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Sample records for reinap rando pikner

  1. Dosimeter placement in the Rando phantom

    Energy Technology Data Exchange (ETDEWEB)

    Archer, B.R.; Glaze, S.; North, L.B.; Bushong, S.C.

    1977-07-01

    Each section of the Alderson Rando phantom contains a tissue-equivalent plastic coating layer approximately 2 mm thick, applied to both faces. This compensates for material removed in the sawing process. Conventional use of thermoluminescent dosimeters positions them totally or partially within the coating layer. Analysis shows that, in the lung region, dosimeters placed in this layer received a dose averaging 39% lower than those placed at midsection. Where bony structures interfere, some dosimeters in the coating layer received an 18% higher dose than those at midsection. Therefore, positioning dosimeters at the center of a section is recommended.

  2. Instituutide areng saab paika / Paavo Kaimre, Rando Värnik, Illar Lemetti, Ants Soon...[jt.

    Index Scriptorium Estoniae

    2007-01-01

    Koostatavaid arengukavasid tutvustavad Metsandus- ja maaehitusinstituudi direktor Paavo Kaimre, Majandus- ja sotsiaalinstituudi direktor Rando Värnik, Põllumajandus- ja keskkonnainstituudi direktor Illar Lemetti, Tehnikainstituudi direktor Ants Soon ja Veterinaarmeditsiini ja loomakasvatuse instituudi direktor Toomas Tiirats

  3. Preparing a voxel-simulator of Alderson Rando physical phantom

    Energy Technology Data Exchange (ETDEWEB)

    Boia, Leonardo S.; Martins, Maximiano C.; Silva, Ademir X., E-mail: lboia@con.ufrj.br, E-mail: ademir@con.ufrj.br [Programa de Engenharia Nuclear (PEN/COPPE/UFRJ). Universidade Federal do Rio de Janeiro, RJ (Brazil); Salmon Junior, Helio A., E-mail: heliosalmon@coinet.com.br [COI - Clinicas Oncologicas Integradas, MD.X Barra Medical Center, Rio de Janeiro, RJ (Brazil); Soares, Alessandro F.N.S., E-mail: afacure@cnen.gov.br [Comissao Nacional de Engenharia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    There are, nowadays, sorts of anthropomorphycal phantoms which are used for simulation of radiation transport by the matter and also the deposition of energy in such radiation in human tissues and organs, because an in-vitro dosimetry becomes very either complicated or even impossible in some cases. In the present work we prepared a computational phantom in voxels based on computational tomography of Rando-Alderson. This phantom is one of the most known human body simulators on the scope of ionizing radiation dosimetry, and it is used for radioprotection issues and dosimetry from radiotherapy and brachytherapy treatments as well. The preparation of a voxel simulator starts with the image acquisition by a tomograph found at COI/RJ (Clinicas Oncologicas Integradas). The images were generated with 1mm cuts and collected for analysis. After that step the images were processed in SAPDI (Sistema Automatizado de Processamento Digital de Imagem) in order to amplify the images regions intending to facilitate the task in their segmentation. SAPDI is based on parameters described by Hounsfield scale. After that, it has begun discretization of elements in IDs voxels using Scan2MCNP software - which converts images to a sequential text file containing the voxels' IDs ready to be introduced into MCNPX input; however, this set can be turned to a voxel's IDs matrix and used in other Monte Carlo codes, such as Geant4, PENELOPE and EGSnrc. Finished this step, the simulator is able to simulate with accurate geometry the physical phantom. It's possible to study a large number of cases by computational techniques of geometry's insertions of tumors and TLDs, which makes this simulator a research material useful for a lot of subjects. (author)

  4. Optimisation need of dental radiodiagnostic procedures: results of effective dose evaluation from Rando phantom measurements

    Energy Technology Data Exchange (ETDEWEB)

    Borio, R.; Chiocchini, S.; Cicioni, R.; Degli Esposti, P.; Rongoni, A.; Sabatini, P.; Saetta, D.M.S. (Perugia Univ. (Italy). Health Physics Lab. Istituto Nazionale di Fisica Nucleare, Perugia (Italy)); Regi, L.; Caprino, G. (Perugia Univ. (Italy). Dept. of Radiology)

    1994-01-01

    Radiological examinations of different types are needed in dental practice both to make a correct diagnosis and to carry out an adequate therapy. Particularly in orthodentic practices, because of the youth of the majority of the patients, an assessment of the detriment to health (through the effective dose equivalent) caused by medical diagnostic exposure to ionising radiation is needed to make decisions about the optimisation of dental radiodiagnostic procedures. Experimental data from measurements on a Rando phantom were collected for the radiological examinations required for dental and for orthodontic practices (with and without protective apron and collar). The results show the effectiveness of the leaded apron and collar in all the examinations carried out, particularly in reducing thyroid dose. (author).

  5. An Assessment of Spinal Cord Dose Following Radiotherapy of Nasopharyngeal Cancer by TLD and Rando Phantom

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Bahreyni Toossi

    2009-12-01

    Full Text Available Introduction: Nasopharyngeal carcinoma is one of the most common malignancies in the head and neck region and radiotherapy is its treatment of choice. In spite of the fact that it is widely used, due to the presence of many sensitive organs or tissues in this region, patients may suffer from a wide range of side effects. One such sensitive tissue is the spinal cord. If the absorbed dose to spinal cord is greater than its tolerance dose, then myelopathy and Lhermitte’s sign are not avoidable. Material and Methods: Thehead and neck of a Rando phantom (reference man was employed as a hypothetical patient suffering from nasopharyngeal carcinoma. The full course of treatment consisted of three phases. At the beginning of every phase, an oncologist used a simulator to delineate the surface of the Rando Phantom for treatment. TLD chips (TLD-100 were employed for dose measurement. TLD chips were inserted in the previously made holes on the surface of selected slices adjacent to second cervical to fourth thoracic vertebra. Absorbed dose by TLDs were read by a Harshaw 3500 TLD reader. Results: Total measured dose (in Gy of various parts of spinal cord adjacent to second cervical to fourth thoracic vertebra varied widely and were as follows respectively: 15.24±1.31, 50.31±1.06, 49.15±2.77, 47.48±1.42, 54.56±2.6, 48.92±0.6, 45.1±0.45. In other words, the range of doses received by different segments of the spinal cord could be as wide as 15.24 to 54.56 Gy. Conclusion: Although the spinal cord was excluded at the end of the first phase, a significant change in the absorbed dose at the end of the first and second phases was not observed. In phase three, the anterior neck field was replaced by a lateral field and the spinal cord absorbed dose was reduced considerably. According to our results, absorbed doses of the spinal cord segments corresponding to the region confined between the third cervical to third thoracic vertebra were more than the 47 Gy

  6. LHV töötajad jäid USA börsil vahele salajase info hankimisega / Aivar Reinap, Aleksei Günter

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2005-01-01

    USA väärtpaberijärelevalve (SEC) ametnike andmetel varastasid Investeerimisfirma Lõhmus, Haavel & Viisemann (LHV) töötajad Oliver Peek ja Kristjan Lepik arvutiprogrammi abil USA börsiettevõtete veel avaldamata pressiteateid, teenides selle abil USA börsidel vähemalt 7,8 miljonit dollarit kasumit. SEC andis LHV ja tema kaks töötajad petuskeemi korraldamise süüdistusega kohtusse. Lisa: LHV tehingud. Vt. samas: Hindrek Riikoja, Aivar Reinap. Skandaal LHV äri Eestis veel ohtu ei sea. Kommenteerivad: ettevõtja Heldur Meerits, Eesti Panga nõukogu esimees Mart Sõrg, IT-spetsialist Linnar Viik, Tallinna Börsi juht Kaidi Oone

  7. Dose Measurements of Parotid Glands and Spinal Cord in Conventional Treatment of Nasopharyngeal Carcinoma Using RANDO Phantom and Thermoluminescent Dosimeters

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Bahreyni Toossi

    2015-07-01

    Full Text Available Introduction Radiotherapy is regarded as the first treatment of choice for nasopharyngeal carcinoma. Despite the advantages of radiotherapy, patients may suffer from a wide range of side-effects due to the presence of many sensitive normal tissues in these regions. If the absorbed dose exceeds the tolerance level in parotid glands and the spinal cord, myelopathy, Lhermitte's sign and xerostomia cannot be avoided. Materials and Methods The head and neck of a RANDO phantom (reference man, which was regarded as a hypothetical patient with nasopharyngeal carcinoma was evaluated. The full course of treatment consisted of three phases. At the beginning of each phase, an oncologist marked conventional fields on the RANDO phantom using a simulator. For measuring the absorbed dose, Thermoluminescent Dosimeters(TLD chips (TLD-100 were utilized.The absorbed dose by TLDs was read by Harshaw 3500 TLD reader. Results The total absorbed dose was calculated by measuring the absorbed dose in each phase, multiplied by the fraction numbers of each phase; the obtained values were summed up. The results showed that the received doses by spinal cord ranged from 15.24 to 54.56 Gy. Also, the absorbed dose of parotid glands was approximately 39.23 Gy. Conclusion Considering the minimum tolerance dose the absorbed doses in the spinal cord and parotid glands were above the tolerance level. The incidence rate of xerostomia and myelopathy were higher in patients, treated by conventional methods.

  8. Experimental Validation of Monte Carlo Simulations Based on a Virtual Source Model for TomoTherapy in a RANDO Phantom.

    Science.gov (United States)

    Yuan, Jiankui; Zheng, Yiran; Wessels, Barry; Lo, Simon S; Ellis, Rodney; Machtay, Mitchell; Yao, Min

    2016-12-01

    A virtual source model for Monte Carlo simulations of helical TomoTherapy has been developed previously by the authors. The purpose of this work is to perform experiments in an anthropomorphic (RANDO) phantom with the same order of complexity as in clinical treatments to validate the virtual source model to be used for quality assurance secondary check on TomoTherapy patient planning dose. Helical TomoTherapy involves complex delivery pattern with irregular beam apertures and couch movement during irradiation. Monte Carlo simulation, as the most accurate dose algorithm, is desirable in radiation dosimetry. Current Monte Carlo simulations for helical TomoTherapy adopt the full Monte Carlo model, which includes detailed modeling of individual machine component, and thus, large phase space files are required at different scoring planes. As an alternative approach, we developed a virtual source model without using the large phase space files for the patient dose calculations previously. In this work, we apply the simulation system to recompute the patient doses, which were generated by the treatment planning system in an anthropomorphic phantom to mimic the real patient treatments. We performed thermoluminescence dosimeter point dose and film measurements to compare with Monte Carlo results. Thermoluminescence dosimeter measurements show that the relative difference in both Monte Carlo and treatment planning system is within 3%, with the largest difference less than 5% for both the test plans. The film measurements demonstrated 85.7% and 98.4% passing rate using the 3 mm/3% acceptance criterion for the head and neck and lung cases, respectively. Over 95% passing rate is achieved if 4 mm/4% criterion is applied. For the dose-volume histograms, very good agreement is obtained between the Monte Carlo and treatment planning system method for both cases. The experimental results demonstrate that the virtual source model Monte Carlo system can be a viable option for the

  9. Design of a head phantom produced on a 3D rapid prototyping printer and comparison with a RANDO and 3M lucite head phantom in eye dosimetry applications.

    Science.gov (United States)

    Homolka, Peter; Figl, Michael; Wartak, Andreas; Glanzer, Mathias; Dünkelmeyer, Martina; Hojreh, Azadeh; Hummel, Johann

    2017-02-13

    An anthropomorphic head phantom including eye inserts allowing placement of TLDs 3 mm below the cornea has been produced on a 3D printer using a photo-cured acrylic resin to best allow tissue equivalence. Thus Hp(3) can be determined in radiological and interventional photon radiation fields. Eye doses and doses to the forehead have been compared to an Alderson RANDO head and a 3M Lucite skull phantom in terms of surface dose per incident air kerma for frontal irradiation since the commercial phantoms do not allow placement of TLDs 3 mm below the corneal surface. A comparison of dose reduction factors (DRFs) of a common lead glasses model has also been performed. Eye dose per incident air kerma were comparable between all three phantoms (printed phantom: 1.40, standard error (SE) 0.04; RANDO: 1.36, SE 0.03; 3M: 1.37, SE 0.03). Doses to the forehead were identical to eye surface doses for the printed phantom and the RANDO head (ratio 1.00 SE 0.04, and 0.99 SE 0.03, respectively). In the 3M Lucite skull phantom dose on the forehead was 15% lower than dose to the eyes attributable to phantom properties. DRF of a sport frame style leaded glasses model with 0.75 mm lead equivalence measured were 6.8 SE 0.5, 9.3 SE 0.4 and 10.5 SE 0.5 for the RANDO head, the printed phantom, and the 3M Lucite head phantom, respectively, for frontal irradiation. A comparison of doses measured in 3 mm depth and on the surface of the eyes in the printed phantom revealed no difference larger than standard errors from TLD dosimetry. 3D printing offers an interesting opportunity for phantom design with increasing potential as printers allowing combinations of tissue substitutes will become available. Variations between phantoms may provide a useful indication of uncertainty budgets when using phantom measurements to estimate individual personnel doses.

  10. Plaadid / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Uutest plaatidest Back in the ESSR "From the Archives of Eesti raadio 1966-1982", The Donnas "Spend the Night", "Furure Sounds of Jazz vol. 9", Dino Saluzzi "Responsorium", The Clash "Essential Clash", Sly & Family Stone "Essential", Madonna "American Life", Louis Armstrong & Ella Fitzgerald "Ella & louis Again"

  11. Plaadid / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Uutest plaatidest Back in the ESSR "From the Archives of Eesti raadio 1966-1982", The Donnas "Spend the Night", "Furure Sounds of Jazz vol. 9", Dino Saluzzi "Responsorium", The Clash "Essential Clash", Sly & Family Stone "Essential", Madonna "American Life", Louis Armstrong & Ella Fitzgerald "Ella & louis Again"

  12. Comparison of the calculated absorbed dose using the Cadplan™ treatment planning software and Tld-100 measurements in an Alderson-Rando phantom for a bronchogenic treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez Castillo, J. G., E-mail: jggc59@hotmail.com [Departamento de Física, Hospital de Oncología, IMSS, CMN Siglo XXI, Cuauhtémoc 330 Col. Doctores (Mexico); Álvarez Romero, J. T., E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx; Calderón, A. Torres, E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx; M, V. Tovar, E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx [SSDL, Departamento de Metrología ININ, Salazar, Estado de México 15245 (Mexico)

    2014-11-07

    To verify the accuracy of the absorbed doses D calculated by a TPS Cadplan for a bronchogenic treatment (in an Alderson-Rando phantom) are chosen ten points with the following D's and localizations. Point 1, posterior position on the left edge with 136.4 Gy. Points: 2, 3 and 4 in the left lung with 104.9, 104.3 and 105.8 Gy, respectively; points 5 and 6 at the mediastinum with 192.4 and 173.5 Gy; points 7, 8 and 9 in the right lung with 105.8, 104.2 and 104.7 Gy, and 10 at posterior position on right edge with 143.7 Gy. IAEA type capsules with TLD 100 powder are placed, planned and irradiated. The evaluation of the absorbed dose is carried out a curve of calibration for the LiF response (nC) {sup vs} {sup DW}, to several cavity theories. The traceability for the DW is obtained with a secondary standard calibrated at the NRC (Canada). The dosimetric properties for the materials considered are determined from the Hounsfield numbers reported by the TPS. The stopping power ratios are calculated for nominal spectrum to 6 MV photons. The percent variations among the planned and determined D in all the cases they are < ± 3%.

  13. Halloween - vallatu karneval / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Rooma katoliku kiriku poolt 835. aastal välja kuulutatud kõikide pühakute päev (halloween) on läbi ajaloo muutunud tänapäevaseks massikultuuri pidustuseks. Sisaldab ka artikleid "Novembriga algas keltide uus aasta" ja "Eesti maarahva hingedeaeg"

  14. Kapo puistab Villu Reiljani jahimaid / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2006-01-01

    Meedias ilmunud kahtlustest ja süüdistustest Keskkonnaministeeriumi haldusalas tehtud tehingutest kaitsealuste maade vahetusega. Autorile on arusaamatu, miks endine keskkonnaminister Villu Reiljan ise midagi ette ei võtnud

  15. Fin de siecle, Beat Generation / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2002-01-01

    Dokumentaalfilm kolmest biitnikute ideoloogist-kirjanikust Jack Kerouac'ist, William S. Burroughs'st ja Allen Ginsburgist "Hipid ja biitnikud" ("The Source") : režissöör Chuck Workman : Ameerika Ühendriigid 1998

  16. "Matrix" sobitub iga filosoofiaga / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Andy ja Larry Wachowski ulmefilmide triloogia "Matrix" fenomeni analüüsist ajakirja "Vikerkaar" 2003. aasta 9. numbris, kus sellele on pühendatud nelja filosoofi artiklid ( Slavoj Zhizhek, Jüri Eintalu, Bruno Mölder, Tanel Tammet)

  17. Fin de siecle, Beat Generation / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2002-01-01

    Dokumentaalfilm kolmest biitnikute ideoloogist-kirjanikust Jack Kerouac'ist, William S. Burroughs'st ja Allen Ginsburgist "Hipid ja biitnikud" ("The Source") : režissöör Chuck Workman : Ameerika Ühendriigid 1998

  18. "Matrix" sobitub iga filosoofiaga / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Andy ja Larry Wachowski ulmefilmide triloogia "Matrix" fenomeni analüüsist ajakirja "Vikerkaar" 2003. aasta 9. numbris, kus sellele on pühendatud nelja filosoofi artiklid ( Slavoj Zhizhek, Jüri Eintalu, Bruno Mölder, Tanel Tammet)

  19. Hinnatõus kasvatas Eesti Energia kasumit / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2005-01-01

    Eesti Energia esimese poolaasta puhaskasum oli 2004. aasta sama perioodiga võrreldes 3,5 korda suurem ehk 200 miljonit krooni. Kuue kuuga investeeris energiakontsern 1,3 miljardit krooni, millest 70% läks elektrivõrkudesse

  20. Streikijate armee paisub iga päevaga / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    23. septembril alanud raudteetöötajate streigist osavõtjate arv kasvab iga päevaga, kaubarongid veel liiguvad, kuid kui vajalikke samme ei astuta, võib kogu rongiliiklus seiskuda. Lisa: Ronge asendavad bussid. Vt. ka: Edelaraudtee rendib streigi ajaks bussid

  1. Eestlased arendavad uudset biodiisli tootmise tehnoloogiat / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2005-01-01

    Eesti kapitalile kuuluv OÜ Nordic Biodiesel leiutas ja patendeeris uudse tehnoloogia biodiisli valmistamiseks, mis on võrreldes senise tehnoloogiaga ligi viiendiku võrra efektiivsem ja keskkonnasõbralikum

  2. Majandusedu kindlustas eakatele pensionitõusu / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 9. märts lk. 7. Tänu sotsiaalmaksu üliheale laekumisele suureneb aprillist keskmine pension 2742 kroonilt 3136 kroonile - tõus 393 krooni ehk 14% võrra. Lisa: Pensionitõus

  3. Eestlased arendavad uudset biodiisli tootmise tehnoloogiat / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2005-01-01

    Eesti kapitalile kuuluv OÜ Nordic Biodiesel leiutas ja patendeeris uudse tehnoloogia biodiisli valmistamiseks, mis on võrreldes senise tehnoloogiaga ligi viiendiku võrra efektiivsem ja keskkonnasõbralikum

  4. Majandustsüklite uurijad said Nobeli preemia / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    2004. aasta Nobeli majanduspreemia said norralane Finn Kydland ja ameeriklane Edward Prescot makroökonoomikavaldkonna uuringute eest, mis puudutavad majandustsükleid ning majanduspoliitiliste otsuste mõjusid

  5. Riik ei loobu plaanitud euro-kampaaniast / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2005-01-01

    Rahandusministeeriumi eurole ülemineku projektijuht Anne Sulling kinnitab, et Eesti ei ole loobunud eesmärgist võtta euro kasutusele 2007. aastal. Koos Euroopa Liiduga plaanib riik kulutada euro teavitamiskampaaniale kuni ühe euro inimese kohta ehk kokku ligi 1,4 miljonit eurot. Lisa: Poolt ja vastu

  6. Streikijate armee paisub iga päevaga / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    23. septembril alanud raudteetöötajate streigist osavõtjate arv kasvab iga päevaga, kaubarongid veel liiguvad, kuid kui vajalikke samme ei astuta, võib kogu rongiliiklus seiskuda. Lisa: Ronge asendavad bussid. Vt. ka: Edelaraudtee rendib streigi ajaks bussid

  7. Majandustsüklite uurijad said Nobeli preemia / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    2004. aasta Nobeli majanduspreemia said norralane Finn Kydland ja ameeriklane Edward Prescot makroökonoomikavaldkonna uuringute eest, mis puudutavad majandustsükleid ning majanduspoliitiliste otsuste mõjusid

  8. Kultuuriministeerium jättis parima harrastusteatri toetuseta / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Kultuuriministeerium loobus toetamast harrastusteatri sõitu Ülemaailmsele amatöörteatrite festivalile Kanadas. Tegemist on Eestit Harrastusteatrite Liidu, Teoteatri, Tallinna Toomklubi ja Botaanikaaia ühisprojektiga - A. Alegria "Niagaara" (lavastaja Jaan Urvet), mille rahvusvaheline žürii valis 300 hulgast 14 parima hulka

  9. Reps tahab koolidele veel 500 miljonit krooni / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2006-01-01

    Haridus- ja teadusministri Mailis Repsi sõnul kuluks praegu kiirelt vananevale õpetajaskonnale piisava järelkasvu meelitamiseks ja maakoolide võrgu säilitamiseks vähemalt 400-500 miljonit krooni

  10. Valgast saab konkurent Tallinnale / Rando Kängsepp

    Index Scriptorium Estoniae

    Kängsepp, Rando

    2006-01-01

    Ilmunud ka: Delovõje Vedomosti 1. märts lk. 8. SA Valgamaa Arenguagentuur soovib projektiga Baltic Tangent hoogustada Lõuna-Eesti kaubatranspordi elavnemist ning Valga kujunemist logistikakeskuseks Ida ja Lääne vahel

  11. NRG-tehing võib lõppeda energiakriisiga / Endel Lippmaa ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Lippmaa, Endel, 1930-

    2001-01-01

    TA akadeemikute esindaja arvates peaks valitsus tunnistama NRG Energy tehingu ebaõnnestunuks ja kuulutama välja uue, avaliku erastamiskonkursi. Kommenteerivad: G. Okk, I. Öpik, V. Reiljan, M. Pärnoja. Avalik kiri Eesti elektrist lk. 24 - alla kirjutanud Eesti TA akadeemikud. Sama vt. vene keeles Estonija, 18. juuni 2001, lk.6. Parlamendisaadik (V. Reiljan). Ilmunud ka: Molodjozh Estonii, 30. juuni 2001, lk. 8

  12. AvtoVAZ tahab lõpetada seniste mudelite tootmist / Aivar Reinap, Erkki Erilaid

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2003-01-01

    Venemaa tuntuim autotehas AvtoVAZ plaanib lähiaastatel lõpetada kõikide vananenud automarkide tootmise ja uuendada täielikult oma mudelivalikut. Vt. samas: AvtoVAZi peagi tootmisse jõudvad mudelid

  13. LHV pankureid vanglakaristus esialgu ei ähvarda / Aleksei Günter, Aivar Reinap

    Index Scriptorium Estoniae

    Günter, Aleksei, 1979-

    2005-01-01

    Ilmunud ka: Postimees : na russkom jazõke 8. nov., lk 10. New Yorgis algavast kohtuprotsessist, milles USA väärtpaberituru järelvalve (SEC) süüdistab Eesti investeerimispanga LHV töötajaid Oliver Peeki ja Kristjan Lepikut ning LHV-d börsiettevõtte siseinfo varguses pressiteateid avaldavast portaalist Business Wire

  14. Energiahiidu üllatas inspektorite äkiline otsus / Sandor Liive ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Liive, Sandor

    2004-01-01

    Eesti Energia finantsdirektori hinnangul põhjustasid kavandatud elektrienergia hinnatõusu nurjumise energiaettevõtte ja energiaturu inspektsiooni erinevad andmed ning raskused teineteise mõistmisel

  15. Hinnakäärid telekomis on kolm miljardit krooni / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    Valitsus hindab Eesti Telekom'i väärtust kõrgemaks kui ettevõtte suuromanik TeliaSonera, mistõttu lükkas riik ülevõtupakkumise otsustavalt tagasi. Rahandusminister Taavi Veskimäe arvamus. Diagramm: Riik soovib 830 miljonit rohkem

  16. Majandusminister Edgar Savisaar loodab arengufondi abil tuua uut hingamist / Edgar Savisaar ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Savisaar, Edgar, 1950-

    2005-01-01

    Majandus- ja kommunikatsiooniminister vastab küsimustele, mis puudutavad arengufondi, võõrtööjõudu, riigiettevõtete vähemusosaluse müümise ideed, reisijateveo doteerimist, sadamatasusid, praamidega seonduvat, põlevkivienergeetikat. Lisad: CV; Ministri viis esimest tööd

  17. EMT ajab Rate.ee abil noori kliente taga / Aivar Reinap, Kaire Uusen

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke, Pärnu Postimees 6. apr. lk. 8,7. Mobiilifirma EMT ostis Sereda Invest OÜ-lt ligi 40 miljoni krooni eest enamusosaluse suhtlusportaalis Rate.ee vältimaks konkurendi mõjujõu kasvu. Vt. samas: Üksikisikud hoiavad internetiäri üleval. Lisa: Internetiäri

  18. Hansapanga võib neelata ka ülevõtupakkumiseta / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2005-01-01

    Selleks, et Hansapanka täielikult üle võtta, piisab Swedbankil oma osaluse suurendamisest kõigest 66 protsendini. Investeerimisfirma Suprema partneri Henrik Igasta hinnangul võib Hansapanga omandamine aktsiavahetuse teel olla teoreetiliselt küll võimalik, kuid tehniliselt keerukas. Graafik: Hansapanga aktsia kallineb

  19. Euroopa Liit võtab Eestilt statistikaga 200 miljonit / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    EL-i arvutusnõuete tõttu kasvas Eesti 2003. aasta SKP ligi 10 miljardi krooni võrra, mistõttu peab Eesti maksma igal aastal 200 miljoni võrra senisest rohkem liikmemaksu. Lisa: Pool miljardit lisaks

  20. LHV pankureid vanglakaristus esialgu ei ähvarda / Aleksei Günter, Aivar Reinap

    Index Scriptorium Estoniae

    Günter, Aleksei, 1979-

    2005-01-01

    Ilmunud ka: Postimees : na russkom jazõke 8. nov., lk 10. New Yorgis algavast kohtuprotsessist, milles USA väärtpaberituru järelvalve (SEC) süüdistab Eesti investeerimispanga LHV töötajaid Oliver Peeki ja Kristjan Lepikut ning LHV-d börsiettevõtte siseinfo varguses pressiteateid avaldavast portaalist Business Wire

  1. Eesti Energia kärpis elektrihinna tõusu / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    Ilmunud ka: Põhjarannik, 13. veebr. 2004, lk. 1. Eesti Energia nõukogu otsustas vähendada taotletavat elektrienergia hinnatõusu 15%ni ja lükkas hinnapakettide lõpliku kinnitamise edasi nädala võrra. Riigikogu ja Eesti Energia nõukogu liikme Janno Reiljani arvamus

  2. Eesti Energia kärpis elektrihinna tõusu / Aivar Reinap

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2004-01-01

    Ilmunud ka: Põhjarannik, 13. veebr. 2004, lk. 1. Eesti Energia nõukogu otsustas vähendada taotletavat elektrienergia hinnatõusu 15%ni ja lükkas hinnapakettide lõpliku kinnitamise edasi nädala võrra. Riigikogu ja Eesti Energia nõukogu liikme Janno Reiljani arvamus

  3. Majandusminister Edgar Savisaar loodab arengufondi abil tuua uut hingamist / Edgar Savisaar ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Savisaar, Edgar, 1950-

    2005-01-01

    Majandus- ja kommunikatsiooniminister vastab küsimustele, mis puudutavad arengufondi, võõrtööjõudu, riigiettevõtete vähemusosaluse müümise ideed, reisijateveo doteerimist, sadamatasusid, praamidega seonduvat, põlevkivienergeetikat. Lisad: CV; Ministri viis esimest tööd

  4. EMT ajab Rate.ee abil noori kliente taga / Aivar Reinap, Kaire Uusen

    Index Scriptorium Estoniae

    Reinap, Aivar, 1968-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke, Pärnu Postimees 6. apr. lk. 8,7. Mobiilifirma EMT ostis Sereda Invest OÜ-lt ligi 40 miljoni krooni eest enamusosaluse suhtlusportaalis Rate.ee vältimaks konkurendi mõjujõu kasvu. Vt. samas: Üksikisikud hoiavad internetiäri üleval. Lisa: Internetiäri

  5. Eesti aidsiennetus saab 52 miljonit välisraha / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Rahvusvaheline finantsorganisatsioon Global Fund (Global Fund to Fight AIDS, Tuberculosis and Malaria) annab Eestile 2 aasta jooksul aidsiennetustööks 52 miljonit krooni. Kommenteerib Nelli Kalikova

  6. Eesti aidsiennetus saab 52 miljonit välisraha / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Rahvusvaheline finantsorganisatsioon Global Fund (Global Fund to Fight AIDS, Tuberculosis and Malaria) annab Eestile 2 aasta jooksul aidsiennetustööks 52 miljonit krooni. Kommenteerib Nelli Kalikova

  7. Matrix - kultusfilm, mis muutus müüdiks / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Andy ja Larry Wachowski ulmefilmide triloogia 3. osa "Matrix : Revolutsioon" ("The Marix Revolutions") jõuab 5. novembril esilinastuseni korraga enam kui 50 riigis, sealhulgas MPDE vahendusel ka Eestis. Eesti filmikriitikute arvamusi Matrix'i fenomenist

  8. Matrix - kultusfilm, mis muutus müüdiks / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2003-01-01

    Andy ja Larry Wachowski ulmefilmide triloogia 3. osa "Matrix : Revolutsioon" ("The Marix Revolutions") jõuab 5. novembril esilinastuseni korraga enam kui 50 riigis, sealhulgas MPDE vahendusel ka Eestis. Eesti filmikriitikute arvamusi Matrix'i fenomenist

  9. Rein Ratase allkiri paneb rattad käima ; kommenteerinud Rein Ratas, Neeme Reinap, Vilmar Rei...[jt.

    Index Scriptorium Estoniae

    Jakobson, Kadri, 1970-

    2010-01-01

    Riigikogu keskkonnakomisjoni liige Rein Ratas surub läbi firma EcoPro, mille üks omanik on Ratase hea tuttav, arendust Saaremaal Ruhve poolsaarel, mis asub kaitsealal ja ehituskeeluvööndis. Rein Ratas on tuludeklaratsioonis jätnud märkimata firmast Adepte Ekspert saadava tulu

  10. Tiit Vähi : ettevõtjad peavad tegutsema seaduse piires / Tiit Vähi ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Vähi, Tiit, 1947-

    2002-01-01

    AS-i Silmet juht Tiit Vähi ärimeeste süüdistustest maksuameti aadressil, off-shore firmade kasutamisest, maksuamnestiast, Eesti maksukoormusest, Eesti majanduskasvust 2002. a. I kvartalis. Kommenteerivad Harri Õunapuu ja Toomas Luman

  11. Eesti keskmine kuupalk võib tänavu kerkida üle 9000 krooni / Kaire Uusen, Aivar Reinap

    Index Scriptorium Estoniae

    Uusen, Kaire

    2006-01-01

    2006. aasta esimeses kvartalis tõusis keskmine brutopalk 8591 kroonini ja esimest korda tõusis ühe majandusharu - finantsvahenduse - keskmine töötasu üle 20 000 krooni. Diagramm: Keskmine brutopalk esimeses kvartalis

  12. Rein Ratase allkiri paneb rattad käima ; kommenteerinud Rein Ratas, Neeme Reinap, Vilmar Rei...[jt.

    Index Scriptorium Estoniae

    Jakobson, Kadri, 1970-

    2010-01-01

    Riigikogu keskkonnakomisjoni liige Rein Ratas surub läbi firma EcoPro, mille üks omanik on Ratase hea tuttav, arendust Saaremaal Ruhve poolsaarel, mis asub kaitsealal ja ehituskeeluvööndis. Rein Ratas on tuludeklaratsioonis jätnud märkimata firmast Adepte Ekspert saadava tulu

  13. ELi majanduslik võimekus jääb konkurentidele alla / Maria Joao Rodrigues ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Rodrigues, Maria Joao

    2004-01-01

    Praxis'e kutsel Eestis viibinud Euroopa Komisjoni nõuniku hinnangul ei suuda Euroopa Liit tõusta lähiaastatel maailma kõige konkurentsivõimelisemaks piirkonnaks. Lissaboni strateegiast, Euroopa konkurentsivõimest, Aasia ohust, Eesti võimalustest. Lisa: Euroopa Liidu majandusideoloog

  14. ELi majanduslik võimekus jääb konkurentidele alla / Maria Joao Rodrigues ; interv. Aivar Reinap

    Index Scriptorium Estoniae

    Rodrigues, Maria Joao

    2004-01-01

    Praxis'e kutsel Eestis viibinud Euroopa Komisjoni nõuniku hinnangul ei suuda Euroopa Liit tõusta lähiaastatel maailma kõige konkurentsivõimelisemaks piirkonnaks. Lissaboni strateegiast, Euroopa konkurentsivõimest, Aasia ohust, Eesti võimalustest. Lisa: Euroopa Liidu majandusideoloog

  15. Radiological protection in pelvis studies by computed tomography in Rando phantom by means of thermoluminescent dosimetry; Proteccion radiologica en estudios de pelvis por tomografia computada en fantoma Rando mediante dosimetria termoluminiscente

    Energy Technology Data Exchange (ETDEWEB)

    Madrid G, O. A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Calz. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin N, J., E-mail: riveramt@hotmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2011-11-15

    The risks of the radiation in computed tomography (CT) studies have been recently reported in many works. Caution should be had in the environment of the exploration in the patient. To maintain the radiation doses so low as is reasonably possible during the CT examination, is important that in the CT the parameters are correctly adjusted for each patient with the purpose of having the minimum dose in the application of the study. Thermoluminescent dosimeters were used to measure the absorbed dose and to measure the CT profiles of dose. The distribution of the dose in the CT abdominal examination in the simulated patients was evaluated. The exploration parameters of the CT were 130 kV, 90 m A, with a cut thickness of 3 mm and a field of 1.0 in the pitch. The assignment dose was increased in an axis along the direction of the study, they were also studied. The equivalent dose due to the direct and dispersed radiation was determined during the procedures of the irradiation in pelvis examinations, for the next areas to the study like is in specific the critical organ (gonads) that is the terminal area of the exploration. During this study of 26 cuts was obtained an equivalent dose to critical organ of 14.27 mSv. (Author)

  16. Tõuni imekitarr kõlab nagu mesi . Pedaal-steel teeb popmuusikas taassündi / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2009-01-01

    Muusik Tõnu Timm jutustab loo, kuidas hankis Ameerikast haruldase pedaal-steel- kitarri. Eesti kasutusel olevatest vanematest pedaal-steel-kitarridest. Ansamblid, kus kasutatakse kõneall olevat kitarri

  17. Tõuni imekitarr kõlab nagu mesi . Pedaal-steel teeb popmuusikas taassündi / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2009-01-01

    Muusik Tõnu Timm jutustab loo, kuidas hankis Ameerikast haruldase pedaal-steel- kitarri. Eesti kasutusel olevatest vanematest pedaal-steel-kitarridest. Ansamblid, kus kasutatakse kõneall olevat kitarri

  18. Ei ole võimalik! Tüdruk on 13, kuid näeb välja nagu 20! / Rando Tooming

    Index Scriptorium Estoniae

    Tooming, Rando

    2010-01-01

    Teismeliste tüdrukute varase küpsemise põhjusi otsivad ja sellega kaasnevat selgitavad sotsioloog Airi-Alina Allaste, IT-visionäär Linnar Viik, koolipsühholoog Kärt Käesel ning Politsei- ja piirivalveameti kriminaalpolitseiosakonna üleminspektor Anu Baum

  19. Valitsusliidu programmi eelnõu: arendada, parendada, analüüsida / Rando Tooming, Margo Pajuste ; kommenteerinud Aivar Haller, Artur Talvik, Rainer Kattel, Eiki Nestor, Rein Raud

    Index Scriptorium Estoniae

    Tooming, Rando

    2011-01-01

    Olulisemad lubadused Reformierakonna ja Isamaa ja Res Publica valitsusliidu programmi eelnõust. Uue koalitsioonileppe kohta avaldavad arvamust Eesti Lastevanemate Liidu juhatuse liige Aivar Haller, Roheliste erakonnas kandideerinud Artur Talvik, TTÜ professor Rainer Kattel, Sotsiaaldemokraatliku Erakonna liige Eiki Nestor ja Tallinna Ülikooli rektor Rein Raud

  20. Liiklus - politsei ja elanike ühine mure / Villu Vane

    Index Scriptorium Estoniae

    Vane, Villu

    2007-01-01

    Autori hinnangul ei piisa liiklusõnnetuste vähendamiseks üksnes politsei liiklusjärelevalve tõhustamisest, oluline on inimeste arusaamade ja hoiakute muutmine ning liikluseeskirjade järgimine. Lisa: Aivar Reinap. Postimees.ee lugejad muretsevad liikluskriisi pärast. Diagramm: Maanteeameti liiklusohutusprogrammi prognoos aastani 2015

  1. Liiklus - politsei ja elanike ühine mure / Villu Vane

    Index Scriptorium Estoniae

    Vane, Villu

    2007-01-01

    Autori hinnangul ei piisa liiklusõnnetuste vähendamiseks üksnes politsei liiklusjärelevalve tõhustamisest, oluline on inimeste arusaamade ja hoiakute muutmine ning liikluseeskirjade järgimine. Lisa: Aivar Reinap. Postimees.ee lugejad muretsevad liikluskriisi pärast. Diagramm: Maanteeameti liiklusohutusprogrammi prognoos aastani 2015

  2. Does multicomponent physical exercise with simultaneous cognitive training boost cognitive performance in older adults? A 6-month rando­mized controlled trial with a 1-year follow-up

    Directory of Open Access Journals (Sweden)

    Eggenberger P

    2015-08-01

    Full Text Available Patrick Eggenberger,1 Vera Schumacher,2,3 Marius Angst,1 Nathan Theill,4,5 Eling D de Bruin1,6,7 1Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, 2Department of Gerontopsychology and Gerontology, 3University Research Priority Program “Dynamics of Healthy Aging”, University of Zurich, Zurich, 4Division of Psychiatry Research, University of Zurich, Schlieren, 5Center for Gerontology, University of Zurich, Zurich, Switzerland; 6CAPHRI School for Public Health and Primary Care, Department of Epidemiology, 7Centre for Evidence Based Physiotherapy, Maastricht University, Maastricht, the Netherlands Background: Cognitive impairment is a health problem that concerns almost every second elderly person. Physical and cognitive training have differential positive effects on cognition, but have been rarely applied in combination. This study evaluates synergistic effects of multicomponent physical exercise complemented with novel simultaneous cognitive training on cognition in older adults. We hypothesized that simultaneous cognitive–physical components would add training specific cognitive benefits compared to exclusively physical training.Methods: Seniors, older than 70 years, without cognitive impairment, were randomly assigned to either: 1 virtual reality video game dancing (DANCE, 2 treadmill walking with simultaneous verbal memory training (MEMORY, or 3 treadmill walking (PHYS. Each program was complemented with strength and balance exercises. Two 1-hour training sessions per week over 6 months were applied. Cognitive performance was assessed at baseline, after 3 and 6 months, and at 1-year follow-up. Multiple regression analyses with planned comparisons were calculated.Results: Eighty-nine participants were randomized to the three groups initially, 71 completed the training, while 47 were available at 1-year follow-up. Advantages of the simultaneous cognitive–physical programs were found in two dimensions of executive function. “Shifting attention” showed a time×intervention interaction in favor of DANCE/MEMORY versus PHYS (F[2, 68] =1.95, trend P=0.075, r=0.17; and “working memory” showed a time×intervention interaction in favor of DANCE versus MEMORY (F[1, 136] =2.71, trend P=0.051, R2=0.006. Performance improvements in executive functions, long-term visual memory (episodic memory, and processing speed were maintained at follow-up in all groups.Conclusion: Particular executive functions benefit from simultaneous cognitive–physical training compared to exclusively physical multicomponent training. Cognitive–physical training programs may counteract widespread cognitive impairments in the elderly. Keywords: elderly, executive function, transfer, cognitive impairment, dance, video game

  3. Bush jätkab maailma dirigeerimist / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2004-01-01

    USA president George W. Bush peab oma tagasivalimise kindlustajaks elluviidud välispoliitikat. Autori hinnangul on Bush varasematest presidentidest jõulisemalt muutmas USA-d kapitalismi lipulaevaks, Bushi USA vastandab end euroopalikule mudelile, kus riik tagab kodanikele turvatunde. Kavandatavatest muudatustest USA sisepoliitikas. Vt. samas: Arko Olesk. Verine aasta Iraagi sõjas; Aivar Reinap. USA majandus mustas augus; Andres Keil. Tsivilisatsiooni häirekell

  4. Encoder Rate ControI AIgorith m Based on Scra mbIing with Pseudo-rando m Code for Distributed ResiduaI Coding of Video%基于伪随机码置乱的分布式视频残差编码端码率控制算法

    Institute of Scientific and Technical Information of China (English)

    胡春筠; 胡斌杰

    2016-01-01

    An encoder rate control algorithm is proposed for the distributed residual video coding,which is based on scrambling the pixels of a residual frame with pseudo-random code in order to realize rate estimation at the fame level,i.e., estimating one rate for each residual frame.A quantization index estimation algorithm is also proposed to increase the ratio of successful decoding and solve the problem of rate underestimation.In the mean time,the statistical characteristics of the re-sidual signal at the encoder can approximately represent the correlation between the signals at both the encoder and the de-coder.No predicted side information needs to be generated at the encoder.The simulation results show that the proposed al-gorithm has low encoder complexity,high successful decoding ratio,less latency,and good RD performance.%提出一种基于伪随机码置乱的分布式视频残差编码端码率控制算法,利用伪随机码对残差视频帧的像素进行置乱处理,将信源图像与其边信息图像之间的差别均匀化,实现帧级别上的码率估计,即每一帧用同一码率发送。如果收端译码失败,利用提出的一种量化序号估计算法能显著提高译码成功率,解决码率低估问题。同时发端视频残差帧的特性能近似表示收发两端信号之间的相关性,因此,发端无需产生一个预测的边信息。仿真结果表明,该算法发端复杂度低、译码成功率高、系统延迟小、率失真性能良好。

  5. Ühisraha peab saama inimestele lähedaseks / Joaquin Almunia

    Index Scriptorium Estoniae

    Almunia, Joaquin, 1948-

    2005-01-01

    Euroopa Komisjoni rahandusasjade volinik hoiatab, et tõenäoliselt peavad mõned Euroopa Liidu rahaliiduga ühineda soovivad riigid kõrge inflatsiooni või eelarvepuudujäägi likvideerimise liialt aeglase tempo tõttu euroalaga ühinemise edasi lükkama. Voliniku sõnul tuleb eurole üleminekut plaanivates riikides tõsta tehniliste ettevalmistuste tempot ja tõhustada teavitustööd elanike seas. Kommenteerivad Riigikogu liige Liina Tõnisson ja rahandusminister Aivar Sõerd. Vt. samas lk. 3: Aivar Reinap. Eurovolinik ründab Eestit vananenud andmetega

  6. Ühisraha peab saama inimestele lähedaseks / Joaquin Almunia

    Index Scriptorium Estoniae

    Almunia, Joaquin, 1948-

    2005-01-01

    Euroopa Komisjoni rahandusasjade volinik hoiatab, et tõenäoliselt peavad mõned Euroopa Liidu rahaliiduga ühineda soovivad riigid kõrge inflatsiooni või eelarvepuudujäägi likvideerimise liialt aeglase tempo tõttu euroalaga ühinemise edasi lükkama. Voliniku sõnul tuleb eurole üleminekut plaanivates riikides tõsta tehniliste ettevalmistuste tempot ja tõhustada teavitustööd elanike seas. Kommenteerivad Riigikogu liige Liina Tõnisson ja rahandusminister Aivar Sõerd. Vt. samas lk. 3: Aivar Reinap. Eurovolinik ründab Eestit vananenud andmetega

  7. Aivar Sõerd tahab olla riigimees / Aivar Sõerd ; interv. Imbi E. Kaljuste

    Index Scriptorium Estoniae

    Sõerd, Aivar, 1964-

    2005-01-01

    Rahandusminister oma ametnikukarjäärist, maailmavaatelistest eelistustest, maksuameti tööst, juriidiliste isikute tulumaksusüsteemi vastavusse viimise vajadusest Eestis Euroopa Liidu nn ema- ja tütarettevõtja direktiiviga, maksumuudatuste etteteatamisajast, Eesti käibemaksuseadusest, dokumenteerimisnõuete kehtestamise vajalikkusest siirdehindade kindlaksmääramisel, maksumaksjate maksuprobleemidest. Lisa: Aivar Sõerd. Kommenteerivad Postimehe majandustoimetuse juhataja Aivar Reinap, Lasse Lehis, Rahvaliidu esimees Villu Reiljan, MTA peadirektori asetäitja Rainer Osanik, Vello Vallaste (OÜ Vallaste ja Partnerid)

  8. Attributable mortality of ventilator-associated pneumonia: a meta-analysis of individual patient data from randomised prevention studies

    NARCIS (Netherlands)

    Melsen, W.G.; Rovers, M.M.; Groenwold, R.H.; Bergmans, D.C.; Camus, C.; Bauer, T.T.; Hanisch, E.W.; Klarin, B.; Koeman, M.; Krueger, W.A.; Lacherade, J.C.; Lorente, L.; Memish, Z.A.; Morrow, L.E.; Nardi, G.; Nieuwenhoven, C.A. van; O'Keefe, G.E.; Nakos, G.; Scannapieco, F.A.; Seguin, P.; Staudinger, T.; Topeli, A.; Ferrer, M.; Bonten, M.J.

