Evaluation of the dosimetric properties of a synthetic single crystal diamond detector in high energy clinical proton beams

Mandapaka, A; Ghebremedhin, A; Patyal, B; Marinelli, M.; Prestopino, G.; Verona, C.; Verona-Rinati, G.

doi:10.1118/1.4828777

Cited by 43 publications

(46 citation statements)

References 34 publications

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“…Major limitations pointed out for both silicon and state-of-the-art diamond detectors were significant LET, dose rate and energy dependence [9,11]. Such undesired effects were not observed in a novel synthetic diamond dosimeter recently reported in the literature by some of the authors of the present paper [18]. Moreover, contrary to diamond detectors, silicon diodes are also affected by a strong lattice radiation damage.…”

Section: Introductionmentioning

confidence: 58%

Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam

Marinelli¹,

Pompili²,

Prestopino³

et al. 2014

Nuclear Instruments and Methods in Physics Research Section A:

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a b s t r a c tA synthetic single crystal diamond based Schottky photodiode was tested at INFN-LNS on the proton beam line (62 MeV) dedicated to the radiation treatment of ocular disease. The diamond detector response was studied in terms of pre-irradiation dose, linearity with dose and dose rate, and angular dependence. Depth dose curves were measured for the 62 MeV pristine proton beam and for three unmodulated range-shifted proton beams; furthermore, the spread-out Bragg peak was measured for a modulated therapeutic proton beam. Beam parameters, recommended by the ICRU report 78, were evaluated to analyze depth-dose curves from diamond detector. Measured dose distributions were compared with the corresponding dose distributions acquired with reference plane-parallel ionization chambers. Field size dependence of the output factor (dose per monitor unit) in a therapeutic modulated proton beam was measured with the diamond detector over the range of ocular proton therapy collimator diameters (5-30 mm). Output factors measured with the diamond detector were compared to the ones by a Markus ionization chamber, a Scanditronix Hi-p Si stereotactic diode and a radiochromic EBT2 film. Signal stability within 0.5% was demonstrated for the diamond detector with no need of any pre-irradiation dose. Dose and dose rate dependence of the diamond response was measured: deviations from linearity resulted to be within 70.5% over the investigated ranges of 0.5-40.0 Gy and 0.3-30.0 Gy/min respectively. Output factors from diamond detector measured with the smallest collimator (5 mm in diameter) showed a maximum deviation of about 3% with respect to the high resolution radiochromic EBT2 film. Depth-dose curves measured by diamond for unmodulated and modulated beams were in good agreement with those from the reference plane-parallel Markus chamber, with relative differences lower than 7 1% in peak-to-plateau ratios, well within experimental uncertainties. A 2.5% variation in diamond detector response was observed in angular dependence measurements carried-out by varying the proton beam incidence angle in the polar direction. The dosimetric characterization of the tested synthetic single crystal diamond detector clearly indicates its suitability for relative dosimetry in ocular therapy proton beams, with no need of any correction factors accounting for dose rate and linear energy transfer dependence.

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Section: Introductionmentioning

confidence: 58%

Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam

Marinelli¹,

Pompili²,

Prestopino³

et al. 2014

Nuclear Instruments and Methods in Physics Research Section A:

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“…[15][16][17][18] The microDiamond active volume is composed of a 1 µm thick intrinsic diamond layer, with a 1 mm radius and a total sensitive volume of 0.004 mm 3 . The effective point of measurement is 1 mm from the housing surface.…”

Section: A1 Microdiamond Ptw-60019mentioning

confidence: 99%

“…The characteristics of the synthetic diamond detector (PTW-60019), such as small active volume (0.004 mm 3 ), near water-equivalence (Z eff = 6), and low energy dependence, make it an interesting candidate for small field dose measurements as demonstrated by many authors. [15][16][17][18][19] To our knowledge, no one demonstrated the feasibility of using this synthetic diamond for OFs measurement for LGKP. Profiles in the three directions were also measured for the 4 mm collimator.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a synthetic single‐crystal diamond detector for relative dosimetry on the Leksell Gamma Knife Perfexion radiosurgery system

