Disclosure and Skin Brachytherapy · Calatayud ,"Prescription Depth in Surface Skin Brachytherapy,"...

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Societal Guidelines in High Energy and Skin Brachytherapy

Jose Perez-CalatayudRadiotherapy Department. La Fe University HospitalMedical Physics Research Group La Fe-UVEG. IRIMEDValencia. Spain

[email protected]

PTB Workshop 30 May 2017 Brunswick

Disclosure

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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

La Fe Hospital & Valencia University

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Hospital La Fe

V. Carmona

F. Lliso

J. Gimeno

B. Ibañez

F. Celada

A. Tormo

Valencia University

F. Ballester

J. Vijande

General Hospital

D. Granero

HEBD Calibrationreport

TG-253ABS Report

Z. Ouhib

S. Rodriguez

M. Kasper

Acknowledgments

R. Fulkerson

F. Ballester

M. Rivard

FA. Siebert

M. Rivard

LA DeWerd

F. Ballester

CND

C. Candela

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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

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TPS: Source characterizationBasic data used by TPS: Dose Rate Table (DRT) in water (cGy h-1 U-1)

TG-43 U1 formalism

Riv

ard

2004

Cs-137 16Ir-192 19

Co-60 5I-125 27Pd-103 7Cs-131 1

26,6

463,

6 Ø11

Laserwelded

center of the source

34 Iridium-192core Ø 6

Steelcable

5

Iridium-192core Ø 6

Steelcable

515

303,

6

Ø11

5

Laserwelded

Laserwelded

Filling piece:Aluminium

R 0.8

1

1.75

Ø1.2Ø1.6

Ir-192 metal Ø 1 1.3 mm

5.5

Ø1.1

Laserwelded

P(y,z)z

y

stainless steelNº: 1.4541

y

r

75Specific calibration and TG-43 datasets

Literature discrepancies

Not clear traceability

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AAPM Prerequisites

Williamson 1998

I. Conditions to guarantee traceabilityII. Availability TG-43 datasets including MC + EXP

by independent investigations.

Li 2007

I-125, Pd-103, Cs-131

Ir-192, Cs-137, Yb-169 Co-60

Extension I and II Prerequisites to HEIII. Conventional sources Cs-137 & Ir-192 with similar design to existing ones just 1 study is sufficient

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Sources that fulfil prerequisites Registry IROC-AAPM

Datasets to be used in clinical TPS ?

AAPM Prerequisites

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AAPM

LEBD

“Low Energy Brachytherapy Dosimetry Working Group”

Disagreements solved (up 15%-20%)

I-125 Pd-103

Consensus datasets for low energy seeds

Cs-131

Consensus datasets

Rivard 2017 to be published.

TG-43 U1 2004

TG-43 U1 S1 2007

TG-43 U1 S2 2017

Selection, comparison, review in depth, complementation published studies

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AAPM LEBD-WG Rivard 2004, 2007, 2012, 2017

Consensus datasets LE � MC and EXP

g(r) � MC

F(r,) � MC

Averaged equal weight

If MC within EXP uncertainty

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AAPM

HEBD

“High Energy Brachytherapy Dosimetry Working Group” Ir-192 Cs-137

TG-43 consensus datasets for high energy

EXP and MC methodology recommendations

Co-60

Consensus datasets HE

Med Phys 2012

http://www.aapm.org/pubs/reports/RPT_229.pdf

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Averaged MC studies, NOT EXP + MC as in low energy

gL(r) & F(r,) from selected MC

gL(r) full scatter conditions

Use GL(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

HEBD: CONSENSUS DATASETS METHODOLOGY

CONSENSUS CRITERIA

To select/combine publications according to: MC quality, EXP validation, resolution, range, phantom, …

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HEBD Consensus methodology

gL(r) varies withphantom size

conversión function

Perez-Calatayud 2004, Granero 2008

35%

192Ir

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HEBD: Consensus methodology

Correction to unbounded (D. Granero)

Monte Carlo en BraquiterapiaDomingo Granero Cabañero

• ¿Kerma or Dose at very short distances?

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CPE

Yb-169: r >1 mmIr-192: r >1.5 mmCs-137: r >2.5 mmCo-60: r >7 mm

Ballester et al. MPH 36, 4250 (2009)

If LE (125I <E>=28 keV, 103Pd <E>=20.7 keV) K is sufficient

If HE (“169Yb”, 192Ir, 137Cs and 60Co)

in function of distance

HEBD: Consensus Methodology

Monte Carlo en BraquiterapiaDomingo Granero Cabañero

• ¿Consideration of emission?