    2013-01-01

    BACKGROUND: Estimating attributable mortality of ventilator-associated pneumonia has been hampered by confounding factors, small sample sizes, and the difficulty of doing relevant subgroup analyses. We estimated the attributable mortality using the individual original patient data of published rando

  9. Early reversal of profound rocuronium-induced neuromuscular blockade by sugammadex in a randomized multicenter study - Efficacy, safety, and pharmacokinetics

    NARCIS (Netherlands)

    Sparr, Harald J.; Vermeyen, Karel M.; Beaufort, Anton M.; Rietbergen, Henk; Proost, Johannes H.; Saldien, Vera; Velik-Salchner, Corinna; Wierda, J. Mark K. H.

    2007-01-01

    Background: Sugammadex reverses the neuromuscular blocking effects of rocuronium by chemical encapsulation. The efficacy, safety, and pharmacokinetics of sugammadex for reversal of profound rocuronium-induced neuromuscular blockade were evaluated. Methods: Ninety-eight male adult patients were rando

  10. Exposure to environmental tobacco smoke (ETS) and determinants of support for complete smoking bans in psychiatric settings.

    NARCIS (Netherlands)

    Willemsen, M.C.; Gorts, C.A.; Soelen, P. van; Jonkers, R.E.; Hilberink, S.R.

    2004-01-01

    OBJECTIVE: To measure environmental tobacco smoke (ETS) exposure in psychiatric settings and to assess determinants of support for complete smoking bans. DESIGN: Cross sectional study SETTING: Dutch psychiatric hospitals, outpatient care institutions, and sheltered home facilities. SUBJECTS: A rando

  11. Transfer of Intestinal Microbiota From Lean Donors Increases Insulin Sensitivity in Individuals With Metabolic Syndrome

    NARCIS (Netherlands)

    Vrieze, Anne; Van Nood, Els; Holleman, Frits; Salojarvi, Jarkko; Kootte, Ruud S.; Bartelsman, Joep F. W. M.; Dallinga-Thie, Geesje M.; Ackermans, Mariette T.; Serlie, Mireille J.; Oozeer, Raish; Derrien, Muriel; Druesne, Anne; van Hylckama Vlieg, Johan E.T.; Bloks, Vincent W.; Groen, Albert K.; Heilig, Hans G. H. J.; Zoetendal, Erwin G.; Stroes, Erik S.; de Vos, Willem M.; Hoekstra, Joost B. L.; Nieuwdorp, Max

    2012-01-01

    Alterations in intestinal microbiota are associated with obesity and insulin resistance. We studied the effects of infusing intestinal microbiota from lean donors to male recipients with metabolic syndrome on the recipients' microbiota composition and glucose metabolism. Subjects were assigned rando

  12. Effects of long-term exposure to traffic-related air pollution on respiratory and cardiovascular mortality in the Netherlands: the NLCS-AIR study.

    NARCIS (Netherlands)

    Brunekreef, B.; Beelen, R.M.J.; Hoek, G.; Schouten, L.J.; Bausch-Goldbohm, S.; Fischer, P.; Armstrong, B.; Hughes, E.; Jerrett, M.; v.d. Brandt, P.A.

    2009-01-01

    Evidence is increasing that long-term exposure to ambient air pollution is associated with deaths from cardiopulmonary diseases. In a 2002 pilot study, we reported clear indications that traffic-related air pollution, especially at the local scale, was related to cardiopulmonary mortality in a rando

  13. Influence of a Saccharomyces cerevisia fermentation product on the pathophysiological response to a combined intranasal bovine herpesvirus-1 and intratracheal Mannheimia haemolytica challenge in Holstein steers

    Science.gov (United States)

    The objective of this study was to determine the effects of supplementing a Saccharomyces cerevisiae fermentation product prototype (Prototype) on the pathophysiological response during a combined viral-bacterial respiratory challenge. Holstein steer calves (126.5±6.11kg; N=16) were completely rando...

  14. Radiation protection of staff in 111In radionuclide therapy--is the lead apron shielding effective?

    Science.gov (United States)

    Lyra, M; Charalambatou, P; Sotiropoulos, M; Diamantopoulos, S

    2011-09-01

    (111)In (Eγ = 171-245 keV, t1/2 = 2.83 d) is used for targeted therapies of endocrine tumours. An average activity of 6.3 GBq is injected into the liver by catheterisation of the hepatic artery. This procedure is time-consuming (4-5 min) and as a result, both the physicians and the technical staff involved are subjected to radiation exposure. In this research, the efficiency of the use of lead apron has been studied as far as the radiation protection of the working staff is concerned. A solution of (111)In in a cylindrical scattering phantom was used as a source. Close to the scattering phantom, an anthropomorphic male Alderson RANDO phantom was positioned. Thermoluminescent dosemeters were located in triplets on the front surface, in the exit and in various depths in the 26th slice of the RANDO phantom. The experiment was repeated by covering the RANDO phantom by a lead apron 0.25 mm Pb equivalent. The unshielded dose rates and the shielded photon dose rates were measured. Calculations of dose rates by Monte Carlo N-particle transport code were compared with this study's measurements. A significant reduction of 65 % on surface dose was observed when using lead apron. A decrease of 30 % in the mean absorbed dose among the different depths of the 26th slice of the RANDO phantom has also been noticed. An accurate correlation of the experimental results with Monte Carlo simulation has been achieved.

  15. Modafinil May Alleviate Poststroke Fatigue

    DEFF Research Database (Denmark)

    Poulsen, Mai Bang; Damgaard, Bodil; Zerahn, Bo

    2015-01-01

    BACKGROUND AND PURPOSE: Poststroke fatigue is common and reduces quality of life. Current evidence for intervention is limited, and this is the first placebo-controlled trial to investigate treatment of poststroke fatigue with the wakefulness promoting drug modafinil. METHODS: The trial was rando......: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01800097....

  16. Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation?

    Science.gov (United States)

    Numerous factors have been identified as risk factors for instability of oral anticoagulation, including variability in vitamin K intake. However few studies have directly tested the feasibility of manipulating dietary vitamin K to achieve stable oral anticoagulation. Recent findings from a rando...

  17. Improviseeritud lugu ja zhanriga mäng / Donald Tomberg

    Index Scriptorium Estoniae

    Tomberg, Donald

    2003-01-01

    Eesti komöödiafilm "Vanad ja kobedad saavad jalad alla" : režissöör Rando Pettai : operaator Mait Mäekivi : näitlejad Henrik Normann, Madis Milling, Robert Gutman jt. : muusika - ansambel Genialistid : Ruut Pictures 2003

  18. Efficacy and safety of sorafenib in patients with advanced hepatocellular carcinoma : Subanalyses of a phase III trial

    NARCIS (Netherlands)

    Bruix, Jordi; Raoul, Jean-Luc; Sherman, Morris; Mazzaferro, Vincenzo; Bolondi, Luigi; Craxi, Antonio; Galle, Peter R.; Santoro, Armando; Beaugrand, Michel; Sangiovanni, Angelo; Porta, Camillo; Gerken, Guido; Marrero, Jorge A.; Nadel, Andrea; Shan, Michael; Moscovici, Marius; Voliotis, Dimitris; Llovet, Josep M.

    2012-01-01

    Background & Aims: The Sorafenib Hepatocellular Carcinoma (HCC) Assessment Randomized Protocol (SHARP) trial demonstrated that sorafenib improves overall survival and is safe for patients with advanced HCC. In this trial, 602 patients with well-preserved liver function (>95% Child-Pugh A) were rando

  19. A randomized controlled trial of the effectiveness of multisystemic therapy in the Netherlands: post-treatment changes and moderator effects

    NARCIS (Netherlands)

    J.J. Asscher; M. Deković; W.A. Manders; P.H. van der Laan; P.J.M. Prins

    2013-01-01

    Objective: In the present randomized controlled trial, the effectiveness of multisystemic therapy (MST) in The Netherlands was examined. Moderator tests were conducted for ethnicity, age and gender. Methods: The sample consisted of N = 256 adolescents, referred because of conduct problems, and rando

  20. Efficacy and safety of sorafenib in patients with advanced hepatocellular carcinoma : Subanalyses of a phase III trial

    NARCIS (Netherlands)

    Bruix, Jordi; Raoul, Jean-Luc; Sherman, Morris; Mazzaferro, Vincenzo; Bolondi, Luigi; Craxi, Antonio; Galle, Peter R.; Santoro, Armando; Beaugrand, Michel; Sangiovanni, Angelo; Porta, Camillo; Gerken, Guido; Marrero, Jorge A.; Nadel, Andrea; Shan, Michael; Moscovici, Marius; Voliotis, Dimitris; Llovet, Josep M.

    2012-01-01

    Background & Aims: The Sorafenib Hepatocellular Carcinoma (HCC) Assessment Randomized Protocol (SHARP) trial demonstrated that sorafenib improves overall survival and is safe for patients with advanced HCC. In this trial, 602 patients with well-preserved liver function (>95% Child-Pugh A) were rando

  1. LBA-2 A randomized trial of long-term tinzaparin, a Low Molecular Weight Heparin (LMWH), versus warfarin for treatment of acute venous thromboembolism (VTE) in cancer patients-the CATCH study

    NARCIS (Netherlands)

    Lee, Agnes Y.Y.; Kamphuisen, Pieter W.; Meyer, Guy; Bauersachs, Rupert; Janas, Mette S.; Jarner, Mikala F.; Khorana, Alok A.

    2014-01-01

    Background Patients with cancer and VTE have a substantial risk of recurrent VTE. LMWH reduces the risk of symptomatic, recurrent VTE compared with warfarin and is recommended as the preferred anticoagulant by consensus guidelines. However, the evidence is based largely on a single, open-label rando

  2. Chronic kidney disease : Defining clinical cut-offs for albumin:creatinine ratio

    NARCIS (Netherlands)

    Bakker, Stephan J L

    2013-01-01

    Albuminuria is rapidly gaining recognition as a marker of the presence and of the progression of chronic kidney disease (CKD). In a new study, Naresh et al. attempt to define cut-off values for percentage change in urinary albumin:creatinine ratio that reflect changes in CKD status rather than rando

  3. Operator radiation exposure in cone-beam computed tomography guidance

    NARCIS (Netherlands)

    Braak, S.J.; Strijen Van, M. J L; Meijer, E.; Heesewijk Van, J. P M; Mali, W. P T M

    2016-01-01

    Objectives: Quantitative analysis of operator dose in cone-beam computed tomography guidance (CBCT-guidance) and the effect of protective shielding. Methods: Using a Rando phantom, a model was set-up to measure radiation dose for the operator hand, thyroid and gonad region. The effect of sterile rad

  4. Assessment of effective dose to staff in brachytherapy.

    Science.gov (United States)

    Faulkner, K; James, H V; Chapple, C L; Rawlings, D J

    1996-11-01

    The aim of this paper is to investigate the problem of monitoring effective dose to hospital staff who are involved in the treatment of tumors using sealed sources placed inside the body (brachytherapy). In addition, the use of an unsealed source to treat the thyroid was also considered. Radiation distributions produced by both sealed sources commonly used in brachytherapy (192I, 137Cs, 226Ra) and an unsealed source used in the treatment of the thyroid (131I) were used to irradiate a Rando phantom. The brachytherapy treatments of esophageal and gynecological carcinoma were simulated. The Rando phantom was loaded with lithium fluoride thermoluminescent dosimeters at positions corresponding to a number of radiosensitive organs. Film badges and electronic personal dosimeters were attached to the Rando phantom at various anatomical sites. The Rando phantom was positioned adjacent to the patient at an angle of 90 degrees to the longitudinal axis of the patient. Irradiations were performed with and without a portable lead screen used on the radiotherapy wards. Effective dose was estimated for each simulated radiotherapy treatment and compared with the personal monitor readings. The data were used as a basis for the provision of advice on the wearing of the film badge dosimeters and the design of portable lead screens. The data also permitted a comparison between the two types of dosimeter when used for personal monitoring in brachytherapy.

  5. Meditation Based Therapies—A Systematic Review and Some Critical Observations

    DEFF Research Database (Denmark)

    Fjorback, Lone; Walach, Harald

    2012-01-01

    This article systematically reviews the evidence for Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT) and analyses the conditions around their rising popularity. MBSR, MBCT and Mindfulness Meditation were used as key words. The inclusion criteria were rando...

  6. Preferred mesh-based inguinal hernia repair in a teaching setting: results of a randomized study.

    NARCIS (Netherlands)

    Nienhuijs, S.W.; Kortmann, B.B.M.; Boerma, M.; Strobbe, L.J.; Rosman, C.

    2004-01-01

    HYPOTHESIS: Surgeons' preferences for any of 3 methods of inguinal hernia repair are comparable in terms of operating time, incision length, perceived difficulty, and surgeon's satisfaction. DESIGN: Randomized patient-blinded study. SETTING: Teaching hospital. PATIENTS: A total of 334 patients rando

  7. Feasibility of a combined aerobic and strength training program and its effects on cognitive and physical function in institutionalized dementia patients. A pilot study

    NARCIS (Netherlands)

    Bossers, Willem J R; Scherder, Erik J A; Boersma, Froukje; Hortobágyi, Tibor; van der Woude, Lucas H V; van Heuvelen, Marieke J G

    2014-01-01

    Objectives: We examined the feasibility of a combined aerobic and strength training program in institutionalized dementia patients and studied the effects on cognitive and physical function. Methods: Thirty-three patients with dementia, recruited from one nursing home, participated in this non-rando

  8. Infant Formula Supplementation With Long-chain Polyunsaturated Fatty Acids Has No Effect on Bayley Developmental Scores at 18 Months of Age-IPD Meta-analysis of 4 Large Clinical Trials

    NARCIS (Netherlands)

    Beyerlein, Andreas; Hadders-Algra, Mijna; Kennedy, Katherine; Fewtrell, Mary; Singhal, Atul; Rosenfeld, Eva; Lucas, Alan; Bouwstra, Hylco; Koletzko, Berthold; von Kries, Ruediger

    2010-01-01

    Objectives: To find out whether supplementation of formula milk by long-chain polyunsaturated fatty acids (LCPUFA) affects neurodevelopment at 18 months of age in term or preterm infants by an individual patient data (IPD) meta-analysis. Materials and Methods: Data of 870 children from 4 large rando

  9. Evaluation of yield and quality of photoperiod sensitive sorghum and sorghum sudangrass

    Science.gov (United States)

    A 2-year study was conducted at 2 sites (Hancock, Marshfield) in central Wisconsin to assess yield and quality of photoperiod sensitive (PS) and non-PS sorghums in relation to corn planted on 2 dates and harvested once or twice. At each site, treatments were arranged as a split-split plot in a rando...

  10. Interventional radiology simulation and measurement of patient doses; Simulacion en radiologia intervencionista y medida de dosis a pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz Lablanca, M. d.; Diaz Romero, F.; Hernandez Armas, J.

    2011-07-01

    In this paper we propose a method of work to calculate the effective dose in any interventional radiology procedure using an Alderson Rando anthropomorphic phantom and dosimeters TLD 100 chip. We applied this method in the case of biliary drainage and allowed us to establish the dose value corresponding reference in the Hospital Universitario de Canarias (HUC).

  11. Improviseeritud lugu ja zhanriga mäng / Donald Tomberg

    Index Scriptorium Estoniae

    Tomberg, Donald

    2003-01-01

    Eesti komöödiafilm "Vanad ja kobedad saavad jalad alla" : režissöör Rando Pettai : operaator Mait Mäekivi : näitlejad Henrik Normann, Madis Milling, Robert Gutman jt. : muusika - ansambel Genialistid : Ruut Pictures 2003

  12. Randomised Comparison of Costs and Cost-Effectiveness of Cryostripping and Endovenous Laser Ablation for Varicose Veins : 2-Year Results

    NARCIS (Netherlands)

    Disselhoff, B. C. V. M.; Buskens, E.; Kelder, J. C.; Kinderen, D. J. der; Moll, F. L.

    2009-01-01

    Background: Although endovenous laser ablation for varicose veins is replacing surgical stripping, proper economic evaluation with adequate follow-up in a randomised clinical trial is important for considered policy decisions regarding the implementation of new techniques. Methods: Data from a rando

  13. SU-F-BRE-04: Construction of 3D Printed Patient Specific Phantoms for Dosimetric Verification Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ehler, E; Higgins, P; Dusenbery, K [University of Minnesota, Minneapolis, MN (United States)

    2014-06-15

    Purpose: To validate a method to create per patient phantoms for dosimetric verification measurements. Methods: Using a RANDO phantom as a substitute for an actual patient, a model of the external features of the head and neck region of the phantom was created. A phantom was used instead of a human for two reasons: to allow for dosimetric measurements that would not be possible in-vivo and to avoid patient privacy issues. Using acrylonitrile butadiene styrene thermoplastic as the building material, a hollow replica was created using the 3D printer filled with a custom tissue equivalent mixture of paraffin wax, magnesium oxide, and calcium carbonate. A traditional parallel-opposed head and neck plan was constructed. Measurements were performed with thermoluminescent dosimeters in both the RANDO phantom and in the 3D printed phantom. Calculated and measured dose was compared at 17 points phantoms including regions in high and low dose regions and at the field edges. On-board cone beam CT was used to localize both phantoms within 1mm and 1° prior to radiation. Results: The maximum difference in calculated dose between phantoms was 1.8% of the planned dose (180 cGy). The mean difference between calculated and measured dose in the anthropomorphic phantom and the 3D printed phantom was 1.9% ± 2.8% and −0.1% ± 4.9%, respectively. The difference between measured and calculated dose was determined in the RANDO and 3D printed phantoms. The differences between measured and calculated dose in each respective phantom was within 2% for 12 of 17 points. The overlap of the RANDO and 3D printed phantom was 0.956 (Jaccard Index). Conclusion: A custom phantom was created using a 3D printer. Dosimetric calculations and measurements showed good agreement between the dose in the RANDO phantom (patient substitute) and the 3D printed phantom.

  14. Hypothyroidism in coronary heart disease and its relation to selected risk factors

    Directory of Open Access Journals (Sweden)

    Otto Mayer Jr

    2006-12-01

    Full Text Available Otto Mayer Jr1, Jaroslav Šimon1, Jan Filipovský1, Markéta Plášková2, Richard Pikner11Center of Preventive Cardiology, 2nd Department of Internal Medicine, Charles University, Medical Faculty, Plze , Czech Republic; 2Department of Preventive Cardiology, Institute for Clinical and Experimental Medicine, Prague, Czech RepublicIntroduction: Hypothyroidism (HT has been found a predictor of cardiovascular diseases. We aimed to ascertain the prevalence of HT in patients with manifest coronary heart disease (CHD, and to establish its association with conventional risk factors.Methods: 410 patients, 6–24 months after hospitalization for acute coronary syndrome, and/or revascularization, were included into the cross-sectional study.Results: The prevalence of thyroid dysfunction was found in males and females as follows: overt HT, ie, thyroid stimulating hormone (TSH > 3.65 mIU/L and free thyroxine (fT4 < 9 pmol/L and/or L-thyroxine substitution, in 2.6% and 8.4%, respectively; subclinical HT (TSH >3.65, fT4 9–23 and no substitution in 4.3% and 15.0%, respectively. Higher prevalence of HT was found in females with hypercholesterolemia, and in males and females with concomitant positive thyroid peroxydase antibodies. Hypothyroid subjects had higher total homocysteine in both genders and von Willebrand factor in males only. Hypothyroid females had higher total  and LDL cholesterol, and were more often treated for diabetes.Conclusions: HT was found highly prevalent in patient with clinical coronary heart disease, mainly in females, and was associated with several cardiovascular risk factors.Keywords: hypothyroidism, coronary heart disease, cholesterol, homocysteine, diabetes

  15. Tomodensitometry images: integration in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dessy, F.; Hoornaert, M.T. [Jolimont Hospital, Haine Saint Paul (France). Cancer and Nuclear Medicine Dept.; Malchair, F. [Biomed Engineering, Boncelles (France)

    1995-12-01

    With a view to utilization of CT scan images in radiotherapy, the effective energy and the linearity of four different scanners (Siemens somatom CR, HiQS, Plus and Picker PQ 2000) and two non standard scanners, simulators with CT option (Webb 1990) (Varian Ximatron and Oldelft Simulx CT) has been measured using the method described by White and Speller in 1980. When the linearity relation in presented using the density or the electron density as the abscissa, a blurred area where two different components of equal density or electron density can have two different Hounsfield`s numbers. Using the linearity relation, the density of Rando`s lung heterogeneity is determined. We calculated a treatment planning (TP) using this value and made a comparison between the TP and the real absorbed dose with was measured using diodes. The comparison between the TP and the relative Absorbed doses showed a difference of up to 4.5%.

  16. Uus-Maailma uued kortermajad

    Index Scriptorium Estoniae

    2008-01-01

    Korter endises büroohoones Luha 16 - rekonstrueerimisprojekt Tormi Sooväljalt, korter uues galeriimajas Koidu 60-62/ Komeedi 14 - arhitektid Rein Murula ja Karl Koosa (Rein Murula Arhitektuuribüroo OÜ) ja korter uues büroo- ja kortermajas Villardi 22 - Humana Grupp Arhitektuuri- ja Inseneribüroolt. Kommenteerivad arhitektid Peeter Tambu ja Eve Arpo ning kinnisvara maakler Rando Vanaveski

  17. Differences in gene expression of granulosa cells from women undergoing controlled ovarian hyperstimulation with either recombinant follicle-stimulating hormone or highly purified human menopausal gonadotropin

    DEFF Research Database (Denmark)

    Grøndahl, Marie Louise; Borup, Rehannah; Lee, Young Bae

    2009-01-01

    OBJECTIVE: To investigate the differences in the gene expression profile of granulosa cells from preovulatory follicles after controlled ovarian hyperstimulation (COH) with recombinant follicle-stimulating hormone (FSH) or urinary human menopausal gonadotropin (hMG) FSH. DESIGN: Prospective rando...... be important for periovulatory events, which suggests that the preparation used for COH is important for granulosa cell function and may influence the developmental competence of the oocyte and the function of corpus luteum....

  18. The Fermi Large Area Telescope on Orbit: Event Classification, Instrument Response Functions, and Calibration

    Science.gov (United States)

    2012-11-01

    Technology (KTH), AlbaNova, SE-106 91 Stockholm, Sweden 8 Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy...France 10 Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste, Italy 11 Dipartimento di Fisica , Università di Trieste, I-34127...Trieste, Italy 12 Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova, Italy; rando@pd.infn.it 13 Dipartimento di Fisica e

  19. Quantifying the impact of between-study heterogeneity in multivariate meta-analyses

    OpenAIRE

    Jackson, Dan; White, Ian R; Riley, Richard D.

    2012-01-01

    Measures that quantify the impact of heterogeneity in univariate meta-analysis, including the very popular I 2 statistic, are now well established. Multivariate meta-analysis, where studies provide multiple outcomes that are pooled in a single analysis, is also becoming more commonly used. The question of how to quantify heterogeneity in the multivariate setting is therefore raised. It is the univariate R 2 statistic, the ratio of the variance of the estimated treatment effect under the rando...

  20. Dung-beetles (Coleoptera: Scarabeidae) from the Zona Protectora Las Tablas, Talamanca, Costa Rica

    OpenAIRE

    Mata-Lorenzen, J.; González-Maya, J. F.

    2008-01-01

    Dung-beetle species are considered an important focal indicator group in tropical forests. During 2007,eighteen traps were set in two permanent biodiversity plots during one week surveys in Las Tablas Protected Zonewithin La Amistad Biosphere Reserve. The main purpose of this study was to determine the group composition anddiversity as the basis for permanent monitoring and to measure potential impacts of land use change and climate changeon mountain diversity. Pitfall traps were placed rando...

  1. Association of Human Papilloma Virus 16 Infection and p53 Polymorphism among Tobacco using Oral Leukoplakia Patients: A Clinicopathologic and Genotypic Study

    OpenAIRE

    Seema Sikka; Pranav Sikka

    2014-01-01

    Background: Human papillomavirus (HPV) and p53 alterations are speculated to play a role in carcinogenesis. This study was carried out to find out the association of HPV and p53 with precancerous lesions of the oral cavity such as leukoplakia: The objective of this study was to find the association among human papilloma virus (HPV) 16 infections and p53 polymorphism in tobacco using the oral leukoplakia patients. Methods: A total of 91 oral leukoplakia patients and 100 controls were rando...

  2. Development of anthropomorphic hand phantoms for personal dosimetry in 90Y-Zevalin preparation and patient delivering.

    Science.gov (United States)

    Ciolini, R; d'Errico, F; Traino, A C; Paternostro, E; Laganà, A; Romei, C; Pazzagli, F; Del Gratta, A

    2014-01-01

    Anthropomorphic tissue-equivalent hand phantoms were achieved to measure the extremity dose involved in Zevalin (90)Y-labelling and patient delivering procedure for radioimmunotherapy treatment of non-Hodgkin lymphoma. The extremity doses to hands and wrists of operators were measured by using thermoluminescent detectors mounted on the developed phantoms. Measurements of chest- and lens-equivalent doses performed on a Rando phantom are also reported.

  3. Satellite Cell Functional Alterations Following Cutaneous Burn in rats Include an Increase in Their Osteogenic Potential

    Science.gov (United States)

    2013-10-07

    skeletal muscle hypertrophy and atrophy. Nat Cell Biol 2003;5:87. [6] Brack AS, Rando TA. Intrinsic changes and extrinsic influences of myogenic stem...Skeletal muscle Muscle precursor cell Thermal injury Atrophy Heterotopic ossification a b s t r a c t Background: Significant consequences of severe burn...include skeletal muscle atrophy and heterotopic ossification (HO). The cellular mechanisms underlying either of these condi- tions are not known

  4. Prevalence of self-reported diagnosis of diabetes mellitus and associated risk factors in a national survey in the US population: SHIELD (Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes)

    OpenAIRE

    Reed Michael L; Lewis Sandra J; Green Andrew J; Gavin James R; Clark Nathaniel G; Bazata Debbra D; Bays Harold E; Stewart Walter; Chapman Richard H; Fox Kathleen M; Grandy Susan

    2007-01-01

    Abstract Background Studies derived from continuous national surveys have shown that the prevalence of diagnosed diabetes mellitus in the US is increasing. This study estimated the prevalence in 2004 of self-reported diagnosis of diabetes and other conditions in a community-based population, using data from the Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD). Methods The initial screening questionnaire was mailed in 2004 to a stratified rando...

  5. Relationships between academic performance, SES school type and perceptual-motor skills in first grade South African learners: NW-CHILD study

    OpenAIRE

    Pienaar, A.E.; Barhorst, R.; Twisk, J. W. R.

    2013-01-01

    Background Perceptual-motor skills contribute to a variety of basic learning skills associated with normal academic success. This study aimed to determine the relationship between academic performance and perceptual-motor skills in first grade South African learners and whether low SES (socio-economic status) school type plays a role in such a relationship. Methods This cross-sectional study of the baseline measurements of the NW-CHILD longitudinal study included a stratified rando...

  6. Uus-Maailma uued kortermajad

    Index Scriptorium Estoniae

    2008-01-01

    Korter endises büroohoones Luha 16 - rekonstrueerimisprojekt Tormi Sooväljalt, korter uues galeriimajas Koidu 60-62/ Komeedi 14 - arhitektid Rein Murula ja Karl Koosa (Rein Murula Arhitektuuribüroo OÜ) ja korter uues büroo- ja kortermajas Villardi 22 - Humana Grupp Arhitektuuri- ja Inseneribüroolt. Kommenteerivad arhitektid Peeter Tambu ja Eve Arpo ning kinnisvara maakler Rando Vanaveski

  7. SU-C-213-05: Evaluation of a Composite Copper-Plastic Material for a 3D Printed Radiation Therapy Bolus

    Energy Technology Data Exchange (ETDEWEB)

    Vitzthum, L; Ehler, E; Sterling, D; Reynolds, T; Higgins, P; Dusenbery, K [University of Minnesota, Minneapolis, MN (United States)

    2015-06-15

    Purpose: To evaluate a novel 3D printed bolus fabricated from a copper-plastic composite as a thin flexible, custom fitting device that can replicate doses achieved with conventional bolus techniques. Methods: Two models of bolus were created on a 3D printer using a composite copper-PLA/PHA. Firstly, boluses were constructed at thicknesses of 0.4, 0.6 and 0.8 mm. Relative dose measurements were performed under the bolus with an Attix Chamber as well as with radiochromic film. Results were compared to superficial Attix Chamber measurements in a water equivalent material to determine the dosimetric water equivalence of the copper-PLA/PHA plastic. Secondly, CT images of a RANDO phantom were used to create a custom fitting bolus across the anterolateral scalp. Surface dose with the bolus placed on the RANDO phantom was measured with radiochromic film at tangential angles with 6, 10, 10 flattening filter free (FFF) and 18 MV photon beams. Results: Mean surface doses for 6, 10, 10FFF and 18 MV were measured as a percent of Dmax for the flat bolus devices of each thickness. The 0.4 mm thickness bolus was determined to be near equivalent to 2.5 mm depth in water for all four energies. Surface doses ranged from 59–63% without bolus and 85–90% with the custom 0.4 mm copper-plastic bolus relative to the prescribed dose for an oblique tangential beam arrangement on the RANDO phantom. Conclusion: Sub-millimeter thickness, 3D printed composite copper-PLA/PHA bolus can provide a build-up effect equivalent to conventional bolus. At this thickness, the 3D printed bolus allows a level of flexure that may provide more patient comfort than current 3D printing materials used in bolus fabrication while still retaining the CT based custom patient shape. Funding provided by an intra-department grant of the University of Minnesota Department of Radiation Oncology.

  8. Evaluation of the reconstruction of image acquired from CT simulator to reduce metal artifact

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Hun; Park, Jin Hong; Choi, Byung Don; Won, Hui Su; Chang, Nam Jun; Goo, Jang Hyun; Hong, Joo Wan [Dept. of Radiation Oncology, Seoul national university bundang hospital, Sungnam (Korea, Republic of)

    2014-12-15

    This study presents the usefulness assessment of metal artifact reduction for orthopedic implants(O-MAR) to decrease metal artifacts from materials with high density when acquired CT images. By CT simulator, original CT images were acquired from Gammex and Rando phantom and those phantoms inserted with high density materials were scanned for other CT images with metal artifacts and then O-MAR was applied to those images, respectively. To evaluate CT images using Gammex phantom, 5 regions of interest(ROIs) were placed at 5 organs and 3 ROIs were set up at points affected by artifacts. The averages of standard deviation(SD) and CT numbers were compared with a plan using original image. For assessment of variations in dose of tissue around materials with high density, the volume of a cylindrical shape was designed at 3 places in images acquired from Rando phantom by Eclipse. With 6 MV, 7-fields, 15x15cm{sup 2} and 100 cGy per fraction, treatment planning was created and the mean dose were compared with a plan using original image. In the test with the Gammex phantom, CT numbers had a few difference at established points and especially 3 points affected by artifacts had most of the same figures. In the case of O-MAR image, the more reduction in SD appeared at all of 8 points than non O-MAR image. In the test using the Rando Phantom, the variations in dose of tissue around high density materials had a few difference between original CT image and CT image with O-MAR. The CT images using O-MAR were acquired clearly at the boundary of tissue around high density materials and applying O-MAR was useful for correcting CT numbers.

  9. The Fricke Xylenol Gel (FXG) dosimetry in the mycosis fungoides radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zaias, Herofen; Petchevist, Paulo C.D.; Parada, Marco A.; Almeida, Adelaide de; Costa, Alessandro M. da [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica]. E-mail: dalmeida@ffclrp.usp.br; Rocha, Jose Renato de Oliveira [Universidade Estadual de Campinas, SP (Brazil). Centro de Engenharia Biomedica]. E-mail: renato@ceb.unicamp.br

    2005-07-01

    We used chemical dosimetry with the Fricke Xylenol Gel (FXG) dosimeter to verify the dose distribution in an electron therapy of mycosis fungoides. Anatomically shaped phantoms were developed and filled with the FXG. The phantoms were inserted in a Rando anthropomorphic phantom and submitted to the Stanford irradiation technique with a 6 MeV electron beam. The absorbances of the FXG after the irradiation were measured with a special FXG reader developed for this purpose. The preliminary results show that the FXG dosimetry system is a promising dosimetry technique. (author)

  10. Defining the optimal biological monotherapy in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Tarp, Simon; Furst, Daniel E; Dossing, Anna;

    2017-01-01

    OBJECTIVES: To summarize and compare the benefits and harms of biological agents used as monotherapy for rheumatoid arthritis (RA) in order to inform decisions for patients who are intolerant to conventional DMARD therapy. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and other sources for rando......OBJECTIVES: To summarize and compare the benefits and harms of biological agents used as monotherapy for rheumatoid arthritis (RA) in order to inform decisions for patients who are intolerant to conventional DMARD therapy. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and other sources...

  11. Nonlinearities with Non-Gaussian Inputs.

    Science.gov (United States)

    1978-03-01

    possessing a spectral density function . a constant. Then Jet arc tan [G(t)J be the input. By Theorem 3 this input is not bandlimited; and if The rando...such that the absolute ,,~~ovalue of any point in the spectrum is less than N. If the Gaussian process X(t) possesses a H ~ ) spectral density function (i.e...Gaussian process and th. series ii convergent pointvise as veil X(t ) possesses a spectral density function . as in an sense (51. Let z~( ) and g2

  12. OPTIMIZACIÓN DE LOS PROTOCOLOS DE EXTRACCIÓN DE ADN Y DEL MARCADOR MOLECULAR TIPO RAPD EN ANONÁCEAS

    OpenAIRE

    Yanet Alfonso Alonso; Caridad Noriega Carrera; Miriam Isidrón Pérez; Lucy Andraca Collazo; Dubiel Alfonso González; Daymara Rodríguez Alfonso

    2016-01-01

    Las técnicas moleculares requieren de protocolos que permitan determinar los niveles de variación genética, dentro de las poblaciones en diferentes condiciones ambientales. Tanto la optimización del aislamiento del ADN, como el de las condiciones de trabajo de las amplificaciones, son fundamentales para alcanzar el éxito de los análisis moleculares, por lo que la presente investigación tiene como objetivo: optimizar los protocolos de extracción de ADN y del marcador molecular tipo RAPD (Rando...

  13. PLACO CHARLES DE GAULLE

    Institute of Scientific and Technical Information of China (English)

    J.H.Rosbach

    1996-01-01

    Fervorpae supreniris la avenuon deChamps Elysees. La celo estis la Triumfarkokaj la Tombo de la Nekonata Soldato.Centon da metroj antaǚ Plato Charles deGaulle mi transiris la avenuon.Mi haltis e la rando de la ronda placo,ob-servante la teruran trafikon. Centoj da aǚtoj,miloj da aǚtoj aperis maldekstre de mi, preter-fulmis, kuris ien, elektante diversajn avenuojnpot eliri el la placo. Estis la sama viglo kiel en

  14. Bone marrow dose in chest radiography: the posteroanterior vs. anteroposterior projection

    Energy Technology Data Exchange (ETDEWEB)

    Archer, B.R.; Whitmore, R.C.; North, L.B.; Bushong, S.C.

