Disclosure. Societal Guidelines in High Energy and Skin Brachytherapy. Content. Acknowledgments. Jose Perez-Calatayud.

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1 Ø1.2 Ø1.6 1 z 46 Ø1.1 3,6 26, r Ø11 P(y,z) y Ir-192 metal Ø mm stainless steel Nº: center of the source Iridium-192 core Ø 6 Steel cable 30 3,6 5 Ø11 Filling piece: Aluminium Iridium-192 core Ø 6 Steel cable Disclosure Societal Guidelines in High Energy and Skin Brachytherapy Jose Perez-Calatayud Radiotherapy Department. La Fe University Hospital Medical Physics Research Group La Fe-UVEG. IRIMED Valencia. Spain perez_jos@gva.es PTB Workshop 30 May 2017 Brunswick 1 La Fe Hospital & Valencia University Research support received from: Elekta-Nucletron: Valencia App, Freiburg flap, QA tools, MRI dummies, MC sources, Esteya ebt PTW: Well chamber inserts, QA tools, x-ray chamber & phantoms Bebig: MC Co-60 HDR, Cs-137 sources, Valencia App, TPS app library 2 Acknowledgments Content Hospital La Fe V. Carmona F. Lliso J. Gimeno B. Ibañez F. Celada A. Tormo ABS Report Z. Ouhib S. Rodriguez M. Kasper CND C. Candela TG-253 R. Fulkerson F. Ballester M. Rivard FA. Siebert HEBD Calibration report High Energy (HE) Photons Brachy HEBD Report 2012 (AAPM-ESTRO) HEBD calibration report (AAPM-ESTRO) in progress Skin Brachy ABS Report 2015 TG-253 (AAPM-ESTRO) in progress General Hospital D. Granero Valencia University F. Ballester J. Vijande M. Rivard LA DeWerd F. Ballester 3 4 TPS: Source characterization Basic data used by TPS: Dose Rate Table (DRT) in water (cgy h -1 U -1 ) TG-43 U1 formalism Rivard 2004 Cs Ir Co-60 5 I Pd Cs Specific calibration and TG-43 datasets R Literature discrepancies Not clear traceability 1

2 AAPM Prerequisites I-125, Pd-103, Cs-131 AAPM Prerequisites Sources that fulfil prerequisites Registry IROC-AAPM Williamson 1998 I. Conditions to guarantee traceability II. Availability TG-43 datasets including MC + EXP by independent investigations. Ir-192, Cs-137, Yb-169 Co-60 Li 2007 Extension I and II Prerequisites to HE III. Conventional sources Cs-137 & Ir-192 with similar design to existing ones just 1 study is sufficient 7 Datasets to be used in clinical TPS? 8 Consensus datasets AAPM Low Energy Brachytherapy Dosimetry Working Group LEBD I-125 Pd-103 Cs-131 TG-43 U TG-43 U1 S Consensus datasets AAPM LEBD-WG Rivard 2004, 2007, 2012, 2017 MC and EXP g(r) MC F(r,) MC Averaged equal weight If MC within EXP uncertainty LE Rivard 2017 to be published. TG-43 U1 S Selection, comparison, review in depth, complementation published studies Consensus datasets for low energy seeds Disagreements solved (up 15%-20%) 9 10 Consensus datasets AAPM High Energy Brachytherapy Dosimetry Working Group Ir-192 Cs-137 Co-60 HEBD Med Phys 2012 HE pubs/reports/rpt_229.pdf HEBD: CONSENSUS DATASETS METHODOLOGY Averaged MC studies, NOT EXP + MC as in low energy g L (r) & F(r,) from selected MC g L (r) full scatter conditions Use G L (r,) NOT punctual approximation Anisotropy Factor NOT RECOMMENDED Rec of just 1 study (MC) for sources similar in design to existing ones extended to Co-60 TG-43 consensus datasets for high energy EXP and MC methodology recommendations 11 CONSENSUS CRITERIA To select/combine publications according to: MC quality, EXP validation, resolution, range, phantom, 12 2

