International Symposium "Standards, Applications And QA In Medical .
International Symposium “Standards, Applications and QA in Medical Radiation Dosimetry ”November 9 12 2010, Vienna, AustriaNew brachytherapy standards paradigm shiftMaria Pia ToniIstituto Nazionale di Metrologia delle Radiazioni IonizzantiAgenzia Nazionale per le Nuove Tecnologie, l’Energia e lo Sviluppo Economico sostenibileItalyINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Rationale for a paradigma shift in BT dosimetryDw, is the quantity of interest for dosimetry in radiotherapy, thisincludes either the dosimetry of external radiation beams or thedosimetry of brachytherapy (BT) sources.to achieve the goal of 5%(k 1) for the uncertainty ofthe dose delivered to thetarget volume at referenceconditions, in the clinic.uclinic 5% (k 1)tumor control (%)toavoidadditionaluncertaintiesinthemeasurement of Dw and tooptimize the dose delivery inradiation therapy;A lower dosedelivered to thetarget volumecould result inlack of tumorcontrolIncreasingdamageto healthy tissuecould result fromexceeding thetolerance levelsincidence of damage (%)The IAEA TRS 398 (2000) recommends a direct traceability chainstarting on Dw primary standards:Dw dose delivered (a.u.)INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Rationale for a paradigma shift in BT dosimetryIn external beam dosimetry, Dw primary standards are currentlyoperating for dosimetry of external radiation beams used inradiotherapy and the uncertainty on Dw,1 cm is about 2% (k 1).In BT dosimetry, no Dw primary standards have been so far madeavailable for dosimetry of the gamma sources used in current BTtreatments and the uncertainty on Dw,1 cm is typically from 5% to8% (k 1).INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Rationale for a paradigma shift in BT dosimetrySTATE OF ART(a)(b)(a)(a) Air Kerma primary standards andsecondary standards calibrated interms of air kerma for the energyspectrum of brachytherapy sourcesor (b) Reference Air Kerma Rateprimary tBTdosimetry is due to this lack ofmetrology,becausetheconversion procedure needed forBT dosimetry is a relevantadditionalcomponentofuncertainty on the final value ofthe absorbed dose imparted to thepatient.(b)(a) Brachytherapy sourcesand (b) transfer standardscalibrated in terms ofReference Air Kerma Rate.Conversion from Reference AirKerma Rate to Absorbed DoseRate to water (AAPM TG 43) G (r , θ ) D& W (r ,θ ) S K Λ g (r ) F (r ,θ )()Gr,θ 0 0 dose rate constantINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Rationale for a paradigma shift in BT nternationalorganizations ESTRO, AAPM-BTSC, IAEA, ICRU, BIPM andEURAMET have ongoing research programs in the field ofBrachytherapy and encouraged the metrological community todevelop absorbed dose standards to assure direct traceabilityof brachytherapy sources.The European project “Brachytherapy” is establishing absorbeddose primary standards for brachytherapy.This new approach is expected to improvethe accuracy of brachytherapy dosimetrytowards a level comparable to that typicalof dosimetry in radiotherapy with externalbeams.9%3%5%Main sitesof tumortreated with8% Brachytherapy(ESTRO, 2007)7%68%gynaecologyprostatebreastbronchushead & neckothersINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The European project “Brachytherapy”The project “Increasing cancer treatment efficacyusing 3D Brachytherapy” is one of the 21 EuropeanJoint Research Projects in metrology selected forfunding in 2008 within the action iMERA plus underthe Seventh Framework Programme for researchand technological development of the EuropeanCommission.The European Commission co-fund the project according to theGrant Agreement No. 217257 signed with the EuropeanAssociation of National Metrology Institutes (EURAMET e.V.).The project was launched on July 2008 for a period of 36months (ending in June 2011), with code T2.J06 and short name“Brachytherapy”.