Abstract：
:Radiation therapy of cancer is today going through a very dynamic development with the introduction of a large number of new treatment principles, new types of treatment units and new radiobiologically based optimization algorithms for treatment planning. All of these make use of the recent developments in three dimensional tumor diagnostics, molecular biology of cancer, the fractionation sensitivity of different tissues and most recently predictive assays of radiation sensitivity. The most efficient but also least developed area of treatment optimization is to use a few (approximately 3) non uniform radiation beams directed towards the tumor. Today patient individual collimation with beam blocks or multileaf collimators protect organs at risk laterally outside the tumor volume. Non uniform dose delivery also allows protection of normal tissues anterior, posterior and even inside the target volume by shaping the isodoses tightly around the tumor tissues and thereby also allowing longitudinal protection of normal tissues. Some of the most advanced new algorithms are even treating therapy optimization as an inverse problem where the optimal incident beam shapes are determined directly from the location of gross disease, presumed microscopic tumor spread and organs at risk. The optimization is then performed such that the probability, P+, to eradicate all clonogenic tumor cells without severely damaging healthy normal tissues is as high as possible. Already with a few non uniform beams the treatment outcome is within a few percent of what can be achieved with infinitely many co-planar beams in a dynamic mood. With such optimized non uniform treatments it should be possible to improve the treatment outcome by as much as 20% and more, particularly in patients with a local complex spread of the disease or several organs at risk.
journal_name
Australas Phys Eng Sci Medjournal_title
Australasian physical & engineering sciences in medicineauthors
Brahme Asubject
Has Abstractpub_date
1996-06-01 00:00:00pages
53-66issue
2eissn
0158-9938issn
1879-5447journal_volume
19pub_type
杂志文章,评审abstract：:Due to large inter- and intra-patient variabilities of arterial input functions (AIFs), accurately modeling and using patient-specific AIF are very important for quantitative analysis of dynamic contrast enhanced MRI. Computer simulations were performed to evaluate and compare nine population AIF models with the Parke...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0632-0
更新日期：2018-06-01 00:00:00
abstract：:Over 90% of craniopharyngeal brain tumors are cystic, which enables the injection of beta emitters such as phosphorus-32 (32P) radio-colloid into cysts for their treatment. The aim of this study was to evaluate the clinical and theoretical modelling of Bremsstrahlung radiation dose resulting from stereotactic radio-co...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0665-4
更新日期：2018-09-01 00:00:00
abstract：:Thermoluminescence dosimetry (TLD) is a versatile tool for the assessment of dose from ionising radiation. The wide variety of TLD materials and their different physical forms allow the determination of different radiation qualities at dose levels from microGy to kGy. Major advantages of TL dosimeters are their small ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章,评审
doi：
更新日期：1994-12-01 00:00:00
abstract：:Cricket bowling generates forces with torques on the upper limb muscles and makes the biceps brachii (BB) muscle vulnerable to overuse injury. The aim of this study was to investigate whether there are differences in the amplitude of the EMG signal of the BB muscle during fast and spin delivery, during the seven phase...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-014-0245-1
更新日期：2014-03-01 00:00:00
abstract：:Linear scaling is used to convert raw computed tomography (CT) pixel values into Hounsfield units corresponding to different tissue values. Analysis of a benchmarking study, presented here, where the same CT scan was imported into and then exported from multiple radiotherapy treatment planning systems, found inconsist...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0651-x
更新日期：2018-09-01 00:00:00
abstract：:The measurement of absorbed dose to water in a solid-phantom may require a conversion factor because it may not be radiologically equivalent to water. One phantom developed for the use of dosimetry is a solid water, RW3 white-polystyrene material by IBA. This has a lower mass-energy absorption coefficient than water d...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-011-0102-4
更新日期：2011-12-01 00:00:00
abstract：:The quality of phantom materials is crucial for accurate dosimetry in radiotherapy. A wide range of factors such as density, electron density and elemental composition can influence the radiation properties, and hence the absorbed dose, of materials. New materials can be tested by direct measurements which requires co...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：:This paper describes a software tool developed for research into the use of an electronic portal imaging device (EPID) to verify dose for intensity modulated radiation therapy (IMRT) beams. A portal dose image prediction (PDIP) model that predicts the EPID response to IMRT beams has been implemented into a commerciall...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03179347
更新日期：2008-09-01 00:00:00
abstract：:Memory plays an important role in human life. Memory can be divided into two categories, i.e., long term memory and short term memory (STM). STM or working memory (WM) stores information for a short span of time and it is used for information manipulations and fast response activities. WM is generally involved in the ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章,评审
doi：10.1007/s13246-016-0438-x
更新日期：2016-06-01 00:00:00
abstract：:Diamond detectors are particularly well suited for dosimetry applications in radiotherapy for reasons including near-tissue equivalence and high-spatial resolution resulting from small sensitive volumes. However, these detectors have not become commonplace due to high cost and poor availability arising from the need f...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-010-0040-6
更新日期：2010-12-01 00:00:00
abstract：:The purpose of this study was to measure skin dose using radiochromic film for two step-and-shoot IMRT fields and compare the results to the skin dose for a conventional open field. All exposures were made using a 6 MV photon beam produced by a Varian 21EX linear accelerator (Varian Medical Systems, CA, USA) equipped ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178577
更新日期：2006-09-01 00:00:00
abstract：:Gating is a relatively new and potentially useful therapeutic addition to external beam radiotherapy applied to regions affected by intra-fraction motion. The impact was of gating on treatment margins, image artifacts, and volume and positional accuracy was investigated by CT imaging of sinusoidally moving spheres. Th...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178368
更新日期：2002-03-01 00:00:00