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Dosis (e-) / Dosis (e- + )

Yb-169: 0.1% r >0.5 mmIr-192: 0.2% r >2 mmCs-137: 0.1% r >1.5 mmCo-60: 0.2% r >4 mm

1% 1%

Ballester et al.MPH 36, 4250 (2009)

HEBD: Consensus Methodology

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HEBD 2012

HEBD: QA tables HE

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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-192 81-01 BI

LDR Ir-192 81-01 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


HEBD: Consensus datasets

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www.uv.es/braphyqs

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TLD, Radicromic, OSL, PSD, Gel

Volume averaging

Energy response

Calibration

Phantom vs liquid water

Phantom geometry

Uncertainty analysis

…


HEBD: EXP meth recommendations

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PTRAN, MCNP, Geant4, Penelope, EGSnrc

Kerma vs Dose

Variance reduction techniques

Βeta consideration

Cross sections

Spectrum

SK simulation

Source geometry

Phantom dimensions

Cells definition

TG-43 range & resolution

Validation with existing data

Uncertainties (analysis and reference values)http://www.aapm.org/pubs/reports/RPT_229.pdf

HEBD: MC meth recommendationsIridium-192core Ø 6

Steelcable

515

303,

6

Ø11

5

Laserwelded

Laserwelded

Filling piece:Aluminium

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HDR Ir-192 HDR Co-60

Andrassy, Niatsetsky, Perez-Calatayud RFM 2012

$$$$$

Room shielding

Treatment time

Pheripheral dose

Shielded App

Treatment typesand workload 24

1st Review AAPM

1st Review ACROP (ESTRO)

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Well chamber calibration frequency 2 years max (Redundancy 1%)

Redundancy: Additional Well chamber + measurement of the HDR source prior replacement.

Agreement hospital physicist SK assay vs manufacturer certificate ±3%

SK input value in the TPS: Hospital physicist one

IN DISCUSSION ¡¡¡¡

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Traceability maintenanceI-125, Pd-103, Cs-131

AAPM CLA2004 DeWerd 2004

Sources introduced in the market for the first timeManufacturer 5 seeds to NIST.NIST: SK and spectrum determination.NIST 3 seeds to ADCLs.Manufacturer receives the 5 seeds calibrating its chambers.

Each 12 month maxManufacturer 3 sedes to NIST.NIST & ADCL SK determination should be ≤2%.Manufacturer receives the 3 seeds validating its calibration.

Not established in Europe.

Pending of new Societal Rec Organisms agreements +

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Paralell CLA2004 for HE for new sources:

Manufacturer ≥2 sources to the Metrology Lab (ML) plus wellchamberML SK determination (inter-source 1%).Manufacturer receives the 2 sources and chamber establishing his calibration

IN DISCUSSION ¡¡¡¡

Periodical evaluation, how and when ????

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Med Phys July 2015

HDR Co-60 well chamber calibration:

Direct or with correction factor from HDR Ir-192 ???

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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

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Skin RadiotherapyElectrons:

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

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ABS Report (2015)Rad Onc + Dermatologist + Med Phys

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Treatment Techniques:Interstitial (>5mm)

Superficial (≤5mm)

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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

Elekta

Varian

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Leipzig vs Valencia (Elekta)Lateral homogeneity, penumbra, and useful beam are improved

treatment time longer

Perez-Calatayud et al 2005, Granero et al 2008

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Prescription depth

Plastic cap:To avoid electron contamination

Applicators: Clinical implementation

High gradient dose:To consider surface dose when prescription is done at larger depth

Typically 3 mm (approx surface dose 130%)

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Plastic cap must be ALWAYS in placeApplicators: Clinical implementation

¡¡¡

Granero, Candela, Vijande, Ballester, Perez-Calatayud, Jacob, Mourtada Med Phys 2016

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New Valencia App (Elekta)

Applicators: Clinical implementation

Leakage Caution in some clinical cases

lateral nose eye dose

Granero, Perez-Calatayud, Ballester, Ouhib EJMP 2012 38

In Progress: New Valencia (up 5 cm )

Candela, Niatsetski, van der Laarse, Granero, Ballester, Perez-Calatayud, Vijande Med Phys 2016

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Skin electronic Brachytherapy ApplicatorsTo mimic radionuclide shielded app

IMPROVING

Treatment time

Leakage

Radiation protection requirements

Shielding requirements

HDR afterloader dependence

Regulations requirements

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Skin electronic Brachytherapy ApplicatorsAxxent Electronic Brachyterapy System (Xoft)

Carl Zeiss INTRABEAM System

50 kVp

App 1-5 cm

SSD = 2.06 – 3.03 cm

50 kVp

App 1-6 cm

SSD = 0.96 – 2.56 cm

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Improvemens vs Valencia:

Penumbra

Treatment time

Gradient on PTV

Leakage

69.5 kVp

App 1-3 cm

SSD = 6 cm

Esteya (Elekta)Skin electronic Brachytherapy Applicators

7 Gy treatment time Esteya Valencia H3

App 3 cm @ 3 mm 153 s 449-898 s 42

"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."

