Abstract：
:A discussion of the thermodynamic aspects of a relatively new treatment method for giant cell tumors of the bone is presented in this paper. The advantages of implanting methylmethacrylate acrylic bone cement into a curetted tumor site are briefly discussed and placed in perspective relative to more prevalent surgical treatments. As the bone cement self-heats while curing, the possibility of heat necrosis in the bone exists. However, the damage due to heat may be beneficial in reducing the rate of tumor recurrence. A thermodynamic consideration of the treatment situation appears to be warranted. After a general introduction and a brief literature review, the theoretical thermodynamic equations are developed. Once the basic equations for the heat transfer from the cement or the bone are derived, there is then a discussion of the various characteristics of bone and methylmethacrylate crucial to the analysis, such as, thermal conductivity, specific heat, density, and heat generation parameters. Finally, in order to reduce the theory to a form which may be used practically, the equations derived are written in terms of finite-difference equations, which approximate them numerically. Different equations are written for each type of heat transfer condition encountered in the cement-bone system as spacial variances in material and geometry occur. The equations derived may be used to model the system allowing one to predict the time-dependent temperature distribution in bone during the curing of acrylic cement. Using computer techniques to reduce the equations obtained from this analysis, and knowing the temperature at which adjacent cells die, a zone of necrosis may be mapped surrounding the acrylic impact.
journal_name
Med Physjournal_title
Medical physicsauthors
Krishnan EC,Nelson C,Neff JRdoi
10.1118/1.595902subject
Has Abstractpub_date
1986-03-01 00:00:00pages
233-9issue
2eissn
0094-2405issn
2473-4209journal_volume
13pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：PURPOSE:Intraventricular hemorrhage (IVH) is a major cause of brain injury in preterm neonates. Three dimensional ultrasound (US) imaging systems have been developed to visualize 3D anatomical structure of preterm neonatal intracranial ventricular system with IVH and ventricular dilation. To allow quantitative analysis...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4932366
更新日期：2015-11-01 00:00:00
abstract：:Stereotactic X-ray mammography (SM) and ultrasound (US) guidance are both commonly used for breast biopsy. While SM provides three-dimensional (3D) targeting information and US provides real-time guidance, both have limitations. SM is a long and uncomfortable procedure and the US guided procedure is inherently two dim...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2794175
更新日期：2007-11-01 00:00:00
abstract：PURPOSE:The most appropriate method of evaluating the effective atomic number necessitates consideration of energy-dependent behavior. Previously, this required quite laborious calculation, which is why many scientists revert to over-simplistic power-law methods. The purpose of this work is to develop user-friendly sof...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3689810
更新日期：2012-04-01 00:00:00
abstract：:We measured the physical imaging performance of a 41 x 41 cm2 amorphous silicon flat panel detector designed for angiographic and R&F imaging applications using methods from the emerging IEC standard for the measurement of detective quantum efficiency (DQE) in digital radiographic detectors. Measurements on 12 product...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1609151
更新日期：2003-10-01 00:00:00
abstract：PURPOSE:A prototype in-house program was developed to assist deriving image guidance shifts clinically using our 4DCT method for lung SBRT. METHODS:Our in-house prototype program was implemented in MATLAB. The 4D DICOM CT dataset of interest is imported by the program from AW and subsequently accepts input from the us...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735493
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4908000
更新日期：2015-04-01 00:00:00
abstract：:The dose distributions in the bifurcated vessels treated with intravascular brachytherapyline sources are complicated and depend on the bifurcation geometry consisting of a main and a branch vessel at different angles. To investigate the dosimetric effects at the bifurcation, calculations were performed on branching v...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1582813
更新日期：2003-07-01 00:00:00
abstract：PURPOSE:Cardiac motion is typically not accounted for during pretreatment imaging for central lung and mediastinal tumors. However, cardiac induced tumor motion averages 5.8 mm for esophageal tumors and 3-5 mm for some lung tumors, which can result in positioning errors. Our aim is to reduce both cardiac- and respirato...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13670
更新日期：2019-09-01 00:00:00
abstract：:The purpose of this study is to incorporate the dosimetric effect of random patient positioning uncertainties directly into a commercial treatment planning system's IMRT plan optimization algorithm through probabilistic treatment planning (PTP) and compare coverage of this method with margin-based planning. In this wo...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3176940
更新日期：2009-09-01 00:00:00
abstract：:Empirical functions that describe primary beam profiles for radiotherapy treatment planning systems generally account for finite source size only on beams unmodified by blocks, wedges, or compensating filters. To incorporate the effects of extended sources on such modified beams and to treat the effect of an extended ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596222
更新日期：1988-09-01 00:00:00
abstract：PURPOSE:To quantify the inter fraction variation of spatial location of high dose regions of OARs in MR-image based cervix brachytherapy using rigid registration algorithm. METHODS:Retrospective analysis of 27 previously treated patients under EMBRACE multi-centric trial was evaluated. Each patient had two application...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735513
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Mammographic density of glandular breast tissue has a masking effect that can reduce lesion detection accuracy and is also a strong risk factor for breast cancer. Therefore, accurate quantitative estimation of breast density is clinically important. In this study, we investigate experimentally the feasibility o...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13031
更新日期：2018-06-03 00:00:00
abstract：PURPOSE:To correlate the Cole relaxation frequencies obtained from measurements of the electrical properties of breast tissue to the presence or absence of cancer. METHODS:Four-lead impedance measurements were obtained on ex vivo specimens extracted during surgery from 187 volunteer patients. Data were acquired with a...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4725172