abstract：:A study was made of calibrating the NACP plane parallel chamber in electron beams from linear accelerators of a different manufacture with energies, Ep,o' from 4.4 to 19.1 MeV, and also in 4 and 6 MV photon beams as well as a cobalt60 beam. The photon beam measurements were both IN-AIR and IN-PHANTOM. With the excepti...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1996-09-01 00:00:00
abstract：:Ischaemic stroke is a major public health issue in both developed and developing nations. Hypothermia is believed to be neuroprotective in cerebral ischaemia. Conversely, elevated brain temperature is associated with poor outcome after ischaemic stroke. Mechanisms of heat exchange in normally-perfused brain are relati...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0595-6
更新日期：2017-12-01 00:00:00
abstract：:Bipolar disorder (BD) is a severe psychiatric disorder and has two common types: type I and type II. Early diagnosis of the subtypes is very challenging particularly in adolescence. In this study, 38 adolescents are participated including 18 patients with BD I and 20 patients with BD II. The electroencephalogram signa...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0375-0
更新日期：2015-12-01 00:00:00
abstract：:The purpose of this study is to develop a novel breast abnormality detection system by utilizing the potential of infrared breast thermography (IBT) in early breast abnormality detection. Since the temperature distributions are different in normal and abnormal thermograms and hot thermal patches are visible in abnorma...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0681-4
更新日期：2018-12-01 00:00:00
abstract：:The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) Radiation Oncology Specialty Group (ROSG) formed a series of working groups in 2011 to develop position papers for guidance of radiation oncology medical physics practice within the Australasian setting. These position papers are intend...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-013-0238-5
更新日期：2014-03-01 00:00:00
abstract：:Two software packages designed for automatic counting nuclear tracks are tested and compared. The image processing in the first package is divided into three parts segmentation, speckle elimination and removal of ill-formed track holes. The second package is also divided into three parts but the last part is modified ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1992-06-01 00:00:00
abstract：:Accuracy of dwell position and reproducibility of dwell time are critical in high dose rate (HDR) brachytherapy. A phantom was designed to verify dwell position and dwell time reproducibility for an Ir-192 HDR stepping source using Computed Radiography (CR). The central part of the phantom, incorporating thin alternat...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-012-0138-0
更新日期：2012-09-01 00:00:00
abstract：:From the time when Roentgen and other physicists made the discoveries which led to the development of radiology, radiotherapy and nuclear medicine, medical physicists have played a pivotal role in the development of new technologies that have revolutionized the way medicine is practiced today. Medical physicists have ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type：
doi：10.1007/BF03178583
更新日期：2008-06-01 00:00:00
abstract：:Interest in human emotion recognition, regarding physiological signals, has recently risen. In this study, an efficient emotion recognition system, based on geometrical analysis of autonomic nervous system signals, is presented. The electrocardiogram recordings of 47 college students were obtained during rest conditio...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0530-x
更新日期：2017-06-01 00:00:00
abstract：:Given the difficulty and potential time- or financial-costs associated with accurate small field dosimetry, this study aimed to establish the clinical necessity of obtaining accurate small field output factor measurements and to evaluate the effects on planned doses that could arise if accurate measurements are not us...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0461-y
更新日期：2016-09-01 00:00:00
abstract：:Cone-beam computed tomography (CBCT) has become the standard imaging technique for many sites treated with Radiotherapy. The Elekta X-ray Volumetric Imaging (XVI) system allows for the acquisition of CBCTs with three different diameters; small (27 cm), medium (41 cm) and large (50 cm) (Elekta in XVI Corrective Mainten...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-019-00817-7
更新日期：2019-12-01 00:00:00
abstract：:In recent years there has been a significant economic growth in South East Asia, along with it a concurrent development of medical physics. The status of four countries--Malaysia, Thailand, the Philippines and Indonesia are presented. Medical physicists in these countries have been experiencing the usual problems of l...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1997-03-01 00:00:00
abstract：:Magnetic resonance imaging has become a key modality within the modern radiology department. In addition to the conventional slice images, three dimensional angiographic images, and quantitative flow measurements can be obtained. More recently methods have been developed which enable one to visualize the motion of obj...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章,评审
doi：
更新日期：1991-12-01 00:00:00
abstract：:The angular distribution for electron beams produced by the Siemens KD-2 linear accelerator has been found by simulating electron transport through the scattering foils and air using two methods: Fermi-Eyges multiple Coulomb scattering calculations, and EGS4 Monte Carlo simulations. Fermi-Eyges theory gives solutions ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1994-09-01 00:00:00
abstract：:Despite ongoing active research, the role of the radiation bystander effect in modifying local tissue response to an ionising radiation dose remains unclear. The present study aims to provide new insight by simulating the diffusion-mediated inter-cellular communication processes in 2D and 3D cell-like structures to ca...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-010-0048-y
更新日期：2011-04-01 00:00:00
abstract：:A general purpose, multi-channel digital data acquisition and analysis system (Amlab, Associative Measurements, Sydney) configured to collect and process physiological signals including electroencephalograph and blood pressure is described. Its advantages over analog and single-purpose instrumentation are discussed as...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1995-09-01 00:00:00
abstract：:Non-linear loading of the utilities supply introduced significant electromagnetic field (EMF) interference severe enough to disrupt electrocardiograph (ECG) monitoring and recordings in the new Emergency Department (ED) at the Royal Melbourne Hospital (RMH). This interference was evident even though standard Mu-metal ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178643
更新日期：2009-09-01 00:00:00
abstract：:Liver metabolic information is considered as a crucial diagnostic marker for the diagnosis of fever of unknown origin, and liver recognition is the basis of automatic diagnosis of metabolic information extraction. However, the poor quality of PET and CT images is a challenge for information extraction and target recog...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0650-y
更新日期：2018-06-01 00:00:00