Mancosu¹,

Reggiori²,

Stravato³

et al. 2015

Medical Physics

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Purpose: To evaluate the new commercial PTW-60019 synthetic single-crystal microDiamond detector (PTW, Freiburg, Germany) for relative dosimetry measurements on a clinical Leksell Gamma Knife Perfexion radiosurgery system. Methods: Detector output ratios (DORs) for 4 and 8 mm beams were measured using a micro- Diamond (PTW-60019), a stereotactic unshielded diode [IBA stereotactic field detector (SFD)], a shielded diode (IBA photon field detector), and GafChromic EBT3 films. Both parallel and transversal acquisition directions were considered for PTW-60019 measurements. Measured DORs were compared to the new output factor reference values for Gamma Knife Perfexion (0.814 and 0.900 for 4 and 8 mm, respectively). Profiles in the three directions were also measured for the 4 mm beam to evaluate full width at half maximum (FWHM) and penumbra and to compare them with the corresponding Leksell GammaPlan profiles. Results: FWHM and penumbra for PTW-60019 differed from the calculated values by less than 0.2 and 0.3 mm, for the parallel and transversal acquisitions, respectively. GafChromic films showed FWHM and penumbra within 0.1 mm. The output ratio obtained with the PTW-60019 for the 4 mm field was 1.6% greater in transverse direction compared to the nominal value. Comparable differences up to 0.8% and 1.0% for, respectively, GafChromic films and SFD were found. Conclusions: The microDiamond PTW-60019 is a suitable detector for commissioning and routine use of Gamma Knife with good agreement of both DORs and profiles in the three directions

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“…[22][23][24] The SCDD is designed to operate as a Schottky barrier photodiode, with no need of an external bias voltage applied (photovoltaic mode). Details on device technology, fabrication process, and detection mechanism can be found elsewhere.…”

Section: B Diamond Dosimeter and Electrometermentioning

confidence: 99%

“…The dosimetric properties of such device, now commercialized by PTW-Freiburg as microDiamond type 60019, were evaluated for clinical photon, electron, and high energy scattered proton radiation therapy beam dosimetry. [22][23][24][25][26][27][28] In addition, a good detector-to-detector reproducibility was recently demonstrated by studying the response of five microDiamonds in small field photon irradiation conditions. 29 In the present paper, the dosimetric properties of a PTW microDiamond in high energy scanned clinical ion beams have been evaluated at the Italian National Center for Oncological Hadron Therapy (CNAO).…”

mentioning

confidence: 99%

Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams

et al. 2015

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Purpose: To investigate for the first time the dosimetric properties of a new commercial synthetic diamond detector (PTW microDiamond) in high-energy scanned clinical carbon ion beams generated by a synchrotron at the CNAO facility. Methods: The detector response was evaluated in a water phantom with actively scanned carbon ion beams ranging from 115 to 380 MeV/u (30-250 mm Bragg peak depth in water). Homogeneous square fields of 3 × 3 and 6 × 6 cm 2 were used. Short-and medium-term (2 months) detector response stability, dependence on beam energy as well as ion type (carbon ions and protons), linearity with dose, and directional and dose-rate dependence were investigated. The depth dose curve of a 280 MeV/u carbon ion beam, scanned over a 3 × 3 cm 2 area, was measured with the microDiamond detector and compared to that measured using a PTW Advanced Markus ionization chamber, and also simulated using  Monte Carlo code. The detector response in two spread-out-Bragg-peaks (SOBPs), respectively, centered at 9 and 21 cm depths in water and calculated using the treatment planning system (TPS) used at CNAO, was measured. Results: A negligible drift of detector sensitivity within the experimental session was seen, indicating that no detector preirradiation was needed. Short-term response reproducibility around 1% (1 standard deviation) was found. Only 2% maximum variation of microDiamond sensitivity was observed among all the evaluated proton and carbon ion beam energies. The detector response showed a good linear behavior. Detector sensitivity was found to be dose-rate independent, with a variation below 1.3% in the evaluated dose-rate range. A very good agreement between measured and simulated Bragg curves with both microDiamond and Advanced Markus chamber was found, showing a negligible LET dependence of the tested detector. A depth dose curve was also measured by positioning the microDiamond with its main axis oriented orthogonally to the beam direction. A strong distortion in Bragg peak measurement was observed, confirming manufacturer recommendation on avoiding such configuration. Very good results were obtained for SOBP measurements, with a difference below 1% between measured and TPS-calculated doses. The stability of detector sensitivity in the observation period was within the experimental uncertainty. Conclusions: Dosimetric characterization of a PTW microDiamond detector in high-energy scanned carbon ion beams was performed. The results of the present study showed that this detector is suitable for dosimetry of clinical carbon ion beams, with a negligible LET and dose-rate dependence. C 2015 American Association of Physicists in Medicine. [http://dx

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Evaluation of the dosimetric properties of a synthetic single crystal diamond detector in high energy clinical proton beams

Cited by 43 publications

References 34 publications

Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam

Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam

Evaluation of a synthetic single‐crystal diamond detector for relative dosimetry on the Leksell Gamma Knife Perfexion radiosurgery system

Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams

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