更新日期：2012-07-01 00:00:00
abstract：PURPOSE:The outcome of radiotherapy can be further improved by combining irradiation with dose enhancers such as high-Z nanoparticles. Since 2004, spectacular results have been obtained when low-energy x-ray irradiations have been combined with nanoparticles. Recently, the same combination has been explored in hadron t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4934370
更新日期：2015-11-01 00:00:00
abstract：PURPOSE:Precise segmentation of clinical target volume (CTV) is the key to stomach cancer radiotherapy. We proposed a novel stochastic width - deep neural network (SW-DNN) for better automatically contouring stomach CTV METHODS: SW-DNN was an end-to-end approach, of which the core component was a novel SW mechanism tha...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14733
更新日期：2021-01-27 00:00:00
abstract：PURPOSE:This study investigated the dosimetry performance of a linear fiber-optic coupled dosimeter with a sensitive element varying from 3 to 15 cm in length. The dosimeter is comprised of a tissue equivalent plastic scintillating fiber coupled to a photomultiplier tube (PMT). The sensitive element has a length repres...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734756
更新日期：2012-06-01 00:00:00
abstract：:Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tis...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4951732
更新日期：2016-06-01 00:00:00
abstract：:Francis Bacon, who with Rene Decartes laid the intellectual foundations for Western science in the seventeenth century, asserted that the purpose of all knowledge is "action in the production of works for ... the relief of man's estate." We assess briefly several aspects of a few of the current efforts directed to the...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1555493
更新日期：2003-04-01 00:00:00
abstract：:Significant advances have been made in recent years to improve photon dose calculation. However, accurate prediction of dose perturbation effects near the interfaces of different media, where charged particle equilibrium is not established, remain unsolved. Furthermore, changes in atomic number, which affect the multi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597611
更新日期：1995-07-01 00:00:00
abstract：PURPOSE:Modulated electron radiation therapy (MERT) represents an active area of interest that offers the potential to improve healthy tissue sparing in treatment of certain cancer cases. Challenges remain however in accurate beamlet dose calculation, plan optimization, collimation method, and delivery accuracy. In thi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4876297
更新日期：2014-06-01 00:00:00
abstract：PURPOSE:Patient-specific QA of highly conformal radiotherapy treatments are usually conducted using 2D or 3D dosimetry of the incident dose distribution in a water-equivalent phantom. However, dosimeters typically used for this task usually lack in either spatial resolution or dose accuracy. The purpose of this work is...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4736526
更新日期：2012-08-01 00:00:00
abstract：PURPOSE:To obtain on-treatment volumetric patient anatomy during respiratory gated volumetric modulated arc therapy (VMAT). METHODS:On-board imaging device integrated with Linacs offers a viable tool for obtaining patient anatomy during radiation treatment delivery. In this study, the authors acquired beam-level kV im...
journal_title：Medical physics
pub_type： 信件
doi：10.1118/1.4794925
更新日期：2013-04-01 00:00:00
abstract：PURPOSE:Robust registration of prone and supine colonie surfaces acquired during CT colonography may lead to faster and more accurate detection of colorectal cancer and polyps. Any directional bias when registering one surface to the other could precipitate incorrect anatomical correspondence and engender reader error....
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4736159
更新日期：2012-06-01 00:00:00
abstract：:We proposed to use the prostate dose-volume factor (PDVF), derived from the dose-volume dataset of planning target volume (PTV) in prostate radiotherapy to evaluate treatment plans of prostate volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT). To demonstrate plan evaluation using PDVF...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4740167
更新日期：2012-07-01 00:00:00
abstract：:In this paper we examine the few-view reconstruction problem as it applies to imaging vascular trees. A fully automated reconstruction algorithm is described that circumvents the traditional "correspondence problem," using only notions of consistency and connectivity. It is assumed that the vascular tree is a connecte...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597704
更新日期：1996-02-01 00:00:00
abstract：PURPOSE:To develop a new scintillating fiber-based electronic portal imaging device (EPID) with a high quantum efficiency (QE) while preserving an adequate spatial resolution. METHODS:Two prototypes were built: one with a single pixel readout and the other with an active matrix flat-panel imager (AMFPI) for readout. T...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13900
更新日期：2020-01-01 00:00:00
abstract：PURPOSE:When an intensity-modulated radiation beam is delivered to a moving target, the interplay effect between dynamic beam delivery and the target motion due to miss-synchronization can cause unpredictable dose delivery. The portal dose image in electronic portal imaging device (EPID) represents radiation attenuated...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4799941
更新日期：2013-05-01 00:00:00
abstract：:We have made a comparative investigation of the estimated spectra obtained by the Laplace transform analysis of the transmitted exposure data measured in an absorption study of a 4-MV x-ray beam. Four transform pair models currently used with this method have been evaluated. It has been determined that the Archer-Wagn...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595878
更新日期：1986-05-01 00:00:00
abstract：:In this paper, we describe an algorithm to segment a needle from a three-dimensional (3D) ultrasound image by using two orthogonal two-dimensional (2D) image projections. Not only is the needle more conspicuous in a projected (volume-rendered) image, but its direction in 3D lies in the plane defined by the projection ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1538231
更新日期：2003-02-01 00:00:00
abstract：PURPOSE:Talbot-Lau x-ray interferometry provides information about the scattering and refractive properties of an object - in addition to the object's attenuation features. Until recently, this method was ineligible for imaging human-sized objects as it is challenging to adapt Talbot-Lau interferometers (TLIs) to the r...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12889
更新日期：2018-06-01 00:00:00