    1979-10-01

    The dose to active bone marrow resulting from anteroposterior (AP) and posteroanterior (PA) chest examinations was estimated using an Alderson Rando phantom and extruded lithium fluoride dosimeters. The AP projections resulted in a mean marrow dose range of 1.9 to 2.6 mrad (0.019 to 0.026 mGy) as compared to doses for PA projections of 3.4 to 3.8 mrad (0.034 to 0.038 mGy) for optimally diagnostic exposures taken at 70, 90, and 120 kVp.

  15. No association between level of vitamin D and chronic low back pain in Swedish primary care: a cross-sectional case-control study

    OpenAIRE

    Thörneby, Andreas; Nordeman, Lena Margareta; Johanson, Else Hellebö

    2016-01-01

    Objective Assessment of vitamin D levels and deficiency status in individuals with chronic low back pain (CLBP) in a Swedish general population, compared with controls matched for sex and age. Design Cross-sectional case-control study. Setting Primary care, southern Sweden. Subjects Participants (n = 44) with self-reported low back pain for at least 3 months and individually sex- and age-matched controls without a chronic pain condition (n = 44), recruited from the general population by rando...

  16. Probability theory

    CERN Document Server

    S Varadhan, S R

    2001-01-01

    This volume presents topics in probability theory covered during a first-year graduate course given at the Courant Institute of Mathematical Sciences. The necessary background material in measure theory is developed, including the standard topics, such as extension theorem, construction of measures, integration, product spaces, Radon-Nikodym theorem, and conditional expectation. In the first part of the book, characteristic functions are introduced, followed by the study of weak convergence of probability distributions. Then both the weak and strong limit theorems for sums of independent rando

  17. Environmental Assessment for Lowering Base Altitude of Military Operations Areas

    Science.gov (United States)

    2010-11-01

    The recording is updated when there is a significant change in the information. It is given a letter designation (e.g. bravo ). When contacting...21 0) 652-1962 Electronic Mail ramo ;!l.flores@lau~in.af.mill .Jlatriciasalas@randoluh.af.mil -- Rallldolph AFB Nru:urt Mr. Mathew Kr~ Ms. Patricia...Rando!Qh AFB TX 78150-4319 Telephone Number (830) 298-5694 (21 0) 652-1962 Electronic Mail ramo ;!l.flores@lau~in.af.mill .Jlatriciasalas@randoluh.af.mil

  18. LongoVital i forebyggelsen af recidiverende aftøs stomatit. 1

    DEFF Research Database (Denmark)

    Pedersen, A; Hougen, H P; Klausen, B

    1991-01-01

    LongoVital (LV) (DK. reg. no. 5178/75) is a herbal based tablet enriched with recommended doses of vitamins. The present study was undertaken to investigate prevention of recurrent aphthous ulceration (RAU) during daily intake of LV for six months as compared with placebo in a double-blind, rando......LongoVital (LV) (DK. reg. no. 5178/75) is a herbal based tablet enriched with recommended doses of vitamins. The present study was undertaken to investigate prevention of recurrent aphthous ulceration (RAU) during daily intake of LV for six months as compared with placebo in a double...

  19. Experimental method for calculation of effective doses in interventional radiology; Metodo experimental para calculo de dosis efectivas en radiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz Lblanca, M. D.; Diaz Romero, F.; Casares Magaz, O.; Garrido Breton, C.; Catalan Acosta, A.; Hernandez Armas, J.

    2013-07-01

    This paper proposes a method that allows you to calculate the effective dose in any interventional radiology procedure using an anthropomorphic mannequin Alderson RANDO and dosimeters TLD 100 chip. This method has been applied to an angio Radiology procedure: the biliary drainage. The objectives that have been proposed are: to) put together a method that, on an experimental basis, allows to know dosis en organs to calculate effective dose in complex procedures and b) apply the method to the calculation of the effective dose of biliary drainage. (Author)

  20. User’s Guide for the SAS (Stand-Off Attack Simulation) Computer Model.

    Science.gov (United States)

    1982-01-15

    69 7f, 71 7? so 81 * 1he firsr target qrouv corresponds to all weapon targets. * * , otice ttqt t~e final tarjet numbers are used when specifling the...NTrwiE Sroup ornzaciities fir all times of interest nave been foune (for :!?)FST -estroyed tarjets ). Write tne-p and find - ,irojo orotanillries for...corner of the fixed * tariet area rejAtive to tne oriitn in the target reference plane. If a * rando tarJet area 4as destred, vmljes for XTCTR and YTCTR

  1. Study about quantification and classification of biological tissues in tomographic images from histograms; Estudo sobre quantificacao e classificacao dos tecidos biologicos em imagens tomograficas a partir de histogramas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Rafael T.F.; Lemke, Ney; Hormaza, Joel Mesa; Alvarez, Matheus, E-mail: rafael@ibb.unesp.b [Universidade Estadual Paulista Julio de Mesquisa Filho (DFB/IB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica; Pina, Diana R.; Teixeira, Altamir S. [Universidade Estadual Paulista Julio de Mesquisa Filho (HC/FM/UNESP), Botucatu, SP (Brazil). Hospital de Clinicas. Dept. de Doencas Tropicais e Diagnostico por Imagem

    2010-06-15

    An algorithm for determining the equivalent thickness of biological tissue by the removal of Gaussian from the histograms was proposed. This algorithm classifies the different biological tissues using histograms, constructed from CT scans in DICOM format and calculates the average thickness of these tissues. The founded results show to be coherent with literature, with discrepancies of up to 21.6% on the bone, and analyzed for the anthropomorphic phantom (RANDO). These results allow the use of this method in living tissues for the construction of chest homogeneous phantoms of newborn and suckling patients, which are subsequently used in the optimization process of pediatric radiographic images. (author)

  2. Nadala pilt

    Index Scriptorium Estoniae

    2005-01-01

    Eesti Meestelaulu Seltsi poiste-solistide Järvamaa konkursi maakondlikust voorust pääsesid piirkondlikku vooru noored lauljad: kuni 7aastased - Rando Haljaste (Türi, juhendaja Helle Laanemets), 8-9aastased - Kaarel Orumägi (Türi, Helle Maalmann), Silver Samun - (Türi vald, Virve Kaljula), 10-11aastased - Sten Paal ja Mattias Simson (mõlemad Türi, Tea Saar) ja Indrek Oidekivi (Türi, Tiiu Schüts), 12aastased - Rene Liivo ja Mikk Dede (mõlemad Türi, Tiiu Schüts)

  3. Feasibility of intrafraction whole-body motion tracking for total marrow irradiation

    Science.gov (United States)

    Sharma, Manju; Santos, Troy Dos; Papanikolopoulos, Nikolaos P.; Hui, Susanta Kumar

    2011-05-01

    With image-guided tomotherapy, highly targeted total marrow irradiation (TMI) has become a feasible alternative to conventional total body irradiation. The uncertainties in patient localization and intrafraction motion of the whole body during hour-long TMI treatment may pose a risk to the safety and accuracy of targeted radiation treatment. The feasibility of near-infrared markers and optical tracking system (OTS) is accessed along with a megavoltage scanning system of tomotherapy. Three near-infrared markers placed on the face of a rando phantom are used to evaluate the capability of OTS in measuring changes in the markers' positions as the rando is moved in the translational direction. The OTS is also employed to determine breathing motion related changes in the position of 16 markers placed on the chest surface of human volunteers. The maximum uncertainty in locating marker position with the OTS is 1.5 mm. In the case of normal and deep breathing motion, the maximum marker position change is observed in anterior-posterior direction with the respective values of 4 and 12 mm. The OTS is able to measure surface changes due to breathing motion. The OTS may be optimized to monitor whole body motion during TMI to increase the accuracy of treatment delivery and reduce the radiation dose to the lungs.

  4. Evaluation of 3D pre-treatment verification for volumetric modulated arc therapy plan in head region

    Science.gov (United States)

    Ruangchan, S.; Oonsiri, S.; Suriyapee, S.

    2016-03-01

    The development of pre-treatment QA tools contributes to the three dimension (3D) dose verification using the calculation software with the measured planar dose distribution. This research is aimed to evaluate the Sun Nuclear 3DVH software with Thermo luminescence dosimeter (TLD) measurement. The two VMAT patient plans (2.5 arcs) of 6 MV photons with different PTV locations were transferred to the Rando phantom images. The PTV of the first plan located in homogeneous area and vice versa in the second plan. For treatment planning process, the Rando phantom images were employed in optimization and calculation with the PTV, brain stem, lens and TLD position contouring. The verification plans were created, transferred to the ArcCHECK for measurement and calculated the 3D dose using 3DVH software. The range of the percent dose differences in both PTV and organ at risk (OAR) between TLD and 3DVH software of the first and the second plans were -2.09 to 3.87% and -1.39 to 6.88%, respectively. The mean percent dose differences for the PTV were 1.62% and 3.93% for the first and the second plans, respectively. In conclusion, the 3DVH software results show good agreement with TLD when the tumor located in the homogeneous area.

  5. A customized bolus produced using a 3-dimensional printer for radiotherapy.

    Science.gov (United States)

    Kim, Shin-Wook; Shin, Hun-Joo; Kay, Chul Seung; Son, Seok Hyun

    2014-01-01

    Boluses are used in high-energy radiotherapy in order to overcome the skin sparing effect. In practice though, commonly used flat boluses fail to make a perfect contact with the irregular surface of the patient's skin, resulting in air gaps. Hence, we fabricated a customized bolus using a 3-dimensional (3D) printer and evaluated its feasibility for radiotherapy. We designed two kinds of bolus for production on a 3D printer, one of which was the 3D printed flat bolus for the Blue water phantom and the other was a 3D printed customized bolus for the RANDO phantom. The 3D printed flat bolus was fabricated to verify its physical quality. The resulting 3D printed flat bolus was evaluated by assessing dosimetric parameters such as D1.5 cm, D5 cm, and D10 cm. The 3D printed customized bolus was then fabricated, and its quality and clinical feasibility were evaluated by visual inspection and by assessing dosimetric parameters such as Dmax, Dmin, Dmean, D90%, and V90%. The dosimetric parameters of the resulting 3D printed flat bolus showed that it was a useful dose escalating material, equivalent to a commercially available flat bolus. Analysis of the dosimetric parameters of the 3D printed customized bolus demonstrated that it is provided good dose escalation and good contact with the irregular surface of the RANDO phantom. A customized bolus produced using a 3D printer could potentially replace commercially available flat boluses.

  6. Radiation dose in computed tomography of the pelvis: comparison of helical and axial scanning.

    Science.gov (United States)

    Pitman, A G; Budd, R S; McKenzie, A F

    1997-11-01

    An anthropomorphic Rando phantom was used to compare radiation doses sustained during helical and conventional axial CT of the pelvis. The values obtained with the Rando phantom were validated against cadaveric phantoms, and show good agreement. For the authors' particular CT unit, helical scanning was found to deliver a lower radiation dose than conventional axial scanning. This was most prominent at 1.0-s tube rotation times (average dose ratio 1.24). For realistic scanning parameters and exposure factors, the ratio of radiation dose to pelvic organs can be expected to lie in the range of 40-100 mGy. The whole-body effective dose (ED) depends on selection of scanning parameters and patients anatomy. In a favourable case scenario, the ED for CT scanning of the pelvis in a male can be expected to be between 10 and 20 mSv if the scrotum is not included in the radiation field, while the ED in a female will be approximately 20 mSv. An examination of scatter radiation fall-off curves from a single slice shows that the spread of scatter radiation is only marginally affected by slice thickness. A total of 10-12 cm of human soft tissue acts as a good barrier against internal scattered radiation. The use of such scatter fall-off curves, together with manufacturers' dosimetry specifications, allows a fast estimate of absorbed dose.

  7. Importance of CBCT setup verification for optical-guided frameless radiosurgery.

    Science.gov (United States)

    Fu, Lei; Perera, Harold; Ying, Xiao; Yu, Yan

    2014-05-08

    The purpose of this study is to quantify the discrepancy between optical guidance platform (OGP) frameless localization system (Varian) and Trilogy on-board imaging (OBI) system (Varian) for setting up phantom and stereotactic radiosurgery (SRS) patient; and to determine whether cone-beam CT (CBCT) is necessary for OGP patient setup, and compare CBCT and orthogonal kV-kV in term of their verification capability. Three different phantoms were used in the study: a custom-made phantom, a Penta-Guide phantom, and a RANDO phantom. Five patients using both OGP and CBCT setup and 14 patients using CBCT setup alone were analyzed. One patient who had big couch shifts discrepancy between OGP and CBCT was selected for further investigation. Same patient's CBCT and planning CT were fused. A RANDO phantom simulation experiment was performed using OGP setup with both CBCT and orthogonal kV-kV verification. For all of three phantom experiments, the shifts performed by CBCT beam and orthogonal kV-kV were all within 1 mm. Among five SRS patients using OGP setup, three had 3D couch corrections more than 3 mm. The image fusion of CBCT and planning CT clearly illustrated a tilt of bite-block in a patient's mouth. For 14 SRS patients using CBCT-guided setup, overall 3D correction was 3.3 ± 1.5 mm. RANDO phantom experiment demonstrated how a tilted bite-block caused isocenter shift. CBCT-calculated shifts are the same as expected, but kV-kV results differed by 1-2 mm if the initial head position is tilted. The bite-block tilting in patient's mouth is a major reason for the cause of positioning error for OGP frameless SRS setup. CBCT verification is necessary. CBCT provides more accurate couch corrections than orthogonal kV-kV when head was tilted. OGP is useful for detecting patient movement, but it does not necessarily imply that the isocenter has moved.

  8. Application of GEANT4 radiation transport toolkit to dose calculations in anthropomorphic phantoms

    CERN Document Server

    Rodrigues, P; Peralta, L; Alves, C; Chaves, A; Lopes, M C

    2003-01-01

    In this paper we present the implementation of a dose calculation application, based on the GEANT4 Monte Carlo toolkit. Validation studies were performed with an homogeneous water phantom and an Alderson--Rando anthropomorphic phantom both irradiated with high--energy photon beams produced by a clinical linear accelerator. As input, this tool requires computer tomography images for automatic codification of voxel based geometries and phase space distributions to characterize the incident radiation field. Simulation results were compared with ionization chamber, thermoluminescent dosimetry data and commercial treatment planning system calculations. In homogeneous water phantom, overall agreement with measurements were within 1--2%. For anthropomorphic simulated setups (thorax and head irradiation) mean differences between GEANT4 and TLD measurements were less than 2%. Significant differences between GEANT4 and a semi--analytical algorithm implemented in the treatment planning system, were found in low density ...

  9. The Principle of Digital Subtraction Angiography and Radiological Protection

    Science.gov (United States)

    Okamoto, K.; Ito, J.; Sakai, K.; Yoshimura, S.

    2000-01-01

    Summary Recent improvements in x-ray technology have greatly contributed to the advancement of diagnostic imaging. Fluoroscopically guided neurointerventional procedures with digital subtraction angiography (DSΛ) are being performed with increasing frequency as the treatment of choice for a variety of neurovascular diseases. Radiation-induced skin injuries can occur after extended fluoroscopic exposure times, and the injuries have recently been reported. In this article, measured radiation doses at the surface of Rando Phantom with Skin Dose Monitor, and estimated and measured entrance skin doses in patients underwent neurointerventional procedures are reported as well as means of reducing radiation doses absorbed by patients and personnel to avoid occurrence of radiation-induced injuries. PMID:20667218

  10. Comparative skin dose measurement in the treatment of anal canal cancer: conventional versus conformal therapy.

    Science.gov (United States)

    Devic, Slobodan; Hegyi, Gyorgy; Vuong, Té; Muanza, Thierry; Podgorsak, Ervin B

    2004-06-01

    The subject of this work was to compare the effect of Conventional and Conformal techniques, used for anal canal cancer treatments, on the skin dose deposition. Skin dose was measured on a Rando phantom using XR-T GAFCHROMIC film. A skin surface dose histogram was constructed and a skin dose profile in the sagittal direction of the perineal region was measured, for both techniques. The measured skin dose in the anterior and posterior region of the skin exposed to radiation is from two to ten times higher when using a conventional technique. In the perineal region, an 85% of the prescription isodose line spreads over 25% of the perineum for conformal technique as compared to 65% with conventional techniques. In addition, conformal technique dose profiles confine better the anatomical position of the anal verge than conventional techniques. Results presented in this work confirm clinically observed improvement in the radiation-induced dermatitis when using the conformal technique.

  11. Evaluation of dosimetry and image quality of computerized tomography abdomen protocols; Avaliacao de dose e qualidade da imagem em protocolos de abdomen em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Maues, Nadine H.P.B.; Alves, Allan F.F.; Bacchim Neto, Fernando A.; Pina, Diana R. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil)

    2016-07-01

    In this study, we evaluate the dosimetry and image quality of computed tomography multislice abdomen protocols for different tube current modulation techniques (ATCM). We used the 16-slice Toshiba Activion CT scanner with the 'SureExposure3D' ATCM system. Thermoluminescent dosimeters were placed inside the anthropomorphic phantom Alderson-Rando for dosimetric assessments. An analytical phantom was used for the objective evaluation of image quality. It is observed that the higher standard deviation technique (SD) has the lowest value of effective dose. The use of different tube current modulation techniques showed significant reduction of radiation doses for the abdomen exams in computed tomography. The ATCM protocols can be an excellent alternative to dose reduction in CT scans, since it does not impair the diagnostic image quality. (author)

  12. Dosimetric evaluation in teletherapy for male breast cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Nilmara Almeida; Crispim, Verginia Reis, E-mail: nguimaraes@con.ufrj.br, E-mail: verginia@nuclear.ufrj.br [Coordenacao dos Cursos de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2013-07-01

    The present study evaluated dose distribution in the male breast using thermoluminescent dosimeters (TLDs). The rate of male breast cancers has increased in recent years, due to the deficiency of preventive examinations (male mammography). Still, male breasts have smaller volumes than female breasts, thus, from the point of view of radiation protection, it is essential to monitor the doses received by the male breast, as well as those received by healthy and critical organs in order to evaluate radiotherapy performance and aid treatment planning. For this reason, the treatment of male breast cancer was simulated with the radiation by linear accelerator in Alderson Rando phantom and doses were measured with thermoluminescent dosimeters. The results of the treatment planning and measured were compared. (author)

  13. Dosimetry of patients submitted to cerebral PET/CT for the diagnosis of mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Priscila do Carmo; Oliveira, Paulo Marcio Campos de; Bernardes, Felipe Dias; Mamede, Marcelo, E-mail: pridili@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Mourao, Arnaldo Prata [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil); Silva, Teogenes Augusto da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2014-11-15

    Objective: the present study was aimed at evaluating the effective radiation dose in patients submitted to PET/CT for the diagnosis of mild cognitive impairment. Materials and methods: TLD-100 detectors inserted into an Alderson Rando® anthropomorphic phantom were utilized to measure the absorbed dose coming from the CT imaging modality. The anthropomorphic phantoms (male and female adult versions) were submitted to the same technical protocols for patients’ images acquisition. The absorbed dose resulting from the radiopharmaceutical injection was estimated by means of the model proposed by the ICRP publication 106. Results: the effective dose in patients submitted to this diagnostic technique was approximately (5.34 ± 1.99) mSv. Conclusion: optimized protocols for calculation of radioactive activity injected into patients submitted to this diagnostic technique might contribute to reduce the effective radiation dose resulting from PET/CT in the diagnosis of mild cognitive impairment. (author)

  14. Organ doses from computerized tomography examinations

    Energy Technology Data Exchange (ETDEWEB)

    Janeczek, J.

    1995-12-31

    Estimates of mean organs doses from five typical computerized tomography (CT) examinations were obtained. Measurements were done using Rando-Alderson anthropomorphic phantom and thermoluminescent dosemeters (TLD). Radiation dose distributions within a phantom has been measured for each examination and results were used for organ dose calculation. Doses to organs specified by ICPR 60 Recommendations were measured for five CT scanners (CT/T8800, CT 9800, CT MAX - made by General Electric; CT 1200 SX - made by Picker; SOMATOM 2 - made by Siemens). Dose distributions from scattered radiation were measured and indicate that scattered radiation dose to thyroid and eye lens can be reduced by proper examination limits setting. The lowest mean organ doses were obtained from CT/T8800 scanner. More advanced scanners using high intensity continuous radiation were giving higher organ doses. (author). 23 refs, 6 figs, 13 tabs.

  15. Dosimetry of patients submitted to cerebral PET/CT for the diagnosis of mild cognitive impairment.

    Science.gov (United States)

    Santana, Priscila do Carmo; Mourão, Arnaldo Prata; de Oliveira, Paulo Márcio Campos; Bernardes, Felipe Dias; Mamede, Marcelo; da Silva, Teógenes Augusto

    2014-01-01

    The present study was aimed at evaluating the effective radiation dose in patients submitted to PET/CT for the diagnosis of mild cognitive impairment. TLD-100 detectors inserted into an Alderson Rando® anthropomorphic phantom were utilized to measure the absorbed dose coming from the CT imaging modality. The anthropomorphic phantoms (male and female adult versions) were submitted to the same technical protocols for patients' images acquisition. The absorbed dose resulting from the radiopharmaceutical injection was estimated by means of the model proposed by the ICRP publication 106. The effective dose in patients submitted to this diagnostic technique was approximately (5.34 ± 1.99) mSv. Optimized protocols for calculation of radioactive activity injected into patients submitted to this diagnostic technique might contribute to reduce the effective radiation dose resulting from PET/CT in the diagnosis of mild cognitive impairment.

  16. Comparison of the Absorbed Dose of Target Organs between Conventional and Digital Panoramic Radiography

    Directory of Open Access Journals (Sweden)

    Zohre Reyhani

    2016-09-01

    Full Text Available The purpose of this study was to measure and compare target organ’s exposure by direct digital and conventional panoramic radiography. Dose measurements were carried out on a RANDO phantom, which TLDs were placed into 5 target area: thyroid gland, left and right submandibular and parotid salivary glands. Panoramic radiographs were taken with two conventional (CRANEX Tome, Soredex, Tusula Finland and direct digital devices (CRANEX D, Soredex, Tusula Finland.In total, the phantom was irradiated 30 times in the two systems. The TLDs were then coded and analyzed. T-test of statistical analysis was used to find the correlation. We found statistically significant reduction in absorbed dose of target organs in digital panoramic radiography(P<0.01. The highest absorbed dose was for submandibular gland and the lowest was for thyroid gland. We concluded that can reduce absorbed dose in vital organs.

  17. Comparison of Super Stuff and paraffin wax bolus in radiation therapy of irregular surfaces.

    Science.gov (United States)

    Humphries, S M; Boyd, K; Cornish, P; Newman, F D

    1996-01-01

    Irregular facial contours can make radiation therapy of head and neck tumors difficult. Isodose lines become skewed, making treatment planning complex. A traditional solution to this problem is the paraffin wax box bolus. Such a bolus is made to fit the irregular surface compensating for the topology and creating an even surface. The fabrication of a wax bolus can be a difficult and time-consuming process. A method that is simple and efficient has been devised. Super Stuff bolus can be easily molded and has approximately the same effect as a similar paraffin wax bolus. This was verified by irradiating a Rando head phantom with both a paraffin wax bolus and a Super Stuff bolus. Doses to various points of interest were measured with thermoluminescent dosimetry (TLD) chips (LiF). The particular case addressed is malignant melanoma of the nasal septum, but the technique described can be useful in the treatment of other sites as well.

  18. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    Science.gov (United States)

    Salleh, H.; Samat, S. B.; Matori, M. K.; Isa, M. J. M.

    2015-09-01

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

  19. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    Energy Technology Data Exchange (ETDEWEB)

    Salleh, H.; Matori, M. K.; Isa, M. J. M. [Agensi Nuklear Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Samat, S. B. [Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

  20. Isolation, purification and characterization of a novel glucose oxidase from Penicillium sp. CBS 120262 optimally active at neutral pH

    CSIR Research Space (South Africa)

    Simpson, C

    2007-02-01

    Full Text Available .51 Two bands at 4.3 and 4.67 5–6 4–6 4.5–6.5 6–8 ND ND 40–50 25–30 ND 6.2 5.2 18.4 [8] [9] [25] Present work strains were reported to contain more than one isoenzyme of GOX, these being, A. niger (Sigma type VII) and P. amagasakiense (ATCC 28686... Penicillium chrysogenum, J. Chromatogr. 397 (1987) 239–249. [8] D. Rando, G-W. Kohring, F. GiVhorn, Production puriWcation and characterization of glucose oxidase from a newly isolated strain of Penicillium pinophilum, Appl. Microbiol. Biotechnol. 48...

  1. Dose Evaluation and Quality Criteria in Dental Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Gori, C.; Rossi, F.; Stecco, A.; Villari, N.; Zatelli, G

    2000-07-01

    Radioprotection in dental radiology is of particular interest in the framework of the Revised Medical Exposure Directive for the great number of examinations involving the adult as well as the paediatric population (Article 9: Special Practice). The present study is intended to find the quality criteria of orthodontic imaging and for evaluating the dose absorbed within the dental and maxillary volume in connection with radiological examinations performed with either spiral CT, dental panoramic tomography or teleradiography. The X ray dose to organs sited in the body, neck, ocular and intracranial area was measured using lithium fluoride dosemeters, positioned in a Rando phantom. Quality criteria have been established by an expert radiologist considering the diagnostic information obtained in the images. The dosimetric data obtained were comparable with other authors', although with some differences due to technical characteristics. These result data are useful for choosing the patient's diagnostic path, considering the radiobiological risk associated with increasing orthodontic imaging. (author)

  2. Secreted microvesicular miR-31 inhibits osteogenic differentiation of mesenchymal stem cells

    DEFF Research Database (Denmark)

    Weilner, Sylvia; Schraml, Elisabeth; Wieser, Matthias

    2016-01-01

    Damage to cells and tissues is one of the driving forces of aging and age-related diseases. Various repair systems are in place to counteract this functional decline. In particular, the property of adult stem cells to self-renew and differentiate is essential for tissue homeostasis and regeneration....... However, their functionality declines with age (Rando, 2006). One organ that is notably affected by the reduced differentiation capacity of stem cells with age is the skeleton. Here, we found that circulating microvesicles impact on the osteogenic differentiation capacity of mesenchymal stem cells....... As a potential source of its secretion, we identified senescent endothelial cells, which are known to increase during aging in vivo (Erusalimsky, 2009). Endothelial miR-31 is secreted within senescent cell-derived microvesicles and taken up by mesenchymal stem cells where it inhibits osteogenic differentiation...

  3. Measurement of radiation dose to ovaries from CT of the head and trunk

    Energy Technology Data Exchange (ETDEWEB)

    Al-Habdhan, M.A.M.; Kinsara, A.R. [King Abdul Aziz Univ., Nuclear Engineering Dept., Jeddah (Saudi Arabia)

    2001-07-01

    With the rise in concern about doses received by patients over recent years, there has been a growing requirement for information on typical doses and the range of dose received during Computerized Tomography (CT). This study was performed for the assessment of radiation dose to the ovaries from various CT protocols for head and trunk imaging. Thermo luminescent dosimeters (TLD) were used for the dosimetry measurement in an anthropomorphic Rando Alderson phantom. The wanted (obligatory) and unwanted (non-useful) radiation doses delivered to the ovaries during CT examinations of head, facial bone, orbits, abdomen, chest, pelvis, neck, nasopharynx, cervical spine, lumber spine and sacroiliac joint were assessed. The results are compared with the corresponding values published in the literature. A comparison of the received dose from CT examinations and general radiography examinations by the ovaries was made. It is found that relatively high doses of unwanted radiation are delivered with computerized tomography. (author)

  4. A New Algorithm for On- Line Handwriting Signature Verification Based on Evolutionary Computation

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jianbin; ZHU Guangxi

    2006-01-01

    The paper proposes an on-line signature verification algorithm, through which test sample and template signatures can be optimizedly matched, based on evolutionary computation (EC). Firstly, the similarity of signature curve segment is defined, and shift and scale transforms are also introduced due to the randoness of on-line signature. Secondly,this paper puts forward signature verification matching algorithm after establishment of the mathematical model. Thirdly, the concrete realization of the algorithm based on EC is discussed as well. In addition, the influence of shift and scale on the matching result is fully considered in the algorithm.Finally, a computation example is given, and the matching results between the test sample curve and the template signature curve are analyzed in detail. The preliminary experiments reveal that the type of signature verification problem can be solved by EC.

  5. An equation-free computational approach for extracting population-level behavior from individual-based models of biological dispersal

    CERN Document Server

    Erban, R; Othmer, H G; Erban, Radek; Kevrekidis, Ioannis G.; Othmer, Hans G.

    2005-01-01

    The movement of many organisms can be described as a random walk at either or both the individual and population level. The rules for this random walk are based on complex biological processes and it may be difficult to develop a tractable, quantitatively-accurate, individual-level model. However, important problems in areas ranging from ecology to medicine involve large collections of individuals, and a further intellectual challenge is to model population-level behavior based on a detailed individual-level model. Because of the large number of interacting individuals and because the individual-level model is complex, classical direct Monte Carlo simulations can be very slow, and often of little practical use. In this case, an equation-free approach may provide effective methods for the analysis and simulation of individual-based models. In this paper we analyze equation-free coarse projective integration. For analytical purposes, we start with known partial differential equations describing biological rando...

  6. Human geography in the French Institute: new discipline or missed opportunity?

    Science.gov (United States)

    Staum, M S

    1987-10-01

    The geography section of the Class of Moral and Political Sciences of the French National Institute, which was in existence from December 1795 to January 1803, responded inadequately to the theoretical challenges of Montesquieu, the hygienists, Volney, and Degérando to study thoroughly native peoples to determine the effects of physical geographic conditions on the body and mind. Most geographers had no interest in human geography, and even statistical geography received only superficial discussion. Despite the emergence of the scientific journal, only a few authors partly transcended the stereotypes of the noble-ignoble savage. The only expedition partly planned by the Institute in this period had an ambitious exploration program that precluded a linguistically sophisticated study of native peoples. Bonaparte's dissolution of the Class hindered further opportunities for studying human geography during the Empire.

  7. Application of digital image processing for the generation of voxels phantoms for Monte Carlo simulation.

    Science.gov (United States)

    Boia, L S; Menezes, A F; Cardoso, M A C; da Rosa, L A R; Batista, D V S; Cardoso, S C; Silva, A X; Facure, A

    2012-01-01

    This paper presents the application of a computational methodology for optimizing the conversion of medical tomographic images in voxel anthropomorphic models for simulation of radiation transport using the MCNP code. A computational system was developed for digital image processing that compresses the information from the DICOM medical image before it is converted to the Scan2MCNP software input file for optimization of the image data. In order to validate the computational methodology, a radiosurgery treatment simulation was performed using the Alderson Rando phantom and the acquisition of DICOM images was performed. The simulation results were compared with data obtained with the BrainLab planning system. The comparison showed good agreement for three orthogonal treatment beams of (60)Co gamma radiation. The percentage differences were 3.07%, 0.77% and 6.15% for axial, coronal and sagital projections, respectively.

  8. Feasibility of Concurrent Treatment with the Scanning Ultrasound Reflector Linear Array System (SURLAS) and the Helical Tomotherapy System

    Science.gov (United States)

    Peñagarícano, José A.; Moros, Eduardo; Novák, Petr; Yan, Yulong; Corry, Peter

    2010-01-01

    Purpose To evaluate the feasibility of concurrent treatment with the Scanning Ultrasound Reflector Linear Array System (SURLAS) and helical tomotherapy (HT) intensity modulated radiation therapy (IMRT). Methods The SURLAS was placed on a RANDO phantom simulating a patient with superficial or deep recurrent breast cancer. A Megavoltage CT (MVCT) of the phantom with and without the SURLAS was obtained in the HT system. MVCT images with the SURLAS were obtained for two configurations: i) with the SURLAS' long axis parallel and ii) perpendicular to the longitudinal axis of the phantom. The MVCT simulation data set was then transferred to a radiation therapy planning station. Organs at risk (OAR) were contoured including the lungs, heart, abdomen and spinal cord. The metallic parts of the SURLAS were contoured as well and constraints were assigned to completely or directionally block radiation through them. The MVCT-simulation data set and regions of interest (ROI) files were subsequently transferred to the HT planning station. Several HT plans were obtained with optimization parameters that are usually used in the clinic. For comparison purposes, planning was also performed without the SURLAS on the phantom. Results All plans with the SURLAS on the phantom showed adequate dose covering 95% of the planning target volume (PTV D95%), average dose and coefficient of variation of the planning target volume (PTV) dose distribution regardless of the SURLAS' orientation with respect to the RANDO phantom. Likewise, all OAR showed clinically acceptable dose values. Spatial dose distributions and dose-volume histogram (DVH) evaluation showed negligible plan degradation due to the presence of the SURLAS. Beam-on time varied depending on the selected optimization parameters. Conclusion From the perspective of the radiation dosage, concurrent treatment with the SURLAS and HT IMRT is feasible as demonstrated by the obtained clinically acceptable treatment plans. In addition, proper

  9. Development of a new metal artifact reduction algorithm by using an edge preserving method for CBCT imaging

    Science.gov (United States)

    Kim, Juhye; Nam, Haewon; Lee, Rena

    2015-07-01

    CT (computed tomography) images, metal materials such as tooth supplements or surgical clips can cause metal artifact and degrade image quality. In severe cases, this may lead to misdiagnosis. In this research, we developed a new MAR (metal artifact reduction) algorithm by using an edge preserving filter and the MATLAB program (Mathworks, version R2012a). The proposed algorithm consists of 6 steps: image reconstruction from projection data, metal segmentation, forward projection, interpolation, applied edge preserving smoothing filter, and new image reconstruction. For an evaluation of the proposed algorithm, we obtained both numerical simulation data and data for a Rando phantom. In the numerical simulation data, four metal regions were added into the Shepp Logan phantom for metal artifacts. The projection data of the metal-inserted Rando phantom were obtained by using a prototype CBCT scanner manufactured by medical engineering and medical physics (MEMP) laboratory research group in medical science at Ewha Womans University. After these had been adopted the proposed algorithm was performed, and the result were compared with the original image (with metal artifact without correction) and with a corrected image based on linear interpolation. Both visual and quantitative evaluations were done. Compared with the original image with metal artifacts and with the image corrected by using linear interpolation, both the numerical and the experimental phantom data demonstrated that the proposed algorithm reduced the metal artifact. In conclusion, the evaluation in this research showed that the proposed algorithm outperformed the interpolation based MAR algorithm. If an optimization and a stability evaluation of the proposed algorithm can be performed, the developed algorithm is expected to be an effective tool for eliminating metal artifacts even in commercial CT systems.

  10. SU-E-T-591: Measurement and Monte Carlo Simulation of Stray Neutrons in Passive Scattering Proton Therapy: Needs and Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Farah, J; Bonfrate, A; Donadille, L; Dubourg, N; Lacoste, V; Martinetti, F; Sayah, R; Trompier, F; Clairand, I [IRSN - Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-roses (France); Caresana, M [Politecnico di Milano, Milano (Italy); Delacroix, S; Nauraye, C [Institut Curie - Centre de Protontherapie d Orsay, Orsay (France); Herault, J [Centre Antoine Lacassagne, Nice (France); Piau, S; Vabre, I [Institut de Physique Nucleaire d Orsay, Orsay (France)

    2014-06-01

    Purpose: Measure stray radiation inside a passive scattering proton therapy facility, compare values to Monte Carlo (MC) simulations and identify the actual needs and challenges. Methods: Measurements and MC simulations were considered to acknowledge neutron exposure associated with 75 MeV ocular or 180 MeV intracranial passively scattered proton treatments. First, using a specifically-designed high sensitivity Bonner Sphere system, neutron spectra were measured at different positions inside the treatment rooms. Next, measurement-based mapping of neutron ambient dose equivalent was fulfilled using several TEPCs and rem-meters. Finally, photon and neutron organ doses were measured using TLDs, RPLs and PADCs set inside anthropomorphic phantoms (Rando, 1 and 5-years-old CIRS). All measurements were also simulated with MCNPX to investigate the efficiency of MC models in predicting stray neutrons considering different nuclear cross sections and models. Results: Knowledge of the neutron fluence and energy distribution inside a proton therapy room is critical for stray radiation dosimetry. However, as spectrometry unfolding is initiated using a MC guess spectrum and suffers from algorithmic limits a 20% spectrometry uncertainty is expected. H*(10) mapping with TEPCs and rem-meters showed a good agreement between the detectors. Differences within measurement uncertainty (10–15%) were observed and are inherent to the energy, fluence and directional response of each detector. For a typical ocular and intracranial treatment respectively, neutron doses outside the clinical target volume of 0.4 and 11 mGy were measured inside the Rando phantom. Photon doses were 2–10 times lower depending on organs position. High uncertainties (40%) are inherent to TLDs and PADCs measurements due to the need for neutron spectra at detector position. Finally, stray neutrons prediction with MC simulations proved to be extremely dependent on proton beam energy and the used nuclear models and

  11. NUNDO: a numerical model of a human torso phantom and its application to effective dose equivalent calculations for astronauts at the ISS.

    Science.gov (United States)

    Puchalska, Monika; Bilski, Pawel; Berger, Thomas; Hajek, Michael; Horwacik, Tomasz; Körner, Christine; Olko, Pawel; Shurshakov, Vyacheslav; Reitz, Günther

    2014-11-01

    The health effects of cosmic radiation on astronauts need to be precisely quantified and controlled. This task is important not only in perspective of the increasing human presence at the International Space Station (ISS), but also for the preparation of safe human missions beyond low earth orbit. From a radiation protection point of view, the baseline quantity for radiation risk assessment in space is the effective dose equivalent. The present work reports the first successful attempt of the experimental determination of the effective dose equivalent in space, both for extra-vehicular activity (EVA) and intra-vehicular activity (IVA). This was achieved using the anthropomorphic torso phantom RANDO(®) equipped with more than 6,000 passive thermoluminescent detectors and plastic nuclear track detectors, which have been exposed to cosmic radiation inside the European Space Agency MATROSHKA facility both outside and inside the ISS. In order to calculate the effective dose equivalent, a numerical model of the RANDO(®) phantom, based on computer tomography scans of the actual phantom, was developed. It was found that the effective dose equivalent rate during an EVA approaches 700 μSv/d, while during an IVA about 20 % lower values were observed. It is shown that the individual dose based on a personal dosimeter reading for an astronaut during IVA results in an overestimate of the effective dose equivalent of about 15 %, whereas under an EVA conditions the overestimate is more than 200 %. A personal dosemeter can therefore deliver quite good exposure records during IVA, but may overestimate the effective dose equivalent received during an EVA considerably.

  12. Organ dose measurement using Optically Stimulated Luminescence Detector (OSLD) during CT examination

    Science.gov (United States)

    Yusuf, Muhammad; Alothmany, Nazeeh; Abdulrahman Kinsara, Abdulraheem

    2017-10-01

    This study provides detailed information regarding the imaging doses to patient radiosensitive organs from a kilovoltage computed tomography (CT) scan procedure using OSLD. The study reports discrepancies between the measured dose and the calculated dose from the ImPACT scan, as well as a comparison with the dose from a chest X-ray radiography procedure. OSLDs were inserted in several organs, including the brain, eyes, thyroid, lung, heart, spinal cord, breast, spleen, stomach, liver and ovaries, of the RANDO phantom. Standard clinical scanning protocols were used for each individual site, including the brain, thyroid, lung, breast, stomach, liver and ovaries. The measured absorbed doses were then compared with the simulated dose obtained from the ImPACT scan. Additionally, the equivalent doses for each organ were calculated and compared with the dose from a chest X-ray radiography procedure. Absorbed organ doses measured by OSLD in the RANDO phantom of up to 17 mGy depend on the organ scanned and the scanning protocols used. A maximum 9.82% difference was observed between the target organ dose measured by OSLD and the results from the ImPACT scan. The maximum equivalent organ dose measured during this experiment was equal to 99.899 times the equivalent dose from a chest X-ray radiography procedure. The discrepancies between the measured dose with the OSLD and the calculated dose from the ImPACT scan were within 10%. This report recommends the use of OSLD for measuring the absorbed organ dose during CT examination.