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The European project “Brachytherapy”This collaborative research project refers toresearch in ionizing radiation metrology focusedon the program “TP2: Health” in the EuropeanMetrology Research Programme.It responds to the necessity that:the dose measurements for brachytherapytreatments be traceable to absorbeddose-to-water primary standards;the uncertainty on the dose delivered tothe target volume be within internationalaccepted tolerance levels.Target programmeTP2: HEALTHIn our centrethe Human as theMeasurement ObjectINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The European project “Brachytherapy”PARTICIPANTSThe project puts together the researchand measurement capabilities of tenEuropeanNationalMetrologyLaboratories in the field of ionizingradiation:BEV (Austria); CMI (Czech Republic);ENEA-INMRI (Italy); ITN (Portugal);LNE-LNHB(France);VSL(TheNetherlands); NPL (United Kingdom);PTB (Germany); SSM (Sweden); STUK(Finland).Project coordination has been entrustedto the ENEA-INRI, Italy (Dr. Maria PiaToni).INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The European project “Brachytherapy”Collaborations for research activities were formalized with:the company PTW-Freiburg GmbH, Germanythe company IBA Dosimetry GmbH, Germanythe Linköping University, SwedenA scientific collaboration has started with the BRAPHYQS(BRAchytherapy PHYsics Quality assurances System ) group of GECESTRO as representative of the project end users.The chair of the BRAPHYQS group, dr. Frank-Andrè Siebert, gives hiscontribute to “Brachytherapy” project meetings.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The European project “Brachytherapy”OBJECTIVES(a)(b)Absorbed dose to water primarystandardsforbrachytherapysources based on calorimetry (a)or ionometry (b) and MonteCarlobasedconversionproceduresThe joint research project “Brachytherapy”developed absorbed dose primary standards forbrachytherapy for a more sound metrology andwith a target uncertainty on the absorbed doseimparted to the patient in the futurebrachytherapy practice:(a)(b)Brachytherapy sources(a)andtransferstandards (b) directlycalibrated in terms ofDw, 1 cmu (Dw, 1 cm) less than 5% (k 1)INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
New brachytherapy standards for LDR BT sourcesDw STANDARDSFOR LOW DOSE RATE BRACHYTHERAPY SOURCES(prescription dose rate from 5 to 20 mGy/min)Development and commissioning of a set of three independentprimary standards to allow the determination of the DW at thereference distance of 1 cm from the source, with an uncertaintyu(Dw) 2%, k 1.Standards are based on ionometric methods (the moreappropriate due the low intensity of the sources): wide-angleand/or variable volume ionisation chambers.A preliminary comparison exercise has started to assess thestandards agreement and identify possible errors (results should beavailable by February 2011).INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
New brachytherapy standards for LDR BT sourcesDw STANDARDSFOR LOW DOSE RATE BRACHYTHERAPY SOURCES(prescription dose rate from 5 to 20 mGy/min)SWaterAir&Kw ,S1 cmENEA standard based ona large angle andvariable volumeionisation chamber thatallows measurements ingraphite phantom.LNE-LNHB standardbased on a free-inair ring-shapedionisation chamberand a waterequivalent sphericalsource phantomassembly.PTB standard basedon a largeextrapolationionisation chamberwith water equivalentfront and back walls.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The LNE-LNHB Dw primary standard for125IBT seedsThe LNE-LNHB primary standard developmentin terms of Dw for 125I brachytherapy seedsI. Aubineau-Lanièce, P. Aviles-Lucas , J.-M. Bordy, B. Chauvenet, D. Cutarella, J. Gouriou, J. PlagnardThe LNE-LNHB is establishing a two-step procedure to overcome practicaldifficulties encountered when measuring Dw.1. Determine the water K& at the surface of a 1 cm radius water equivalentspherical phantom placed in air and containing the LDR seed in itscentre.K& col ,wD& w ?1 cmWaterWhat we want to assess1 cm1 cmAirTheoretical configuration reallyconsidered - a correction factorwill be applied to compensatefor the lack of backscatteringphotons because the watersphere is surrounded by airinstead of water.AirK& col , PMMAPMMALiquid water is replaced byPMMA - a correction factorwill be applied for the nonperfect equivalence of PMMAwith liquid waterINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The LNE-LNHB Dw primary standard for125IBT seedsThe LNE-LNHB is establishing a two-step procedure to overcome practicaldifficulties encountered when measuring Dw.2. Use a free-in-air circular ring-shaped ionization chamber to measure K&appropriate MC correction factors to go from K& col , air to K& col , PMMAD& w Fglobal. I . w .1 e air ρair.11. .