3 HEBD Consensus methodology HEBD: Consensus methodology g L (r) varies with phantom size 192 Ir 35% conversión function Perez-Calatayud 2004, Granero 2008 Correction to unbounded (D. Granero) HEBD: Consensus Methodology Kerma or Dose at very short distances? HEBD: Consensus Methodology Consideration of emission? Dosis (e - ) / Dosis (e - + ) If LE ( 125 I <E>=28 kev, 103 Pd <E>=20.7 kev) K is sufficient If HE ( 169 Yb, 192 Ir, 137 Cs and 60 Co) in function of distance CPE Yb-169: r >1 mm Ir-192: r >1.5 mm Cs-137: r >2.5 mm Co-60: r >7 mm 1% 1% Yb-169: 0.1% r >0.5 mm Ir-192: 0.2% r >2 mm Cs-137: 0.1% r >1.5 mm Co-60: 0.2% r >4 mm Ballester et al. MPH 36, 4250 (2009) Ballester et al. MPH 36, 4250 (2009) Monte Carlo en Braquiterapia Domingo Granero Cabañero 15 Monte Carlo en Braquiterapia Domingo Granero Cabañero 16 HEBD 2012 HEBD: QA tables HE HEBD: Consensus datasets HDR Ir-19 v1 Nucletron HDR Ir-19 v2 Nucletron HDR Ir-192 VS2000 Varian HDR Ir-192 Butchler Ibt-Bebig HDR Ir-192 GammaMed 12i HDR Ir-192 GammaMed Plus HDR Ir-192 GI192M11 IBt-Bebig HDR Ir-192 Ir2.A85-2 IBt-Bebig HDR Ir-192 M19 SPECT HDR Ir-192 Flexisource Nucletron PDR Ir-192 GammaMed 12i PDR Ir-192 GammaMed Plus PDR Ir-192 mpdr-v1 Nucletron LDR Ir BI LDR Ir wires Ibt-Bebig LDR Cs-137 CSM3 IBt-Bebig LDR Cs-137 IPL RPD LDR Cs-137 CSM11 IBt-Bebig HDR Co-60 GK60M21 Ibt-Bebig HDR Co-60 GK60M21 Ibt-Bebig

4 30 3,6 5 Ø11 Filling piece: Aluminium Iridium-192 core Ø 6 Steel cable HEBD: EXP meth recommendations TLD, Radicromic, OSL, PSD, Gel Volume averaging Energy response Calibration HEBD: MC meth recommendations PTRAN, MCNP, Geant4, Penelope, EGSnrc Kerma vs Dose Variance reduction techniques Βeta consideration Cross sections 5 15 Phantom vs liquid water Spectrum Phantom geometry Uncertainty analysis S K simulation Source geometry Phantom dimensions Cells definition TG-43 range & resolution Validation with existing data 21 Uncertainties (analysis and reference values) 22 HDR Ir-192 Andrassy, Niatsetsky, Perez-Calatayud RFM 2012 HDR Co-60 1st Review AAPM 1st Review ACROP (ESTRO) $$$$$ Room shielding Treatment time Pheripheral dose Shielded App Treatment types and workload

5 IN DISCUSSION Well chamber calibration frequency 2 years max (Redundancy 1%) Redundancy: Additional Well chamber + measurement of the HDR source prior replacement. Agreement hospital physicist S K assay vs manufacturer certificate ±3% S K input value in the TPS: Hospital physicist one 25 Traceability maintenance I-125, Pd-103, Cs-131 AAPM CLA2004 DeWerd 2004 Sources introduced in the market for the first time Manufacturer 5 seeds to NIST. NIST: S K and spectrum determination. NIST 3 seeds to ADCLs. Manufacturer receives the 5 seeds calibrating its chambers. Each 12 month max Manufacturer 3 sedes to NIST. NIST & ADCL S K determination should be 2%. Manufacturer receives the 3 seeds validating its calibration. Not established in Europe. Pending of new Societal Rec+ Organisms agreements 26 IN DISCUSSION HDR Co-60 well chamber calibration: Direct or with correction factor from HDR Ir-192??? Paralell CLA2004 for HE for new sources: Manufacturer 2 sources to the Metrology Lab (ML) plus well chamber ML S K determination (inter-source 1%). Manufacturer receives the 2 sources and chamber establishing his calibration Med Phys July 2015 Periodical evaluation, how and when???? Content High Energy (HE) Photons Brachy HEBD Report 2012 (AAPM-ESTRO) HEBD calibration report (AAPM-ESTRO) in progress Skin Brachy ABS Report 2015 TG-253 (AAPM-ESTRO) in progress Skin Radiotherapy Electrons: Practical problems with surface irregularity and obliquity (dose inhomogeneity), small field sizes (special dosimetry), small depths (non practical bolus), Brachytherapy: Superficial: up 5 mm, because the gradient Interstitial: > 5 mm

6 ABS Report (2015) Rad Onc + Dermatologist + Med Phys Treatment Techniques: Interstitial (>5mm) Superficial ( 5mm) HDR Ir-192 based Applicators (Leipzig) High shielding surrounding healthy tissue Treatment planning & delivery simple Typical prescription depth at 3 mm Limited to flat surfaces up to 3-4,5 cm Leipzig vs Valencia (Elekta) Lateral homogeneity, penumbra, and useful beam are improved treatment time longer Varian Elekta 33 Perez-Calatayud et al 2005, Granero et al Applicators: Clinical implementation Prescription depth Typically 3 mm (approx surface dose 130%) High gradient dose:to consider surface dose when prescription is done at larger depth Plastic cap:to avoid electron contamination Applicators: Clinical implementation Plastic cap must be ALWAYS in place Granero, Candela, Vijande, Ballester, Perez-Calatayud, Jacob, Mourtada Med Phys

