1. Peter Dendooven LaBr 3 and LYSO monolithic crystals coupled to photosensor arrays for TOF-PET Physics for Health in Europe Workshop February 2-4, 2010, CERN

2. Physics for Health in Europe February 2-4, 2010, CERN Peter DendoovenContents introduction –time-of-flight positron emission tomography (TOF-PET) –monolithic vs. block detectors experiments results conclusions and outlook

3. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Time-of-flight PET (TOF-PET) 500 ps  7.5 cm uniform probability on line-of-response W.W. Moses, IEEE Trans. Nucl. Sci. 50 (2003)1325

4. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Monolithic vs. block detectors scintillator read out by pixellated photosensor scintillator pixellated sensor pixellated scintillator block read out by 4 photosensors scintillator pixels PMTs

5. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven 3D photoconversion position Anger logic x,y position resolution: pixel size depth-of-interaction (DOI) requires special tricks light distribution over sensor array x,y,z position resolution < sensor pixel size depth-of-interaction (DOI) “included” x y z (DOI) DOI

6. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Effect of time walk vs. position W.W. Moses and S.E. Derenzo, IEEE Trans. Nucl. Sci. 46 (1999) 474-478 γ crystal pixelmonolithic crystal γ γ PMT ~150 ps/cm surface reflection crystal surfaces are far away: smaller time walk ? how to correct ?

7. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Detector components for fast timing fast photonsensor arrays Multi-anode PMT Hamamatsu H8711-03 SiPM array Hamamatsu MPPC S11064- 050P(X1) fast dedicated electronics LYSO:CeLaBr 3 :Ce(5%) rise time (ns)~0.3 ≤1 decay time (ns)~40~15 light yield (photons/MeV)~25 000~65 000 fast and bright crystals 16-channel fast amplifier for SiPM array

8. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Set-up LYSO:Ce + MA PMT XP2020Q BaF 2  25.4 mm x 20 mm collimator 22 Na monolithic LYSO:Ce 20x20x12 mm 3 H8711-03 spectralon x y z  5 mm 40 cm 5 cm translation stages high-speed digitizer 16-channel QDC anode dynode 16 anodes last dynode AND ch 1ch 2 trigger in trigger out gate inin anode #6 4.2 mm 1 event = 16 energies + 2 timing signal traces

9. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Set-up LaBr 3 :Ce(5%) + SiPM array 22 Na bare LaBr 3 :Ce(5%) 3x3x5 mm 3 Hamamatsu S11064-050P(X1) 4 x 4 array, 3x3 mm 2 pixels 50  m microcell (3600 per pixel) bare LaBr 3 :Ce(5%) 16.2x18x10 mm 3 polished, teflon-wrapped combined timing output with extra amplification to 8 GS/s digitizer 16 channel preamp 16 energy outputs

10. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven 3D photoconversion position: method procedure: calibration scan across the front surface (XY-scan) calibration scan across one side surface (YZ-scan) 3D photoconversion position determination using a maximum likelihood estimation (MLE) algorithm FWHM position resolution ~2.5 mm in 3D R. Vinke, et al. “Time walk correction for TOF-PET detectors based on a monolithic scintillation crystal coupled to a photosensor array”, submitted to Nucl. Instr. Meth. A.

11. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven 3D photoconversion position: results x,y resolution(FWHM) ~2.4 mm slight DOI dependence DOI-resolution (FWHM) 2.3 mm near PMT 4 mm at 10 mm from PMT edge artifacts y profile x profile LYSO:Ce + MAPMT

12. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Coincidence timing resolution (CTR) FWHM: 235 ps single detector resolution: 224 ps FWHM “scanner” CTR: 315 ps LaBr 3 :Ce(5%) + SiPM array vs. small LaBr 3 :Ce(5%) + SiPM LYSO:Ce + MA PMT vs. BaF 2 + PMT single detector resolution: 310 ps FWHM “scanner” CTR: 440 ps FWHM: 358 ps

13. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven DOI (mm) 02468 20 0 -20 10 Position-dependent time walk LaBr 3 :Ce(5%) + SiPM arrayLYSO:Ce + MA PMT R. Vinke et al., 2008 IEEE Nucl. Sci. Symp. Conf. Rec. M06-207 R. Vinke et al., 2009 IEEE Nucl. Sci. Symp. Conf. Rec. M06-2 R. Vinke et al., submitted to Nucl. Instr. Meth. A

14. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Time walk correction LYSO:Ce + MA PMT residual time walk is negligeable resulting CTR = 354 ps FWHM

15. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven crystal: 3x3x5 mm 3 bare LaBr 3 :Ce(5%) LYSO Hamamatsu SiPM S10362-33-050c spectralon reflective material Agilent DC282 digitizer 8 GS/s 700 MHz anti-aliasing filter extra amplification timing channel Timing resolution with small crystals indicates the limit of a crystal-sensor combination

16. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Time pickoff digitized timing signal

17. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Time pickoff cubic spline interpolation to recover waveform

18. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven Time pickoff cubic spline interpolation to recover waveform determination of baseline level directly before pulse onset baseline

19. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven baseline Time pickoff cubic spline interpolation to recover waveform determination of baseline level directly before pulse onset timestamp based on constant level with respect to baseline (leading edge pickoff)

20. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven 100 ps CTR for LaBr 3 + SiPM timing spectrum shifts according to 103.4 ps99.5 ps101.8 ps 20 mm R.Vinke et al., 2009 IEEE Nucl. Sci. Symp. Conf. Rec. M06-2 S.Seifert et al., 2009 IEEE Nucl. Sci. Symp. Conf. Rec. J01-4 CTR for LYSO: 170 ps FWHM

21. Physics for Health in Europe February 2-4, 2010, CERN Peter DendoovenConclusions benefits of monolithic detectors for TOF-PET: maximum sensitivity 3D photoconversion position can be determined FWHM ~2.5 mm position-dependent time walk can be corrected to < ±10 ps parallax error can be avoided LYSO:CeLaBr 3 :Ce(5%) monolithic440315 small crystal170100 coincidence timing resolutions (ps)

22. Physics for Health in Europe February 2-4, 2010, CERN Peter DendoovenOutlook thicker crystals up to 20 mm new project: use of TOF-PET for proton dose verification in proton therapy ? 16 channel preamp small crystal timing channels new 16-channel amplifier CTR < 300 ps for LYSO:Ce CTR < 200 ps for LaBr 3 :Ce ? R. Vinke, H. Löhner, F. Schreuder, P. Dendooven D. Schaart, S. Seifert, M. de Boer, H. van Dam, F. Beekman

23. Physics for Health in Europe February 2-4, 2010, CERN Peter Dendooven no TOF~600 ps TOF www.medical.philips.comPhilips Gemini TruFlight PET/CT promo brochure Why do we do this ? TOF-PET allows better image shorter scan smaller radiation dose to patient