  13. A customized bolus produced using a 3-dimensional printer for radiotherapy.

    Directory of Open Access Journals (Sweden)

    Shin-Wook Kim

    Full Text Available OBJECTIVE: Boluses are used in high-energy radiotherapy in order to overcome the skin sparing effect. In practice though, commonly used flat boluses fail to make a perfect contact with the irregular surface of the patient's skin, resulting in air gaps. Hence, we fabricated a customized bolus using a 3-dimensional (3D printer and evaluated its feasibility for radiotherapy. METHODS: We designed two kinds of bolus for production on a 3D printer, one of which was the 3D printed flat bolus for the Blue water phantom and the other was a 3D printed customized bolus for the RANDO phantom. The 3D printed flat bolus was fabricated to verify its physical quality. The resulting 3D printed flat bolus was evaluated by assessing dosimetric parameters such as D1.5 cm, D5 cm, and D10 cm. The 3D printed customized bolus was then fabricated, and its quality and clinical feasibility were evaluated by visual inspection and by assessing dosimetric parameters such as Dmax, Dmin, Dmean, D90%, and V90%. RESULTS: The dosimetric parameters of the resulting 3D printed flat bolus showed that it was a useful dose escalating material, equivalent to a commercially available flat bolus. Analysis of the dosimetric parameters of the 3D printed customized bolus demonstrated that it is provided good dose escalation and good contact with the irregular surface of the RANDO phantom. CONCLUSIONS: A customized bolus produced using a 3D printer could potentially replace commercially available flat boluses.

  14. A Customized Bolus Produced Using a 3-Dimensional Printer for Radiotherapy

    Science.gov (United States)

    Kim, Shin-Wook; Shin, Hun-Joo; Kay, Chul Seung; Son, Seok Hyun

    2014-01-01

    Objective Boluses are used in high-energy radiotherapy in order to overcome the skin sparing effect. In practice though, commonly used flat boluses fail to make a perfect contact with the irregular surface of the patient’s skin, resulting in air gaps. Hence, we fabricated a customized bolus using a 3-dimensional (3D) printer and evaluated its feasibility for radiotherapy. Methods We designed two kinds of bolus for production on a 3D printer, one of which was the 3D printed flat bolus for the Blue water phantom and the other was a 3D printed customized bolus for the RANDO phantom. The 3D printed flat bolus was fabricated to verify its physical quality. The resulting 3D printed flat bolus was evaluated by assessing dosimetric parameters such as D1.5 cm, D5 cm, and D10 cm. The 3D printed customized bolus was then fabricated, and its quality and clinical feasibility were evaluated by visual inspection and by assessing dosimetric parameters such as Dmax, Dmin, Dmean, D90%, and V90%. Results The dosimetric parameters of the resulting 3D printed flat bolus showed that it was a useful dose escalating material, equivalent to a commercially available flat bolus. Analysis of the dosimetric parameters of the 3D printed customized bolus demonstrated that it is provided good dose escalation and good contact with the irregular surface of the RANDO phantom. Conclusions A customized bolus produced using a 3D printer could potentially replace commercially available flat boluses. PMID:25337700

  15. SU-E-T-541: Bolus Effect of Thermoplastic Masks in IMRT and VMAT Head and Neck Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Zhen, H; Nedzi, L; Chen, S; Jiang, S; Zhao, B [UT Southwestern Medical Center, Dallas, TX (United States)

    2014-06-01

    Purpose: To quantitatively evaluate the bolus effect of thermoplalstic mask on patient skin dose during multi-field IMRT and VMAT treatment. Methods: The clinically approved target contours for five head and neck patients were deformably registered to an anthropomorphic Rando phantom. Two plans: Multifield IMRT plan with 7-9 beams and VMAT plan with 2-4 arcs were created for each patient following same dose constraints. 3mm skin was excluded from PTVs but not constrained during optimization. The prescription dose was 200-220 cGy/fraction. A thermoplastic head and shoulder mask was customized for the Rando phantom. Each plan was delivered to the phantom twice with and without mask. During each delivery, two rectangular strips of EBT3 films (1cm x 6.8cm) were placed across the anterior upper and lower neck near PTVs to measure the surface dose. For consistency films were positioned at same locations for same patient. A total of 8 film strips were obtained for each patient. Film dose was calibrated in the range of 0-400cGy on the day of plan delivery. For dose comparison 3 regions of interests (ROIs) of 1×1 cm{sup 2} were selected at left, right and middle part of each film, resulting in 6 point doses at each plan delivery. Results: The films without mask show relatively uniform dose distribution while those with mask clearly show mesh pattern of mask, usually indicating an increase in skin dose. On average the increase in skin dose over all ROIs with mask was 31.9%(±14.8%) with a range of 11.4%- 58.4%. There is no statistically significant difference (p=0.44) between skin dose increase in VMAT (30.8%±15.3%) and IMRT delivery (33.0%±14.9%). Conclusion: Thermoplastic immobilization masks increase surface dose for HN patient by around 30%. The magnitude is comparable between multi-field IMRT and VMAT. Radiochromic EBT3 film serves as an effective tool to quantify bolus effect.

  16. The impact of the AEC mode of tube current on the dose at CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Il Bong; Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Kim, Kwang Cheol [Dept. of of Nuclear Engineering, Chosun University,Gwangju (Korea, Republic of)

    2016-11-15

    In this study, the automatic exposure control (AEC) modes of tube current (SIEMENSCare Dose 4D and GE AEC mode) that CT manufacturers are using was applied to neck, chest and abdomen in order to determine the difference in the respective dose parameters (CTDIvol, DLP and mSv) resulting from the dose reduction. Equipment in use at C university adopted Care Dose 4D of Siemens and AEC mode of General Electric (GE), and the x-ray exposure conditions were adjusted to be as identical as possible between the experiments. For the assessment of the dose reduction, the differences between the doses with and without the use of the tube current AEC mode by the respective manufacturer were measured for each body part including neck, chest and abdomen of a human phantom, Rando Phantom (Art-200x, Fluke Biomedical, USA). First, the assessment of SIEMENS-Care Dose 4D yielded the following results. At the neck, the automatic exposure control resulted in a 3.3% reduction in CTDIvol and DLP, and a 3% reduction in the effective dose, mSv, compared to manual exposure control. The automatic exposure control at the chest displayed the reduction in CTDIvol and DLP by 25.5%, and in the effective dose, mSv, by 25.4% compared to the manual exposure control. In case of abdomen, CTDIvol and DLP were shown to be reduced by 16%, and the effective dose (mSv) by 16.3% under the automatic exposure control compared to the manual exposure. Second, the assessment results of GE AEC mode are as follows. The automatic exposure control at the neck resulted in a 45.1% reduction in CTDIvol and DLP, and a 44.7% reduction in the effective dose (mSv) in comparison to the manual exposure control. At the chest, the automatic exposure control displayed a 47.6% reduction in CTDIvol and DLP, and a 47.5% reduction in the effective dose, mSv, compared to the manual exposure control. At the abdomen, it was shown that CTDIvol and DLP were reduced by 26.9%, and the effective dose (mSv) by 26.8% under the automatic

  17. Evaluation of the peripheral dose to uterus in breast carcinoma radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rincon, C.; Jerez Sainz, I.; Modelell Farre, I.; Espana Lopez, M.L.; Lopez Franco, P.; Muniz, J.L.; Romero, A.M.; Rodriguez, R

    2002-07-01

    The absorbed dose outside of the direct fields of radiotherapy treatment (or peripheral dose, PD) is responsible for radiation exposure of the fetus in pregnant women. Because the radiological protection of the unborn child is of particular concern in the early period of the pregnancy, the aim of this study is to estimate the PD in order to assess the absorbed dose in the uterus in a pregnant patient irradiated for breast carcinoma therapy. The treatment was simulated on an Alderson-Rando anthropomorphic phantom, and the radiation dose to the fetus was measured using an ionisation chamber and thermoluminescence dosemeters. Two similar treatments plans with and without wedges were delivered, using a 6 MV photon beam with two isocentric opposite tangential fields with a total dose of 50 Gy, in accordance with common established procedures. Average field parameters for more than 300 patients were studied. Measurements showed the fetal dose to be slightly lower than 50 mGy, a level at which the risk to the fetus is uncertain, although several authors consider this value as the dose threshold for deterministic effects. The planning system underestimated PD values and no significant influence was found with the use of wedge filters. (author)

  18. Mycosis Fungoides electron beam absorbed dose distribution using Fricke xylenol gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Michely C. da [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Sampaio, Francisco G.A., E-mail: francisampaio@pg.ffclrp.usp.br [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Petchevist, Paulo C.D., E-mail: petchevist12@yahoo.com.br [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Instituto de Radioterapia e Megavoltagem, Ribeirao Preto, Sao Paulo (Brazil); Oliveira, Andre L. de [Servico de Radioterapia do Hospital das Clinicas da Unicamp, Campinas, Sao Paulo (Brazil); Almeida, Adelaide de, E-mail: dalmeida@ffclrp.usp.br [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil)

    2011-12-15

    Radiotherapy uses ionizing radiation to destroy tumor cells. The absorbed dose control in the target volume is realized through radiation sensors, such as Fricke dosimeters and radiochromic film, which permit to realize bi-dimensional evaluations at once and because of that, they will be used in this study as well. Among the several types of cancer suitable for ionizing radiation treatment, the Mycosis Fungoides, a lymphoma that spreads on the skin surface and depth, requires for its treatment total body irradiation by high-energy electrons. In this work the Fricke xylenol gel (FXG) was used in order to obtain information about the absorbed dose distribution induced by the electron interactions with the irradiated tissues and to control this type of treatment. FXG can be considered as an alternative dosimeter, since up to now only films have been used. FXG sample cuvettes, simulating two selected tomos (cranium and abdomen) of the Rando anthropomorphic phantom, were positioned along with radiochromic films for comparison. The phantom was subjected to Stanford total body irradiation using 6 MeV electrons. Tomographic images were acquired for both dosimeters and evaluated through horizontal and vertical profiles along the tomographic centers. These profiles were obtained through a Matlab routine developed for this purpose. From the obtained results, one could infer that, for a superficial and internal patient irradiation, the FXG dosimeter showed an absorbed dose distribution similar to the one of the film. These results can validate the FXG dosimeter as an alternative dosimeter for the Mycosis Fungoides treatment planning.

  19. Mycosis Fungoides electron beam absorbed dose distribution using Fricke xylenol gel dosimetry

    Science.gov (United States)

    da Silveira, Michely C.; Sampaio, Francisco G. A.; Petchevist, Paulo C. D.; de Oliveira, André L.; Almeida, Adelaide de

    2011-12-01

    Radiotherapy uses ionizing radiation to destroy tumor cells. The absorbed dose control in the target volume is realized through radiation sensors, such as Fricke dosimeters and radiochromic film, which permit to realize bi-dimensional evaluations at once and because of that, they will be used in this study as well. Among the several types of cancer suitable for ionizing radiation treatment, the Mycosis Fungoides, a lymphoma that spreads on the skin surface and depth, requires for its treatment total body irradiation by high-energy electrons. In this work the Fricke xylenol gel (FXG) was used in order to obtain information about the absorbed dose distribution induced by the electron interactions with the irradiated tissues and to control this type of treatment. FXG can be considered as an alternative dosimeter, since up to now only films have been used. FXG sample cuvettes, simulating two selected tomos (cranium and abdomen) of the Rando anthropomorphic phantom, were positioned along with radiochromic films for comparison. The phantom was subjected to Stanford total body irradiation using 6 MeV electrons. Tomographic images were acquired for both dosimeters and evaluated through horizontal and vertical profiles along the tomographic centers. These profiles were obtained through a Matlab routine developed for this purpose. From the obtained results, one could infer that, for a superficial and internal patient irradiation, the FXG dosimeter showed an absorbed dose distribution similar to the one of the film. These results can validate the FXG dosimeter as an alternative dosimeter for the Mycosis Fungoides treatment planning.

  20. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)

    1998-12-31

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  1. Investigation of conformal and intensity-modulated radiation therapy techniques to determine the absorbed fetal dose in pregnant patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Öğretici, Akın, E-mail: akinogretici@gmail.com; Akbaş, Uğur; Köksal, Canan; Bilge, Hatice

    2016-07-01

    The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for breast cancers. An Alderson Rando phantom was chosen to simulate a pregnant patient with breast cancer who is receiving radiation therapy. This phantom was irradiated using the Varian Clinac DBX 600 system (Varian Medical System, Palo Alto, CA) linear accelerator, according to the standard treatment plans of both three-dimensional conformal radiation therapy (3-D CRT) and IMRT techniques. Thermoluminescent dosimeters were used to measure the irradiated phantom's virtually designated uterus area. Thermoluminescent dosimeter measurements (in the phantom) revealed that the mean cumulative fetal dose for 3-D CRT is 1.39 cGy and for IMRT it is 8.48 cGy, for a pregnant breast cancer woman who received radiation treatment of 50 Gy. The fetal dose was confirmed to increase by 70% for 3-D CRT and 40% for IMRT, if it is closer to the irradiated field by 5 cm. The mean fetal dose from 3-D CRT is 1.39 cGy and IMRT is 8.48 cGy, consistent with theoretic calculations. The IMRT technique causes the fetal dose to be 5 times more than that of 3-D CRT. Theoretic knowledge concerning the increase in the peripheral doses as the measurements approached the beam was also practically proven.

  2. Amiodarone is a cost-neutral way of preventing atrial fibrillation after surgery for lung cancer

    DEFF Research Database (Denmark)

    Riber, Lars P; Christensen, Thomas D; Pilegaard, Hans K

    2013-01-01

    OBJECTIVES: Our aim was to estimate the costs and health benefits of routinely administered postoperative amiodarone as a prophylactic agent in reducing the risk of atrial fibrillation in patients undergoing surgery for lung cancer. METHODS: This was a cost-effectiveness study, based on the rando......OBJECTIVES: Our aim was to estimate the costs and health benefits of routinely administered postoperative amiodarone as a prophylactic agent in reducing the risk of atrial fibrillation in patients undergoing surgery for lung cancer. METHODS: This was a cost-effectiveness study, based...... on the randomized, controlled, double-blinded PASCART study, using avoidance of atrial fibrillation as the measure of benefit. Two hundred and fifty-four eligible, consecutively enrolled patients, undergoing surgery for lung cancer at the department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital.......23). There were no signs of adverse developments referable to amiodarone in this prophylactic regime. CONCLUSIONS: For patients undergoing surgery for lung cancer, routine use of postoperative prophylactic intravenous bolus and five subsequent days of oral amiodarone therapy reduces the risk of atrial...

  3. Influence of lead apron shielding on absorbed doses from cone-beam computed tomography.

    Science.gov (United States)

    Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

    2016-09-24

    The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO(®) phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500(®), ProMax(®) 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax(®) 3D with shielding, the ED was 149 µSv, and for the examination protocol without shielding 148 µSv (SD = 0.31 µSv). For the CS 9500(®), the ED was 88 and 86 µSv (SD = 0.95 µSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam.

  4. SOCIO - DEMOGRAPHIC PROFILE OF OLD AGE PEOPLE LIVING IN URBAN & URBAN SLUM AREAS IN MAHARASHTRA, KARAD: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Leena Rahul Salunkhe

    2015-01-01

    Full Text Available NTRODUCTION: Aging refers to normal, progressive and irreversible biological changes that occur over an individual’s life span. The advancement of medical science and increased awareness among the people has brought about a sharp decline in mortality and a steady decline in fertility. This has resulted in a worldwide shift in the demographic profile and has led to significant increase in the aged population. About two thirds of all older people are concentrated in the developing world. OBJECTIVES: to study & compare socio - demographic variables of old age people living in Urban & Urban slum areas. MATERIAL & METHODS: all the old age people living in urb a n slum area & rando mly selected one urban area of K arad town were interviewed by using pre structured proforma about socio - demographic variable & compared with each other. OBSERVATIONS: Total 153 from urban & 135 from urban slum were enrolled for the study. Nearly 2/3 rd subjects were above age 65yrs in both areas with more female proportions in slum area than urban area. Significant difference was found with education, occupation & socio - economic status in both areas. CONCLUSION: Ageing is a universal phenomenon, with advanced fertility control, improvement in health and social services life expectancy has increased. Ageing has profound effect on the individual status in the family, the work force, goals and organization of health, social services, policies and practices of the government

  5. 基于改进RRT算法的无人机航迹规划%Path planning of UAV based on the improved rapidly-exploring random tree algorithm

    Institute of Scientific and Technical Information of China (English)

    崔挺; 李俨; 张明庄

    2013-01-01

    为了提高无人机的作战效率,航迹规划系统必须为无人机设计出安全系数高,能量消耗少,处理时间短,同时还必须满足飞行器自身物理特性的威胁回避轨迹.基于上述研究目的,本文选择快速随机搜索树算法(RRT)作为迹规划航算法主体,结合Dijkstra算法改进了RRT算法,完成最小航迹代价飞行轨迹的设计.%In order to improve the operational efficiency of the uav,path planning for uav system must design a high safety coefficient,less energy consumption,the short processing time,but also must satisfy the physical characteristics of the vehicle itself threat avoidance path.Based on the above research purpose,this article chooses fast rando.m-exploring search tree algorithm (RRT) as a trace planning navigation algorithm,combined with the main Dijkstra algorithm improved the RRT algorithm,complete the minimum path cost trajectory design.

  6. Assessment of dose in thyroid and salivary glands in dental radiology using thermoluminescent dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano, Natalia de O.; Silva, Ademir X. da [Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa em Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Canevaro, Luca V.; Mauricio, Claudia Lucia P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ) Rio de Janeiro, RJ (Brazil); Correa, Samanda C.A., E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Radiobiological and epidemiological studies have provided evidence of risk of salivary and thyroid glands tumors incidence associated with oral radiology. Based on these studies, the tissue weighting factors were reviewed by the International Commission on Radiological Protection (ICRP) in 2007. The main objective of the present work is to estimate the absorbed dose on thyroid and salivary glands (parotid, submandibular and sublingual), during a complete periapical examination. The complete periapical examination was simulated using a Spectro 70X Seletronic X-ray dental equipment on an Alderson Rando phantom with Harshaw LiF:Mg,Ti thermoluminescent dosemeters (TLD100). A PTW DIADOS dosimetric system was used for calibration. The TLD100 were inserted into the phantom slices corresponding to the organs of interest. During a complete periapical examination, the highest evaluated mean absorbed dose was 4.9 mGy in the right submandibular gland and the lowest one of 1.5 mGy in the left thyroid lobe. Entrance surface doses ranged from 2.1 to 2.6 mGy, measured, respectively, for the techniques of upper left molar and lower right molar. When compared with the diagnostic reference levels (DRL), the entrance surface doses values were lower than the DRLs recommended in Brazilian current legislation. However, the dosimetric results show the need of optimization for complete periapical examination to minimize patient exposure. Measurements were performed without the use of thyroid protectors. The use of this device is certainly an easy and simple method of dose reduction. (author)

  7. Monte Carlo modeling of proton therapy installations: a global experimental method to validate secondary neutron dose calculations.

    Science.gov (United States)

    Farah, J; Martinetti, F; Sayah, R; Lacoste, V; Donadille, L; Trompier, F; Nauraye, C; De Marzi, L; Vabre, I; Delacroix, S; Hérault, J; Clairand, I

    2014-06-07

    Monte Carlo calculations are increasingly used to assess stray radiation dose to healthy organs of proton therapy patients and estimate the risk of secondary cancer. Among the secondary particles, neutrons are of primary concern due to their high relative biological effectiveness. The validation of Monte Carlo simulations for out-of-field neutron doses remains however a major challenge to the community. Therefore this work focused on developing a global experimental approach to test the reliability of the MCNPX models of two proton therapy installations operating at 75 and 178 MeV for ocular and intracranial tumor treatments, respectively. The method consists of comparing Monte Carlo calculations against experimental measurements of: (a) neutron spectrometry inside the treatment room, (b) neutron ambient dose equivalent at several points within the treatment room, (c) secondary organ-specific neutron doses inside the Rando-Alderson anthropomorphic phantom. Results have proven that Monte Carlo models correctly reproduce secondary neutrons within the two proton therapy treatment rooms. Sensitive differences between experimental measurements and simulations were nonetheless observed especially with the highest beam energy. The study demonstrated the need for improved measurement tools, especially at the high neutron energy range, and more accurate physical models and cross sections within the Monte Carlo code to correctly assess secondary neutron doses in proton therapy applications.

  8. An investigation into the use of CMOS active pixel technology in image-guided radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Osmond, J P F; Holland, A D [School of Engineering and Design, Brunel University, Uxbridge, UB8 3PH (United Kingdom); Harris, E J; Ott, R J; Evans, P M [Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Trust, Downs Road, Sutton, Surrey, SM2 5PT (United Kingdom); Clark, A T [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX11 0QX (United Kingdom)], E-mail: john.osmond@brunel.ac.uk

    2008-06-21

    The increased intelligence, read-out speed, radiation hardness and potential large size of CMOS active pixel sensors (APS) gives them a potential advantage over systems currently used for verification of complex treatments such as IMRT and the tracking of moving tumours. The aim of this work is to investigate the feasibility of using an APS-based system to image the megavoltage treatment beam produced by a linear accelerator (Linac), and to demonstrate the logic which may ultimately be incorporated into future sensor and FPGA design to evaluate treatment and track motion. A CMOS APS was developed by the MI{sup 3} consortium and incorporated into a megavoltage imaging system using the standard lens and mirror configuration employed in camera-based EPIDs. The ability to resolve anatomical structure was evaluated using an Alderson RANDO head phantom, resolution evaluated using a quality control (QC3) phantom and contrast using an in-house developed phantom. A complex intensity-modulated radiotherapy (IMRT) treatment was imaged and two algorithms were used to determine the field-area and delivered dose, and the position of multi-leaf collimator (MLC) leaves off-line. Results were compared with prediction from the prescription and found to agree within a single image frame time for dose delivery and 0.02-0.03 cm for the position of collimator leaves. Such a system therefore shows potential as the basis for an on-line verification system capable of treatment verification and monitoring patient motion.

  9. A new species of extinct scops owl (Aves: Strigiformes: Strigidae: Otus) from São Miguel Island (Azores Archipelago, North Atlantic Ocean).

    Science.gov (United States)

    Rando, Juan Carlos; Alcover, Josep Antoni; Olson, Storrs L; Pieper, Harald

    2013-01-01

    The extinct São Miguel Scops Owl Otusfrutuosoi n. sp. is described from fossil bones found in Gruta de Água de Pau, a volcanic tube in São Miguel Island (Azores Archipelago, North Atlantic Ocean). It is the first extinct bird described from the Azores and, after the Madeiran Scops Owl (O. mauli Rando, Pieper, Alcover & Olson 2012a), the second extinct species of Strigiformes known in Macaronesia. The forelimb elements of the new taxon are shorter, the hindlimb elements are longer, and the pelvis is shorter and broader than in the Eurasian Scops Owl (O. scops Linnaeus). The new species differs from O. mauli in the smaller size of many of its bones, especially the ulna and tibiotarsus. Its measurements (estimated weight, wing area, and wing loading, and the ratio of humerus + ulna + carpometacarpus length/femur length) indicate weak powers of flight and ground-dwelling habits. The latest occurrence of the new species, as evidenced by a radiocarbon date of 1970 ± 40 BP from bone collagen, indicates a Late Holocene extinction event subsequent to 49 cal BC, and was probably linked to human arrival and subsequent habitat alterations.

  10. Digital orthodontic radiographic set versus cone-beam computed tomography: an evaluation of the effective dose

    Directory of Open Access Journals (Sweden)

    Lillian Atsumi Simabuguro Chinem

    Full Text Available ABSTRACT Objective: The aim of this study was to compare the equivalent and effective doses of different digital radiographic methods (panoramic, lateral cephalometric and periapical with cone-beam computed tomography (CBCT. Methods: Precalibrated thermoluminescent dosimeters were placed at 24 locations in an anthropomorphic phantom (Alderson Rando Phantom, Alderson Research Laboratories, New York, NY, USA, representing a medium sized adult. The following devices were tested: Heliodent Plus (Sirona Dental Systems, Bernsheim, Germany, Orthophos XG 5 (Sirona Dental Systems, Bernsheim, Germany and i-CAT (Imaging Sciences International, Hatfield, PA, USA. The equivalent doses and effective doses were calculated considering the recommendations of the International Commission of Radiological Protection (ICRP issued in 1990 and 2007. Results: Although the effective dose of the radiographic set corresponded to 17.5% (ICRP 1990 and 47.2% (ICRP 2007 of the CBCT dose, the equivalent doses of skin, bone surface and muscle obtained by the radiographic set were higher when compared to CBCT. However, in some areas, the radiation produced by the orthodontic set was higher due to the complete periapical examination. Conclusion: Considering the optimization principle of radiation protection, i-CAT tomography should be used only in specific and justified circumstances. Additionally, following the ALARA principle, single periapical radiographies covering restricted areas are more suitable than the complete periapical examination.

  11. Dosimetric study of the effective doses resulting during dental X-ray and panoramic radiography

    Science.gov (United States)

    Shousha, Hany A.; Abd-El Hafez, A. I.; Ahmad, Fawzia

    2011-01-01

    The panoramic image is one of the most commonly used radiographic examinations in dentistry, owing to its low dose and large area for evaluation, including bone and teeth in the same image. Although digital images are usually reported to deliver a lower radiation dose to the patient, conventional images are still available, especially in countries where digital systems are not widely economically available. Dentists should weigh the benefits of dental radiographs against the consequences of increasing a patient's exposure to radiation, the effects of which accumulate from multiple sources over time. The "as low as reasonably achievable" principle should be followed to minimize the exposure to radiation. The purpose of this investigation is to measure the absorbed radiation doses at 12 anatomical sites of a Rando-phantom and calculate the effective doses result from a full-mouth survey and panoramic radiography. Organ-absorbed doses are measured using thermoluminescent dosimeters (TLD 100) and effective organ doses (μ Sv) are estimated according to the International Commission on Radiological Protection in 2007. The total effective dose results from the panoramic imaging system have so far been below those obtained using the full-mouth survey technique used in intra-oral radiographic examination.

  12. Effective dose from cone beam CT examinations in dentistry.

    Science.gov (United States)

    Roberts, J A; Drage, N A; Davies, J; Thomas, D W

    2009-01-01

    Cone beam CT (CBCT) is becoming an increasingly utilized imaging modality for dental examinations in the UK. Previous studies have presented little information on patient dose for the range of fields of view (FOVs) that can be utilized. The purpose of the study was therefore to calculate the effective dose delivered to the patient during a selection of CBCT examinations performed in dentistry. In particular, the i-CAT CBCT scanner was investigated for several imaging protocols commonly used in clinical practice. A Rando phantom containing thermoluminescent dosemeters was scanned. Using both the 1990 and recently approved 2007 International Commission on Radiological Protection recommended tissue weighting factors, effective doses were calculated. The doses (E(1990), E(2007)) were: full FOV head (92.8 microSv, 206.2 microSv); 13 cm scan of the jaws (39.5 microSv, 133.9 microSv); 6 cm high-resolution mandible (47.2 microSv, 188.5 microSv); 6 cm high-resolution maxilla (18.5 microSv, 93.3 microSv); 6 cm standard mandible (23.9 microSv, 96.2 microSv); and 6 cm standard maxilla (9.7 microSv, 58.9 microSv). The doses from CBCT are low compared with conventional CT but significantly higher than conventional dental radiography techniques.

  13. Effective dose span of ten different cone beam CT devices.

    Science.gov (United States)

    Rottke, D; Patzelt, S; Poxleitner, P; Schulze, D

    2013-01-01

    Evaluation and reduction of dose are important issues. Since cone beam CT (CBCT) has been established now not just in dentistry, the number of acquired examinations continues to rise. Unfortunately, it is very difficult to compare the doses of available devices on the market owing to different exposition parameters, volumes and geometries. The aim of this study was to evaluate the spans of effective doses (EDs) of ten different CBCT devices. 48 thermoluminescent dosemeters were placed in 24 sites in a RANDO(®) head phantom. Protocols with lowest exposition parameters and protocols with highest exposition parameters were performed for each of the ten devices. The ED was calculated from the measured energy doses according to the International Commission on Radiological Protection 2007 recommendations for each protocol and device, and the statistical values were evaluated afterwards. The calculation of the ED resulted in values between 17.2 µSv and 396 µSv for the ten devices. The mean values for protocols with lowest and highest exposition parameters were 31.6 µSv and 209 µSv, respectively. It was not the aim of this study to evaluate the image quality depending on different exposition parameters but to define the spans of EDs in which different CBCT devices work. There is a wide span of ED for different CBCT devices depending on the selected exposition parameters, required spatial resolution and many other factors.

  14. Protection of eye lens in computed tomography. Dose evaluation on an anthropomorphic phantom using thermo-luminescent dosimeters and Monte-Carlo simulations; Schutz der Augenlinse in der Computertomografie. Dosisevaluation an einem antropomorphen Phantom mittels Thermolumineszenzdosimetrie und Monte-Carlo-Simulationen

    Energy Technology Data Exchange (ETDEWEB)

    Keil, B.; Heverhagen, J.T.; Madsack, B.; Klose, K.J. [Klinik fuer Strahlendiagnostik, Philipps-Univ. Marburg (Germany); Wulff, J.; Schmitt, R.; Fiebich, M.; Zink, K. [Inst. fuer Medizinische Physik und Strahlenschutz, Fachhochschule Giessen-Friedberg (Germany); Auvanis, D.; Danova, D. [Klinik fuer Strahlendiagnostik, Philipps-Univ. Marburg (Germany); Inst. fuer Medizinische Physik und Strahlenschutz, Fachhochschule Giessen-Friedberg (Germany); Leppek, R. [Klinik fuer Strahlendiagnostik, Philipps-Univ. Marburg (Germany); Zentrum fuer Angewandte Radiologische Forschung, TransMit Giessen (Germany)

    2008-12-15

    Purpose: the lens of an eye is a particularly radiosensitive organ. This study investigates two different materials for eye shielding during CT scanning, i.e. a commercially available bismuth protector and a newly developed material for eye shielding, comprised of an alloy of Bi/Sb/Gd/W. Materials and methods: the radiation dose during head CT scanning was measured using thermoluminescence dosimeters and an anthropomorphic Alderson-RANDO phantom. A radiation dose reduction was compared to two shielding materials and to the condition without any eye shielding. The effect of gantry angulation that excludes the eyes from beam path was also investigated. Radiation dose measurements were validated using a Monte-Carlo simulation. For this simulation we used the EGSsnr code system, and a new application CTDOSPP was developed for simulation of the computed tomography examination. Eight radiologists evaluated the diagnostic quality of the images. Results: dose measurements and Monte-Carlo simulations are in good agreement. If the eye shields are placed in the primary beam path, bismuth eye shielding and the new material reduce the dose by up to 38% and 48%, respectively. Angling the gantry causes an 88% reduction in radiation dose. All shielding materials generate beam hardening artifacts located close to the protector, but the artifacts do not spread into the brain. (orig.)

  15. Comparison between effective radiation dose of CBCT and MSCT scanners for dentomaxillofacial applications

    Energy Technology Data Exchange (ETDEWEB)

    Loubele, M. [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven (Belgium); Department of Periodontology, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven (Belgium); ESAT-PSI, Centre for the Processing of Speech and Images. Department of Electrotechnical Engineering, Group Science, Engineering and Technology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 10 - bus 2440 Belgium (Belgium)], E-mail: Miet.Loubele@uzleuven.be; Bogaerts, R. [Department of Experimental Radiotherapy, University Hospital Gasthuisberg, Katholieke Universiteit Leuven, Herestraat 49 - bus 7003, 3000 Leuven (Belgium)], E-mail: Ria.Bogaerts@med.kuleuven.be; Van Dijck, E. [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven (Belgium); Pauwels, R. [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven (Belgium)], E-mail: ruben.pauwels@med.kuleuven.be; Vanheusden, S. [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven (Belgium); Suetens, P. [ESAT-PSI, Centre for the Processing of Speech and Images. Department of Electrotechnical Engineering, Group Science, Engineering and Technology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 10 - bus 2440 Belgium (Belgium)], E-mail: Paul.Suetens@esat.kuleuven.be; Marchal, G. [Department of Radiology, University Hospital Gasthuisberg, Katholieke Universiteit Leuven, Herestraat 49 - bus 7003, 3000 Leuven (Belgium)], E-mail: Guy.Marchal@uzleuven.be (and others)

    2009-09-15

    Objectives: To compare the effective dose levels of cone beam computed tomography (CBCT) for maxillofacial applications with those of multi-slice computed tomography (MSCT). Study design: The effective doses of 3 CBCT scanners were estimated (Accuitomo 3D, i-CAT, and NewTom 3G) and compared to the dose levels for corresponding image acquisition protocols for 3 MSCT scanners (Somatom VolumeZoom 4, Somatom Sensation 16 and Mx8000 IDT). The effective dose was calculated using thermoluminescent dosimeters (TLDs), placed in a Rando Alderson phantom, and expressed according to the ICRP 103 (2007) guidelines (including a separate tissue weighting factor for the salivary glands, as opposed to former ICRP guidelines). Results: Effective dose values ranged from 13 to 82 {mu}Sv for CBCT and from 474 to 1160 {mu}Sv for MSCT. CBCT dose levels were the lowest for the Accuitomo 3D, and highest for the i-CAT. Conclusions: Dose levels for CBCT imaging remained far below those of clinical MSCT protocols, even when a mandibular protocol was applied for the latter, resulting in a smaller field of view compared to various CBCT protocols. Considering this wide dose span, it is of outmost importance to justify the selection of each of the aforementioned techniques, and to optimise the radiation dose while achieving a sufficient image quality. When comparing these results to previous dosimetric studies, a conversion needs to be made using the latest ICRP recommendations.

  16. The Wave Function and Quantum Reality

    CERN Document Server

    Gao, Shan

    2011-01-01

    We investigate the meaning of the wave function by analyzing the mass and charge density distribution of a quantum system. According to protective measurement, a charged quantum system has mass and charge density proportional to the modulus square of its wave function. It is shown that the mass and charge density is not real but effective, and it is formed by the ergodic motion of a localized particle with the total mass and charge of the system. Moreover, it is argued that the ergodic motion is not continuous but discontinuous and random. This result suggests a new interpretation of the wave function, according to which the wave function is a description of random discontinuous motion of particles, and the modulus square of the wave function gives the probability density of the particles being in certain locations. It is shown that the suggested interpretation of the wave function disfavors the de Broglie-Bohm theory and the many-worlds interpretation but favors the dynamical collapse theories, and the rando...

  17. Dosimetry verification on VMAT and IMRT radiotherapy techniques: In the case of prostate cancer

    Science.gov (United States)

    Maulana, A.; Pawiro, S. A.

    2016-03-01

    Radiotherapy treatment depends on the accuracy of the dose delivery to patients, the purpose of the study is to verify the dose in IMRT and VMAT technique in prostate cancer cases correspond to TPS dose using phantom base on ICRU No.50. The dose verification of the target and OAR was performed by placing the TLD Rod LiF100 and EBT2 Gafchromic film at slab hole of pelvic part of the Alderson RANDO phantom for prostate cancer simulation. The Exposed TLDs was evaluated using the TLD Reader Harshaw while EBT2 film was scanned using Epson scanner. The point dose measurements were compared between planned dose and measured dose at target volume and OAR. The result is the dose difference at target volume, bladder and rectum for IMRT and VMAT are less than 5%. On the other hand, the dose difference at the Femoral head is more than 5% for both techniques because the location of OAR already in low gradient dose. Furthermore, the difference dose of the target volume for IMRT technique tends to be smaller than VMAT either for TLD and EBT2 film detectors. From the measurement showed that the delivered dose on the phantom simulation match with ICRU No.50 criteria.

  18. The implementation in-house dose verification for IMRT and VMAT on breast cancer and NPC cases

    Science.gov (United States)

    Azzi, A.; Dimitri, F. Y.; Pawiro, S. A.

    2016-03-01

    IMRT and VMAT have been widely implemented on breast cancer and NPC cases. Dose verification was conducted to ensure the comparison between dose delivered and prescribe dose in TPS to obtain optimal results and the dose delivered. The gafchromic films measurement was done for breast and NPC simulation on RANDO Phantom, irradiating film by 6 MV photon with 200 cGy and scanned with EPSON V700 using 72 dpi. Dose distribution was calculated using the MATLAB-based in-house algorithm. In order to evaluate the gamma index, gafchromic films and MatriXX 2D array were placed in the Multi Cube and irradiated with EPID in same position. Dose distribution differences for IMRT and VMAT with modalities to TPS on film was 5.34% and 6.68% for NPC PTV70; 12.81% and 6.15% for NPC PTV50; 11.14% and 10.80% for breast cancer. Gamma index differences on IMRT with modalities to MatriXX 2D array and EPID was -0.09% and 5.13% for NPC; 0.51% and 2.28% for breast cancer. On the other hand, gamma index difference on VMAT was -1.65% and 1.43% for NPC; 0.19% and 4.38% for breast cancer. This measurement method can be used to verify dose for breast cancer and NPC cases in IMRT and VMAT.

  19. Evaluation of DQA for tomography using 3D volumetric phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Uk [Dept. of Radiation Oncology, Catholic University of Incheon St. Mary' s Hospital, Incheon (Korea, Republic of); Kim, Jeong Koo [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of)

    2016-12-15

    The study investigates the necessity of 3 dimensional dose distribution evaluation instead of point dose and 2 dimensional dose distribution evaluation. Treatment plans were generated on the RANDO phantom to measure the precise dose distribution of the treatment site 0.5, 1, 1.5, 2, 2.5, 3 cm with the prescribed dose; 1,200 cGy, 5 fractions. Gamma analysis (3%/3 mm, 2%/2 mm) of dose distribution was evaluated with gafchromic EBT2 film and ArcCHECK phantom. The average error of absolute dose was measured at 0.76±0.59% and 1.37±0.76% in cheese phantom and ArcCHECK phantom respectively. The average passing ratio for 3%/3 mm were 97.72±0.02% and 99.26±0.01% in gafchromic EBT2 film and ArcCHECK phantom respectively. The average passing ratio for 2%/2 mm were 94.21±0.02% and 93.02±0.01% in gafchromic EBT2 film and ArcCHECK phantom respectively. There was a more accurate dose distribution of 3D volume phantom than cheese phantom in patients DQA using tomotherapy. Therefor it should be evaluated simultaneously 3 dimensional dose evaluation on target and peripheral area in rotational radiotherapy such as tomotherapy.

  20. Connectivity of Large Scale Networks: Distribution of Isolated Nodes

    CERN Document Server

    Mao, Guoqiang

    2011-01-01

    Connectivity is one of the most fundamental properties of wireless multi-hop networks. A network is said to be connected if there is a path between any pair of nodes. A convenient way to study the connectivity of a random network is by investigating the condition under which the network has no isolated node. The condition under which the network has no isolated node provides a necessary condition for a connected network. Further the condition for a network to have no isolated node and the condition for the network to be connected can often be shown to asymptotically converge to be the same as the number of nodes approaches infinity, given a suitably defined random network and connection model. Currently analytical results on the distribution of the number of isolated nodes only exist for the unit disk model. This study advances research in the area by providing the asymptotic distribution of the number of isolated nodes in random networks with nodes Poissonly distributed on a unit square under a generic rando...

  1. Long-term dose measurements applying a human anthropomorphic phantom onboard an aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Berger, T. [DLR-German Aerospace Center, Institute for Aerospace Medicine, Radiation Biology, Linder Hoehe, DE-51147 Cologne (Germany)], E-mail: thomas.berger@dlr.de; Meier, M.; Reitz, G. [DLR-German Aerospace Center, Institute for Aerospace Medicine, Radiation Biology, Linder Hoehe, DE-51147 Cologne (Germany); Schridde, M. [Lufthansa Cargo AG, DE-65441 Kelsterbach (Germany)

    2008-02-15

    The exposure of aircrew personnel to cosmic radiation has been considered as occupational exposure in the European Union since the European Council Directive 96/26/EURATOM became effective on 13th May 1996. In Germany the corresponding safety standards for aircrew are regulated by the German Radiation Protection Ordinance, which implemented the European law in 2001. The radiation exposure of the flight crew of the LUFTHANSA group is calculated by the DLR Institute of Aerospace Medicine in Cologne, applying the calculation program EPCARD in the framework of the aircrew dose determination system CALculated and Verified Aviation DOSimetry (CALVADOS). Besides the operational dose calculations, DLR performs measurements at airflight altitudes using active (e.g. TEPC, DOSTEL, etc.) and passive (Thermoluminescence detectors (TLDs), bubble detectors) radiation detectors to verify the calculation codes. Within these activities the project BOdy DOsimetry (BODO) comprised a long-term exposure of a RANDO anthropomorphic phantom to measure the skin and the depth dose distribution inside a human torso applying TLDs at aviation altitudes for the first time. The torso was flown onboard a LUFTHANSA Cargo aircraft for 3 months from mid of July to mid of October 2004. Over 800 TLDs were positioned for depth dose measurements in the head, the thorax and the abdomen of the torso. In addition dosemeter packages have been distributed on the surface of the torso to measure the skin dose as well as in the transport container and on the flight deck.