Controversy eBT and BT definitionAAPM, ABS, ASTRO, ACR, ….

Different charge (reimbursement) in USA

Brachy definition revisited:

Proposal TG-253, WGBCA, BTSC:

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PDD different Superficial APPLICATIONS

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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 2017 44

1st Review AAPM

Pending to be submitted for Review ACROP (ESTRO)

Applicators Ir-192 VALENCIA

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Small volume chambercalibrated Co-60 (eg PTW Markus, PinPoint), Film.

CF reference values for HDR 1000Plus (SI) and TM3304 (PTW)

Perez-Calatayud 2006

Granero 2008

Granero 2012

VALENCIA & ESTEYA

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JCB 2016 8(5) 441-447

JCB 2015 7(2) 189-195

eBT: ESTEYA Absolute surface dose rate

Method I Measure in solid water with a chamber calibrated in absorbed dose to water

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0.005 cm3 Soft X-ray chamberType 34013

dc=0.25 mm


Traceable to PTB (Germany)

0.005 cm3 Soft X-ray chamber, Type 34013

(k=2)

Calibrated with beam size Ø = 3 cm, with SSD = 75 cm.

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Method I Measure in solid water with a chamber calibrated in absorbed dose to water

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TRS-398

0.25 mm for T34013 (PTW)

6 cm (Esteya) 1.00 for T34013

From calibration certificate

KpT

Kion

Kpol

Kelec

1.000 More direct and robust ¡¡


Caution: Equivalence plastic water with liquid water

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Hill

et

al 2

010

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

CIRS Plastic Water Low Range: 0.2%

Candela-Juan et al 2015 using MC Penelope with Esteya spectrum

Hill et al 2014

Summary suitable/unsuitable phantoms for kV dosimetry


Method II Measure in air with a chamber calibrated in air kerma

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0.074 cm3 Exradin A20


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±1% (k = 2)

ADCL Wisconsin USA

The calibration in wateris not available

Calibrated with beam size 10x10 cm2, with SSD = 100

cm.


Method II Measure in air with a chamber calibrated in air kerma

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TG-61

From Table V TG-61Depends of: SSD, Ø, HVL

KpT

Kion

Kpol

Kelec

1.000

From calibration certificate

1.80 mm for A20 (SI)

6 cm (Esteya) 1.00 for A20

From Table IV TG-61Depends of HVL


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ADCL Wisconsin USA

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Absolute surface dose rate

Esteya

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Comparison with different chambers & methods

Candela-Juan et al 2015 Perez-Calatayud et al 2015

T34013 chamber in plastic water

T34013 chamber in air

Exradin A20 chamber in air

eBT: ESTEYA

Candela-Juan et al 2015

(±2.3%) (±2.7%) (±2.5%)

Relative difference (%) between the surface dose rates measured andthe surface dose rates included in the Esteya console.

In contradiction with Fulkerson et al 2014 this study demonstrated that the stemeffect of the T34013 is negligible

Perez-Calatayud et al 2015

(k=1)


EsteyaComparison with different chambers & methods

eBT: ESTEYA

Absolute surface dose rateeBT: ESTEYA

UNPUBLISHED, pending PTW serial design


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Proposed formalism based on in air measurements but using MC derived correction factors instead TG-61

Fulkerson et al 2014 Xoft

MC chamber replacement factorMC conversion factor from air to water

Differences between the proposed formalism and TG-61:5.1% to 6.1%, being the dose rate measured with TG-61 higher.

Results

eBT: ESTEYA

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.

Skin brachy progresses significantly (ABS & ESTRO), mainly with shielded appl. AAPM-ESTRO is trying to establish dosimetric recommendations (TG-253).

Conclusions

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Thank you

[email protected]

Disclosure and Skin Brachytherapy · Calatayud ,"Prescription Depth in Surface Skin Brachytherapy,"...

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