Characterization of heavy charged particle fields using fluorescent nuclear track detectors

Transcription

1 PTCOG 53, Shanghai June 12, 2014 Characterization of heavy charged particle fields using fluorescent nuclear track detectors Grischa M. Klimpki 1, P. Incardona 2, H. Mescher 1, T. Pfeiler 1, M.S. Akselrod 3, O. Jäkel 1, S. Greilich 1 1 German Cancer Research Center, Heidelberg, Germany 2 Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany 3 Landauer Inc., Stillwater, Oklahoma, USA

2 6/12/2014 Page 2 Concepts of dosimetry ionization-based dosimetry ionization chambers

3 6/12/2014 Page 2 Concepts of dosimetry ionization-based dosimetry ionization chambers D phys = f Q

4 6/12/2014 Page 2 Concepts of dosimetry ionization-based dosimetry fluence-based dosimetry ionization chambers Faraday cups D phys = f Q

5 6/12/2014 Page 2 Concepts of dosimetry ionization-based dosimetry fluence-based dosimetry upload/2009/12/medipix-chip.jpg ionization chambers silicon-based detectors D phys = f Q

6 6/12/2014 Page 2 Concepts of dosimetry ionization-based dosimetry fluence-based dosimetry FNTD ionization chambers fluorescent nuclear track detectors D phys = f Q

7 6/12/2014 Page 2 Concepts of dosimetry ionization-based dosimetry fluence-based dosimetry FNTD ionization chambers fluorescent nuclear track detectors D phys = f Q D biol = f Φ, S, Z

8 6/12/2014 Page 3 Measurement principle with fluorescent nuclear track detectors (FNTDs): measure dose in-vivo estimate biological effect FNTD

9 6/12/2014 Page 3 Measurement principle with fluorescent nuclear track detectors (FNTDs): measure dose in-vivo estimate biological effect FNTD measured quantities: D biol = f Φ, S, Z

10 6/12/2014 Page 3 Measurement principle with fluorescent nuclear track detectors (FNTDs): measure dose in-vivo estimate biological effect FNTD measured quantities: D biol = f Φ, S, Z particle fluence Φ calculated from normalized particle number N/A

11 6/12/2014 Page 3 Measurement principle with fluorescent nuclear track detectors (FNTDs): measure dose in-vivo estimate biological effect FNTD measured quantities: D biol = f Φ, S, Z particle fluence Φ stopping power S calculated from calculated from normalized particle number N/A track intensity I

12 6/12/2014 Page 3 Measurement principle with fluorescent nuclear track detectors (FNTDs): measure dose in-vivo estimate biological effect FNTD measured quantities: D biol = f Φ, S, Z particle fluence Φ stopping power S atomic number Z calculated from calculated from calculated from normalized particle number N/A track intensity I track intensity straggling σ(i)

13 6/12/2014 Φ PART 1 particle fluence

14 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) FNTD z

15 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) 12C FNTD z

16 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) δ electron 12C track core FNTD z

17 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions)

18 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions)

19 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) mixed field (e.g. fragments) 11B 1H 7Li 9Be FNTD z

20 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) mixed field (e.g. fragments) FNTD z

21 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) mixed field (e.g. fragments)

22 6/12/2014 Page 4 FNTD technology uniform field (e.g. 12C ions) mixed field (e.g. fragments) Φ = N A counting particles sufficient number and angular distribution

23 6/12/2014 Page 5 Proof of principle Irradiation Heidelberg Ion-Beam Therapy Center 1 detector under 6 angles: (ϑ = 0, 15, 30, 45, 60, 75 )

24 6/12/2014 Page 5 Proof of principle Irradiation Heidelberg Ion-Beam Therapy Center 1 detector under 6 angles: (ϑ = 0, 15, 30, 45, 60, 75 ) ion type: 12C energy: 90 MeV/u total fluence: 1.2 x 10 6 cm -2

25 6/12/2014 Page 5 Proof of principle Irradiation Heidelberg Ion-Beam Therapy Center 1 detector under 6 angles: (ϑ = 0, 15, 30, 45, 60, 75 ) ion type: 12C energy: 90 MeV/u total fluence: 1.2 x 10 6 cm -2 Readout Zeiss LSM 710 microscope (30 min)

26 6/12/2014 Page 5 Proof of principle Irradiation Heidelberg Ion-Beam Therapy Center 1 detector under 6 angles: (ϑ = 0, 15, 30, 45, 60, 75 ) ion type: 12C energy: 90 MeV/u total fluence: 1.2 x 10 6 cm -2 Readout Zeiss LSM 710 microscope (30 min)

27 6/12/2014 Page 6 Angular distribution ϑ histogram 701 carbon ion trajectories

28 6/12/2014 Page 6 Angular distribution ϑ histogram 701 carbon ion trajectories Φ Φ ref = ± 5. 8 % reference fluence: Φ ref = N A = cm 2

29 6/12/2014 Page 6 Angular distribution ϑ histogram 701 carbon ion trajectories Φ Φ ref = ± 5. 8 % reference fluence: Φ ref = N A = cm 2 fluence conclusion: < 5% deviation for differentiated carbon ion fields

30 6/12/2014 S PART 2 stopping power

31 6/12/2014 Page 7 Stopping power determination FNTD in mixed field FNTD

32 6/12/2014 Page 7 Stopping power determination FNTD in mixed field high S low S local fluorescence intensity ~ # liberated secondary electrons [Sykora et al., Radiat. Meas. 43, 2008] FNTD