  2. Image quality and effective dose of a robotic flat panel 3D C-arm vs computed tomography.

    Science.gov (United States)

    Kraus, Michael; Fischer, Eric; Gebhard, Florian; Richter, Peter H

    2016-12-01

    The aim of this study was to determine the effective dose and corresponding image quality of different imaging protocols of a robotic 3D flat panel C-arm in comparison to computed tomography (CT). Dose measurements were performed using a Rando-Alderson Phantom. The phantom was exposed to different scanning protocols of the 3D C-arm and the CT. Pedicle screws were inserted in a fresh swine cadaver. Images were obtained using the same scanning protocols. At the thoracolumbar junction, the effective dose was comparable for 3D high-dose protocols, with (4.4 mSv) and without (4.3 mSv) collimation and routine CT (5 mSv), as well as a dose-reduction CT (4.0 mSv). A relevant reduction was achieved with the 3D low-dose protocol (1.0 mSv). Focusing on Th6, a similar reduction with the 3D low-dose protocol was achieved. The image quality of the 3D protocols using titanium screws was rated as 'good' by all viewers, with excellent correlation. Modern intra-operative 3D-C-arms produce images of CT-like quality with low-dose radiation. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Description of load progression and pain response during progressive resistance training early after total hip arthroplasty

    DEFF Research Database (Denmark)

    Mikkelsen, Lone R; Petersen, Annemette K; Mechlenburg, Inger

    2016-01-01

    OBJECTIVE: To describe a progressive resistance training intervention implemented shortly after total hip arthroplasty, including a detailed description of load progression, pain response and adverse events to the training. DESIGN: Secondary analyses of data from the intervention group in a rando......OBJECTIVE: To describe a progressive resistance training intervention implemented shortly after total hip arthroplasty, including a detailed description of load progression, pain response and adverse events to the training. DESIGN: Secondary analyses of data from the intervention group...... in a randomized controlled trial. SUBJECTS: This study reports data from the intervention group ( n = 37). INTERVENTIONS: The protocol described supervised progressive resistance training of the operated leg two days/week in addition to home-based exercise five days/week and for 10 weeks. The relative load...... progressed from 12 repetition maximum to 8 repetition maximum during 10 weeks for the exercises: knee extension, hip abduction, -flexion and -extension. MAIN MEASURES: Training load in kilograms (kg) for each exercise, hip pain during, before and after exercise using the Visual Analog Scale and adverse...

  4. On the Recovery of the Star Formation History of the LMC from the VISTA Survey of the Magellanic System

    CERN Document Server

    Kerber, L; Rubele, S; Cioni, M -R

    2009-01-01

    The VISTA near infrared survey of the Magellanic System (VMC) will provide deep YJKs photometry reaching stars in the oldest turn-off point all over the Magellanic Clouds (MCs). As part of the preparation for the survey, we aim to access the accuracy in the Star Formation History (SFH) that can be expected from VMC data, in particular for the LMC. To this aim, we first simulate VMC images containing not only the LMC stellar populations but also the foreground MW stars and background galaxies. We perform aperture photometry over these simulated images, access the expected levels of photometric errors and incompleteness, and apply the classical technique of SFH-recovery based on the reconstruction of colour-magnitude diagrams (CMD) via the minimization of a chi-squared-like statistics. We then evaluate the expected errors in the recovered star formation rate as a function of stellar age, SFR(t), starting from models with a known Age--Metallicity Relation (AMR). It turns out that, for a given sky area, the rando...

  5. Estimation of absorbed and effective dose in {sup 18}F-FDG em PET- CT exams for diagnosis of lung cancer; Estimativa de dose absorvida e efetiva em exames de {sup 18}F-FDG em PET- CT para diagnostico de cancer de pulmao

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Guilherme Neto de Pinho; Santana, Priscila do Carmo, E-mail: guinpc1@ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Oliveira, Paulo Marcio Campos de; Reis, Lucas Paixao dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-04-15

    This paper presents an evaluation of tissues and organs absorbed doses as well as the effective dose resulting from PET-CT scans performed with {sup 18}F-FDG radiopharmaceutical for lung cancer diagnosis in whole body scans. The ICRP-106 biokinetic model was used to estimate the absorbed and effective doses from the radiopharmaceutical for both male and female patient according to the characteristics of anthropomorphic Alderson Rando® simulators. Computer Tomography doses were evaluated using thermoluminescent detectors inserted in the same anthropomorphic simulators. Optimization protocols for image acquisition and the use of automatic exposure control were used in order to reduce patient doses, taking into account the equipment model and its system. The effective dose in female patients was 5.8 mSv. The effective dose in male patients was 8.4 mSv. The dose values estimated for the {sup 18}F-FDG PET-CT scan are below the values described in the literature. This is because the CT was not used for diagnostic but for morphological mapping. (author)

  6. Sci—Thur AM: YIS - 10: Use of the Microsoft Kinect for applications of patient surface data to radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Guillet, Dominique; Syme, Alasdair; DeBlois, François [McGill University, Montréal, QC (Canada)

    2014-08-15

    Current techniques to acquire patient surface data are often very expensive and lack flexibility. In this study, the use of the Microsoft Kinect to reliably acquire 3D scans of patient surface is investigated. A design is presented to make the system easily applicable to the clinic. Potential applications of the device to radiotherapy are also presented. Scan reproducibility was tested by repeatedly scanning an anthropomorphic phantom. Scan accuracy was tested by comparing Kinect scans to the surface extracted from a CT dataset of a Rando® anthropomorphic phantom, which was considered as the true reference surface. Average signed distances of 0.12 ± 2.34 mm and 0.13 ± 2.04 mm were obtained between the compared surfaces for reproducibility and accuracy respectively. This is conclusive, since it indicates that the variations observed come largely from noise distributed around an average distance close to 0 mm. Moreover, the range of the noise is small enough for the system to reliably capture a patient's surface. A system was also designed using two Kinects used together to acquire 3D surfaces in a quick and stable way that is applicable to the clinic. Finally, applications of the device to radiotherapy are demonstrated. Its use to detect local positioning errors is presented, where small local variations difficult to see with the naked eye are clearly visible. The system was also used to predict collisions using gantry and patient scans and thus ensure the safety of unconventional trajectories.

  7. The effect of maneuvers for shoulder delivery on perineal trauma

    DEFF Research Database (Denmark)

    Aabakke, Anna J M; Willert, Hanne; Krebs, Lone

    2016-01-01

    INTRODUCTION: Approximately 85% of vaginal deliveries are accompanied by perineal trauma. The objective of this trial was to compare the incidence of perineal trauma after primary delivery of either the anterior or posterior shoulder during vaginal delivery. MATERIAL AND METHODS: This was a rando......INTRODUCTION: Approximately 85% of vaginal deliveries are accompanied by perineal trauma. The objective of this trial was to compare the incidence of perineal trauma after primary delivery of either the anterior or posterior shoulder during vaginal delivery. MATERIAL AND METHODS......: This was a randomized single-blinded trial comparing primary delivery of either the anterior or posterior shoulder in women having their first vaginal delivery. Primary outcome was any perineal trauma. Results were analyzed according to the intention-to-treat principle and supplemented with a per-protocol and as......-treated analysis. RESULTS: Between June 2013 and March 2015, 650 women were randomized, and 543 (posterior, n = 281; anterior, n = 262) were included in the final intention-to-treat analysis. Most group characteristics were similar. The frequency of any perineal trauma did not differ between the two groups...

  8. Optimization and objective and subjective analysis of thorax image for computerized radiology; Otimizacao e analise objetiva e subjetiva de imagem de torax para radiologia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Velo, Alexandre F.; Miranda, Jose Ricardo A., E-mail: afvelo@ibb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Inst. Biociencias. Dept. de Fisica e Biofisica; Pina, Diana R.; Ribeiro, Sergio M., E-mail: drpina@fmb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicais e Diagnostico por Imagem; Duarte, Sergio, E-mail: sbd@cbpf.br [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro,RJ (Brazil)

    2013-07-01

    This research aimed at optimizing computational chest radiographic images (in previous posterior projection-PA). To this end, we used a homogeneous patient equivalent phantom in Computational Imaging System calibration, in order to obtain a satisfactory noise signal relation for a diagnosis, adjusting to a minimum dose received by the patient. The techniques have been applied in an anthropomorphic phantom (RANDO). The images obtained were evaluated by a radiologist, which identified the best image to determine possible pathologies (fracture or pneumonia). The technique were quantified objectively (Detective Quantum Efficiency - DQE, Modulation Transfer Function MTF, Noise Power Spectrum, NPS). Comparing optimized techniques with the clinical routine, it is concluded that all provide doses below reference levels. However the choice of the best technique for viewing possible pneumonia and/or fracture, was determined based on the first 3D (Dose, Diagnostic, Dollar) and regarded as gold standard. This image presented a reduction of dose and loading of tube around 70.5% and 80% respectively when compared with the clinical routine.

  9. Global Testing under Sparse Alternatives: ANOVA, Multiple Comparisons and the Higher Criticism

    CERN Document Server

    Arias-Castro, Ery; Plan, Yaniv

    2010-01-01

    Testing for the significance of a subset of regression coefficients in a linear model, a staple of statistical analysis, goes back at least to the work of Fisher who introduced the analysis of variance (ANOVA). We study this problem under the assumption that the coefficient vector is sparse, a common situation in modern high-dimensional settings. Suppose the regression vector is of dimension p with S non-zero coefficients with S = p^{1 -alpha}. Under moderate sparsity levels, i.e. alpha 1/2. In such settings, a multiple comparison procedure is often preferred and we establish its optimality when alpha >= 3/4. However, these two very popular methods are suboptimal, and sometimes powerless, under moderately strong sparsity where 1/2 1/2. This optimality property is true for a variety of designs, including the classical (balanced) multi-way designs and more modern `p > n' designs arising in genetics and signal processing. In addition to the standard fixed effects model, we establish similar results for a rando...

  10. Estimating the produced power by photovoltaic installations in shaded environments

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2015-01-01

    Full Text Available En este artículo se propone un mode lo para mejorar la estimació n de la potencia y energía de instalaciones fotovoltaicas bajo condiciones de sombreado dinámicas. El modelo considera el perfil de sombre ado en cada módulo fotovoltaico y el perfil de temperatura para actualizar los parámetros del modelo de cada módulo. El impacto de las som bras dinámicas en la producción de potencia es analizado, ilust rando grandes errores introducidos por l as aproximaciones de predicci ón clásicas, las cuales o no consideran sombreado alguno o cons ideran un sombreado promedio. Más aún, se describe y se ilustra un proced imiento para modelar el perfil de sombras en cualquier ambiente . Finalmente, perfiles experimental es de radiación y temperatura ambiente son utilizados para evaluar el desempeño del modelo pr opuesto en contraste con las aproximacion es clásicas. Los resultados mu estran que las aproximaciones clásicas sobreestiman la potencia producida por el arreglo fotovoltaico, en contraste con la potencia produ cida por el modelo propuesto.

  11. Digital orthodontic radiographic set versus cone-beam computed tomography: an evaluation of the effective dose

    Science.gov (United States)

    Chinem, Lillian Atsumi Simabuguro; Vilella, Beatriz de Souza; Maurício, Cláudia Lúcia de Pinho; Canevaro, Lucia Viviana; Deluiz, Luiz Fernando; Vilella, Oswaldo de Vasconcellos

    2016-01-01

    ABSTRACT Objective: The aim of this study was to compare the equivalent and effective doses of different digital radiographic methods (panoramic, lateral cephalometric and periapical) with cone-beam computed tomography (CBCT). Methods: Precalibrated thermoluminescent dosimeters were placed at 24 locations in an anthropomorphic phantom (Alderson Rando Phantom, Alderson Research Laboratories, New York, NY, USA), representing a medium sized adult. The following devices were tested: Heliodent Plus (Sirona Dental Systems, Bernsheim, Germany), Orthophos XG 5 (Sirona Dental Systems, Bernsheim, Germany) and i-CAT (Imaging Sciences International, Hatfield, PA, USA). The equivalent doses and effective doses were calculated considering the recommendations of the International Commission of Radiological Protection (ICRP) issued in 1990 and 2007. Results: Although the effective dose of the radiographic set corresponded to 17.5% (ICRP 1990) and 47.2% (ICRP 2007) of the CBCT dose, the equivalent doses of skin, bone surface and muscle obtained by the radiographic set were higher when compared to CBCT. However, in some areas, the radiation produced by the orthodontic set was higher due to the complete periapical examination. Conclusion: Considering the optimization principle of radiation protection, i-CAT tomography should be used only in specific and justified circumstances. Additionally, following the ALARA principle, single periapical radiographies covering restricted areas are more suitable than the complete periapical examination. PMID:27653266

  12. Maximum embryo absorbed dose from intravenous urography: interhospital variations

    Energy Technology Data Exchange (ETDEWEB)

    Damilakis, J.; Perisinakis, K. [University of Crete (Greece). Dept. of Medical Physics; Koukourakis, M. [University of Crete (Greece). Dept. of Radiology; Gourtsoyiannis, N. [University Hospital of Iraklion, Crete (Greece). Dept. of Radiotherapy

    1997-12-01

    The purpose of this study was to determine the maximum embryo dose during intravenous urography (IVU) examinations, when inadvertent irradiation of a pregnant woman occurs, and to investigate the variation of doses received from different institutions. Doses at average embryo depth from IVU examinations have been measured in four institutions using a Rando phantom and thermoluminescent crystals. In order to estimate the maximum range of embryo doses, radiologists were asked to carry out the examinations with the same technique as in female patients with acute ureteral obstruction. The range of doses estimated at embryo depth for the institutions participating in this study was 5.77 to 35.2 mGy. The considerable interhospital variation found in dose can be explained by different equipment and techniques used. A simple method of estimating embryo dose from pelvic radiographs reported previously was found to be also applicable to IVU examinations. Absorbed dose at 6 cm, the average embryo depth, was found significantly less than 50 mGy. (Author).

  13. Dosimetry of cone beam computed tomography scanning for diagnosis and planning in implant dentistry

    Energy Technology Data Exchange (ETDEWEB)

    Santos Pinto de A, E. L.; Manzi, F. R.; Goncalves Z, E. [Pontifical Catholic University of Minas Gerais, Av. Jose Gaspar 500, 30535-901 Belo Horizonte, Minas Gerais (Brazil); Nogueira, M. S.; Fernandes Z, M. A., E-mail: madelon@cdtn.br [Development Center of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: The radiation dose and estimate the radiation induced risk of cancer and morpho functional alterations according to BEIR VII (2006) and recommendations of the ICRP 103 (2007) were measured in cone beam computed tomography (CBCT) scanning (Tc Kodak 9000C 3D) in different oral and maxillofacial regions for diagnosis and planning in implant dentistry for each examination protocol: jaw full, maxilla full and jaw and maxilla full associated. Thermoluminescent dosimeters (TLD- 100 H) were placed in an Alderson-Rando in regions corresponding to the crystalline, parotid, submandibular and thyroid glands and ovaries. The highest values for entrance skin dose were observed in the region of the parotid and submandibular glands, 9.612 mGy to 7.912 mGy and 8.818 mGy to 0.483 mGy, respectively. All examination protocols presented on the right and left sides in the region of the submandibular gland the highest values for absorbed dose (D). In the jaw full exam the thyroid glands on both sides presented highest dose values than maxilla full exam. This study allowed measuring the entrance skin dose and the absorbed dose (D) highlighting a dosimetric preponderance to the salivary glands. With danger of to radiation that induces cancer risk was observed that the age group most likely to have to risk of cancer was 20 years, compared to 30, 40, 50, 60,70 and 80 years. (Author)

  14. Total Body Irradiation with Step Translation and Dynamic Field Matching

    Directory of Open Access Journals (Sweden)

    Ho-Hsing Chen

    2013-01-01

    Full Text Available The purpose of this study is to develop a total body irradiation technique that does not require additional devices or sophisticated processes to overcome the space limitation of a small treatment room. The technique aims to deliver a uniform dose to the entire body while keeping the lung dose within the tolerance level. The technique treats the patient lying on the floor anteriorly and posteriorly. For each AP/PA treatment, two complementary fields with dynamic field edges are matched over an overlapped region defined by the marks on the body surface. A compensator, a spoiler, and lung shielding blocks were used during the treatment. Moreover, electron beams were used to further boost the chest wall around the lungs. The technique was validated in a RANDO phantom using GAFCHROMIC films. Dose ratios at different body sites along the midline ranged from 0.945 to 1.076. The dose variation in the AP direction ranged from 96.0% to 104.6%. The dose distribution in the overlapped region ranged from 98.5% to 102.8%. Lateral dose profiles at abdomen and head revealed 109.8% and 111.7% high doses, respectively, at the body edges. The results confirmed that the technique is capable of delivering a uniform dose distribution to the midline of the body in a small treatment room while keeping the lung dose within the tolerance level.

  15. Monte Carlo modeling of proton therapy installations: a global experimental method to validate secondary neutron dose calculations

    Science.gov (United States)

    Farah, J.; Martinetti, F.; Sayah, R.; Lacoste, V.; Donadille, L.; Trompier, F.; Nauraye, C.; De Marzi, L.; Vabre, I.; Delacroix, S.; Hérault, J.; Clairand, I.

    2014-06-01

    Monte Carlo calculations are increasingly used to assess stray radiation dose to healthy organs of proton therapy patients and estimate the risk of secondary cancer. Among the secondary particles, neutrons are of primary concern due to their high relative biological effectiveness. The validation of Monte Carlo simulations for out-of-field neutron doses remains however a major challenge to the community. Therefore this work focused on developing a global experimental approach to test the reliability of the MCNPX models of two proton therapy installations operating at 75 and 178 MeV for ocular and intracranial tumor treatments, respectively. The method consists of comparing Monte Carlo calculations against experimental measurements of: (a) neutron spectrometry inside the treatment room, (b) neutron ambient dose equivalent at several points within the treatment room, (c) secondary organ-specific neutron doses inside the Rando-Alderson anthropomorphic phantom. Results have proven that Monte Carlo models correctly reproduce secondary neutrons within the two proton therapy treatment rooms. Sensitive differences between experimental measurements and simulations were nonetheless observed especially with the highest beam energy. The study demonstrated the need for improved measurement tools, especially at the high neutron energy range, and more accurate physical models and cross sections within the Monte Carlo code to correctly assess secondary neutron doses in proton therapy applications.

  16. The use of the eyes protection for dose reduction in CT scans of skull; O uso do protetor de olhos para reducao da dose varreduras de TC de cranio

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, Arnaldo P. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil); Silva, Teogenes A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Alonso, Thessa C., E-mail: alonso@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2013-11-01

    The technique for imaging the brain scans of the skull by computed tomography (CT) scanning is the volume bounded by the foramen magnum and the apex of the skull. The lenses are radiosensitive tissues and CT scans of the head deposited significant doses on them, since they are in the region of incidence of the primary beam of X-rays. Thus, the variation of the dose deposited in the crystalline skull CT scans for diagnostic imaging of the brain was investigated. Cranial scans were performed using the acquisition protocol routine with or without the use of bismuth to shield the eyes. To carry out the scans we used a male anthropomorphic phantom, Alderson Rando model and dosimeters (TLD-100) were used to record the doses. These TLDs were used to record specific doses internally to the phantom in specific organs (crystalline, pituitary, thyroid, spinal cord and breasts). The scans were performed on a GE machine, model 64 Discovery channels. The data obtained allowed to observe the variation of dose in organs. The highest dose was recorded in the lens (26,18 mGy), followed by spinal cord (17,79 mGy). Comparing the doses of the two scans it was significant variation in the crystal. Scan using bismuth shield generated smaller doses in the eyes and in the eyes occurred the higher dose reduction, about 37%. The results may contribute to spread a suitable procedure for the optimization of CT scans of the skull.

  17. Investigation of the characteristics of Automatic Exposure Control (AEC) of a Computed Tomography (CT) scanner by utilising cylindrical and anthropomorphic phantoms

    Science.gov (United States)

    Rulaidi, W. E. P.; Huri, M. S. N.; Ng, K. H.

    2017-05-01

    One method to optimise the use of x-rays in CT and hence a reduction in patient dose is the application of automatic exposure control (AEC). This study measured the effective mAs, image noise and volume CT dose index (CTDIvol) as the result of changing the AEC index on a Siemens Somatom Definition 64 slices dual source CT scanner. The scans were performed on four phantoms of different geometries, namely the 16 and 32 cm cylindrical CTDI phantoms and two anthropomorphic phantoms, RANDO (20 cm effective diameter) and ATOM (19.8 cm effective diameter). Results showed that the effective mAs increased with increasing tube potential (kVp) and Quality Reference mAs (QRM), therefore increasing CTDIvol while reducing image noise. Meanwhile, no changes of radiation dose and image noise were observed when the pitch was increased. However, for the largest phantom (32 cm effective diameter), a constant effective mAs was found between 120 and 140 kVp. The same trend was also found with increasing QRM from 300 mAs to 400 mAs suggesting a certain limitation of the AEC has been reached. In conclusion, this study showed that AEC is affected by kVp and QRM but not by pitch selection. Further work is required to quantify the characteristics of the AEC system in relation to the mentioned parameters for better optimisation.

  18. Bidding for Representative Allocations for Display Advertising

    CERN Document Server

    Ghosh, Arpita; Papineni, Kishore; Vassilvitskii, Sergei

    2009-01-01

    Display advertising has traditionally been sold via guaranteed contracts -- a guaranteed contract is a deal between a publisher and an advertiser to allocate a certain number of impressions over a certain period, for a pre-specified price per impression. However, as spot markets for display ads, such as the RightMedia Exchange, have grown in prominence, the selection of advertisements to show on a given page is increasingly being chosen based on price, using an auction. As the number of participants in the exchange grows, the price of an impressions becomes a signal of its value. This correlation between price and value means that a seller implementing the contract through bidding should offer the contract buyer a range of prices, and not just the cheapest impressions necessary to fulfill its demand. Implementing a contract using a range of prices, is akin to creating a mutual fund of advertising impressions, and requires {\\em randomized bidding}. We characterize what allocations can be implemented with rando...

  19. Optimization of megavoltage CT scan registration settings for brain cancer treatments on tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Woodford, Curtis; Yartsev, Slav; Van Dyk, Jake [London Regional Cancer Program, London Health Sciences Centre, 790 Commissioners Road East, London, Ontario (Canada)

    2007-04-21

    This study aims to determine the settings that provide the optimal clinical accuracy and consistency for the registration of megavoltage CT (MVCT) with planning kilovoltage CT image sets on the Hi-ART tomotherapy system. The systematic offset between the MVCT and the planning kVCT was determined by registration of multiple MVCT scans of a head phantom aligned with the planning isocentre. Residual error vector lengths and components were used to quantify the alignment quality for the phantom shifted by 5 mm in different directions obtained by all 27 possible combinations of MVCT inter-slice spacing, registration techniques and resolution. MVCT scans with normal slices are superior to coarse slices for registration of shifts in the superior-inferior, lateral and anterior-posterior directions. Decreasing the scan length has no detrimental effect on registration accuracy as long as the scan lengths are larger than 24 mm. In the case of bone technique and fine resolution, normal and fine MVCT scan slice spacing options give similar accuracy, so normal mode is preferable due to shorter procedure and less delivered dose required for patient set-up. A superior-inferior field length of 24-30 mm, normal slice spacing, bone technique, and fine resolution is the optimum set of registration settings for MVCT scans of a Rando head phantom acquired with the Hi-ART tomotherapy system, provided the registration shifts are less than 5 mm. (note)

  20. In vivo dosimetry with semiconductor and thermoluminescent detectors applied to head and neck cancer treatment; Dosimetria in vivo com uso de detectores semicondutores e termoluminescentes aplicada ao tratamento de cancer de cabeca e pescoco

    Energy Technology Data Exchange (ETDEWEB)

    Viegas, Claudio Castelo Branco

    2003-03-15

    In vivo dosimetry in radiotherapy, i. e, the assessment of the doses received by patients during their treatments, permits a verification of the therapy quality. A routine of in vivo dosimetry is, undoubtedly, a direct benefit for the patient. Unfortunately, in Brazil and in Latin America this procedure is still a privilege for only a few patients. This routine is of common application only in developed countries. The aim of this work is to show the viability and implementation of a routine in vivo dosimetry, using diodes semiconductors and thermoluminescent dosimeters (TLD), at the radiotherapy section of the National Institute of Cancer in Brazil, in the case of head and neck cancer treatment. In order to reach that aim, the characteristics of the response of diodes ISORAD-p and LiF:Mg;Ti (TLD-100) thermoluminescent detectors in powder form were determined. The performance of those detectors for in vivo dosimetry was tested using an RANDO Alderson anthropomorfic phantom and, once their adequacy proved for the kind of measurements proposed, they were used for dose assessment in the case of tumour treatments in the head and neck regions, for Cobalt-60 irradiations. (author)

  1. Use of 3D printers to create a patient-specific 3D bolus for external beam therapy.

    Science.gov (United States)

    Burleson, Sarah; Baker, Jamie; Hsia, An Ting; Xu, Zhigang

    2015-05-08

    The purpose of this paper is to demonstrate that an inexpensive 3D printer can be used to manufacture patient-specific bolus for external beam therapy, and to show we can accurately model this printed bolus in our treatment planning system for accurate treatment delivery. Percent depth-dose measurements and tissue maximum ratios were used to determine the characteristics of the printing materials, acrylonitrile butadiene styrene and polylactic acid, as bolus material with physical density of 1.04 and 1.2 g/cm3, and electron density of 3.38 × 10²³ electrons/cm3 and 3.80 × 10²³ electrons/ cm3, respectively. Dose plane comparisons using Gafchromic EBT2 film and the RANDO phantom were used to verify accurate treatment planning. We accurately modeled a printing material in Eclipse treatment planning system, assigning it a Hounsfield unit of 260. We were also able to verify accurate treatment planning using gamma analysis for dose plane comparisons. With gamma criteria of 5% dose difference and 2 mm DTA, we were able to have 86.5% points passing, and with gamma criteria of 5% dose difference and 3 mm DTA, we were able to have 95% points passing. We were able to create a patient-specific bolus using an inexpensive 3D printer and model it in our treatment planning system for accurate treatment delivery.

  2. Multislice spiral CT of the paranasal sinuses; Mehrschicht-Spiral-CT der Nasennebenhoehlen: Erste Erfahrungen unter besonderer Beruecksichtigung der Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, F.; Bode, A.; Heuschmid, M.; Kopp, A.; Georg, C.; Pereira, P.L.; Claussen, C.D. [Tuebingen Univ. (Germany). Radiologische Universitaetsklinik

    2000-08-01

    Purpose: To evaluate the potential of multislice CT in the diagnosis of the paranasal sinuses. Methods: Dose measurements were performed exposing an Alderson Rando phantom in a four-slice spiral CT (MS-CT) while applying a variety of scan parameters. Additionally, 30 consecutive patients underwent a transversal examination by the MS-CT using 1/1/3.5/0.5 mm spiral parameters and an additional transversal or coronal scan on a conventional single slice spiral CT (SS-CT) with 2/3/1 mm. Coronal reformations of the MS-CT were compared with the primary coronal SS-CT, or coronal reformations of the transversal SS-CT, respectively, with regard to image quality and depiction of relevant anatomical details of the region. Results: Superficial exposure values at the level of the eye lenses as well as for the thyroid gland were superior for MS-CT (3.62 mGy, and 0.12 mGy, resp.) as compared to SS-CT (2.96 mGy, and 0.07 mGy). Image quality was equal or superior for MS-CT as compared to SS-CT in all but one case. Drawbacks of SS-CT, such as dental amalgam artifacts, stair step artifacts or partial volume artifacts did not notably affect the coronal reformations of MS-CT. Conclusions: MS-CT seems to have the potential to replace primary coronal CT of the paranasal sinuses without any loss of image quality, but may even improve the overall diagnostic value. Radiation doses may still have to be reduced. (orig.) [German] Ziel: Erprobung eines Multislice-CT (MS-CT) zur Diagnostik der Nasennebenhoehlen (NNH). Methode: An einem Alderson Rando Phantom wurden Dosismessungen bei der Spiral-CT der NNH mit einem Mehrschicht-CT (MS-CT) unter Verwendung unterschiedlicher Scanparameter durchgefuehrt. Anschliessend wurden 30 konsekutive Patienten an dem MS-CT mit den Spiralparametern 1/1/3,5/0,5 mm und einem konventionellen Einzeilen Spiral-CT (SS-CT; 2/3/1 mm) untersucht. Die koronaren Rekonstruktionen der transversalen MS-CT wurden mit den koronaren Rekonstruktionen bzw. den primaeren koronaren

  3. Personal operator dose in invasive cardiology as a function of body height and tube angulation; Hoehe und Roehrenangulation als die Determinanten der moeglichen Untersucher-Ortsdosisleistung in der invasiven Kardiologie

    Energy Technology Data Exchange (ETDEWEB)

    Kuon, E.; Reuter, G. [Kardiologische Abt., Klinik Fraenkische Schweiz, Ebermannstadt (Germany); Empen, K.; Dahm, J.B. [Kardiologische Klinik, Ernst-Moritz-Arndt-Univ., Greifswald (Germany)

    2004-05-01

    Purpose: to map in an experimental setting of the local personal operator dose for 55 selected tube angulations as a function of body height above ground. Materials and methods: on an alderson-rando phantom representing the patient, we performed measurements of fluoroscopy scatter radiation ({mu}Sv/h) at the operator's position, for the range of 20 - 200 cm body height, for all tube angulations in 30 steps from right anterior oblique (RAO) 90 to left anterior oblique (LAO) 90 position, and for planes angulated cranially (+) and caudally (-) by 10 , 20 , 30 , and 40 , unless rendered unfeasible by geometric circumstances. Results: radiation exposure to the operator is lowest between posteroanterior (PA) 0 and RAO 30 angulation, and continuously increases by a factor of approx. 2 towards steep RAO, and to factors of 5 - 10 towards steep LAO views. Craniocaudal angulation at 30 likewise generates personal dose levels 2 - 3 times as high. For all body heights and all LAO tube angulations, the corridor between 0 - 10 caudal angulation generates the least personal scatter dose, likewise irrespective of body height and craniocaudal tube angulations, the corridor between 0 PA - 30 RAO angulation. RAO angulations, however, being inverse to the respective 90 LAO angulations, are generally 4 to 5 times less radiation extensive. Peak levels of the local personal dose vary from 160 cm body height for steep cranial LAO 90 /30 + views (3,500 {mu}Sv/h), to 50 cm for cranial PA 0 /30 + (400 {mu}Sv/h), and to {>=} 170 cm (600 {mu}Sv/h) and {<=} 40 cm (300 {mu}Sv/h) for steep cranial RAO 90 /30 + views. Caudal angulations generate slightly lower doses, with peak levels at 120 cm for LAO 90 /30 - views (3,000 {mu}Sv/h), at 50 cm for PA 0 /30 - views (300 {mu}Sv/h), and above 170 cm (900 {mu}Sv/h) and below 40 cm (500 {mu}Sv/h) for steep caudal RAO 90 /30 - views. (orig.) [German] Ziel: Experimentelle Bestimmung der Ortsdosisleistung des Untersuchers in der invasiven Kardiologie

  4. Study of dose distribution in a human body in international space station compartments with the tissue-equivalent spherical phantom

    Science.gov (United States)

    Shurshakov, Vyacheslav A.; Tolochek, Raisa V.; Kartsev, Ivan S.; Petrov, Vladislav M.; Nikolaev, Igor V.; Moskalyova, Svetlana I.; Lyagushin, Vladimir I.

    2014-01-01

    Space radiation is known to be key hazard of manned space mission. To estimate accurately radiation health risk detailed study of dose distribution inside human body by means of human phantom is conducted. In the space experiment MATROSHKA-R, the tissue-equivalent spherical phantom (32 kg mass, 35 cm diameter and 10 cm central spherical cave) made in Russia has been used on board the ISS for more than 8 years. Owing to the specially chosen phantom shape and size, the chord length distributions of the detector locations are attributed to self-shielding properties of the critical organs in a real human body. If compared with the anthropomorphic phantom Rando used inside and outside the ISS, the spherical phantom has lower mass, smaller size and requires less crew time for the detector installation/retrieval; its tissue-equivalent properties are closer to the standard human body tissue than the Rando-phantom material. Originally the spherical phantom was installed in the star board crew cabin of the ISS Service Module, then in the Piers-1, MIM-2 and MIM-1 modules of the ISS Russian segment, and finally in JAXA Kibo module. Total duration of the detector exposure is more than 1700 days in 8 sessions. In the first phase of the experiment with the spherical phantom, the dose measurements were realized with only passive detectors (thermoluminescent and solid-state track detectors). The detectors are placed inside the phantom along the axes of 20 containers and on the phantom outer surface in 32 pockets of the phantom jacket. After each session the passive detectors are returned to the ground. The results obtained show the dose difference on the phantom surface as much as a factor of 2, the highest dose being observed close to the outer wall of the compartment, and the lowest dose being in the opposite location along the phantom diameter. Maximum dose rate measured in the phantom is obviously due to the galactic cosmic ray (GCR) and Earth' radiation belt contribution on

  5. Dual-source computed tomography: Estimation of radiation exposure of ECG-gated and ECG-triggered coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany)], E-mail: dominik.ketelsen@med.uni-tuebingen.de; Thomas, Christoph; Werner, Matthias; Luetkhoff, Marie H. [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Buchgeister, Markus [Departments of Radiotherapy and Radiooncology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Tsiflikas, Ilias; Reimann, Anja [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Burgstahler, Christof [Department of Cardiology, University Hospital Tuebingen, Ottfried-Mueller-Strasse 10, 72076 Tuebingen (Germany); Brodoefel, Harald; Kopp, Andreas F.; Claussen, Claus D.; Heuschmid, Martin [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany)

    2010-02-15

    Purpose: The aim of the study was to estimate radiation exposure of coronary calcium scoring and angiography using ECG-gated and ECG-triggered dual-source computed tomography. Materials and methods: An Alderson Rando phantom equipped with thermoluminescent dosimeters was used for all dose measurements. Effective dose was calculated according to ICRP 103. Radiation exposure was performed on a dual-source computed tomography (DSCT) scanner with standard protocols for calcium scoring (DSCT-Ca) and coronary angiography (DSCTA) at different heart rates (40-100 beats/min). Furthermore, a scanning protocol with ECG-triggering as well as a standard chest CT scan were evaluated. Results: Depending on gender, heart rate and ECG-pulsing, the effective dose of a complete cardiac DSCT (DSCT-Ca and DSCTA) scan varies from 10.2 to 32.6 mSv. The effective radiation dose increased significantly with lower heart rates (p < 0.035). ECG-pulsing reduced the radiation exposure significantly in DSCTA (p < 0.001). Due to breast tissue in the primary scan range, females' doses showed an increase up to 69.9% compared to males in scan protocols without ECG-pulsing. Prospective ECG-triggered DSCTA resulted in estimated effective doses from 2.8 mSv (males) to 4.1 mSv (females). Conclusion: The ECG-pulsing technique has proven its effectiveness to reduce effective dose in coronary CT angiography and is recommended for all patients with regular heart rates. The patient's heart rate influences the radiation exposure with a significant decrease at higher heart rates. Due to its lower dose, ECG-triggered DSCTA should be implemented for special indications, i.e. for diagnosis of pathologies of the aortic root and the ascending aorta.

  6. Assessment of fetal radiation dose to patients and staff in diagnostic radiology

    Energy Technology Data Exchange (ETDEWEB)

    Osei, E.K

    2000-07-01

    A major source of uncertainty in the estimation of fetal absorbed radiation dose is the influence of fetal size and position as these change with gestational age. Consequently, dose to the fetus is related to gestational age. Most studies of fetal dose estimation during pregnancy assume that the uterus dose is equal to fetal dose. These dose estimates do not take account of gestational age and individual fetal depth, factors which are significant when calculating dose. To establish both positional and size data for estimation of fetal absorbed dose from radiological examinations, the depths from the mother's anterior surface to the mid-line of the fetal head and abdomen were measured from ultrasound scans in 215 pregnant women. Depths were measured along a ray path projected in the anterior-posterior direction from the mother's abdomen. The fetal size was estimated from measurements of the fetal abdominal and head circumference, femur length and the biparietal diameter. The effects of fetal presentation, maternal bladder volume, placenta location, gestational age and maternal AP thickness on fetal depth and size were analysed. A Monte Carlo (MC) model was developed, and used to derive factors for converting dose-area product and free-in-air entrance surface dose from medical exposure of a pregnant patient to absorbed dose to the uterus/embryo, and for converting uterus dose to fetal dose in the later stages of pregnancy. Also presented are factors for converting thermoluminescence dosimeter reading from occupational exposure of a pregnant worker to equivalent dose to the fetus. The MC model was verified experimentally by direct measurement of uterus depth dose in a female Rando phantom, and also by comparison with other experimental work and MC results in the literature. The application of the various conversion factors is demonstrated by a review of the dose estimation process in 50 cases of fetal irradiation from medical exposures. (author)

  7. Estimation of Radiation Exposure of 128-Slice 4D-Perfusion CT for the Assessment of Tumor Vascularity

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik; Horger, Marius; Buchgeister, Markus; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Schulze, Maximilian; Tsiflikas, Ilias; Claussen, Claus D.; Heuschmid, Martin [University Hospital Tuebingen, Tuebingen (Germany)

    2010-10-15

    We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4D Perfusion-CT. Phantom measurements were performed on a 128-slice single source scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue (lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans

  8. Evaluation of Contralateral Breast Surface Dose in FIF (Field In Field) Tangential Irradiation Technique for Patients Undergone Breast Conservative Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Moon; Bang, Dong Wan; Bae, Yong Ki; Lee, Jeong Woo [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of); Kim, You Hyun [Dept. of Radiological Science, College of Health Science, Korea University, Seoul (Korea, Republic of)

    2008-12-15

    The aim of this study is to evaluate contra-lateral breast (CLB) surface dose in Field-in-Field (FIF) technique for breast conserving surgery patients. For evaluation of surface dose in FIF technique, we have compared with other techniques, which were open fields (Open), metal wedge (MW), and enhanced dynamic wedge (EDW) techniques under same geometrical condition and prescribed dose. The three dimensional treatment planning system was used for dose optimization. For the verification of dose calculation, measurements using MOSFET detectors with Anderson Rando phantom were performed. The measured points for four different techniques were at the depth of 0 cm (epidermis) and 0.5 cm bolus (dermis), and spacing toward 2 cm, 4 cm, 6 cm, 8 cm, 10 cm apart from the edge of tangential medial beam. The dose calculations were done in 0.25 cm grid resolution by modified Batho method for inhomogeneity correction. In the planning results, the surface doses were differentiated in the range of 19.6-36.9, 33.2-138.2 for MW, 1.0-7.9, 1.6-37.4 for EDW, and for FIF at the depth of epidermis and dermis as compared to Open respectively. In the measurements, the surface doses were differentiated in the range of 11.1-71, 22.9-161 for MW, 4.1-15.5, 8.2-37.9 for EDW, and 4.9% for FIF at the depth of epidermis and dermis as compared to Open respectively. The surface doses were considered as underestimating in the planning calculation as compared to the measurement with MOSFET detectors. Was concluded as the lowest one among the techniques, even if it was compared with Open method. Our conclusion could be stated that the FIF technique could make the optimum dose distribution in Breast target, while effectively reduce the probability of secondary carcinogenesis due to undesirable scattered radiation to contra-lateral breast.

  9. SU-E-T-71: A Radiochromic Film Based Quantitative Assessment of Thermoplastic Mask Bolus Effect in Head and Neck IMRT/VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Kalavagunta, C; Lin, M; Snider, J; Xu, H; Schrum, A; Vadnais, P; Marter, K; Suntharalingam, M; Prado, K [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: To quantify the factors leading to thermoplastic mask bolus-associated-increased skin dose in head and neck IMRT/VMAT using EBT2 film. Methods: EBT2 film placed beneath a dual layer 3-point ORFIT head, neck and shoulder mask was used to test the effect of mask thickness, beam modulation, air gap, and beam obliquity on bolus effect. Mask thickness was varied based on the distribution of 1.6mm Orfilight layer on top of 2 mm Efficast layer. Beam modulation was varied by irradiating the film with an open field (no beam modulation) and a step and shoot field (beam modulation). Air gap between mask and film was varied from 0 to 5mm. Beam obliquity was varied by irradiating the film at gantry angles of 0°, 35°, and 70°.Finally, film strips placed on a Rando phantom under an Orfit mask, in regions of expected high dose, were irradiated using 5 IMRT and 5 VMAT plans with various modulation levels (modulation factor 2 to 5) and the results were compared with those obtained placing OSLDs at the same locations. Results: An 18–34% increase in mask bolus effect was observed for three factors where the effect of beam obliquity ≥ beam modulation > mask thickness. No increase in mask bolus effect was observed for change in air gap. A 6–13% increase in dose due to mask bolus effect was observed on film strips. Conclusion: This work underlines the role of beam obliquity and beam modulation combined with thermoplastic mask thickness in increasing mask bolus-associated skin dose in head and neck IMRT/VMAT. One possible method of dose reduction, based on knowledge gained from this work, is inclusion of skin as an avoidance structure in treatment planning. Another approach is to design a mask with the least amount of thermoplastic material necessary for immobilization.

