Investigation of the suitability of commercially available CVD diamond for megavoltage X-ray dosimetry

Lansley, Stuart P.; Betzel, G; Baluti, F.; Reinisch, Lou; Meyer, Juergen

doi:10.1016/j.nima.2009.06.022

Cited by 21 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A considerable progress in diamond growth has recently been achieved due to the adaptation of the chemical vapour deposition (CVD) method to the growth of high-quality single crystal diamond films [9][10][11][12]. In this process, high pressure high temperature (HPHT) single crystals with a special orientation are usually used as a substrate or seed.…”

Section: Introductionmentioning

confidence: 99%

Single crystal diamond detector for radiotherapy

Schirru¹,

Kisielewicz²,

Nowak³

et al. 2010

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

show abstract

Section: Introductionmentioning

confidence: 99%

Single crystal diamond detector for radiotherapy

Schirru¹,

Kisielewicz²,

Nowak³

et al. 2010

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…It is possible, for example, to understand if the crystal structure is pure (peak at 1,332.8 cm -1 ) or if there are other contributions due to vacancies that could act as a trapping center for charges (other peaks). For the pcCVD substrate, the level of defects could also depend on the large concentration of grain boundaries [46][47][48][49]. This analysis is sometimes complemented by optical spectrophotometry or FTIR methods to detect substitutional defects in the diamond lattice.…”

Section: Characterization Techniquesmentioning

confidence: 99%

Diamond Detectors for Radiotherapy X-Ray Small Beam Dosimetry

et al. 2021

View full text Add to dashboard Cite

Many new X-Ray treatment machines using small and/or non-standard radiation fields, e.g., Tomotherapy, Cyber-knife, and linear accelerators equipped with high-resolution multi-leaf collimators and on-board imaging system, have been introduced in the radiotherapy clinical routine within the last few years. The introduction of these new treatment modalities has led to the development of high conformal radiotherapy treatment techniques like Intensity Modulated photon Radiation Therapy, Volumetric Modulated Arc Therapy, and stereotactic radiotherapy. When using these treatment techniques, patients are exposed to non-uniform radiation fields, high dose gradients, time and space variation of dose rates, and beam energy spectrum. This makes reaching the required degree of accuracy in clinical dosimetry even more demanding. Continuing to use standard field procedures and detectors in fields smaller than 3 × 3 cm2, will generate a reduced accuracy of clinical dosimetry, running the risk to overshadowing the progress made so far in radiotherapy applications. These dosimetric issues represent a new challenge for medical physicists. To choose the most appropriate detector for small field dosimetry, different features must be considered. Short- and long-term stability, linear response to the absorbed dose and dose rate, no energy and angular dependence, are all needed but not sufficient. The two most sought-after attributes for small field dosimetry are water equivalence and small highly sensitive (high sensitivity) volumes. Both these requirements aim at minimizing perturbations of charged particle fluence approaching the Charged Particle Equilibrium condition as much as possible, while maintaining high spatial resolution by reducing the averaging effect for non-uniform radiation fields. A compromise between different features is necessary because no dosimeter currently fulfills all requirements, but diamond properties seem promising and could lead to a marked improvement. Diamonds have long been used as materials for dosimeters, but natural diamonds were only first used for medical applications in the 80 s. The availability of reproducible synthetic diamonds at a lower cost compared to natural ones made the diffusion of diamonds in dosimetry possible. This paper aims to review the use of synthetic poly and single-crystal diamond dosimeters in radiotherapy, focusing on their performance under MegaVoltage photon beams. Both commercial and prototype diamond dosimeters behaviour are described and analyzed. Moreover, this paper will report the main related results in literature, considering diamond development issues like growth modalities, electrical contacts, packaging, readout electronics, and how do they affect all the dosimetric parameters of interest such as signal linearity, energy dependence, dose-rate dependence, reproducibility, rise and decay times.

show abstract

“…This detector contains an air cavity around the diamond crystal; the diameter of this cavity is about 6 mm. Further details of the detector fabrication, including contacts, bonding and encapsulation, can be found in [13]. The diamond film used in this detector was a commercially-available synthetic diamond film manufactured by CVD [19]; details of this film are listed in Table 1.…”

Section: Detectorsmentioning

confidence: 99%

“…At the University of Canterbury, we have been fabricating and characterising X-ray detectors from commercially-available synthetic diamond films [13][14][15]. In this paper we present a comparison between one of these synthetic diamond X-ray detectors and a commercial natural diamond detector.…”

Section: Introductionmentioning

confidence: 99%

Comparison of natural and synthetic diamond X-ray detectors

Lansley

Betzel

Metcalfe

et al. 2010

Australas Phys Eng Sci Med

Self Cite

View full text Add to dashboard Cite

Diamond detectors are particularly well suited for dosimetry applications in radiotherapy for reasons including near-tissue equivalence and high-spatial resolution resulting from small sensitive volumes. However, these detectors have not become commonplace due to high cost and poor availability arising from the need for high-quality diamond. We have fabricated relatively cheap detectors from commercially-available synthetic diamond fabricated using chemical vapour deposition. Here, we present a comparison of one of these detectors with the only commercially-available diamond-based detector (which uses a natural diamond crystal). Parameters such as the energy dependence and linearity of charge with dose were investigated at orthovoltage energies (50-250 kV), and dose-rate dependence of charge at linear accelerator energy (6 MV). The energy dependence of a synthetic diamond detector was similar to that of the natural diamond detector, albeit with slightly less variation across the energy range. Both detectors displayed a linear response with dose (at 100 kV) over the limited dose range used. The sensitivity of the synthetic diamond detector was 302 nC/Gy, compared to 294 nC/Gy measured for the natural diamond detector; however, this was obtained with a bias of 246.50 V compared to a bias of 61.75 V used for the natural diamond detector. The natural diamond detector exhibited a greater dependency on dose-rate than the synthetic diamond detector. Overall, the synthetic diamond detector performed well in comparison to the natural diamond detector.

show abstract

Investigation of the suitability of commercially available CVD diamond for megavoltage X-ray dosimetry

Cited by 21 publications

References 29 publications

Single crystal diamond detector for radiotherapy

Single crystal diamond detector for radiotherapy

Diamond Detectors for Radiotherapy X-Ray Small Beam Dosimetry

Comparison of natural and synthetic diamond X-ray detectors

Contact Info

Product

Resources

About