00
abstract::The purpose of this study was to investigate amplitude gating combined with a coached breathing strategy for 10 MV flattening filter-free (FFF) volumetric-modulated arc therapy (VMAT) on the Varian TrueBeam linac. Ten patient plans for VMAT SABR liver were created using the Eclipse treatment planning system (TPS). The...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i4.5350
更新日期:2015-07-08 00:00:00
abstract::The goal of the present study was to develop a new dose-volume histogram (DVH)- based homogeneity index for effectively evaluating the dose homogeneity of intensity-modulated radiotherapy plans. The new index, called the sigma-index ("S-index") is defined as the standard deviation of the normalized differential DVH cu...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v8i2.2390
更新日期:2007-03-20 00:00:00
abstract::The purpose of this study is to simulate random and systematic RapidArc delivery errors for external beam prostate radiotherapy plans in order to determine the dose sensitivity for each error type. Ten prostate plans were created with a single 360° arc. The DICOM files for these treatment plans were then imported into...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i3.3409
更新日期:2011-05-20 00:00:00
abstract::Quality control (QC) of CT scanners is important to evaluate image quality and radiation dose. Different QC phantoms for testing image quality parameters on CT are commercially available, and Catphan phantoms are widely used for this purpose. More data from measured image quality parameters on CT are necessary to asse...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12186
更新日期:2017-11-01 00:00:00
abstract:PURPOSE:To present an open-source software (https://github.com/CHUSRadOncPhys/FluoMV) for monitoring intrafraction motion that is based on the visualization of superimposed contours of projected region-of-interests from DICOM RTSTRUCT files on cine-MV images acquired and displayed in real-time during radiation therapy ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12940
更新日期:2020-08-01 00:00:00