7 Leakage Applicators: Clinical implementation Caution in some clinical cases lateral nose eye dose In Progress: New Valencia (up 5 cm ) New Valencia App (Elekta) Granero, Perez-Calatayud, Ballester, Ouhib EJMP Candela, Niatsetski, van der Laarse, Granero, Ballester, Perez-Calatayud, Vijande Med Phys Skin electronic Brachytherapy Applicators To mimic radionuclide shielded app IMPROVING Treatment time Leakage Radiation protection requirements Shielding requirements HDR afterloader dependence Regulations requirements 39 Skin electronic Brachytherapy Applicators Axxent Electronic Brachyterapy System (Xoft) 50 kvp App 1-5 cm SSD = cm Carl Zeiss INTRABEAM System 50 kvp App 1-6 cm SSD = cm 40 Skin electronic Brachytherapy Applicators Esteya (Elekta) 69.5 kvp App 1-3 cm SSD = 6 cm Improvemens vs Valencia: Penumbra Treatment time Gradient on PTV Leakage 7 Gy treatment time Esteya Valencia H3 Controversy ebt and BT definition AAPM, ABS, ASTRO, ACR,. Different charge (reimbursement) in USA Brachy definition revisited: Proposal TG-253, WGBCA, BTSC: "Brachytherapy: radiotherapy using one or more radiation sources with the radiation source/sources inside or close to the target volume. Typically brachytherapy is within 10 cm and thus close is interpreted to include distances of < 10 cm." App 3 3 mm 153 s s

8 PDD different Superficial APPLICATIONS 1st Review AAPM Pending to be submitted for Review ACROP (ESTRO) Domingo Granero, Javier Vijande, Facundo Ballester, Silvia Rodriguez, Jose Perez- Calatayud,"Prescription Depth in Surface Skin Brachytherapy," Brachytherapy, Volume 16, Issue 3, Supplement, S50-S51, May June Applicators Ir-192 VALENCIA Small volume chamber calibrated Co-60 (eg PTW Markus, PinPoint), Film. VALENCIA & ESTEYA CF reference values for HDR 1000Plus (SI) and TM3304 (PTW) JCB (5) Perez-Calatayud 2006 Granero 2008 Granero JCB (2) Method I Measure in solid water with a chamber calibrated in absorbed dose to water cm 3 Soft X-ray chamber, Type cm 3 Soft X-ray chamber Type (k=2) d c =0.25 mm 47 Traceable to PTB (Germany) Calibrated with beam size Ø = 3 cm, with SSD = 75 cm. 8

9 Method I TRS-398 Measure in solid water with a chamber calibrated in absorbed dose to water 1.00 for T cm (Esteya) Hill et al 2010 Caution: Equivalence plastic water with liquid water Difference (%) in the dose to a small voxel of water located on the surface of the phantom material relative to the surface dose in a water phantom Hill et al 2014 Summary suitable/unsuitable phantoms for kv dosimetry K pt K ion From calibration certificate K pol More direct and robust K elec 0.25 mm for T34013 (PTW) 49 Candela-Juan et al 2015 using MC Penelope with Esteya spectrum CIRS Plastic Water Low Range: 0.2% 50 Method II Measure in air with a chamber calibrated in air kerma ADCL Wisconsin USA cm 3 Exradin A20 The calibration in water is not available ±1% (k = 2) Calibrated with beam size 10x10 cm 2, with SSD = 100 cm Method II Measure in air with a chamber calibrated in air kerma ADCL Wisconsin USA TG for A20 6 cm (Esteya) K pt K ion K pol K elec From calibration certificate From Table V TG-61 Depends of: SSD, Ø, HVL From Table IV TG-61 Depends of HVL 1.80 mm for A20 (SI)

10 Comparison with different chambers & methods T34013 chamber in plastic water Esteya T34013 chamber in air Exradin A20 chamber in air Comparison with different chambers & methods Esteya Relative difference (%) between the surface dose rates measured and the surface dose rates included in the Esteya console. Candela-Juan et al 2015 Perez-Calatayud et al (±2.3%) (±2.7%) (±2.5%) (k=1) In contradiction with Fulkerson et al 2014 this study demonstrated that the stem effect of the T34013 is negligible Candela-Juan et al 2015 Perez-Calatayud et al 2015 Fulkerson et al 2014 Xoft Proposed formalism based on in air measurements but using MC derived correction factors instead TG-61 MC chamber replacement factor MC conversion factor from air to water UNPUBLISHED, pending PTW serial design Results Differences between the proposed formalism and TG-61: 5.1% to 6.1%, being the dose rate measured with TG-61 higher. 58 Conclusions AAPM-ESTRO Societal recommendations are available (HEBD) for consensus datasets and MC & EXP methodology. Calibration report in HE is in progress with some difficult issues as manufacturer constancy evaluation. Thank you Skin brachy progresses significantly (ABS & ESTRO), mainly with shielded appl. AAPM-ESTRO is trying to establish dosimetric recommendations (TG-253)