33 6/12/2014 Page 7 Stopping power determination FNTD in mixed field high S low S local fluorescence intensity ~ # liberated secondary electrons [Sykora et al., Radiat. Meas. 43, 2008] FNTD correlate stopping power and intensity

34 6/12/2014 Page 7 Stopping power determination FNTD in mixed field high S low S local fluorescence intensity ~ # liberated secondary electrons [Sykora et al., Radiat. Meas. 43, 2008] FNTD list of limitations: correlate stopping power and intensity FNTD: detector sensitivity fluctuations; PHYSICS: stochastic energy deposition; intensity loss of angular tracks; intensity measurements itself (maximum, Gauss peak, mean); MICROSCOPE: flat field correction; spherical aberration;

35 6/12/2014 Page 8 Calibration curve I ~ S plot based on 9 irradiations [H. Mescher, pers. comm., 2014] I S

36 6/12/2014 Page 9 Application on mixed fields Bragg peak irradiation

37 6/12/2014 Page 9 Application on mixed fields Bragg peak irradiation primary 12C ~ 90 kev/µm

38 6/12/2014 Page 9 Application on mixed fields Bragg peak irradiation fragment e.g. 1H ~ 1 kev/µm primary 12C ~ 90 kev/µm

39 6/12/2014 Page 9 Application on mixed fields fragment e.g. 1H ~ 1 kev/µm primary 12C ~ 90 kev/µm

40 6/12/2014 Page 9 Application on mixed fields fragment e.g. 1H ~ 1 kev/µm primary 12C ~ 90 kev/µm stopping power conclusion: reliable relative intensity spectroscopy

41 6/12/2014 Z PART 3 atomic number

42 6/12/2014 Page 10 Charge spectroscopy 1. correlate Z and track width

43 6/12/2014 Page 10 Charge spectroscopy 1. correlate Z and track width proton ~ 1 kev/µm 2 µm

44 6/12/2014 Page 10 Charge spectroscopy 1. correlate Z and track width proton ~ 1 kev/µm carbon ~ 90 kev/µm 2 µm 2 µm

45 6/12/2014 Page 10 Charge spectroscopy 1. correlate Z and track width proton ~ 1 kev/µm carbon ~ 90 kev/µm 2 µm 2 µm

46 6/12/2014 Page 10 Charge spectroscopy 1. correlate Z and track width proton ~ 1 kev/µm carbon ~ 90 kev/µm 2 µm 2 µm σ = 0.14 µm σ = 0.17 µm

47 6/12/2014 Page 10 Charge spectroscopy 1. correlate Z and track width proton ~ 1 kev/µm carbon ~ 90 kev/µm 2 µm 2 µm σ = 0.14 µm σ = 0.17 µm information on track width lost during confocal readout [Niklas et al., Radiat. Meas. 56, 2013]

48 6/12/2014 Page 11 Charge spectroscopy 2. correlate Z and energy loss straggling

49 6/12/2014 Page 11 Charge spectroscopy 2. correlate Z and energy loss straggling FNTD z

50 6/12/2014 Page 11 Charge spectroscopy 2. correlate Z and energy loss straggling track intensity I FNTD z depth z

51 6/12/2014 Page 11 Charge spectroscopy 2. correlate Z and energy loss straggling track intensity I µ(i) 2 σ(i) FNTD z depth z track information µ(i) and σ(i)

52 6/12/2014 Page 11 Charge spectroscopy 2. correlate Z and energy loss straggling track intensity I µ(i) 2 σ(i) FNTD z depth z track information µ(i) and σ(i) σ I = f S, Z,?

53 6/12/2014 Page 12 Calculated energy straggling σ(e) ~ S plot based on 21 calculations [S. Greilich, pers. comm., 2014]

54 6/12/2014 Page 13 Measured intensity straggling σ(i) ~ S plot based on 22 irradiations σ rel I 1 S

55 6/12/2014 Page 13 Measured intensity straggling σ(i) ~ S plot based on 22 irradiations

56 6/12/2014 Page 13 Measured intensity straggling σ(i) ~ S plot based on 22 irradiations atomic number conclusion: measured intensity straggling independent from Z

57 6/12/2014 Page 14 Conclusion level of accuracy

58 6/12/2014 Page 14 Conclusion level of accuracy fluence: primary ion fields (< 5%) light and fast fragments

59 6/12/2014 Page 14 Conclusion level of accuracy fluence: primary ion fields (< 5%) light and fast fragments stopping power: relative determination absolute calibration

60 6/12/2014 Page 14 Conclusion level of accuracy fluence: primary ion fields (< 5%) light and fast fragments stopping power: relative determination absolute calibration atomic number: primary ions / fragments full charge spectroscopy

61 6/12/2014 Page 14 Conclusion level of accuracy fluence: primary ion fields (< 5%) light and fast fragments stopping power: relative determination absolute calibration atomic number: primary ions / fragments full charge spectroscopy fluence-based dosimetry using FNTDs

62 Thank you for your attention! Collaboration partners: Mosaic Group (MPI Dresden) Theoretical Bioinformatics (BioQuant) Heidelberg Ion-Beam Therapy Center Light Microscopy Facility (DKFZ)