(1 g ) Vcol , airand apply kiiINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The PTB Dw primary standard for125IBT seedsINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The PTB Dw primary standard for125IBT seedsNew extrapolation concept for the GROVEX IIAs in phantom extrapolation measurements are having a nonlineardependence of Q(x) due to attenuation and scatter, a Monte-Carlobased conversion factor was introducedThis factor converts the difference of air kerma at chamber depths xi aand xi 1 directly into the water kerma at chamber depth x 0 .If the thickness of the chamber front wallis equivalent to 1 cm of water, then:K& WPh (0) D& W (1cm)INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The PTB Dw primary standard for125IBT seedsMeasurements with the Grovex II inthe PTB reference fields for X-radiationINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The ENEA-INMRI Dw primary standard forSet-up Avariablemeasuringvolume1Da ( x) 125IW 1 dQ ( x)e ma dxDa (ν ) K a (ν ) B (ν ) Potential rings (V/2) ν KνiC(MCxi 1 , xi ) ρdivΨe (ν ) K a (ν ) 1ρdivΨe (ν ) KEphotons 40 keVW 1[Q( xi 1 ) Q( xi )] ΔΨee maK g (0)Vx 1x0K g ( P) 1ν )dν K a (ν )dν a(i 1PeffectivemeasuringvolumeBT seedssourceν )dν K a (ν )dνPr 30 cma(VxW 1 MCC( x , x ) [Q( xi 1 ) Q ( xi )] C(MCx , x ) ΔΨee Ai 1i 1ii3MCMCD(P) Cw 0P , P Dw ( P )Dw ( P ) K w ( P) C g ,w K g ( P )20PΔxsourcerxP0airleadINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010polystyrenegraphiteP
The ENEA-INMRI Dw primary standard for125IBT seedsPreliminary results by Monte Carlo calculation EGS code (set-upA)ongoingN.B.Minimum chamber depth x0 and distances between theeffective measuring volume and the lateral chamber wallare greater than the CSDA range for secondary particlesgenerated in air by photons with E 40 keVThe measurement method applied to the ENEA-INMRI standard was developed by PTB as described in:T Schneider, B Lange and H-J Selbach, Towards a determination of the absorbed dose to water inwater for low-energy photon-emitting brachytherapy seeds, Metrologia 44 (2007) 407–414T Schneider, A method to determine the water kerma in a phantom for x-rays with energies up to40 keV, Metrologia 46 (2009) 95–100INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The ENEA-INMRI Dw primary standard forSet-up Bvariablemeasuringvolume1Da ( x) 125IBT seedsW 1 dQ( x)e ma dxDa (ν ) K a (ν ) B (ν ) Potential rings (0 V) Kνν )dν K a (ν )dν νiC('MCx ,x ) i 1iK g ( P0 ) 1ρdivΨe (ν )Ephotons 40 keVW 1[Q( xi 1 ) Q( xi )] ΔΨee ma K a (ν ) K a (ν )P0Vx 1x0divΨe (ν ) K a (ν ) K g ( P0 )Veffectivemeasuringvolumeρa(i 1source P1xW 1 'MCC( x , x ) [Q( xi 1 ) Q ( xi )] C('MCx , x ) ΔΨee Ai 1ii 1i2sourcePΔxDw ( P0 ) K w ( P0 ) C 'MCg , w K g ( Po )P0xairleadINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010polystyrenegraphite
New brachytherapy standards for HDR BT sourcesDw STANDARDSFOR HIGH DOSE RATE BRACHYTHERAPY SOURCES(prescription dose rate of 200 mGy/min or higher)Development and commissioning of a set of four independentprimary standards to allow the determination of the Dw at thereference distance of 1 cm from the source, with an uncertaintyu(Dw) 2%, k 1.The standards are based on calorimetry: water calorimeters andgraphite calorimeters.A preliminary comparison exercise has started to assess thestandards agreement and identify possible errors (results should beavailable by February 2011).INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