  10. SU-E-T-557: Measuring Neutron Activation of Cardiac Devices Irradiated During Proton Therapy Using Indium Foils

    Energy Technology Data Exchange (ETDEWEB)

    Avery, S; Christodouleas, J; Delaney, K; Diffenderfer, E; Brown, K [University of Pennsylvania, Sicklerville, NJ (United States)

    2014-06-01

    Purpose: Measuring Neutron Activation of Cardiac devices Irradiated during Proton Therapy using Indium Foils Methods: The foils had dimensions of 25mm x 25mm x 1mm. After being activated, the foils were placed in a Canberra Industries well chamber utilizing a NaI(Tl) scintillation detector. The resulting gamma spectrum was acquired and analyzed using Genie 2000 spectroscopy software. One activation foil was placed over the upper, left chest of RANDO where a pacemaker would be. The rest of the foils were placed over the midline of the patient at different distances, providing a spatial distribution over the phantom. Using lasers and BBs to align the patient, 200 MU square fields were delivered to various treatment sites: the brain, the pancreas, and the prostate. Each field was shot at least a day apart, giving more than enough time for activity of the foil to decay (t1=2 = 54.12 min). Results: The net counts (minus background) of the three aforementioned peaks were used for our measurements. These counts were adjusted to account for detector efficiency, relative photon yields from decay, and the natural abundance of 115-In. The average neutron flux for the closed multi-leaf collimator irradiation was measured to be 1.62 x 106 - 0.18 x 106 cm2 s-1. An order of magnitude estimate of the flux for neutrons up to 1 keV from Diffenderfer et al. gives 3 x 106 cm2 s-1 which does agree on the order of magnitude. Conclusion: Lower energy neutrons have higher interaction cross-sections and are more likely to damage pacemakers. The thermal/slow neutron component may be enough to estimate the overall risk. The true test of the applicability of activation foils is whether or not measurements are capable of predicting cardiac device malfunction. For that, additional studies are needed to provide clinical evidence one way or the other.

  11. Effective dose for patient in multimode panoramic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Yasaki, Shiro; Daibo, Motoji [Ohu Univ., Koriyama, Fukushima (Japan). School of Dentistry

    1999-06-01

    In recent years, multimode panoramic radiography has had various functions, such as the auto exposure function, auto focus function (auto function), TMJ radiography and tomogram radiography functions. The purpose of this study was to estimate the effective dose for patients in each mode of the new multimode panoramic radiography (J. MORITA MFG. CORP. Dental Panorama X-ray Apparatus: Veraview Scope X 600). The absorbed doses in important organs involved in the causation of stochastic effects were measured by a thermoluminescent dosimeter using RANDO phantom. The effective doses were calculated using modified tissue weighting factors recommended by the International Commission on Radiological Protection (ICRP) in 1999. The mean field size over skin in typical panoramic and tomographic examinations was about 3% and 0.4% of the total body surface area of 15000 cm{sup 2}. Assuming that the incidence of skin cancer is proportional to the area of skin exposed to ionizing radiation, the tissue weighting factor of skin can be estimated to be about 0.0003 and 0.00004. The estimate in effective dose was lower (5.3 {mu}Sv) in the panoramic auto function mode (an average exposure condition of 69 kV 7 mA) than that (6.5-13.8 {mu}Sv) in the linear tomogram modes. Since the linear tomogram mode requires a scout view, such as standard panoramic radiography, the dose in the linear tomogram mode becomes higher than other modes. A percentage of gonad doses in effective doses was negligible. (author)

  12. Planning and delivering high doses to targets surrounding the spinal cord at the lower neck and upper mediastinal levels: static beam-segmentation technique executed by a multileaf collimator

    Energy Technology Data Exchange (ETDEWEB)

    Schelfhout, J.; Derycke, S.; Fortan, L.; Van Duyse, B.; Colle, C.; De Wagter, C.; De Neve, W. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

    1995-12-01

    The possibility to plan and deliver beam intensity modulated radiotherapy using a general purpose 3D-planning system (Sherouse`s GRATISTM) and a linear accelerator equipped with a standard multileaf collimator (MLC) was investigated in view of limiting the dose at the spinal cord below tolerance. During the planning process, dose homogenization at the target is obtained by the calculation of the weights, given to beam segments of a specific predetermined geometry. This specific geometry maximizes the area of each segment and thus reduces the number of segments. With a virtual patient in supine position, a first planning using a single isocenter, with gantry positions of -60, -30, 0, 30 and 60 degrees was performed. Medial edges of all segments were located tangential to the spinal cord. The resulting dose distribution allowed to encompass the target by an isodose surface of 66-70 Gy without exceeding spinal cord tolerance but required 42 segments distributed over 5 gantry angles. Therefore, dose-volume histogram analysis were performed for those cases where: (1) for some gantry positions, all beam segments could be omitted; (2) at the remaining gantry angles, segments could be omitted; (3) at least 2 segments could be traded off against 1 additional gantry angle. This procedure resulted in a final plan containing 22 segments spread over 8 gantry angles. Preliminary dosimetric results on a RANDO phantom support the robustness of the method. The first clinical applications have been planned. Although up to 99 beam segments can be programmed on the Philips SL25 linear accelerator, it remained impossible to use these segments synchronized with the MLC. From a clinical viewpoint, the proposed treatment for irradiating lower neck and upper mediastinal targets could be used as a standard against which other solutions might be tested.

  13. Reduction of uterus dose in clinical thoracic computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Danova, D.; Keil, B.; Kaestner, B.; Klose, K.J.; Heverhagen, J.T. [Marburg Univ. (Germany). Dept. of Diagnostic Radiology; Wulff, J.; Fiebich, M.; Zink, K. [Univ. of Applied Sciences Giessen-Friedberg (Germany). Inst. of Medical Physics and Radiation Protection

    2010-12-15

    Purpose: The aim of this study was to investigate the potential dose reduction in the uterus as a result of lead apron protection during thoracic CT scans. Moreover, the distribution of the radiation dose in the uterus was determined in order to obtain information about the ratio of internally and externally scattered radiation. Materials and Methods: The uterus doses during thoracic CT were determined by measuring organ doses using an Alderson-RANDO {sup registered} -Phantom and thermoluminescent dosimeters. A 0.25 mm lead equivalent protective apron was used to shield the abdominal area. Three measurement conditions were evaluated: without lead apron, covered with lead apron and wrapped with lead apron. The uterus dose with and without shielding describes the mean value and standard deviation of all examinations and all measurement points in the organ. Results: The uterus dose by thoracic CT was measured to be approximately 66.5 {+-} 3.1 {mu}Gy. If the abdomen is covered with a 0.25 mm Pb equivalent lead apron in the front area and on both sides, the uterus dose is reduced to 49.4 {+-} 2.8 {mu}Gy (26 % reduction, p < 0.001). If a lead apron is wrapped around the abdomen, providing 0.50 mm Pb shielding in the anterior section due to overlap, and 0.25 mm Pb in the posterior section and on both sides, the uterus dose is reduced even more to 43.8 {+-} 2.5 {mu}Gy (34 % reduction, p < 0.001). The dose distribution when the lead apron covers the abdomen shows that the shielding is effective for the scatter radiation that comes from the anterior part. Moreover, the wrapped apron protects the uterus from all directions and is even more effective for dose reduction than the covering apron. Conclusion: Our findings demonstrate that protective aprons are an effective dose reduction technique without additional costs and little effect on patient examination time. (orig.)

  14. WE-G-BRF-05: Feasibility of Markerless Motion Tracking Using Dual Energy Cone Beam Computed Tomography (DE-CBCT) Projections

    Energy Technology Data Exchange (ETDEWEB)

    Panfil, J; Patel, R; Surucu, M; Roeske, J [Loyola University Medical Center, Maywood, IL (United States)

    2014-06-15

    Purpose: To compare markerless template-based tracking of lung tumors using dual energy (DE) cone-beam computed tomography (CBCT) projections versus single energy (SE) CBCT projections. Methods: A RANDO chest phantom with a simulated tumor in the upper right lung was used to investigate the effectiveness of tumor tracking using DE and SE CBCT projections. Planar kV projections from CBCT acquisitions were captured at 60 kVp (4 mAs) and 120 kVp (1 mAs) using the Varian TrueBeam and non-commercial iTools Capture software. Projections were taken at approximately every 0.53° while the gantry rotated. Due to limitations of the phantom, angles for which the shoulders blocked the tumor were excluded from tracking analysis. DE images were constructed using a weighted logarithmic subtraction that removed bony anatomy while preserving soft tissue structures. The tumors were tracked separately on DE and SE (120 kVp) images using a template-based tracking algorithm. The tracking results were compared to ground truth coordinates designated by a physician. Matches with a distance of greater than 3 mm from ground truth were designated as failing to track. Results: 363 frames were analyzed. The algorithm successfully tracked the tumor on 89.8% (326/363) of DE frames compared to 54.3% (197/363) of SE frames (p<0.0001). Average distance between tracking and ground truth coordinates was 1.27 +/− 0.67 mm for DE versus 1.83+/−0.74 mm for SE (p<0.0001). Conclusion: This study demonstrates the effectiveness of markerless template-based tracking using DE CBCT. DE imaging resulted in better detectability with more accurate localization on average versus SE. Supported by a grant from Varian Medical Systems.

  15. Dosimetric Comparison of Two Craniospinal Radiotherapy Techniques for Treatment Optimization

    Directory of Open Access Journals (Sweden)

    Hamidreza Baghani

    2010-06-01

    Full Text Available Introduction: Orthogonal radial fields are those in which the central axes are perpendicular to each other. An example of these orthogonal fields is the set of craniospinal orthogonal fields that are used for radiotherapy of medulloblastoma. Craniospinal radial fields consist of two parallel-opposed fields for brain exposure and one or two posterior spinal fields for spinal cord exposure. The main problem in using these combinative fields is the overlap of radial fields, where they adjoin. Therefore, adjusting radial fields in craniospinal radiotherapy is of remarkable significance and can outstandingly affect the reduction of the side effects due to radiotherapy. In doing so, two different setups were used for craniospinal radiotherapy, and by using dosimetry in each adjustment in the junction region between brain and upper spine fields and in organs at risk, the results of the two adjustments were compared. Materials and Methods: Each one of these two setups was separately performed on a Rando phantom. In the first setup, the arrangement of radial fields was performed without the rotation of the treatment bed and the collimators of the brain fields. In the second setup, the arrangement of radial fields was performed using the rotation of the treatment bed and the collimators of brain fields. For dosimetry, GR-200 TLDs were used. For radiotherapy, a varian linac (2100 C/D Model was used. Results: The results of dosimetry in the brain CTV, junction of brain and upper spine fields, thyroid and heart in the first setup were equal to 105, 168, 46 and 44 cGy, respectively, and in second setup, 106, 140, 48 and 44 cGy, respectively. Absorbed dose to the testes in both setups was negligible.  Discussion and Conclusion: The results of dosimetry in both setups showed that angling the bed and the collimators for the brain fields prevents the overlap of radial fields and reduces the side effects due to radiotherapy.

  16. Estilos de aprendizaje y desempeño en educación a distancia: un estudio empírico con alumnos de las disciplinas de contabilidad general y de gestión

    Directory of Open Access Journals (Sweden)

    Daniel Ramos Nogueira

    2012-01-01

    Full Text Available El objetivo de la presente pesquisa es verificar si el desempeño de los alumnos de educación a distancia en las disciplinas de contabilidad general, gerencial y en el módulo de contabilidad es diferente de acuerdo con su estilo de aprendizaje. La pesquisa fue realizada con 109 alumnos de un curso de educación a distancia y utilizó como variable independiente el estilo de aprendizaje (verificado por el LSI de Kolb y como variable dependiente la nota en las disciplinas de contabilidad general, gerencial y del módulo de contabilidad (media entre la nota de contabilidad general y gerencial. Fueron realizados testes de confiabilidad ( Alpha de Cronba - ch para el instrumento LSI de Kolb y tests de normalidad de los datos. Además de eso, se procedió a análisis estadísticos descriptivos y tests de diferencias de medias ( Kruskall-wallis y ANOVA para responder a la cues - tión de pesquisa. Los resultados evidencian que la mayor parte de los alumnos es del estilo Asimilador (44% y Divergente (34%. E indican que no fue posible constatar que los estilos de aprendizaje proporcionasen diferencias en el desempeño de los alumnos. De esa forma, no se puede afirmar que un estilo de aprendizaje presente medias de desempeño superior a los demás estilos estudiando en la modalidad a distancia. Conside - rando el pequeño número de observaciones las conclusiones no deben ser generalizadas, quedando restrictas a la población pesquisada

  17. A practical alternative to conventional five-field irradiation postmastectomy for locally advanced breast cancer.

    Science.gov (United States)

    Steeves, R A; Thomadsen, B R; Hansen, H; Phromratanapongse, P; Paliwal, B R

    1994-01-01

    A combination of electron and photon beams has been used as an alternative for the conventional five-field method to irradiate patients postmastectomy for locally advanced breast cancer. Anterior and posterior opposed photon beams treat in continuity the lateral chest wall, axilla, and supraclavicular lymph nodes. An adjacent anterior electron beam is used at an energy matched to the depth of the internal mammary nodes. It includes the anterior chest wall, but bolus is used in the lateral aspect to spare underlying lung. This electron beam eliminates the diverging junction between the internal mammary and medial tangential fields used in the conventional five-field technique. Overlaps along the junction between the photon and electron beams are minimized by placing the center of the photon field along its medial border. Measurements with an Alderson-Rando phantom show dose-distribution advantages for this technique over the conventional five-field approach. There is less chance of underdosing tumor cells or of overdosing normal tissue along beam junctions. Clinical studies on 29 patients treated by this technique between July 1985 and December 1989 show increased rates of acute skin reactions, but otherwise similar side effects compared with 57 breast cancer patients treated with the five-field technique over the same time period. Local recurrence rates and patient survival rates were similar for the two groups. Given the dose-distribution advantages of this technique and its simple adaptation to accommodate unusual surgical scars or cancer recurrences, its use should be considered for postmastectomy patients with locally advanced breast cancer in well-equipped cancer treatment centers.

  18. Comparison of radiation absorbed dose in target organs in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography and computed tomography

    Directory of Open Access Journals (Sweden)

    Panjnoush M.

    2009-12-01

    Full Text Available "nBackground and Aim: The objective of this study was to measure and compare the tissue absorbed dose in thyroid gland, salivary glands, eye and skin in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography (CBCT and computed tomography (CT."nMaterials and Methods: Thermoluminescent dosimeters (TLD were implanted in 14 sites of RANDO phantom to measure average tissue absorbed dose in thyroid gland, parotid glands, submandibular glands, sublingual gland, lenses and buccal skin. The Promax (PLANMECA, Helsinki, Finland unit was selected for Panoramic, conventional linear tomography and cone beam computed tomography examinations and spiral Hispeed/Fxi (General Electric,USA was selected for CT examination. The average tissue absorbed doses were used for the calculation of the equivalent and effective doses in each organ."nResults: The average absorbed dose for Panoramic ranged from 0.038 mGY (Buccal skin to 0.308 mGY (submandibular gland, linear tomography ranged from 0.048 mGY (Lens to 0.510 mGY (submandibular gland,CBCT ranged from 0.322 mGY (thyroid glad to 1.144 mGY (Parotid gland and in CT ranged from 2.495 mGY (sublingual gland to 3.424 mGY (submandibular gland. Total effective dose in CBCT is 5 times greater than Panoramic and 4 times greater than linear tomography, and in CT, 30 and 22 times greater than Panoramic and linear tomography, respectively. Total effective dose in CT is 6 times greater than CBCT."nConclusion: For obtaining 3-dimensional (3D information in maxillofacial region, CBCT delivers the lower dose than CT, and should be preferred over a medical CT imaging. Furthermore, during maxillofacial imaging, salivary glands receive the highest dose of radiation.

  19. SU-E-T-206: Comparison of EBT and EBT3 RadioChromic Films in Radiation Field of Parotid Cancer Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Toosi, T Bahreyni; Mianaei, F Khorshidi; Ghorbani, M; Khabbaz Kazemi, N Mohammadian; Mohammadi, M [Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States)

    2015-06-15

    Purpose: The aim of the current study is to compare EBT and EBT3 RadioChromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. Methods: The calibrations of EBT and EBT3 films were performed with the same setups for doses ranging from 0.2 Gy to 5 Gy using 6 MV photon beam of a Siemens Primus linac. These films were scanned in color mode (RGB) by a Microtek (1000XL) scanner and the red color channel data was extracted. Treatment planning for parotid cancer radiation therapy was performed on a RANDO phantom. Skin dose was measured at different points in the right anterior oblique (RAO) and right posterior oblique (RPO) fields by EBT and EBT3 films. Results: Dosimetry was performed with the same conditions for the two film types for calibration and in-phantom in parotid cancer radiotherapy. The measured net optical density (NOD) in EBT film was in some extent higher than that from EBT3 film. The minimum difference between these two films under calibration conditions was about 2.9% (for 0.2 Gy). However, the maximum difference was 35.5% (for 0.5 Gy). In the therapeutic fields of parotid cancer radiotherapy at different points, the measured dose from EBT film was higher than the EBT3 film. In these fields the minimum and maximum measured dose differences were 16.0% and 25.5%, respectively. Conclusion: With the same irradiation and reading conditions, EBT film demonstrates higher NOD than the EBT3 film. This effect may be related to the higher sensitivity of EBT film over EBT3 film. However, the obtained dose differences between these two films in low dose range can be due to the differences in fitting functions applied following the calibration process.

  20. SU-E-J-31: Monitor Interfractional Variation of Tumor Respiratory Motion Using 4D KV Conebeam Computed Tomography for Stereotactic Body Radiation Therapy of Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tai, A; Prior, P; Gore, E; Johnstone, C; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2015-06-15

    Purpose: 4DCT has been widely used to generate internal tumor volume (ITV) for a lung tumor for treatment planning. However, lung tumors may show different respiratory motion on the treatment day. The purpose of this study is to evaluate 4D KV conebeam computed tomography (CBCT) for monitoring tumor interfractional motion variation between simulation and each fraction of stereotactic body radiation therapy (SBRT) for lung cancer. Methods: 4D KV CBCT was acquired with the Elekta XVI system. The accuracy of 4D KV CBCT for image-guided radiation therapy (IGRT) was tested with a dynamic thorax motion phantom (CIRS, Virginia) with a linear amplitude of 2 cm. In addition, an adult anthropomorphic phantom (Alderson, Rando) with optically stimulated luminescence (OSL) dosimeters embedded at the center and periphery of a slab of solid water was used to measure the dose of 4D KV CBCT and to compare it with the dose with 3D KV CBCT. The image registration was performed by aligning\\ each phase images of 4D KV CBCT to the planning images and the final couch shifts were calculated as a mean of all these individual shifts along each direction.A workflow was established based on these quality assurance tests for lung cancer patients. Results: 4D KV CBCT does not increase imaging dose in comparison to 3D KV CBCT. Acquisition of 4D KV CBCT is 4 minutes as compared to 2 minutes for 3D KV CBCT. Most of patients showed a small daily variation of tumor respiratory motion about 2 mm. However, some patients may have more than 5 mm variations of tumor respiratory motion. Conclusion: The radiation dose does not increase with 4D KV CBCT. 4D KV CBCT is a useful tool for monitoring interfractional variations of tumor respiratory motion before SBRT of lung cancer patients.

  1. Evaluation on organ dose and image quality of lumber spine radiography using glass dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Kyeom [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Kim, Jeong Koo [Dept. of Radiology, The Catholic University of Korea Incheon St. Mary' s Hospital, Incheon (Korea, Republic of)

    2016-03-15

    The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from 8″×17″ to 14″×17″ by 1″ in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1″ in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1″. Organ dose difference for internal and external of collimator measured 549.8 μGy in the liver and 264.6 μGy in the stomach. There were no significant changes organ dose difference that measured 1,135.1 μG in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than 9″×17″ on AP projection and 10″×17″ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography.

  2. MO-F-CAMPUS-T-01: IROC Houston QA Center’s Anthropomorphic Proton Phantom Program

    Energy Technology Data Exchange (ETDEWEB)

    Lujano, C; Hernandez, N; Keith, T; Nguyen, T; Taylor, P; Molineu, A; Followill, D [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To describe the proton phantoms that IROC Houston uses to approve and credential proton institutions to participate in NCI-sponsored clinical trials. Methods: Photon phantoms cannot necessarily be used for proton measurements because protons react differently than photons in some plastics. As such plastics that are tissue equivalent for protons were identified. Another required alteration is to ensure that the film dosimeters are housed in the phantom with no air gap to avoid proton streaming. Proton-equivalent plastics/materials used include RMI Solid Water, Techron HPV, blue water, RANDO soft tissue material, balsa wood, compressed cork and polyethylene. Institutions wishing to be approved or credentialed request a phantom and are prioritized for delivery. At the institution, the phantom is imaged, a treatment plan is developed, positioned on the treatment couch and the treatment is delivered. The phantom is returned and the measured dose distributions are compared to the institution’s electronically submitted treatment plan dosimetry data. Results: IROC Houston has developed an extensive proton phantom approval/credentialing program consisting of five different phantoms designs: head, prostate, lung, liver and spine. The phantoms are made with proton equivalent plastics that have HU and relative stopping powers similar (within 5%) of human tissues. They also have imageable targets, avoidance structures, and heterogeneities. TLD and radiochromic film are contained in the target structures. There have been 13 head, 33 prostate, 18 lung, 2 liver and 16 spine irradiations with either passive scatter, or scanned proton beams. The pass rates have been: 100%, 69.7%, 72.2%, 50%, and 81.3%, respectively. Conclusion: IROC Houston has responded to the recent surge in proton facilities by developing a family of anthropomorphic phantoms that are able to be used for remote audits of proton beams. Work supported by PHS grant CA10953 and CA081647.

  3. The evaluation of properties for radiation therapy techniques with flattening filter-free beam and usefulness of time and economy to a patient with the radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Jang Hyeon; Won, Hui Su; Hong, Joo Wan; Chang, Nam Jun; Park, Jin Hong [Dept. of Radiation Oncology, Seoul national university Bundang hospital, Sungnam (Korea, Republic of)

    2014-12-15

    The aim of this study was to appraise properties for radiation therapy techniques and effectiveness of time and economy to a patient in the case of applying flattening filter-free (3F) and flattening filter (2F) beam to the radiation therapy. Alderson rando phantom was scanned for computed tomography image. Treatment plans for intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and stereotactic body radiation therapy (SBRT) with 3F and 2F beam were designed for prostate cancer. To evaluate the differences between the 3F and 2F beam, total monitor units (MUs), beam on time (BOT) and gantry rotation time (GRT) were used and measured with TrueBeam{sup TM} STx and Surveillance And Measurement (SAM) 940 detector was used for photoneutron emitted by using 3F and 2F. To assess temporal and economical aspect for a patient, total treatment periods and medical fees were estimated. In using 3F beam, total MUs in IMRT plan increased the highest up to 34.0% and in the test of BOT, GRT and photoneutron, the values in SBRT plan decreased the lowest 39.8, 38.6 and 48.1%, respectively. In the temporal and economical aspect, there were no differences between 3F and 2F beam in all of plans and the results showed that 10 days and 169,560 won was lowest in SBRT plan. According as the results, total MUs increased by using 3F beam than 2F beam but BOT, GRT and photoneutron decreased. From above the results, using 3F beam can decrease intra-fraction setup error and risk of radiation-induced secondary malignancy. But, using 3F beam did not make the benefits of temporal and economical aspect for a patient with the radiation therapy.

  4. A new cone-beam computed tomography system for dental applications with innovative 3D software

    Energy Technology Data Exchange (ETDEWEB)

    Pasini, Alessandro; Bianconi, D.; Rossi, A. [University of Bologna, Department of Physics, Bologna (Italy); NECTAR Imaging srl Imola (Italy); Casali, F. [University of Bologna, Department of Physics, Bologna (Italy); Bontempi, M. [CEFLA Dental Group Imola (Italy)

    2007-02-15

    Objective Cone beam computed tomography (CBCT) is an important image technique for oral surgery (dentoalveolar surgery and dental implantology) and maxillofacial applications. This technique requires compact sized scanners with a relatively low radiation dosage, which makes them suitable for imaging of the craniofacial region. This article aims to present the concept and the preliminary findings obtained with the prototype of a new CBCT scanner with dedicated 3D software, specifically designed for dental imaging. Methods The prototype implements an X-ray tube with a nominal focal spot of 0.5 mm operating at 70-100 kVp and 1-4 mA. The detector is a 6 in. image intensifier coupled with a digital CCD camera. Dosimetry was performed on a RANDO anthropomorphic phantom using Beryllium Oxide thermo-luminescent dosimeters positioned in the phantom in the following site: eyes, thyroid, skin (lips, cheeks, back of the neck), brain, mandible, maxilla and parotid glands. Doses were measured using four configurations, changing the field-of-view (4'' and 6'') and acquisition time (10 and 20 s) of the CBCT. Acquisitions were performed with different parameters regarding the x-ray tube, pixel size and acquisition geometries to evaluate image quality in relation to modulation transfer function (MTF), noise and geometric accuracy. Results The prototype was able to acquire a complete maxillofacial scan in 10-15 s. The CT reconstruction algorithm delivered images that were judged to have high quality, allowing for precise volume rendering. The radiation dose was determined to be 1-1.5 times that of the dose applied during conventional dental panoramic studies. Conclusion Preliminary studies using the CBCT prototype indicate that this device provides images with acceptable diagnostic content at a relatively low radiation dosage, if compared to systems currently available on the market. (orig.)

  5. SU-E-T-815: In Vivo Dosimetry and Daily Arc Junction Verification Using EBT3 Gafchromic Film for Pediatric Cranio-Spinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H; Ferjani, S; Masssey, V; Howlin, T; Pokhrel, D [University of Kansas Hospital, Kansas City, KS (United States)

    2015-06-15

    Purpose: Perform dosimetric comparison between planned and delivered dose in the junction area, measure daily dose variation in the arc junction area for pediatric patients treated for medulloblastoma using Craniospinal axis irradiation(CSI) Material and methods Dose comparison in the junction area, daily dose variation in the arc junction area for a Rando Phantom and 5 pediatric patients treated using CSI technique were analyzed. Plans were created using the Eclipse treatment planning system. Two arcs for cranium and 1 arc for spine region were used. Planar dose matrix was created by projecting phantom and patient plan into the ArcCheck phantom. EBT3 film was placed in the middle of ArcCheck plug to measure dose distribution in the junction areaDuring patient treatment, strip of EBT3 film was placed daily at each junction area for verification. EBT3 films were scanned using a flatbed scanner, Epson Expression 10000 XL. Film QA pro software was used to analyze film. Scanning and analysis was performed according to vendor recommendations and AAPM TG-55 report. Films were scanned and analyzed daily after each treatment and at the end of treatment course. Planar dose distributions from films were compared with planar dose distribution from treatment planning system. Results: Comparison of planned vs. measured dose distributions for patients have passing rates of 90%–100% with 3% and 3 mm gamma analysis. In some of the treatment fractions, daily setup film showed variation in dose distribution in the junction area. Conclusion: It is critical to measure dose distribution in the arc junction area and use additional quality assurance measures to verify daily setup for CSI patient where one or more junctions are present. EBT3 film prove to be a good tool to achieve this task considering flexibility associated with the film such as symmetry, self-developing and ease of use.

  6. Comparison of exposure dose by using AEC mode of abdomen AP study in radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Won [Dept. of Radiology, Gang-dong Kyung Hee Medical Center, Seoul (Korea, Republic of); Kwon, Yong Rak; Seo, Seong Won [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Kwon, Kyung Tae [Dept. of Radiology, Dongnam Health University, Suwon (Korea, Republic of); Oh, Joo Young; Son, Soon Yong [Asan Medical Center, Seoul (Korea, Republic of); Min, Jung Whan [Dept. of Radiology, Shingu University, Sungnam (Korea, Republic of)

    2015-09-15

    We evaluated the effectiveness of TL (Time Limit) method by comparing with NTL (Non-time limit) method when it is used for examinations for abdomen Anterior Posterior (AP) in this paper. The evaluation was conducted based on the comparison of dose, and of signal to noise ratio (SNR) and contrast to ratio (CNR) on both methods. The experiments were conducted with XGEO GC 80 (Samsung, Korea), Unfors ThinX RAD (Unfors, Sweden) and Rando Phantom (Alderson research laboratories, USA) and shielding material with the size of 5.5 × 9 × 0.1 cm{sup 3}. It was set to activate only two upper ionization chambers in automatic exposure control (AEC) mode and the tube-voltage was set to 80kVp. When the exposure time was limited, it is limited to 51 msec. The images both by NTL AEC method and TL AEC method were acquired when with and without attachment of shielding material on the upper ionization chambers. The images were evaluated by SNR and CNR which are the image evaluation methods using ‘Image J’. The NTL AEC method showed increases in dose as much as 130.7% at maximum and 80% at minimum than other methods. The TL AEC method showed decreases in mAs and exposure dose than the NTL AEC method as much as 43.8% and 44.4% respectively. There were no significant differences in SNR or CNR for the experiments (p≥0.05). Therefore, it is suggested that the TLAEC mode is more effective when examining patients who have high BMI index or a patient with a metallic substance in the body after surgery.

  7. Validation of a technique for estimating organ doses for kilovoltage cone-beam CT of the prostate using the PCXMC 2.0 patient dose calculator.

    Science.gov (United States)

    Wood, T J; Moore, C S; Saunderson, J R; Beavis, A W

    2015-03-01

    The use of cone beam CT in common radiotherapy treatments is increasing with the growth of image guided radiotherapy. Whilst the benefits that this technology offers are clear, such as improved patient positioning prior to treatment, it is always important to consider the implications of such intensive imaging regimes on the patient, especially when considering the fundamental radiation protection requirements for justification and optimisation.The purpose of this study was to develop a technique that uses readily available dose calculation software (PCXMC 2.0) to estimate the organ and effective doses that result from these types of examination in prostate treatments on the Varian OBI system. It has been shown that by separating these types of examinations into 28 different projections, with a range of x-ray beam qualities, it is possible to reproduce the complex geometry that is used on these imaging systems in PCXMC i.e. asymmetric radiation field with a half bowtie filter rotating 360° around the patient.This new technique has been validated with thermo-luminescent dosimeter measurements in the Rando anthropomorphic phantom, and has been shown to give excellent agreement with this established method (R(2) = 0.995). This technique will prove to be valuable to radiotherapy departments that are looking to optimise their CBCT imaging protocols as it allows a rapid evaluation of the impact of any changes on patient dose. It also serves to further highlight the levels of dose that these types of patient are subject to when having daily CBCT scans as part of the treatment, which further reinforces the need for optimisation of both patient dose and image quality on these systems.

  8. SU-E-J-137: Image Registration Tool for Patient Setup in Korea Heavy Ion Medical Accelerator Center

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M; Suh, T [Department of Biomedical Engineering, Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Cho, W [Borame Medical Center, Seoul National University Hospital, Seoul, Seoul (Korea, Republic of); Jung, W [Korea Institute of Radiological & Medical Sciences, Seoul, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: A potential validation tool for compensating patient positioning error was developed using 2D/3D and 3D/3D image registration. Methods: For 2D/3D registration, digitally reconstructed radiography (DRR) and three-dimensional computed tomography (3D-CT) images were applied. The ray-casting algorithm is the most straightforward method for generating DRR. We adopted the traditional ray-casting method, which finds the intersections of a ray with all objects, voxels of the 3D-CT volume in the scene. The similarity between the extracted DRR and orthogonal image was measured by using a normalized mutual information method. Two orthogonal images were acquired from a Cyber-Knife system from the anterior-posterior (AP) and right lateral (RL) views. The 3D-CT and two orthogonal images of an anthropomorphic phantom and head and neck cancer patient were used in this study. For 3D/3D registration, planning CT and in-room CT image were applied. After registration, the translation and rotation factors were calculated to position a couch to be movable in six dimensions. Results: Registration accuracies and average errors of 2.12 mm ± 0.50 mm for transformations and 1.23° ± 0.40° for rotations were acquired by 2D/3D registration using an anthropomorphic Alderson-Rando phantom. In addition, registration accuracies and average errors of 0.90 mm ± 0.30 mm for transformations and 1.00° ± 0.2° for rotations were acquired using CT image sets. Conclusion: We demonstrated that this validation tool could compensate for patient positioning error. In addition, this research could be the fundamental step for compensating patient positioning error at the first Korea heavy-ion medical accelerator treatment center.

  9. Measuring pacemaker dose: A clinical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Studenski, Matthew T., E-mail: matthew.studenski@jeffersonhospital.org [Department of Radiation Oncology at the Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States); Xiao Ying; Harrison, Amy S. [Department of Radiation Oncology at the Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States)

    2012-07-01

    Recently in our clinic, we have seen an increased number of patients presenting with pacemakers and defibrillators. Precautions are taken to develop a treatment plan that minimizes the dose to the pacemaker because of the adverse effects of radiation on the electronics. Here we analyze different dosimeters to determine which is the most accurate in measuring pacemaker or defibrillator dose while at the same time not requiring a significant investment in time to maintain an efficient workflow in the clinic. The dosimeters analyzed here were ion chambers, diodes, metal-oxide-semiconductor field effect transistor (MOSFETs), and optically stimulated luminescence (OSL) dosimeters. A simple phantom was used to quantify the angular and energy dependence of each dosimeter. Next, 8 patients plans were delivered to a Rando phantom with all the dosimeters located where the pacemaker would be, and the measurements were compared with the predicted dose. A cone beam computed tomography (CBCT) image was obtained to determine the dosimeter response in the kilovoltage energy range. In terms of the angular and energy dependence of the dosimeters, the ion chamber and diode were the most stable. For the clinical cases, all the dosimeters match relatively well with the predicted dose, although the ideal dosimeter to use is case dependent. The dosimeters, especially the MOSFETS, tend to be less accurate for the plans, with many lateral beams. Because of their efficiency, we recommend using a MOSFET or a diode to measure the dose. If a discrepancy is observed between the measured and expected dose (especially when the pacemaker to field edge is <10 cm), we recommend analyzing the treatment plan to see whether there are many lateral beams. Follow-up with another dosimeter rather than repeating multiple times with the same type of dosimeter. All dosimeters should be placed after the CBCT has been acquired.

  10. Usability of Smartphones for dose alerts; Smartphones jetzt noch smarter? Moeglichkeit des Einsatzes als 'Dosiswarner'

    Energy Technology Data Exchange (ETDEWEB)

    Kaireit, T.; Stamm, G.; Wacker, F.K. [Medizinische Hochschule Hannover (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Hoeschen, C. [Helmholtz-Zentrum Neuherberg (Germany). Abt. Medizinische Strahlenphysik und Diagnostik

    2013-06-15

    Purpose: Smartphone apps for measuring ionizing radiation use the capability of (CMOS) camera chips to detect not only perceivable light but also electromagnetic wave radiation. The present study evaluates the accuracy of hardware and software and defines possible applications for the detection of X-ray radiation fields. Materials and Methods: 2 apps and 2 different devices were tested in comparison with a calibrated ionization chamber and a personal electronic dosimeter. A calibration curve was determined for dose rates between 12 700 {mu}Sv/h and 5.7 {mu}Sv/h generated by a C-arm system. Results: The measured scattered radiation produced by an Alderson-Rando phantom ranged from 117 {mu}Sv/h (at a distance of 2 m) to 5910 {mu}Sv/h (at a distance of 0.3 m) and was 1.4 times less than the values of the ionization chamber. The exposure rate for the operator's thyroid was within 4200 - 4400 {mu}Sv/h. We found a strong dependence of the measurements on the angulation of the Smartphone, especially for short distances from the phantom (at a distance of 0.3 m, a 45 rotation downwards in a vertical direction caused a decrease from 3000 {mu}Sv/h to 972 {mu}Sv/h, while an upwards rotation resulted in an increase to 5000 {mu}Sv/h). For a distance of 1 m, this effect was remarkably smaller. Conclusion: Smartphones can be used to detect ionizing radiation but showed limited accuracy and are heavily dependent on the angulation of the device. Qualitative measurements and utilization for dose alerts are possible. (orig.)

  11. [Clinical efficacy on peripheral facial paralysis at acute stage treated with opposing needling technique].

    Science.gov (United States)

    Li, Ying; Zhang, Zhongyi; Chen, Yuelai; Zong, Lei; Li, Jing; Tao, Ying; Zeng, Liang; Hou, Wenguang

    2015-01-01

    To compare the differences in clinical efficacy on peripheral facial paralysis at acute stage between the opposing needling technique and routine acupuncture at the affected side so as to provide the evidence on the acupuncture treatment for peripheral facial paralysis at acute stage. Forty patients were rando- mized into an opposing needling technique group (19 cases) and an affected side needling technique group (21 cases). The basic medication was same in the two groups. The acupoints were Fengchi (GB 20), Yangbai (GB 14) to Yuyao (EX-HN 4) (penetrating needling method), Jingming (BL 1), Chengqi (ST 1), Xiaguan (ST 7), Jiache (ST 6) to Dicang (ST 4), Hegu (LI 4) and Zusanli (ST 36). In supplementation, in the opposing needling technique group, the acupoints were stimulated on the face of healthy side. In the affected side needling technique group, the acupoints were stimulated on the face of the affected side. The treatment was given three times a week, for 4 weeks. House-Brackmann (H-B) facial nerve function assessment was used to evaluate facial nerve function before and after treatment in the patients of the two groups. The efficacy was compared between the two groups. The facial nerve function was recovered in the two groups and the total effective rate was 100.0% in the two groups (P>0.05). The curative rate was 68.4% (13/19) in the opposing needling technique group and better than 47.6% (10/21) in the affected side needling technique group (Pfacial nerve function in peripheral facial paralysis at acute stage and apparently shortens the curative time. The efficacy is better than that in acupuncture on the affect- ed side of the face.

  12. A phantom study on the positioning accuracy of the Novalis Body system.

    Science.gov (United States)

    Yan, Hui; Yin, Fang-Fang; Kim, Jae Ho

    2003-12-01

    A phantom study was conducted to investigate inherent positioning accuracy of an image-guided patient positioning system-the Novalis Body system for three-dimensional (3-D) conformal radiotherapy. This positioning system consists of two infrared (IR) cameras and one video camera and two kV x-ray imaging devices. The initial patient setup was guided by the IR camera system and the target localization was accomplished using the kV x-ray imaging system. In this study, the IR marker shift and phantom rotation were simulated and their effects on the positioning accuracy were examined by a Rando phantom. The effects of CT slice thickness and treatment sites on the positioning accuracy were tested. In addition, the internal target shift was simulated and its effect on the positioning accuracy was examined by a water tank. With the application of the Novalis Body system, the positioning error of the planned isocenter was significantly reduced. The experimental results with the simulated IR marker shifts indicated that the positioning errors of the planned isocenter were 0.6 +/- 0.3, 0.5 +/- 0.2, and 0.7 +/- 0.2 mm along the lateral, longitudinal, and vertical axes, respectively. The experimental results with the simulated phantom rotations indicated that the positioning errors of the planned isocenter were 0.6 +/- 0.3, 0.7 +/- 0.2, and 0.5 +/- 0.2 mm along the three axes, respectively. The experimental results with the simulated target shifts indicated that the positioning errors of the planned isocenter were 0.6 +/- 0.3, 0.7 +/- 0.2, and 0.5 +/- 0.2 mm along the three axes, respectively. On average, the positioning accuracy of 1 mm for the planned isocenter was achieved using the Novalis Body system.