New brachytherapy standards for HDR BT sourcesDw STANDARDSFOR HIGH DOSE RATE BRACHYTHERAPY SOURCES(prescription dose rate of 200 mGy/min or higher)NPL standard based ona ring-shaped graphitecalorimeterPTB standard based on awater calorimeterThermistor (4x)ENEA-INMRIstandard based on aring-shaped graphitecalorimeterVSL standard basedon water calorimeterHeat sink (Al)Glass cell wallINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The PTB Dw primary standard for192IrHDR BT sourcesDetector arrangement changed for use with HDR BT sourcesstainless steel needle for 1.1 mm sourcepossible meassurement positions: 60 mm, 48 mm, 24 mm, -24 mmINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The PTB Dw primary standard for192IrHDR BT sourcesDetector arrangement changed for use with HDR BT sourcesINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The VSL Dw primary standard for192IrHDR BT sourcesSourceentranceconnected toafter‐loaderThermistor (4x)Glass cell wallAluminumheat sinkPEEKcell wallINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The VSL Dw primary standard for192IrHDR BT sourcesValidation heat transport modelINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The NPL Dw primary standard for192IrHDR BT sourcesWednesday, 17 November 2010Complete system of NPL’s new brachytherapy calorimeterVacuum housingfor tronics:NanovoltmetersPower suppliesfor heatersWheatstonebridges forsensorsElectricalconnections ofheating andsensingthermistorsVacuum pumpINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRI27IAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The NPL Dw primary standard for192IrHDR BT sourcesWednesday, 17 November2010Sectional viewCylindrical graphite phantom (radius 10 cm,height 14 cm) enclosed in vacuum can (notshown)Ring shaped graphite core(2 mm x 5 mm, radius 2.5 cm)Vacuum gaps between core, inner graphitetubes and central aluminium tube to controlsource self-heatingHDR brachytherapy source will be insertedthrough aluminium tubeObjective: Direct measurement of absorbed dose to graphite at2.5 cm due to HDR 192Ir brachytherapy source Æ conversion toquantity of interest: absorbed dose to water at 1 cmINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The ENEA-INMRI Dw primary standard for192IrHDR BT sourcesSchematic section of the ENEA-INMRI calorimeter (left) with the core inblack and the calorimeter assembled (right) in the PMMA housing, (13cm ext dia, 10 cm int dia ).PMMA housingmediumj-core baseheater holdersource holderheater holdermediumj-core basePMMA housingtop graphite disc withsource holderBottom graphite discINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The ENEA-INMRI Dw primary standard for192IrHDR BT sourcesLeft: the core and the jacket base fixed to the jacket-core base afterembedding the thermistors in the core and in the jacket base. The core issuspended on the jacket base by 3 polystyrene 1 mm dia pins.Right: detail of the core and the 0.3 mm dia NTC thermistor, used in the core and inthe jacket.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
The ENEA-INMRI Dw primary standard for192IrHDR BT sourcesThe calorimeter is inserted in a larger graphite phantom (left) to ensureat the core position the full backscattering conditions for 192Ir .11 cm20 cmOn the right, detail of the 3D heat transfer calculations: irradiation13 cm20 cmINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Novel LDR&HDR standards comparison exercisesMethodologyStar-shaped comparisonsIndirect comparisons by circulating two transferinstruments from one NMI to another, for each comparisonstandardTwo ionisation well-type chambers of different types have beenselected to act as transfer standard instruments: the same chambermodels, but different samples, for LDR and HDR comparisonsEach partner will have to determine:the calibration coefficient of the transfer instruments based on theD& Wvalue determinedwith its novel primary standard for its own source .the calibration coefficient of the transfer instruments in terms ofto allow an experimental determination of the conversion gammaconstantK&ΛR with an improved uncertainty.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Novel LDR&HDR standards comparison exercisesTransfer standard instrumentsPTW 33004Outer Height19.05 cmOuter base diameter17.8 cmOuter well diameter9.3 cmInner well diameter3.2 cmWeight2.4 kgVolume200 cm3Potential of HV electrode withrespect to collecting electrode300 VSI HDR 1000 (ref 90008)Height15.6 cmDiameter10.2 cmWeight2.7 kgVolume245 cm3Potential of HV electrode withrespect to collecting electrode300 VINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Novel LDR&HDR standards comparison exercisesSOURCES USED FOR THE LDR COMPARISONBEBIG IsoSeeds I-125 sources (reference I25.S16)RangeAir kerma strength(µGy m²/h)Apparent activity(mCi)Apparent activity(MBq)A2526.10 – 31.7520.6 – 25.0761 - 925The IsoSeeds I-125 sources contain a cylindrical-shaped ceramicsaturated with an iodine-125 compound, which is enclosed in a laserwelded titanium tube.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Novel LDR&HDR standards comparison exercisesSOURCES USED FOR THE LDR COMPARISONNucletron microSelectron-v1 classic HDRNucletron microSelectron-v2 HDR192Ir192Irsource (PTB and NPL)source (ENEA-INMRI and VSL)INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-1235November 2010
Novel LDR&HDR standards comparison exercisesLDR comparison schedulePTB provided the transfer chambers and carry out the stability checksThe participants will have two weeks to realize the calibration of bothtransfer chambers.The instruments will circulate according to the schedule given below.All the results would be exchanged between participants at the end ofJanuaryMeasurements at NMIPTBPTB: from 13 to 26 September 2010(done)LNE-LNHB: from 04 to 17 October2010 (done)StabilitychecksLNELNHBENEA INMRIENEA-INMRI: from 15 to 28November 2010INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Novel LDR&HDR standards comparison exercisesHDR comparison scheduleNPL provided the transfer chambersand carry out the stability checksCalibration at PTB:7-18 Jun 10 (done)Calibration at VSL:6-16 Jul 10 (done)PTB(DE)18NPL(UK)7Calibration at ENEA-INMRI:25 Oct - 7 Nov 10 (done)All the results would be exchangedbetween participants at the end INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-1237November 2010
Dissemination of the novel BT standardsDw BASED METROLOGICAL CHAINThe final objective of the “Brachytherapy” project is toimplementat a metrological chain to assure the traceabilityof brachytherapy dosimetry to the new absorbed dose towater standards.Transfer standard:well-type ionization chamber;small volume ionization chambers associated with waterphantomplastic scintillator dosemeters (PSDs) associated with waterphantomINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Dissemination of the novel BT standardsWell type chambers actingas transfer standard (dosecalibrators)System with six 0,08 cm3ionizing chambersformeasurements in waterphantomINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Dissemination of the novel BT standardsDevelopment of thesecondary standardbased on well-typeionization chamber(PTW TM33004):BEVsecondarystandard for absorbeddose to water quantity forbrachytherapysourceswas calibrated at the PTB.Calibration sheet wasissued also forNDwquantitywithsourcerelevant Λ conversionfactorexperimentallydetermined according tothe new standard.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
What does it change in treatment plans?The updating of the tretment plans for the shift from Airkerma to Absorbed dose to water as reference quantityfor calibration of BT source just need to substitute theproduct (Sk L) with Dw, in the formalism of the AAPM TG43 protocol: G (r , θ ) D& W (r ,θ ) S K Λ g (r ) F (r ,θ )()Gr,θ 0 0 DwINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Dissemination of the novel BT standardsA three-day scientific Symposium is organized to present the resultsobtained to the interested Medical Physics community and promote aupdated brachytherapy dosimetry protocol based on direct calibrationsin terms of Dw .The symposium is organized together with the project “EBCT” thatdeals with external beam cancer therapy using ionising radiationand high-intensity ultrasoundTitle: "Symposium on developments in physical measurement forcancer therapy".Period: 29.11.2011 to 01.12.2011.Place: PTB, Braunsweigh, GermanyRepresentative of the association and task group relevant on thesetopics are expected to contribute to the symposiumINV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
ConclusionA set of Dw primary standards have been developed withinthe project “Brachytherapy”.The dissemination of project results is of direct interest to theinternational community of radiotherapy centres performingBT clinical treatments.The possibility given by the present project of basing BTdosimetry on Dw primary standards will potentially increasethe accuracy and safety of BT to a level comparable to thattypical of radiotherapy with external accelerator beams.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