  13. SU-E-T-366: Estimation of Whole Body Dose From Cranial Irradiation From C and Perfexion Series Gamma Knife Units

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S [Indiana University Health Methodist Hospital, Indianapolis, IN (United States); Indiana University School of Medicine, Indianapolis, IN, University Hospitals Case Medical Center, Cleaveland, OH (United States); Andersen, A; Lulu, B; Das, I [Indiana University School of Medicine, Indianapolis, IN, University Hospitals Case Medical Center, Cleaveland, OH (United States); Cheng, C

    2015-06-15

    Purpose: The Leksell Gamma Knife (GK) B & C series contains 201 Cobalt-60 sources with a helmet. The new model, Perfexion uses 192 Cobalt-60 sources without a helmet; using IRIS system for collimation and stereotactic guidance to deliver SRS to brain tumors. Relative dose to extracranial organs at risk (OARs) is measured in phantom in this study for Perfexion and C-series GK. Materials & Methods: Measurements were performed in a Rando anthropomorphic phantom on both systems using a large ion chamber (Keithley-175) for each collimator. The Keithley-175 cc ion chamber was sandwiched between phantom slices at various locations in the phantom to correspond to different extracranial OARs (thyroid, heart, kidney, ovary and testis, etc.) The dose measurement was repeated with OSL detectors for each position and collimator. Results: A large variation is observed in the normalized dose between these two systems. The dose beyond the housing falls off exponentially for Perfexion. Dose beyond the C-series GK housing falls off exponentially from 0–20cm then remains relatively constant from 20–40cm and again falls off with distance but less rapidly. The variation of extracranial dose with distance for each collimator is found to be parallel to each other for both systems. Conclusion: Whole body dose is found to vary significantly between these systems. It is important to measure the extracranial dose, especially for young patients. It is estimated that dose falls off exponentially from the GK housing and is about 1% for large collimators at 75 cm. The dose is two-orders of magnitude smaller for the 4mm collimator. However, this small dose for patient may be significant radiologically.

  14. SU-E-J-183: Quantifying the Image Quality and Dose Reduction of Respiratory Triggered 4D Cone-Beam Computed Tomography with Patient- Measured Breathing

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, B; OBrien, R; Kipritidis, J; Keall, P [The University of Sydney, Sydney, New South Wales (Australia)

    2014-06-01

    Purpose: Respiratory triggered four dimensional cone-beam computed tomography (RT 4D CBCT) is a novel technique that uses a patient's respiratory signal to drive the image acquisition with the goal of imaging dose reduction without degrading image quality. This work investigates image quality and dose using patient-measured respiratory signals for RT 4D CBCT simulations instead of synthetic sinusoidal signals used in previous work. Methods: Studies were performed that simulate a 4D CBCT image acquisition using both the novel RT 4D CBCT technique and a conventional 4D CBCT technique from a database of oversampled Rando phantom CBCT projections. A database containing 111 free breathing lung cancer patient respiratory signal files was used to create 111 RT 4D CBCT and 111 conventional 4D CBCT image datasets from realistic simulations of a 4D RT CBCT system. Each of these image datasets were compared to a ground truth dataset from which a root mean square error (RMSE) metric was calculated to quantify the degradation of image quality. The number of projections used in each simulation is counted and was assumed as a surrogate for imaging dose. Results: Based on 111 breathing traces, when comparing RT 4D CBCT with conventional 4D CBCT the average image quality was reduced by 7.6%. However, the average imaging dose reduction was 53% based on needing fewer projections (617 on average) than conventional 4D CBCT (1320 projections). Conclusion: The simulation studies using a wide range of patient breathing traces have demonstrated that the RT 4D CBCT method can potentially offer a substantial saving of imaging dose of 53% on average compared to conventional 4D CBCT in simulation studies with a minimal impact on image quality. A patent application (PCT/US2012/048693) has been filed which is related to this work.

  15. Comparative Evaluation of Two Bis-GMA Based Orthodontic Bonding Adhesives - A Randomized Clinical Trial.

    Science.gov (United States)

    Samantha, Christine; Sundari, Shantha; Chandrasekhar, Shyamala; Sivamurty, Gautham; Dinesh, Saravana

    2017-04-01

    Of the various orthodontic bonding materials, orthofix is a fairly new entrant into this field. This material was exclusively introduced for orthodontic bonding purposes; however, the application of this material for orthodontic purpose has not been scientifically evaluated so far. The aim of the present study was to evaluate by an in-vivo double blinded split mouth rando mized clinical trial, the overall bond failure rates of two Bis-GMA based composite materials namely Transbond XT and Orthofix. Thirty three participants who fulfilled the inclusion criteria were randomly allocated by lottery method into two groups. Group A participants had maxillary right and the mandibular left quadrants bonded using Orthofix and the remaining quadrants were bonded using Transbond XT. In Group B, the quadrants were reversed. Both groups were followed for a period of six months and were reviewed every 3-4 weeks. If a bond failed, the details were recorded and the duration of treatment before each breakage was calculated. Data were analyzed using Independent t-test and chi-square test. (pbond failure rate for 263 brackets was 2.7% for Orthofix and 3.6% for Transbond XT. The mean esitmated survival time was 221.58 days for Transbond XT and for Orthofix was 220.07 days. The difference between these mean values were statistically insignificant (p>0.05). Similarly, failure rates of the anterior and posterior segment were compared and no difference was observed between the groups (p>0.05). The maxillary and mandibular teeth were compared and more failures were found in the mandibular teeth among both the groups but they were not statistically significant (p>0.05). The overall bond failure rate and mean survival time for Transbond XT was similar to Orthofix with no statistically significant difference.

  16. Estimation of radiation exposure of retrospective gated and prospective triggered 128-slice triple-rule-out CT angiography.

    Science.gov (United States)

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Buchgeister, Markus; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin

    2011-09-01

    CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4-13.4 mSv and from 10.1-17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% ± 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% ± 6.5% in comparison to standard ECG-pulsing (p TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner.

  17. SU-E-T-540: Volumetric Modulated Total Body Irradiation Using a Rotational Lazy Susan-Like Immobilization System

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X; Hrycushko, B; Lee, H; Lamphier, R; Jiang, S; Abdulrahman, R; Timmerman, R [UT Southwestern Medical Center, Dallas, TX (United States)

    2014-06-01

    Purpose: Traditional extended SSD total body irradiation (TBI) techniques can be problematic in terms of patient comfort and/or dose uniformity. This work aims to develop a comfortable TBI technique that achieves a uniform dose distribution to the total body while reducing the dose to organs at risk for complications. Methods: To maximize patient comfort, a lazy Susan-like couch top immobilization system which rotates about a pivot point was developed. During CT simulation, a patient is immobilized by a Vac-Lok bag within the body frame. The patient is scanned head-first and then feet-first following 180° rotation of the frame. The two scans are imported into the Pinnacle treatment planning system and concatenated to give a full-body CT dataset. Treatment planning matches multiple isocenter volumetric modulated arc (VMAT) fields of the upper body and multiple isocenter parallel-opposed fields of the lower body. VMAT fields of the torso are optimized to satisfy lung dose constraints while achieving a therapeutic dose to the torso. The multiple isocenter VMAT fields are delivered with an indexed couch, followed by body frame rotation about the pivot point to treat the lower body isocenters. The treatment workflow was simulated with a Rando phantom, and the plan was mapped to a solid water slab phantom for point- and film-dose measurements at multiple locations. Results: The treatment plan of 12Gy over 8 fractions achieved 80.2% coverage of the total body volume within ±10% of the prescription dose. The mean lung dose was 8.1 Gy. All ion chamber measurements were within ±1.7% compared to the calculated point doses. All relative film dosimetry showed at least a 98.0% gamma passing rate using a 3mm/3% passing criteria. Conclusion: The proposed patient comfort-oriented TBI technique provides for a uniform dose distribution within the total body while reducing the dose to the lungs.

  18. Spatial distribution patterns and environmental interpretation of Anthriscus sylvestris clonal buds

    Institute of Scientific and Technical Information of China (English)

    Weicheng LI; Haiyan SHENG

    2008-01-01

    Anthriscus sylvestris, a weed found both in Europe and China, is a kind of representative clustered clonal plant and is a foe on dams and banks. It has been widely investigated in Europe for its powerful progenitive ability and tolerance to severely adverse environments. Our aims were to investigate and quantify its spatial dis-tribution patterns in four types of community habitats, using a clustering method and adjacency lattice estab-lished by Greig-Smith. We concluded our environmental interpretation based on canonical correspondence ana-lysis (CCA) appended to a Monte Carlo test with rando-mized seeding. The results indicate that the buds around the parent roots are in an aggregation distribution pattern in all scales (0.002-5.12 m2), but theoretical distribution fitting, like negative binomial and Poisson distribution, show that some sizes of several sampling locations are out of place. For this, spatial ordination gives a satisfact-ory answer implying the effect of environmental variables such as depth of humus layer, soil moisture, light con-dition, disturbance intensity and herb abundance. CCA accounts for 64.7% of the total environmental variation and the remaining variation may be counteracted in those five variances or can be interpreted by other factors like accumulating temperature, annual rainfall and altitude in landscape scale. With the aid of temporal sequencing, the suppressed type Ⅱ (monodominant) may be the former mode of suppressed type Ⅰ (stable type), where invasion is done with the help of disturbance from both humans and nature. The abundance of A. sylvestris can add to our cognition in diversity resistance hypothesis and our hypo-thesis on disturbance before or upon immigration.

  19. WE-F-16A-05: Use of 3D-Printers to Create a Tissue Equivalent 3D-Bolus for External Beam Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Burleson, S; Baker, J; Hsia, A; Xu, Z [Stony Brook Medicine, Stony Brook, NY (United States)

    2014-06-15

    Purpose: The purpose of this project is to demonstrate that a non-expensive 3D-printer can be used to manufacture a 3D-bolus for external beam therapy. The printed bolus then can be modeled in our treatment planning system to ensure accurate dose delivery to the patient. Methods: We developed a simple method to manufacture a patient-specific custom 3Dbolus. The bolus is designed using Eclipse Treatment Planning System, contoured onto the patients CT images. The bolus file is exported from Eclipse to 3D-printer software, and then printed using a 3D printer. Various tests were completed to determine the properties of the printing material. Percent depth dose curves in this material were measured with electron and photon beams for comparison to other materials. In order to test the validity of the 3D printed bolus for treatment planning, a custom bolus was printed and tested on the Rando phantom using film for a dose plane comparison. We compared the dose plane measured on the film to the same dose plane exported from our treatment planning system using Film QA software. The gamma-dose distribution tool was used in our film analysis. Results: We compared point measurements throughout the dose plane and were able to achieve greater than 95% passing rate at 3% dose difference and 3 mm distance to agreement, which is our departments acceptable gamma pixel parameters. Conclusion: The printed 3D bolus has proven to be accurately modeled in our treatment planning system, it is more conformal to the patient surface and more durable than other bolus currently used (wax, superflab etc.). It is also more convenient and less costly than comparable bolus from milling machine companies.

  20. Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon [Yonsei Univ., Seoul (Korea, Republic of)

    2002-03-15

    High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

  1. Estimation of radiation exposure of retrospective gated and prospective triggered 128-slice triple-rule-out CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin (Dept. of Diagnostic and Interventional Radiology, Univ. Hospital Tuebingen, Tuebingen (Germany)), email: dominik.ketelsen@med.uni-tuebingen.de; Buchgeister, Markus (Depts. of Radiotherapy and Radiooncology, Univ. Hospital Tuebingen, Tuebingen (Germany))

    2011-09-15

    Background: CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. Purpose: To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). Material and Methods: An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). Results: The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4-13.4 mSv and from 10.1-17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% +- 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% +- 6.5% in comparison to standard ECG-pulsing (p < 0.001). The effective dose increased significantly with lower heart rates (p < 0.001). Prospective ECG-triggered TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Conclusion: Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner

  2. Dose delivered from Varian's CBCT to patients receiving IMRT for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wen Ning; Guan Huaiqun; Hammoud, Rabih; Pradhan, Deepak; Nurushev, T; Li Shidong; Movsas, Benjamin [Henry Ford Health System, Detroit, MI (United States)

    2007-04-21

    With the increased use of cone beam CT (CBCT) for daily patient setup, the accumulated dose from CBCT may be significantly higher than that from simulation CT or portal imaging. The objective of this work is to measure the dose from daily pelvic scans with fixed technical settings and collimations. CBCT scans were acquired in half-fan mode using a half bowtie and x-rays were delivered in pulsed-fluoro mode. The skin doses for seven prostate patients were measured on an IRB-approved protocol. TLD capsules were placed on the patient's skin at the central axis of three beams: AP, left lateral (Lt Lat) and right lateral (Rt Lat). To avoid the ring artefacts centred in the prostate, the treatment couch was dropped 3 cm from the patient's tattoo (central axis). The measured AP skin doses ranged 3-6 cGy for 20-33 cm separation. The larger the patient size the less the AP skin dose. Lateral doses did not change much with patient size. The Lt Lat dose was {approx}4.0 cGy, which was {approx}40% higher than the Rt Lat dose of {approx}2.6 cGy. To verify this dose asymmetry, surface doses on an IMRT QA phantom (oval shaped, 30 cm x 20 cm) were measured at the same three sites using TLD capsules with 3 cm table-drop. The dose asymmetry was due to: (1) kV source rotation which always starts from the patient's Lt Lat and ends at Lt Lat. Gantry rotation gets much slower near the end of rotation but dose rate stays constant and (2) 370{sup 0} scan rotation (10{sup 0} scan overlap on the Lt Lat side). In vivo doses were measured inside a Rando pelvic heterogeneous phantom using TLDs. The left hip (femoral head and neck) received the highest doses of {approx}10-11 cGy while the right hip received {approx}6-7 cGy. The surface and in vivo doses were also measured for phantoms at the central-axis setup. The difference was less than {approx}12% to the table-drop setup.

  3. Theoretical and experimental characterization of novel water-equivalent plastics in clinical high-energy carbon-ion beams

    Science.gov (United States)

    Lourenço, A.; Wellock, N.; Thomas, R.; Homer, M.; Bouchard, H.; Kanai, T.; MacDougall, N.; Royle, G.; Palmans, H.

    2016-11-01

    Water-equivalent plastics are frequently used in dosimetry for experimental simplicity. This work evaluates the water-equivalence of novel water-equivalent plastics specifically designed for light-ion beams, as well as commercially available plastics in a clinical high-energy carbon-ion beam. A plastic- to-water conversion factor {{H}\\text{pl,w}} was established to derive absorbed dose to water in a water phantom from ionization chamber readings performed in a plastic phantom. Three trial plastic materials with varying atomic compositions were produced and experimentally characterized in a high-energy carbon-ion beam. Measurements were performed with a Roos ionization chamber, using a broad un-modulated beam of 11  ×  11 cm2, to measure the plastic-to-water conversion factor for the novel materials. The experimental results were compared with Monte Carlo simulations. Commercially available plastics were also simulated for comparison with the plastics tested experimentally, with particular attention to the influence of nuclear interaction cross sections. The measured H\\text{pl,w}\\exp correction increased gradually from 0% at the surface to 0.7% at a depth near the Bragg peak for one of the plastics prepared in this work, while for the other two plastics a maximum correction of 0.8%-1.3% was found. Average differences between experimental and numerical simulations were 0.2%. Monte Carlo results showed that for polyethylene, polystyrene, Rando phantom soft tissue and A-150, the correction increased from 0% to 2.5%-4.0% with depth, while for PMMA it increased to 2%. Water-equivalent plastics such as, Plastic Water, RMI-457, Gammex 457-CTG, WT1 and Virtual Water, gave similar results where maximum corrections were of the order of 2%. Considering the results from Monte Carlo simulations, one of the novel plastics was found to be superior in comparison with the plastic materials currently used in dosimetry, demonstrating that it is feasible to tailor plastic

  4. Imaging dose evaluations on image guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sun Boong; KIm, Ki Hwan; Kim, Il Hwan; Kim, Woong; Im, Hyeong Seo; Han, Su Chul; Kang, Jin Mook; Kim, Jin Ho [Dept. of Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul(Korea, Republic of)

    2015-06-15

    Evaluating absorbed dose related to 2D and 3D imaging confirmation devices. According to the radiographic projection conditions, absorbed doses are measured that 3 glass dosimeters attached to the centers of 0°, 90°, 180°and 270° in the head, thorax and abdomen each with Rando phantom are used in field size 26.6×20, 15×15. In the same way, absorbed doses are measured for width 16 cm and 10 cm of CBCT each. OBI(version 1.5) system and calibrated glass dosimeters are used for the measurement. AP projection for 2D imaging check, In 0° absorbed doses measured in the head were 1.44±0.26 mGy with the field size 26.6×20, 1.17±0.02 mGy with the field size 15×15. With the same method, absorbed doses in the thorax were 3.08±0.86 mGy to 0.57±0.02 mGy by reducing field size. In the abdomen, absorbed dose were reduced 8.19±0.54 mGy to 4.19±0.09 mGy. Finally according to the field size, absorbed doses has decreased by average 5-12%. With Lateral projection, absorbed doses showed average 5-8% decrease. CBCT for 3D imaging check, CBDI in the head were 4.39±0.11 mGy to 3.99±0.13 mGy by reducing the width 16 cm to 10 cm. In the same way in thorax the absorbed dose were reduced 34.88±0.93(10.48±0.09) mGy to 31.01±0.3(9.30±0.09) mGy and 35.99±1.86 mGy to 32.27±1.35 mGy in the abdomen. With variation of width 16 cm and 10 cm, they showed 8-11% decrease. By means of reducing 2D field size, absorbed dose were decreased average 5-12% in 3D width size 8-11%. So that it is necessary for radiation therapists to recognize systematical management for absorbed dose for Imaging confirmation. and also for frequent CBCT, it is considered whether or not prescribed dose for RT refer to imaging dose.

  5. Space radiation absorbed dose distribution in a human phantom

    Science.gov (United States)

    Badhwar, G. D.; Atwell, W.; Badavi, F. F.; Yang, T. C.; Cleghorn, T. F.

    2002-01-01

    The radiation risk to astronauts has always been based on measurements using passive thermoluminescent dosimeters (TLDs). The skin dose is converted to dose equivalent using an average radiation quality factor based on model calculations. The radiological risk estimates, however, are based on organ and tissue doses. This paper describes results from the first space flight (STS-91, 51.65 degrees inclination and approximately 380 km altitude) of a fully instrumented Alderson Rando phantom torso (with head) to relate the skin dose to organ doses. Spatial distributions of absorbed dose in 34 1-inch-thick sections measured using TLDs are described. There is about a 30% change in dose as one moves from the front to the back of the phantom body. Small active dosimeters were developed specifically to provide time-resolved measurements of absorbed dose rates and quality factors at five organ locations (brain, thyroid, heart/lung, stomach and colon) inside the phantom. Using these dosimeters, it was possible to separate the trapped-proton and the galactic cosmic radiation components of the doses. A tissue-equivalent proportional counter (TEPC) and a charged-particle directional spectrometer (CPDS) were flown next to the phantom torso to provide data on the incident internal radiation environment. Accurate models of the shielding distributions at the site of the TEPC, the CPDS and a scalable Computerized Anatomical Male (CAM) model of the phantom torso were developed. These measurements provided a comprehensive data set to map the dose distribution inside a human phantom, and to assess the accuracy and validity of radiation transport models throughout the human body. The results show that for the conditions in the International Space Station (ISS) orbit during periods near the solar minimum, the ratio of the blood-forming organ dose rate to the skin absorbed dose rate is about 80%, and the ratio of the dose equivalents is almost one. The results show that the GCR model dose

  6. Intitial observation of the clinical efficacy of endoscopic dacryocystorhinostomy with silicone intubation or silver clip fixation%鼻内窥镜下泪囊鼻腔造孔联合置管与银夹法临床疗效初步观察

    Institute of Scientific and Technical Information of China (English)

    许福荣; 黄碧文; 伍雪芬; 姚卫兰; 罗燕红

    2012-01-01

    Objective To observe the clinical efficacy of endoscopic dacryocystorhinostomy with silicone intubation or silver clip fixation. Methods Thirteen subjects (with fifteen sick eyes) underwent chronic dacryocystitis were divided into Group A and B rando nuy. Patients in Group A were performed endoscopic dacryocystorhinostomy with silioone intubation while Group B were undergone endoscopic dacryocystorhinostomy with silver clip fixation. The condition of symptom improvement, irrigation of lacrimal passages and stoma obstruction after surgery were surveyed. Results Followed up fcr 4 -18 months, seven patients in Group A (with nine sick eyes) were healing well. The cure rate was 100%. In Group B(6 patients with 6 eyes) , one patient who appeared stoma obstruction were cured after cleaning the stoma. And another patient needed silicone intubation to be cuerd because the epiphoraing was unimproved after iterative cleaning and the stoma was tended to atresia. Group B' s effective power was 83%. Condusioil Endoscopic dacryocystorhinostomy with silicone intubation is safe and effective. Patient have endoscopic dacryocystorhinostomy with silver clip fixation needed endoscopy examination and stoma cleaning regularly.%目的 观察鼻内窥镜下泪囊鼻腔造孔联合置管与银夹法的临床疗效.方法 将13例患者(15只眼)随机分到A组及B组,A组患者施行经鼻内窥镜下泪囊鼻腔造孔联合置管术,B组患者施行经鼻内窥镜下银夹法泪囊鼻腔造孔术.术后观察症状改善、泪道通畅和造孔口的情况.结果 术后随访4~18个月,A组7例(9只眼)治愈,治愈率100%;B组6例(6只眼),其中1只眼出现吻合口阻塞,经清理后治愈,1只眼吻合口阻塞经反复清理后溢泪症状无改善,造孔有闭锁趋向,予置管后治愈,有效率83%.结论 鼻内镜下鼻腔泪囊造孔联合置管较稳妥,疗效确切,联合银夹法需定期予内窥镜检查、清理造孔口.

  7. Evaluation of ovary dose for woman of childbearing age woman with breast cancer in tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hyeong; Park, Soo Yeon; Choi, Ji Min; Park, Ju Young; Kim, Jong Suk [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2014-12-15

    The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of 64.94±0.84 mGy and 37.64±1.20 mGy in left ovary part and average of 64.38±1.85 mGy and 32.96±1.11 mGy in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.

  8. Dosimetric analysis for photon and electron beams in Whole body irradiation; Analisis dosimetrico para haces de fotones y electrones en irradiacion corporal total

    Energy Technology Data Exchange (ETDEWEB)

    Hurtado G, M. [Posgrado. Fisica Medica Radiologica. Universidad Nacional de Colombia, Bogota. Instituto Nacional de Cancerologia. Instituto Regional de Cancer de la Orinoquia. Hospital Regional de Villavicencio, Meta (Colombia)

    1998-12-31

    To initiate the Whole body irradiation as an alternative for the treatment of the hematological diseases, leukemia and assistant for the osseous marrow transplantation, it may be taken account the application of International Protocols about control and quality assurance. It is established the intercomparison by the different dosimetric methods: cylindrical ionization chambers and parallel plane, radiographic emulsion film, semiconductor diodes (Mosfet transistors) and TLD-100 thermoluminescent crystals, obtained measurements for 140 x 140 cm{sup 2} fields and large distances 340 cm respect conventional fields in Radiotherapy. The in vitro dosimetry was realized at the Universal Anthropomorphic puppet Alderson Rando basically with the cylindrical crystals (1 mm diameter) of TLD-100 lithium fluoride. It was obtained the dose value with a 0.6 cm{sup 3} cylindrical ionization chamber and the Farmer electrometer for Whole body irradiation (ICT) with photons for electrons and were obtained values with the Markus plane parallel camera. Knowing the dose rate value to the source-surface distance DFS= 80 cm, it was calibrated the crystals with the reference radiation beam of {sup 60} Co for obtaining the response curve: Dose vs. Tl lecture. It was characterized the 10 % of the total population for 300 crystals for applying the statistics corresponding. The luminescence curve obtained of Gaussian form was considered satisfactory by its stability during the pre-anneal lecture and anneal process, getting the main peak lecture at 300 Centigrade according to assigned parameters at lecture equipment TLD Harshaw model 4500. The results indicate the functional dependence with the distance DFS= 340 cm for the following depth PPD, the relations TMR and TPR, the TAR is not calculated by the increment of the dispersion in air. The penumbra increment indicates an increase of the radiation field respect of luminous field. The dispersion angle q{sub 1} respect at the field central axis

  9. Investigating the low-dose limits of multidetector CT in lung nodule surveillance.

    Science.gov (United States)

    Paul, N S; Siewerdsen, J H; Patsios, D; Chung, T B

    2007-09-01

    The purpose of this study was to evaluate the factors limiting nodule detection in thoracic computed tomography (CT) and to determine whether prior knowledge of nodule size and attenuation, available from a baseline CT study, influences the minimum radiation dose at which nodule surveillance CT scans can be performed while maintaining current levels of nodule detectability. Multiple nodules varying in attenuation (-509 to + 110 HU) and diameter (1.6 to 9.5 mm) were layered in random and ordered sequences within 2 lung cylinders made of Rando lung material and suspended within a custom-built CT phantom. Multiple CT scans were performed at varying kVp (120, 100, and 80), mA (200, 150, 100, 50, 20, and 10), and beam collimation (5, 2.5, and 1.25 mm) on a four-row multidetector scanner (Lightspeed, General Electric, Milwaukee, WI) using 0.8 s gantry rotation. The corresponding range of radiation dose over which images were acquired was 0.3-26.4 mGy. Nine observers independently performed three specific tasks, namely: (1) To detect a 3.2 mm nodule of 23 HU; (2) To detect 3.2 mm nodules of varying attenuation (-509 to -154 HU); and (3) To detect nodules varying in size (1.6-9 mm) and attenuation (-509 to 110 HU). A two-alternative forced-choice test was used in order to determine the limits of nodule detection in terms of the proportion of correct responses (Pcorr, related to the area under the ROC curve) as a summary metric of observer performance. The radiation dose levels for detection of 99% of nodules in each task were as follows: Task 1 (1 mGy); Task 2 (5 mGy); and Task 3 (7 mGy). The corresponding interobserver confidence limits were 1, 5, and 10 mGy for Tasks 1, 2, and 3, respectively. There was a fivefold increase in the radiation dose required for detection of lower-density nodules (Tasks 1 to 2). Absence of prior knowledge of the nodule size and density (Task 3) corresponds to a significant increase in the minimum required radiation dose. Significant image

  10. Evaluation of the lens absorbed dose of MVCT and kV-CBCT use for IMRT to the nasopharyngeal cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Won; Kim, Cheol Chong; Park, Su Yeon; Song, Ki Weon [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2013-09-15

    Quantitative comparative evaluation of the difference in eye lens absorbed dose when measured by MVCT and kV-CBCT, though such a dose was not included in the original IMRT treatment plan for the nasopharyngeal cancer patient. We used CT (Lightspeed Ultra 16, General Electric, USA) against an Anderson rando phantom (Alderson Research Laboratories Inc, USA) and established the plan for tomotherapy treatment (Tomotherapy, Inc, USA) and linear accelerator treatment (Pinnacle 8.0, Philips Medicle System) for the achieved CT images on the same condition with the nasopharyngeal cancer patient treatment plan. Then, align the thermoluminescence dosimeter (TLD100 Harshaw, USA) with the eye lens, shot the lens with Tomotherapy MVCT under 3 conditions (Fine, Normal, and Coarse), and shot both lenses with kV-CBCT under 2 conditions (Low Dose Head and Standard Dose Head) 3 times each. When we analyzed the eye lens absorbed dose according to MVCT and kV-CBCT images by using both Tomotherapy and Pinacle 8.0, we achieved the following result; According to Tomotherapy MVCT, RT 0.8257 cGy in the Coarse mode, LT 0.8137 cGy, RT 1.089 cGy and LT 1.188 cGy in the Normal mode, and RT 2.154 cGy and LT 2.082 cGy in the Fine mode. According to Pinacle 8.0 kV-CBCT, RT 0.2875 cGy and LT 0.1676 cGy in the Standard Dose mode and RT 0.1648 cGy and LT 0.1212 cGy in the Low-Dose mode. In short, the MVCT result was significantly different from that of kV-CBCT, up to 20 times. We think kV-CBCT is more effective for reducing the amount of radiation which a patient is receiving during intensity modulated radiation treatment for other purposes than treatment than MVCT, when we consider the absorbed dose only from the viewpoint of image-guided radiation therapy. Besides, we understood the amount of radiation is too sensitive to the shooting condition, even when we use the same equipment.

  11. Analysis of the Imaging Dose for IGRT/Gated Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Suk; Han, Young Yih; Ju, Sang Gyu; Shin, Eun Hyuk; Hong, Chae Seon; Ahn, Yong Chan [Samsung Medical Center, Seoul (Korea, Republic of)

    2009-03-15

    The introduction of image guided radiation therapy/four-dimensional radiation therapy (IGRT/4DRT) potentially increases the accumulated dose to patients from imaging and verification processes as compared to conventional practice. It is therefore essential to investigate the level of the imaging dose to patients when IGRT/4DRT devices are installed. The imaging dose level was monitored and was compared with the use of pre-IGRT practice. A four-dimensional CT (4DCT) unit (GE, Ultra Light Speed 16), a simulator (Varian Acuity) and Varian IX unit with an on-board imager (OBI) and cone beam CT (CBCT) were installed. The surface doses to a RANDO phantom (The Phantom Laboratory, Salem, NY USA) were measured with the newly installed devices and with pre-existing devices including a single slice CT scanner (GE, Light Speed), a simulator (Varian Ximatron) and L-gram linear accelerator (Varian, 2100C Linac). The surface doses were measured using thermo luminescent dosimeters (TLDs) at eight sites-the brain, eye, thyroid, chest, abdomen, ovary, prostate and pelvis. Compared to imaging with the use of single slice non-gated CT, the use of 4DCT imaging increased the dose to the chest and abdomen approximately ten-fold (1.74{+-}0.34 cGy versus 23.23{+-}3.67 cGy ). Imaging doses with the use of the Acuity simulator were smaller than doses with the use of the Ximatron simulator, which were 0.91{+-}0.89 cGy versus 6.77{+-}3.56 cGy, respectively. The dose with the use of the electronic portal imaging device (EPID; Varian IX unit) was approximately 50% of the dose with the use of the L-gram linear accelerator (1.83{+-}0.36 cGy versus 3.80{+-}1.67 cGy). The dose from the OBI for fluoroscopy and low-dose mode CBCT were 0.97{+-}0.34 cGy and 2.3{+-}0.67 cGy, respectively. The use of 4DCT is the major source of an increase of the radiation (imaging) dose to patients. OBI and CBCT doses were small, but the accumulated dose associated with everyday verification need to be considered.

  12. Characterization of the secondary neutron field produced during treatment of an anthropomorphic phantom with x-rays, protons and carbon ions.

    Science.gov (United States)

    Tessa, C La; Berger, T; Kaderka, R; Schardt, D; Burmeister, S; Labrenz, J; Reitz, G; Durante, M

    2014-04-21

    Short- and long-term side effects following the treatment of cancer with radiation are strongly related to the amount of dose deposited to the healthy tissue surrounding the tumor. The characterization of the radiation field outside the planned target volume is the first step for estimating health risks, such as developing a secondary radioinduced malignancy. In ion and high-energy photon treatments, the major contribution to the dose deposited in the far-out-of-field region is given by neutrons, which are produced by nuclear interaction of the primary radiation with the beam line components and the patient's body. Measurements of the secondary neutron field and its contribution to the absorbed dose and equivalent dose for different radiotherapy technologies are presented in this work. An anthropomorphic RANDO phantom was irradiated with a treatment plan designed for a simulated 5 × 2 × 5 cm³ cancer volume located in the center of the head. The experiment was repeated with 25 MV IMRT (intensity modulated radiation therapy) photons and charged particles (protons and carbon ions) delivered with both passive modulation and spot scanning in different facilities. The measurements were performed with active (silicon-scintillation) and passive (bubble, thermoluminescence ⁶LiF:Mg, Ti (TLD-600) and ⁷LiF:Mg, Ti (TLD-700)) detectors to investigate the production of neutral particles both inside and outside the phantom. These techniques provided the whole energy spectrum (E ≤ 20 MeV) and corresponding absorbed dose and dose equivalent of photo neutrons produced by x-rays, the fluence of thermal neutrons for all irradiation types and the absorbed dose deposited by neutrons with 0.8 thermal neutrons is observed for photons and, among ions, for passively modulated beams. For the treatment with high-energy x-rays, the contribution of secondary neutrons to the dose equivalent is of the same order of magnitude as the primary radiation. In carbon therapy delivered with

  13. Pilot study of the dose in crystalline lens in the interventional radiology practice; Estudio piloto de la dosis en cristalino en la practica de radiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Castro, A.; Martinez, A.; Fernandez, A.; Molina, D. [Centro de Proteccion e Higiene de las Radiaciones, Carretera de la Cantera, Victoria II, Km. 21.5 Guanabacoa, La Habana (Cuba); Sanchez, L.; Diaz, A., E-mail: ailza@cphr.edu.cu [Hospital Clinico Quirurgico Hermanos Ameijeiras, San Lazaro 701, Centro Habana, La Habana (Cuba)

    2014-08-15

    The interventional radiology involves considerable exposure levels for the occupationally exposed personnel (OEP). The doses can encompass a wide range of values in dependence of the function that develops the personnel and the complexity of each procedure. In organs like the crystalline lens and skin values can be reached that imply the appearance of deterministic effects if is not fulfilled the appropriate measures of radiological protection. This has been demonstrated through multiple studies, among those that the retrospective study of damages in the crystalline lens and dose has been one of those most commented, known as RELID. The objective of that study was to examine the opacity prevalence in the crystalline lens in workers linked to the interventional cardiology and to correlate it with the occupational exposition. The obtained results contributed to that the ICRP recommend a new limit value of equivalent dose for crystalline lens of 20 mSv in one year. With the objective of analyzing the operational implications, in the radiological surveillance programs that they could originate with the new recommendations was developed a pilot study to evaluate the dose in crystalline lens in the OEP linked to the interventional radiology in a Cuban hospital. For this, an anthropomorphic mannequin RANDO-ALDERSON was used on which thermoluminescent dosimeters were placed below and above of the leaded apron and in different positions at level of the crystalline lens: above, below and to the sides of the leaded lenses that the personnel uses routinely. The mannequin was located on the same positions that occupy the main specialist that execute the procedure, as well as of the nurse to assist him. The measurements were made simulating the more representative procedures about complexity, duration time and exposure rate. The used dosimeters were RADOS model for whole body composed of two thermoluminescent detectors Gr-200 (LiF: Mg, Cu, P) to evaluate personal equivalent dose

  14. Study on Quality and Nutrition of Eggs from Hy - line Brown and Jingbai%海兰褐鸡与京白鸡蛋品质与营养对比分析

    Institute of Scientific and Technical Information of China (English)

    宋爱祎; 逢焕明; 李瑾瑜; 朱正兰; 古丽娜孜; 王子荣

    2012-01-01

    [Objective] This experiment compared the differences of egg quality and nutrient content of Hy- line brown and Jingbai hen. [ Method] 100 eggs were rando mLy selected from 40 to 43 - week - old of Hy- line brown and Jingbai hen to determine the quality and nutrition, using Duncan method for multiple comparisons. [Result]Except egg white pH value, the Hy -Line Browns external quality and internal quality indicators were higher than those of Jingbai hen; Cholesterol levels have a very significant difference (P < 0.01) ,the unit is g/100 g; Gram each piece for unit, protein and fat content have a very significant difference (P <0. 01). [ Conclusion] Egg quality of Hy - line brown was better than that of Jingbai hen; nutrient content of Hy -line brown was lower than Jingbai hen,the unit is g/100 g;Gram each piece, nutrient content of Hy - line brown hen was higher than that of Jingbai hens, except for cholesterol.%[目的]分析海兰褐鸡和京白鸡蛋品质及营养成分的差异.[方法]随机抽取40~ 43周龄的海兰褐鸡、京白鸡蛋各100枚,测定其蛋品质和营养,并采用Duncan新复极差法进行多重比较.[结果]除蛋清pH值外,海兰褐鸡蛋外在品质和内在品质指标均高于京白鸡的;以g/100 g为单位,胆固醇含量有极显著差异(P<0.01);而以g/枚为单位,蛋白质和脂肪含量有极显著差异(P<0.01).[结论]蛋品质海兰褐鸡的比京白鸡的好;蛋以g/100 g为单位,京白鸡的营养成分比海兰褐鸡的高;以g/枚为单位,除胆固醇外京白鸡的营养成分比海兰褐鸡的低.

  15. Measurement of neutron dose equivalent outside and inside of the treatment vault of GRID therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xudong; Charlton, Michael A.; Esquivel, Carlos; Eng, Tony Y.; Li, Ying; Papanikolaou, Nikos [University of Texas Health Science Center, San Antonio, Texas 78229 (United States)

    2013-09-15

    Purpose: To evaluate the neutron and photon dose equivalent rates at the treatment vault entrance (H{sub n,D} and H{sub G}), and to study the secondary radiation to the patient in GRID therapy. The radiation activation on the grid was studied.Methods: A Varian Clinac 23EX accelerator was working at 18 MV mode with a grid manufactured by .decimal, Inc. The H{sub n,D} and H{sub G} were measured using an Andersson–Braun neutron REM meter, and a Geiger Müller counter. The radiation activation on the grid was measured after the irradiation with an ion chamber γ-ray survey meter. The secondary radiation dose equivalent to patient was evaluated by etched track detectors and OSL detectors on a RANDO{sup ®} phantom.Results: Within the measurement uncertainty, there is no significant difference between the H{sub n,D} and H{sub G} with and without a grid. However, the neutron dose equivalent to the patient with the grid is, on average, 35.3% lower than that without the grid when using the same field size and the same amount of monitor unit. The photon dose equivalent to the patient with the grid is, on average, 44.9% lower. The measured average half-life of the radiation activation in the grid is 12.0 (±0.9) min. The activation can be categorized into a fast decay component and a slow decay component with half-lives of 3.4 (±1.6) min and 15.3 (±4.0) min, respectively. There was no detectable radioactive contamination found on the surface of the grid through a wipe test.Conclusions: This work indicates that there is no significant change of the H{sub n,D} and H{sub G} in GRID therapy, compared with a conventional external beam therapy. However, the neutron and scattered photon dose equivalent to the patient decrease dramatically with the grid and can be clinical irrelevant. Meanwhile, the users of a grid should be aware of the possible high dose to the radiation worker from the radiation activation on the surface of the grid. A delay in handling the grid after the beam

  16. SU-E-J-123: Targeting Accuracy of Image-Guided Radiosurgery for Intracranial Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Wen, N; Zhao, B; Kim, J; Gordon, J; Chetty, I [Henry Ford Health System, Detroit, MI (United States)

    2014-06-01

    Purpose: To evaluate the setup accuracies of image-guided intracranial radiosurgery across several different linear accelerator platforms. Methods: A CT scan with a slice thickness of 1.0 mm was acquired of a Rando head phantom (The Phantom Laboratory) in a U-frame mask (BrainLAB AG). The phantom had three embedded BBs, simulating a central, left, and anterior lesion. The phantom was setup with each BB placed at the radiation isocenter under image guidance. Four different setup procedures were investigated: (1) NTX-ExacTrac: 6 degree-of-freedom (6D) correction on a Novalis Tx (BrainLAB AG) with ExacTrac localization (BrainLAB AG); (2) NTX-CBCT: 4D correction on the Novalis Tx with cone-beam computed tomography (CBCT); (3) TrueBeam-CBCT: 4D correction on a TrueBeam (Varian) with CBCT; (4) Edge-CBCT: 6D correction on an Edge (Varian) with CBCT. The experiment was repeated 5 times with different initial setup error at each BB location on each platform, and the mean (μ) and one standard deviation (σ) of the residual error was compared.The congruence between radiation and imaging isocenters on each platform was evaluated by acquiring Winston Lutz (WL) images of a WL jig followed by imaging using ExacTrac or CBCT. The difference in coordinates of the jig relative to radiation and imaging isocenters was then recorded. Results: Averaged over all three BB locations, the residual vector setup errors (μ±σ) of the phantom in mm were 0.6±0.2, 1.0±0.5, 0.2±0.1, and 0.3±0.1 on NTX-ExacTrac, NTX-CBCT, TrueBeam-CBCT, and Edge-CBCT, with their ranges in mm being 0.4∼1.1, 0.4∼1.9, 0.1∼0.5, and 0.2∼0.6, respectively. And imaging isocenter was found stable relative to radiation isocenter, with the congruence to radiation isocenter in mm being 0.6±0.1, 0.7±0.1, 0.3±0.1, 0.2±0.1, respectively, on the four systems in the same order. Conclusion: Millimeter accuracy can be achieved with image-guided radiosurgery for intracranial lesions based on this set of experiments.

  17. Measurement of mean cardiac dose for various breast irradiation techniques and corresponding risk of major cardiovascular event.