ConclusionBased on the current developments, a progress is encouragedfor a more direct and accurate traceability chain of BT sourcesaccording to the demand for a more sound metrology and anoptimization of dose delivery in BT treatments.No efforts are required at SSDL or clinic level: the samereference chamber (well type ionization chambers) could bestill used and to update the software for treatment planresults easy.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
Future workOrganization, late next year, of a key comparison to validatethe new Dw BT standards.Implementation of a Dw based metrological chain todisseminate the new standards througt the SSDL laboratoriesAvailability of calibrations in terms of DW to brachytherapycentres.Availability of updated protocols in terms of DW for moreaccurate dosimetry to brachytherapy centres.INV015, “New brachytherapy standards paradigm shift”, Maria Pia Toni, ENEA-INMRIIAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)“, Vienna, 9-12 November 2010
AcknowledgementsThe research within the EURAMET joint research project “Brachytherapy”receives funding from the European Community’s Seventh FrameworkProgramme, ERA-NET Plus, under the iMERA-Plus Project - GrantAgreement No. 217257.The author would like to thank the partners of the “Brachytherapy”project for their support to this contribute.In particular:Isabelle Aubineau-Lanièce(CEA, LIST, Labo
IAEA International Symposium "Standards, Applications and QA in Medical Radiation Dosimetry (IDOS)", Vienna, 9-12 November 2010. In . external beam dosimetry, D. w . primary standards are currently operating for dosimetry of external radiation beams used in radiotherapy and the uncertainty on D. w,1 cm . is about . 2% (k 1). In . BT .
Essays on Modern Japanese Thought. 4,2 Symposium: Japan in the 1970's. 5,2 Symposium: Translation and Japanese Studies. Introduction by Roy Andrew Miller. 6,1 Symposium on Japanese Society. Introduction by Susan B. Hanley. 8,1 Symposium on Ie Society. Introduction by Kozo Yamamura. 11,1 Symposium: Transition From Medieval to Early Modern Japan.
The IEEE/IPSJ International Symposium on Applications and the Internet (SAINT) is intended to provide a forum for researchers in the Internet and its applications to discuss the current status, technical challenges, standards, fundamental issues, future services, and applications. This symposium covers
produce this symposium. We hope that this year's symposium will enable all attendees to reach new heights in applying the perspectives and science of human factors/ergonomics to the future of health care. Joseph R. Keebler, PhD Anthony D. (Tony) Andre, Symposium Chair PhD, CPE Symposium Cochair :HOFRPH 1
Invitation to the International Scientific Symposium Institute of Researches and International Symposiums IRIS –ALKONA and Department of International Development of Baltic Center invite you to take part in the International Scientific Symposium "Economics, Business & Finance", which will be held in JURMALA, LATVIA 5 –. 9 July 2016
INTERNATIONAL SYMPOSIUM, SEMINAR & EXHIBITION June 7 -12, 2020 . www.displayweek.org. The Display Week 2020 Technical Symposium will place emphasis on three special topics of interest to address rapid growth in the following areas: . and Other Applications Standards and Guidelines Related to the Design or
Symposium sessions All meals and breaks 7:30 AM - 1:30 PM Symposium sessions Breakfast, break and lunch 1:30 PM or 2:30 PM 2 complimentary shuttle departures to Toronto Pearson International Airport Symposium Objectives RELATIONSHIPS To build relationships among stakeholders to advance outdoor play and early learning in Canada. CONNECTIONS
Vienna Motor Symposium 2021 42nd International Vienna Motor Symposium 29 - 30 April 2021 VIRTUAL PROGRAMME
Peter Friz and Martin Hairer (2014), A Course on Rough Paths, Springer. Terry Lyons, M. Caruana, and T. L evy (2007), Di erential equations driven by Rough Paths, Springer. Future direction: Application to stochastic control and reinforcement learning: (i)Extend control theory to dynamical systems perturbed by coloured noise. (ii)Find e cient Monte-Carlo schemes to compute optimal path and .