    Directory of Open Access Journals (Sweden)

    Tomas Rodrigo Merino Lara

    2014-10-01

    Full Text Available After breast conserving surgery, early stage breast cancer patients are currently treated with a wide range of radiation techniques including whole breast irradiation (WBI, accelerated partial breast irradiation (APBI using high dose rate (HDR brachytherapy, or 3D conformal radiotherapy (3D-CRT. This study compares the mean heart’s doses for a left breast irradiated with different breast techniques.An anthropomorphic Rando phantom was modified with gelatin-based breast of different sizes and tumors located medially or laterally. The breasts were treated with WBI, 3D-CRT or HDR APBI. The heart’s mean doses were measured with Gafchromic films and controlled with optically stimulated luminescent dosimeters (OSLDs. Following the model reported by Darby (16, major cardiac were estimated assuming a linear risk increase with the mean dose to the heart of 7.4% per gray.Whole breast irradiation lead to the highest mean heart dose (2.99 Gy compared to 3D-CRT APBI, (0.51 Gy, multicatheter (1.58 Gy and balloon HDR (2.17 Gy for a medially located tumor. This translated into long-term coronary event increases of 22%, 3.8%, 11.7%, and 16% respectively. The sensitivity analysis showed that the tumor location had almost no effect on the mean heart dose for 3D-CRT APBI and a minimal impact for HDR APBI. For WBI large breast size and set-up errors lead to sharp increases of the mean heart dose. Its value reached 10.79 Gy for women with large breast and a set-up error of 1.5 cm. Such a high value could increase the risk of having long-term coronary events by 80%.Comparison among different irradiation techniques demonstrates that 3D-CRT APBI appears the safest one with less probability of having cardiovascular events in the future. A sensitivity analysis showed that WBI is the most challenging technique for patients with large breasts or when significant set-up errors are anticipated. In those cases additional heart shielding techniques are required.

  18. SU-E-J-146: A Research of PET-CT SUV Range for the Online Dose Verification in Carbon Ion Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L; Hu, W [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China); Moyers, M [Shanghai Proton and Heavy Ion Center, Colton, CA (China); Zhao, J [Shanghai Proton and Heavy Ion Center, Shanghai, Shanghai (China); Hsi, W [Shanghai Proton and Heavy Ion Center, Shanghai (China)

    2015-06-15

    Purpose: Positron-emitting isotope distributions can be used for the image fusion of the carbon ion planning CT and online target verification PETCT, after radiation in the same decay period,the relationship between the same target volume and the SUV value of different every single fraction dose can be found,then the range of SUV for the radiation target could be decided.So this online range also can provide reference for the correlation and consistency in planning target dose verification and evaluation for the clinical trial. Methods: The Rando head phantom can be used as real body,the 10cc cube volume target contouring is done,beam ISO Center depth is 7.6cm and the 90 degree fixed carbon ion beams should be delivered in single fraction effective dose of 2.5GyE,5GyE and 8GyE.After irradiation,390 seconds later the 30 minutes PET-CT scanning is performed,parameters are set to 50Kg virtual weight,0.05mCi activity.MIM Maestro is used for the image processing and fusion,five 16mm diameter SUV spheres have been chosen in the different direction in the target.The average SUV in target for different fraction dose can be found by software. Results: For 10cc volume target,390 seconds decay period,the Single fraction effective dose equal to 2.5Gy,Ethe SUV mean value is 3.42,the relative range is 1.72 to 6.83;Equal to 5GyE,SUV mean value is 9.946,the relative range is 7.016 to 12.54;Equal or above to 8GyE,SUV mean value is 20.496,the relative range is 11.16 to 34.73. Conclusion: Making an evaluation for accuracy of the dose distribution using the SUV range which is from the planning CT with after treatment online PET-CT fusion for the normal single fraction carbon ion treatment is available.Even to the plan which single fraction dose is above 2GyE,in the condition of other parameters all the same,the SUV range is linearly dependent with single fraction dose,so this method also can be used in the hyper-fraction treatment plan.

  19. Comparative dose evaluations between XVI and OBI cone beam CT systems using Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Giaddui, Tawfik; Cui Yunfeng; Galvin, James; Yu Yan; Xiao Ying [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

    2013-06-15

    Purpose: To investigate the effect of energy (kVp) and filters (no filter, half Bowtie, and full Bowtie) on the dose response curves of the Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters (OSLDs) in CBCT dose fields. To measure surface and internal doses received during x-ray volume imager (XVI) (Version R4.5) and on board imager (OBI) (Version 1.5) CBCT imaging protocols using these two types of dosimeters. Methods: Gafchromic XRQA2 film and nanoDot OSLD dose response curves were generated at different kV imaging settings used by XVI (software version R4.5) and OBI (software version 1.5) CBCT systems. The settings for the XVI system were: 100 kVp/F0 (no filter), 120 kVp/F0, and 120 kVp/F1 (Bowtie filter), and for the OBI system were: 100 kVp/full fan, 125 kVp/full fan, and 125 kVp/half fan. XRQA2 film was calibrated in air to air kerma levels between 0 and 11 cGy and scanned using reflection scanning mode with the Epson Expression 10000 XL flat-bed document scanner. NanoDot OSLDs were calibrated on phantom to surface dose levels between 0 and 14 cGy and read using the inLight{sup TM} MicroStar reader. Both dosimeters were used to measure in field surface and internal doses in a male Alderson Rando Phantom. Results: Dose response curves of XRQA2 film and nanoDot OSLDs at different XVI and OBI CBCT settings were reported. For XVI system, the surface dose ranged between 0.02 cGy in head region during fast head and neck scan and 4.99 cGy in the chest region during symmetry scan. On the other hand, the internal dose ranged between 0.02 cGy in the head region during fast head and neck scan and 3.17 cGy in the chest region during chest M20 scan. The average (internal and external) dose ranged between 0.05 cGy in the head region during fast head and neck scan and 2.41 cGy in the chest region during chest M20 scan. For OBI system, the surface dose ranged between 0.19 cGy in head region during head scan and 4.55 cGy in the pelvis region during

  20. Investigation of Characteristics for Yield and Quality of Curcuma phaeocaulis Val.from Sichuan Province%川产莪术植株产量与品质特性的调查研究

    Institute of Scientific and Technical Information of China (English)

    甘愿; 程方叙; 张兴国; 张川钱

    2011-01-01

    [目的]调查川产莪术植株各部位生物学产量,初步研究其资源品质特性,为茎叶资源的开发利用提供科学依据.[方法]在主产区随机采集川产莪术代表性植株,以植株不同部位为试验研究材料,应用《中华人民共和国药典》及文献中的品质检测方法,调研川产莪术植株产量并检测品质特性.[结果]植株每窝二母姜(莪术)干品平均产量为224.44g,其中茎叶光合产物、脂溶性组分、蛋白质积累量分别占植株资源总量的40.61%、42.05%、38.06%,以叶片的脂溶性组分含量(2.897%)最高;川产莪术植株的灰分含量均符合《中华人民共和国药典》(2010版,二部)莪术、郁金要求.[结论]川产莪术植株茎叶为可利用的优良资源,建议在主产区川产莪术植株枯萎前采收,对茎叶加以回收利用,以提高川产莪术植株的产油率或用作饲料.%[Objective]To study the yield of different parts of Curcuma phaeocaulis Val. From Sichuan and make preliminary study on different resource quality characteristics so as to provide scientific basis for the development and utilization of the stems and leaves resources. [ Methods]To investigate the yield of Curcuma phaeocaulis Val. From Sichuan and detect quality characteristics with quality identification methods recorded in Chinese Pharmacopoeia and some literature, different parts of the representative plants picked rando mly from the main production area Sichuan were regarded as experimental materials. [ Result]The average yield of dried goods is 224.44 g,among which photosynthates in stems and leaves, fat-soluble ingredients,protein yields account for 40.61% ,42.05% and 38.06% of the total resource,respectively. The content of fat-soluble ingredients in leaves was the highest at 2.897%. The ash content was all fulfilled the requirements on RADIX CURCUMAE of Chinese Pharmacopoeia (2010 Edition II). [ Conclusion ] Stems and leaves of Curcuma phaeocaulis Val. From

  1. ERRATUM: FERMI Large Area Telescope Study of Cosmic-Rays and the Interstellar Medium in Nearby Molecular Clouds

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; hide

    2013-01-01

    systematic uncertainty into account." 3. Table 1 and Figure 13, which show gas emissivities and spectra for the Chamaeleon region in the original paper, should be changed to the Table 1 and Figure 1 as shown below. 4. Figure 16, which compares Hi gas emissivities among several regions in the original paper, should be changed to Figure 2 as shown below. 5. The text from the line 13 to the last one in the first paragraph of Section 4.1, "The spectral shapes for the three regions..., indicating a difference of the CR density between the Chamaeleon and the others as shown in Figure 16." should be changed to the paragraph that follows. "The shaded area of each spectrum indicates the systematic uncertainty as described in Section 3. We note that the systematic uncertainty of the LAT effective area (5% at 100 MeV and 20% at 10 GeV; Rando et al. 2009) does not affect the relative value of emissivities. The effect of unresolved point sources is small; we have verified that the obtained emissivities are almost unaffected by decreasing the threshold for point sources from TS = 100 to TS = 50. We also confirmed that the residual excess of photons around (l = 280deg to 288deg, b = -20deg to -12deg; see the bottom panel of Figure 8) in the Chamaeleon region does not affect the local Hi emissivity very much. Thus the total systematic uncertainty is reasonably expressed by the shaded area shown in Fig. 1.

  2. A comparison of measurement techniques for quality assurance of RapidArc treatment plans

    Science.gov (United States)

    Konieczny, Jeff

    A new form of intensity modulated radiation therapy (IMRT) using the Varian RapidArc® treatment system has the potential to improve cancer treatments by delivering comparable dose distributions as TomoTherapy ®1 at a rate that is 5 to 15 times faster 2. The goal of this thesis was to compare the sensitivity of an electronic portal imaging device (EPID), film, and the ArcCheck™ device as tools for evaluation of IMRT treatments. To accomplish this, we introduced systematic errors in MLC leaf position and perform theoretical and experimental evaluations. The comparisons were made by analyzing changes in the gamma function as systematic MLC gap errors were introduced into the patient treatment plan. To study this, dynamic prostate Rapidarc™ plans were developed in Eclipse™ using the RANDO anthropomorphic phantom. After the plans were developed, the files were exported in DICOM-RT (Digital Imaging and Communications in Medicine — Radiation Therapy) format, and a program was written to modify the MLC leaf position. The files were imported back into Eclipse and recalculated using simulated film, EPID, and ArcCheck phantoms. Before measuring the plans with the devices, each instrument was calibrated and repeatability tests were performed to determine the variation in a single plan. After the delivery of the same plan eight times, film was found to have the largest variation in average gamma of 0.31 ± 0.13. When the setup was not moved in between measurements, the ArcCheck and EPID had significantly smaller variations in average gamma of 0.10 ± 0.04 and 0.07 ± 0.03 respectively. When the setup was moved and realigned in between measurements, the average gamma variation was found to be 0.22 ± 0.10 and 0.11 ± 0.05 for the ArcCheck and EPID. As a result of the higher variation, it was decided that testing should be performed without moving the detector during the course of the measurements. Film, unfortunately, had to be changed in between tests, which resulted

  3. A study on developing customized bolus using 3D prints

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sang Min; Yang, Jin Ho; Lee, Seung Hyun; Kim, Jin Uk; Yeom, Du Seok [Dept. of Proton Therapy Center, National Cancer Center, Ilsan (Korea, Republic of)

    2015-06-15

    3D Printers are used to create three-dimensional models based on blueprints. Based on this characteristic, it is feasible to develop a bolus that can minimize the air gap between skin and bolus in radiotherapy. This study aims to compare and analyze air gap and target dose at the branded 1 cm bolus with the developed customized bolus using 3D printers. RANDO phantom with a protruded tumor was used to procure images using CT simulator. CT DICOM file was transferred into the STL file, equivalent to 3D printers. Using this, customized bolus molding box (maintaining the 1 cm width) was created by processing 3D printers, and paraffin was melted to develop the customized bolus. The air gap of customized bolus and the branded 1 cm bolus was checked, and the differences in air gap was used to compare D{sub max}, D{sub min}, D{sub mean}, D{sub 95%} and V{sub 95%} in treatment plan through Eclipse. Customized bolus production period took about 3 days. The total volume of air gap was average 3.9 cm{sup 3} at the customized bolus. And it was average 29.6cm{sup 3} at the branded 1 cm bolus. The customized bolus developed by the 3D printer was more useful in minimizing the air gap than the branded 1 cm bolus. In the 6 MV photon, at the customized bolus, D{sub max}, D{sub min}, D{sub mean}, D{sub 95%}, V{sub 95%} of GTV were 102.8%, 88.1%, 99.1%, 95.0%, 94.4% and the D{sub max}, D{sub min}, D{sub mean}, D{sub 95%}, V{sub 95%} of branded 1 cm bolus were 101.4%, 92.0%, 98.2%, 95.2%, 95.7%, respectively. In the proton, at the customized bolus, D{sub max}, D{sub min}, D{sub mean}, D{sub 95%}, V{sub 95%} of GTV were 104.1%, 84.0%, 101.2%, 95.1%, 99.8% and the D{sub max}, D{sub min}, D{sub mean}, D{sub 95%}, V{sub 95%} of branded 1cm bolus were 104.8%, 87.9%, 101.5%, 94.9%, 99.9%, respectively. Thus, in treatment plan, there was no significant difference between the customized bolus and 1 cm bolus. However, the normal tissue nearby the GTV showed relatively lower radiation dose. The

  4. Analgesia effects of sertraline combined with pregabalin in the treatment of elderly patients with postherpetic neuralgia%舍曲林联合普瑞巴林治疗老年带状疱疹后神经痛镇痛疗效的研究

    Institute of Scientific and Technical Information of China (English)

    陈英; 杨军; 李莺; 张剑江

    2015-01-01

    Objective To evaluate the efficacy of sertraline combined with pregabalin in the treatment of elderly patients with postherpetic neu-ralgia( PHN).Metheds Sixty elderly patients with PHN were rando-mized divided into control group (n=32)(pregabalin 150 mg· d-1orally bid)and treatment group (n=28)(on the basis of control group, sertra-line 50 mg · d-1 orally qd was added ). All patients accepted routine nerve nutrition drug therapy and superliser irradiation .Pain intensity was evaluated with visual analogue scale ( VAS ) before and 4 weeks after treatment, and the pain relief was assessed.The quality of life was eva-luated with the medical outcomes study 36-item short form health survey ( SF-36 ) before and 4 weeks after treatment.Results Compared with before treatment , the pain intensity of elderly patients with PHN decreased after treatment in both groups ( P<0.05 ).The data of remi-ssion of pain intensity in treatment group was higher than that in control group ( P<0.05 ).Six areas of the quality of life in treatment group were obviously improved ( P<0.05 ).No serious sertraline -related adverse reaction was found.Conclusion Sertraline combined with pregabalin can improve the curative effect on elderly patients with PHN.%目的:评价舍曲林联合普瑞巴林治疗老年带状疱疹后神经痛的临床疗效。方法60例老年带状疱疹后神经痛患者随机分为对照组(n=32)和试验组(n=28)。对照组用普瑞巴林150 mg · d-1,试验组在对照组基础上加用舍曲林50 mg· d-1,2组均常规营养神经药物治疗及物理治疗。治疗前、治疗后4周用视觉模拟评分( VAS )评估患者的疼痛强度变化,中文版简明健康测量量表(SF-36)评定生活质量的变化。结果2组治疗后疼痛强度均较治疗前显著降低(P<0.05),试验组疼痛缓解显著高于对照组(P<0.05)。试验组在6个领域的生活质量较对照组明显改善( P<0.05)。2组不

  5. Contribution to the planning and dosimetry of photon beams applied to radiosurgery and stereotactic radiotherapy; Contribuicao ao planejamento e a dosimetria de feixes de fotons aplicados a radiocirurgia e a radioterapia estereotaxica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter Menezes

    2003-08-15

    radiosurgery. Measurements were also performed with thermoluminescent dosimeters in order to verify the degree of compliance between the doses calculated through the Radionics{sup TM} Planning System and the actual treatment dose. This was accomplished by using a Rando(R) anthropomorphic phantom. The results showed that the two doses agree within {+-} 2%. The influence of the presence of inhomogeneities within the irradiated volume, due to the presence of air or bone in the radiation path was assessed. The results showed that these inhomogeneities significantly affect both the dose distribution pattern and the beam profiles in the treatment volume. The results of this study show that the dosimetry of small diameter radiation beams is still challenging, due mainly to the limited resolution of available detectors and to the lack of lateral equilibrium in small diameter radiation beams. (author)

  6. Absorbed Dose and Effective Dose for Lung Cancer Image Guided Radiation Therapy(IGRT) using CBCT and 4D-CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Yong; Lee, Woo Suk; Koo, Ki Lae; Kim, Joo Seob; Lee, Sang Hyeon [Dept. of Radiation Oncology, GangNeung Asan Hospital, Gangneung (Korea, Republic of)

    2016-06-15

    To evaluate the results of absorbed and effective doses using CBCT and 4D-CBCT settings for lung cancer. This experimental study. Measurements were performed using a Anderson rando phantom with OSLD(optically stimulated luminescent dosimeters). It was performed computed tomography(Lightspeed GE, USA) in order to express the major organs of the human body. Measurements were obtained a mean value is repeated three times each. Evaluations of effective dose and absorbed dose were performed the CL-IX-Thorax mode and Truebeam-Thorax mode CBCT. Additionally, compared Truebeam-Thorax mode CBCT with Truebeam-Thorax mode 4D-CBCT(Four-dimensional Cone Beam Computed Tomography). Average absorbed dose in the CBCT of CL-IX was measured in lung 2.505cGy, heart 2.595cGy, liver 2.145cGy, stomach 1.934cGy, skin 2.233cGy, in case of Truebeam, It was measured lung 1.725cGy, heart 2.034cGy, liver 1.616cGy, stomach 1.470cGy, skin 1.445cGy. In case of 4D-CBCT, It was measured lung 3.849cGy, heart 4.578cGy, liver 3.497cGy, stomach 3.179cGy, skin 3.319cGy Average effective dose, considered tissue weighting and radiation weighting, in the CBCT of CL-IX was measured lung 2.164mSv, heart 2.241mSVv, liver 0.136mSv, stomach 1.668mSv, skin 0.009mSv, in case of Turebeam, it was measured lung 1.725mSv, heart 1.757mSv, liver 0.102mSv, stomach 1.270mSv, skin 0.005mSv, In case of 4D-CBCT, It was measured lung 3.326mSv, heart 3.952mSv, liver 0.223mSv, stomach 2.747mSv, skin 0.013mSv. As a result, absorbed dose and effective Dose in the CL-IX than Truebeam was higher about 1.3 times and in the 4D-CBCT Truebeam than CBCT of Truebeam was higher about 2.2times However, a large movement of the patient and respiratory gated radiotherapy may be more accurate treatment in 4D-CBCT. Therefore, it will be appropriate to selectively used.

  7. 心理护理干预对维持性血液透析患者的临床影响观察%The application research of psychological nursing intervention in maintenance hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    王娟

    2015-01-01

    目的:探讨心理干预对维持性血液透析患者的临床影响(透析疗效及生存质量)。方法将80例行维持性血液透析的慢性肾功能衰竭患者随机分为干预组和对照组,每组各40例。对照组采用常规护理;干预组在常规护理的基础上加强心理护理。采取Zung抑郁评定量表(Self-Rating Depression Scale,SDS)和焦虑评定量表(Self-Rating Anxiety Scale,SAS),观察比较两组患者干预前后的心理状况。结果干预前两组SDS、SAS评分比较,差异无统计学意义( P>0.05);干预后对照组SDS、SAS均高于干预组评分,差异有统计学意义(P<0.05);干预组干预前SDS、SAS均高于干预后评分,差异有统计学意义(P<0.05);对照组干预前后SDS、SAS比较,差异无统计学意义( P>0.05)。结论护理人员采取恰当的心理护理干预措施,可以提高维持性血液透析患者的透析疗效,提高患者的生存质量。%Objective To explore the effect of psychological nursing intervention in maintenance hemodialysis patients. Methods 80 cases of chronic renal failure patients on maintenance hemodialysis were rando mly divided into trial group with 40 cases and control group with 40 cases.In addition to routine nursing in the 2 groups,the trial group were carried out with psychological nursing intervention. The scores of Zung�s Self-Rating Depression Scale( SDS) and Self-Rating Anxiety Scale( SAS) were used before and after intervention in the two groups. Results Before intervention,SDS and SAS scores between two groups have no statistically significant difference(P > 0.05).After interven⁃tion,SDS and SAS scores in the control group were higher than that of the trial group,the difference of which was statistically significant( P 0.05).Conclusion Appropriate psychological nursing intervention carried out in patients with maintenance hemodialysis can improve patients� quality of

  8. 应用小干扰RNA技术阻断VEGF-C基因体内抑制乳癌细胞增殖%BLOCKING VASCULAR ENDOTHELIAL GROWTH FACTOR-C GENE TO INHIBIT BREAST CANCER CELL PROLIFERATION IN VIVO BY USING siRNA TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    李鲲; 葛银林; 张金玉

    2009-01-01

    目的 应用化学修饰的小干扰RNA(siRNA)阻断裸鼠乳癌移植瘤中血管内皮生长因子C(VEGF-C)基因, 探讨其对人乳癌MCF-7裸鼠移植瘤生长的影响.方法 于雌裸鼠皮下种植MCF-7细胞,将成瘤阳性的裸鼠随机分为VEGF-C siRNA处理组、脂质体组和对照组,每组5只.VEGF-C siRNA处理组肿瘤局部注射VEGF-C siRNA 1 mg/kg和PEITM,脂质体组肿瘤局部注射PEITM和PBS,对照组仅注射PBS,每3 d注射1次,连续注射8次.22 d后拉颈处死全部动物, 取肿瘤,采用半定量 RT-PCR 分析VEGF-C mRNA水平,Western blotting检测VEGF-C蛋白表达水平.结果 VEGF-C siRNA处理组瘤组织的增长受到明显抑制,VEGF-C基因的mRNA和蛋白表达水平显著降低(F=73.64~197.15,q=8.74~25.56,P<0.05).对照组各指标无显著变化.结论 化学修饰的siRNA介导的RNAi在体内能成功下调人乳癌裸鼠移植瘤中VEGF-C基因的表达, 抑制肿瘤的生长,是潜在的肿瘤基因治疗新方法.%Objective Using chemically-modified siRNA technique, vascular endothelial growth factor-C (VEGF-C) gene in transplanted breast cancer in nude mice was blocked and its effects on the growth of transplanted tumor investigated. MethodsHuman breast cancer cells MCF-7 were subcutaneously transplanted into the female mice, those with tumor-positive were rando-mized to three groups as VEGF-C siRNA, liposome and control, with five mice in each group. For VEGF-C siRNA group: VEGF-C siRNA 1 mg/kg and in vivo jetPEITM were injected locally; for liposome group: intra-tumor injection of in vivo jetPEITM and PBS was done; for control group: PBS alone was given. The medication was given every three days for eight times. The experimental animals were sacrificed 22 days later and tumors taken. Semiquantitative RT-PCR was applied for VEGF-C Mrna detection, and Western blotting for VEGF-C. Results The growth of tumor in VEGF-C siRNA group was greatly inhibited, the expressions of VEGF-C gene and protein

  9. ERRATUM: FERMI Large Area Telescope Study of Cosmic-Rays and the Interstellar Medium in Nearby Molecular Clouds

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A.W.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Busetto, G.; S.Buson; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Ferrara, E. C.; Harding, A. K.; Nemmen, R.; Thompson, D. J.; Troja, E.

    2013-01-01

    systematic uncertainty into account." 3. Table 1 and Figure 13, which show gas emissivities and spectra for the Chamaeleon region in the original paper, should be changed to the Table 1 and Figure 1 as shown below. 4. Figure 16, which compares Hi gas emissivities among several regions in the original paper, should be changed to Figure 2 as shown below. 5. The text from the line 13 to the last one in the first paragraph of Section 4.1, "The spectral shapes for the three regions..., indicating a difference of the CR density between the Chamaeleon and the others as shown in Figure 16." should be changed to the paragraph that follows. "The shaded area of each spectrum indicates the systematic uncertainty as described in Section 3. We note that the systematic uncertainty of the LAT effective area (5% at 100 MeV and 20% at 10 GeV; Rando et al. 2009) does not affect the relative value of emissivities. The effect of unresolved point sources is small; we have verified that the obtained emissivities are almost unaffected by decreasing the threshold for point sources from TS = 100 to TS = 50. We also confirmed that the residual excess of photons around (l = 280deg to 288deg, b = -20deg to -12deg; see the bottom panel of Figure 8) in the Chamaeleon region does not affect the local Hi emissivity very much. Thus the total systematic uncertainty is reasonably expressed by the shaded area shown in Fig. 1.

  10. MSCT and C-ARM units: doses to patients in the angiographic procedures

    Energy Technology Data Exchange (ETDEWEB)

    Staniszewska, M.A. [Nofer Institute of Occupational Medicine, Lodz (Poland); Jazwinski, J. [Military Institute of Hygiene and Epidemiology, Warsaw (Poland)

    2006-07-01

    Full text of publication follows: Computed Tomography Angiography (C.T.A.) is an attractive non -invasive alternative to invasive traditional angiography. The coronary arteries are the most frequent angiography procedure. Because of a high resolution and wide possibilities offered by software for image reconstruction, a number of scanner types having sixteen rows of detectors at least make possible to visualise and analyse of the blood flow in the thin vessels, without an aggressive interference into the patient body. This is achieved at the x -rays exposure pattern quite different to that used for the C-arm units. Consequently, both the organ dose values and their spatial distribution are also different for C.T.A. and C-arm conducted procedures, what can influence on a radiation risk to patients. This paper is aimed on evaluation of doses obtained by patients during coronarography performed using multislice computed tomographs (M.S.C.T.) and C-arm units. Materials and Methods The doses were evaluated experimentally, using thermoluminescent dosimeters (TLD) (Polish product, equivalent TLD-100) and anthropomorphic Rando Man phantom (made by Alderson). The measurements were performed for CT protocols covering the coronary arteries used at 16-row and 64-row M.S.C.T. scanners and the C-arm units. Before the use TLDs were calibrated for the two x-ray spectra corresponding to the energies of photon emitted by CT scanners and C -arm units. The organ doses were calculated on the basis of the TLDs readings for the specified volume of the phantom. The effective dose to each the analysed procedure were computed according to the ICRP recommendations given in Publication 60. Results The measurements were carried out for 3 M.S.C.T. scanners. The protocols covering the chest and allowing to achieve a good contrast resolution were checked for the patient dose, i.e.: the chest angiography R.C.T. of the chest and the coronary arteries. The organ doses ranged from the tenths of m

  11. Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Rampado, Osvaldo, E-mail: orampado@cittadellasalute.to.it; Giglioli, Francesca Romana; Rossetti, Veronica; Ropolo, Roberto [Struttura Complessa Fisica Sanitaria, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, Corso Bramante 88, Torino 10126 (Italy); Fiandra, Christian; Ragona, Riccardo [Radiation Oncology Department, University of Turin, Torino 10126 (Italy)

    2016-05-15

    Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined. Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using PCXMC software (PCXMC 2.0, STUK, Helsinki, Finland) for calculating organ doses, adapting the input parameters to simulate the exposure geometry, and beam dose distribution in an appropriate way. The calculated doses were compared to readouts of TLDs placed in an anthropomorphic Rando phantom. After this validation, the software was used for analyzing organ dose variability associated with patients’ differences in size and gender. At the same time, various dose indicators were evaluated: kerma area product (KAP), cumulative air-kerma at the isocenter (K{sub air}), cone-beam dose index, and central cumulative dose. The latter was evaluated in a single phantom and in a stack of three adjacent computed tomography dose index phantoms. Based on the different dose indicators, a set of coefficients was calculated to estimate organ doses for a range of patient morphologies, using their equivalent diameters. Results: Maximum organ doses were about 1 mGy for head and neck and 25 mGy for chest and pelvis protocols. The differences between PCXMC and TLDs doses were generally below 10% for organs within the field of view and approximately 15% for organs at the boundaries of the radiation beam. When considering patient size and gender variability, differences in organ doses up to 40% were observed especially in the pelvic region; for the organs in the thorax, the maximum differences ranged between 20% and 30%. Phantom dose indexes provided better correlation with organ

  12. 抗甲状腺药物对妊娠合并甲状腺功能亢进患者的疗效及对胎儿的影响分析%Efficacy and impact on fetus of antithyroid drugs on pregnant women with hyperthyroidism

    Institute of Scientific and Technical Information of China (English)

    施伟; 邱长莲

    2015-01-01

    Objective:To investigate the efficacy of antithyroid drugs on pregnant woMen with hyperthyroidisM and the iM-pact on fetus. Methods:96 cases of pregnant woMen with hyperthyroidisM in our hospital froM May 2009 to May 2014 were se-lected and randoMly divided into control group and observation group,each group 48 cases. Patients in control group were not adMinistrated with anti - thyroid drugs,and patients in observation group were dealed with antithyroid drugs. The thyroid func-tion,the pregnant woMen coMplications,the newborn average weight and the one Minute Apgar scores of two groups were ana-lyzed and coMpared. Results:The FT3,FT4 and TSH levels of observation group were significantly lower than control group(P﹤ 0. 05). The pregnant woMen coMplications rate of observation group was significantly lower than control group(P ﹤ 0. 05). The newborn average weight of observation group was significantly higher than control group,and the Apgar score high of obser-vation group was significantly higher than control group. The differences were statistically significant(P ﹤ 0. 05). Conclusion:For pregnant woMen with hyperthyroidisM,antithyroid drugs can significantly iMprove thyroid function,the newborn average weight and one Minute Apgar scores.%目的:探讨抗甲状腺药物对妊娠合并甲状腺功能亢进患者的治疗效果及对胎儿的影响。方法:选取2009年5月—2014 年5月收治的妊娠合并甲状腺功能亢进患者96例,随机分成对照组和观察组,每组48例。对照组患者不接受抗甲状腺药物治疗,观察组接受抗甲状腺药物治疗。对两组患者甲状腺功能、孕妇并发症以及新生儿平均体重和1 Min Apgar 评分进行分析比较。结果:观察组患者的游离三碘甲状腺原氨酸(FT3)、游离甲状腺激素(FT4)以及血清促甲状腺激素(TSH)水平均显著低于对照组;观察组并发症发生率显著低于对照组,差异均有统计学意义(P ﹤0.05

  13. Fast polyenergetic forward projection for image formation using OpenCL on a heterogeneous parallel computing platform.

    Science.gov (United States)

    Zhou, Lili; Clifford Chao, K S; Chang, Jenghwa

    2012-11-01

    Simulated projection images of digital phantoms constructed from CT scans have been widely used for clinical and research applications but their quality and computation speed are not optimal for real-time comparison with the radiography acquired with an x-ray source of different energies. In this paper, the authors performed polyenergetic forward projections using open computing language (OpenCL) in a parallel computing ecosystem consisting of CPU and general purpose graphics processing unit (GPGPU) for fast and realistic image formation. The proposed polyenergetic forward projection uses a lookup table containing the NIST published mass attenuation coefficients (μ∕ρ) for different tissue types and photon energies ranging from 1 keV to 20 MeV. The CT images of interested sites are first segmented into different tissue types based on the CT numbers and converted to a three-dimensional attenuation phantom by linking each voxel to the corresponding tissue type in the lookup table. The x-ray source can be a radioisotope or an x-ray generator with a known spectrum described as weight w(n) for energy bin E(n). The Siddon method is used to compute the x-ray transmission line integral for E(n) and the x-ray fluence is the weighted sum of the exponential of line integral for all energy bins with added Poisson noise. To validate this method, a digital head and neck phantom constructed from the CT scan of a Rando head phantom was segmented into three (air, gray∕white matter, and bone) regions for calculating the polyenergetic projection images for the Mohan 4 MV energy spectrum. To accelerate the calculation, the authors partitioned the workloads using the task parallelism and data parallelism and scheduled them in a parallel computing ecosystem consisting of CPU and GPGPU (NVIDIA Tesla C2050) using OpenCL only. The authors explored the task overlapping strategy and the sequential method for generating the first and subsequent DRRs. A dispatcher was designed to drive

  14. Dosimetric evaluation of a commercial proton spot scanning Monte-Carlo dose algorithm: comparisons against measurements and simulations

    Science.gov (United States)

    Saini, Jatinder; Maes, Dominic; Egan, Alexander; Bowen, Stephen R.; St. James, Sara; Janson, Martin; Wong, Tony; Bloch, Charles

    2017-10-01

    RaySearch Americas Inc. (NY) has introduced a commercial Monte Carlo dose algorithm (RS-MC) for routine clinical use in proton spot scanning. In this report, we provide a validation of this algorithm against phantom measurements and simulations in the GATE software package. We also compared the performance of the RayStation analytical algorithm (RS-PBA) against the RS-MC algorithm. A beam model (G-MC) for a spot scanning gantry at our proton center was implemented in the GATE software package. The model was validated against measurements in a water phantom and was used for benchmarking the RS-MC. Validation of the RS-MC was performed in a water phantom by measuring depth doses and profiles for three spread-out Bragg peak (SOBP) beams with normal incidence, an SOBP with oblique incidence, and an SOBP with a range shifter and large air gap. The RS-MC was also validated against measurements and simulations in heterogeneous phantoms created by placing lung or bone slabs in a water phantom. Lateral dose profiles near the distal end of the beam were measured with a microDiamond detector and compared to the G-MC simulations, RS-MC and RS-PBA. Finally, the RS-MC and RS-PBA were validated against measured dose distributions in an Alderson–Rando (AR) phantom. Measurements were made using Gafchromic film in the AR phantom and compared to doses using the RS-PBA and RS-MC algorithms. For SOBP depth doses in a water phantom, all three algorithms matched the measurements to within  ±3% at all points and a range within 1 mm. The RS-PBA algorithm showed up to a 10% difference in dose at the entrance for the beam with a range shifter and  >30 cm air gap, while the RS-MC and G-MC were always within 3% of the measurement. For an oblique beam incident at 45°, the RS-PBA algorithm showed up to 6% local dose differences and broadening of distal fall-off by 5 mm. Both the RS-MC and G-MC accurately predicted the depth dose to within  ±3% and distal fall-off to within

  15. Effects of two different kinds of opiate receptor agonists associated with intercostal nerve blockade for pain relief after Video assisted thoracoscopic surgery%两种不同阿片受体激动剂联合肋间神经阻滞用于胸腔镜肺叶切除术患者的镇痛

    Institute of Scientific and Technical Information of China (English)

    冯建伟; 刘金龙; 陈新荣; 钟茂林; 彭道珍; 叶军明

    2012-01-01

    Objective To investigate the effects of butorphanol or sulfentanyl associated with intercostal nerve block (INB) for postoperative pain relief after Video assisted thoracoscopic surgery (VATS). Methods 80 patients (28 - 56 years) who underwent VATS lobectomy were rando mLy divided into butorphanol group 1 (group Bl, re = 20), INB associated with butorphanol (group B2, n = 20), sufentanil group (group S1, n = 20) and INB associated with sufentanil (group S2, n = 20). Postoperative analgesia consisted of continuous intravenous infusion of for 48 h butorphanol or sufentanil for all patients. Loading dose of butorphanol was 30 μg/kg in group Bl and B2, and that of sufentanil was 0.1 M-g/kg in group SI and S2 30 min before the end of operation. 20 mL of 0.375% ropivacaine was ad ministrated for INB in group B2 and S2. Intravenous analgesia maintenance dose of butorphanol in group Bl and B2 was 3 μg/(kg·h), and that of sufentanil was 0.075 μg/(kg·h) in group SI and S2 after operation, respectively. Recorded the visual analogue score (VAS) , Ramsay sedative scores, blood pressure, heart rate, respiratory rate and SpO2 at 0, 6, 12, 18 ,24, 36 h , and 48 h after ad ministration; VAS was recorded when patients coughing at 24, 48h and 7 days after ad ministration. Arterial blood gas analysis was performed at the first postoperative day. Results There were no significant differences between the four groups about sedative scores, blood pressure, heart rate, respiratory rate, and SpO2 48 h. The VAS was higher in group B1 and S1 than those in group B2 and S2 during 6 - 24 h and when patients coughing after ad ministration, but no significant difference between group B2 and S2 (P < 0.05). Moreover, INB improved PaO2 and oxygenation index in group B2 and S2 significantly. Conclusion INB associated with butorphanol or sufentanil reduces postoperative pain and provides a better postoperative recovery for adult patients of VATS.%目的:探讨布托啡诺和舒芬太尼两种不

  16. The liraglutide for curative effect analysis of overweight or obese type 2 diabetes%利拉鲁肽对超重或肥胖的2型糖尿病的疗效分析

    Institute of Scientific and Technical Information of China (English)

    梁怡; 重远

    2016-01-01

    Objective Sample observation glucagon peptide 1 (glp-1) analogue, liraglutide of overweight or obese type 2 diabetes efficacy and safety. Methods In August 2012~August 2014 in our hospital endocrinology inpatient and outpatient treatment of 68 patients with type 2 diabetes, in BMI ≥ 24 kg/m2 for overweight, ≥28 Kg/m2 for obesity, overweight 29 cases, obesity 39 cases . On the basis of diet control, strengthen the movement, patients rando mLy divided into observation group and control group. Observation group (n= 36) applied the liraglutide injection subcutaneously 1 times a day, from 0.6 mg starting, after a week if not a severe gastrointestinal reaction (loss of appetite, nausea, vomiting) and FPG 8 or higher tendency tendency for L/L or 2 hPG acuity 11 has added amount to 1.2 mg/day, by parity of reasoning the maximum dose of 1.8 mg per day; The control group (n= 32) application of insulin injection subcutaneously 1 times a day, joint metfor min after a meal. Observe two groups before and after treatment the change of body weight, BMI, blood pressure, blood sugar control and standard time、TC、TG、LDL-C、HDL – C、HbA1c、24hUMA . Record during hypoglycemia occurrence and other adverse reactions. Results Observation group after treatment body weight, BMI, blood pressure, TC、TG、LDL-C all fell, The difference was statistically significant, FPG、2hPG、HbA1c and 24hUMA decreased significantly. Control group after treatment of blood pressure、FPG、2 hPG、HbA1c、24hUMA have declined, the difference was statistically significant, TC、TG、LDL - C decline is not obvious, no statistical difference, Body weight 、BMI、HDL - C has increased, but no statistical difference, Observation group and treatment group after treatment of blood pressure、FPG、2 hPG、HbA1c、HDL – C、24 Huma compared with no statistical difference, Observation group the treatment group of body weight、BMI、TC、TG、LDL - C drop, statistically significant. Observation

  17. 铅暴露对大鼠血脑脊液屏障通透性、分泌及转运功能的影响%Effect of lead exposure on permeability,secretion and transportation function of blood-cerebro-spinal fluid barrier of rats

    Institute of Scientific and Technical Information of China (English)

    王苗苗; 董亚楠; 闫立成; 曹福源; 吕志伟; 李清钊; 张艳淑

    2014-01-01

    OBJECTIVE To investigate the effects of lead exposure on the permeability,secretion and transportation function of blood-cerebro-spinal fluid barrier (BCB)of rats in order to provide the theo-rical basis for elucidating the mechanis m of lead induced neurotoxicity.MEHTODS 60 SPF SD rats were rando mly divided into 4 groups,including a control group and three doses lead exposed groups. Rat in the lead exposure groups were given drinking water containning 0.05%,0.1 % and 0.2% lead acetate (at dose of 80,160,320 mg·kg -1 )for 8 weeks.Laser scanning confocal microscopy was uti-lized to determine the lead content in seru m,cerebrospinal fluid (CSF)and choroid plexus sa mples. Morris maze was used to test learning and me mory.Fe moral artery perfusion of Evans blue (EB)and fluorescein sodiu m (NaFI)was performed to measure BCB permeability function.Confocal laser scan-ning was applied to detect junction adhesion molecule (JAM)and occludin protein expression in choroid plexus.ELISA was used to measure the concentration of transthyretin (TTR)and leptin in seru m and CSF.RESULTS The lead content in seru m,choroid plexus and CSF significantly increased,especially the lead level in CSF.Morris water maze data showed that escape latency of rat in lead acetate 160 and 320 mg·kg -1 group were 52 ±12,(89 ±19)s,respectively,longer than that of control group 〔(28 ±7)s, P<0.05〕.The ti mes across platform of rats in lead acetate 160 and 320 mg·kg -1 group were lower than that of control group(P <0.05).The NaFI content in CSF of rats in all lead acetate exposure groups were 0.94 ±0.09,1 .02 ±0.03 and (1 .08 ±0.18)mg·L -1 ,respectively,and were higher than those of control group〔(0.74 ±0.04)mg·L -1 〕;While the EB content in CSF of rat in lead acetate 160 and 320 mg·kg -1 group were higher than the control group(P <0.05),which indicated that lead acetate exposure at low dose can lead to the increase of permeability of BCB.Laser scanning confocal micro-scope i mages