1
|
Hjørringgaard JG, Ankjærgaard C, Miller A, Andersen CE. Kilovoltage X-ray beam quality effect on the relative response of alanine pellet dosemeters. RADIATION PROTECTION DOSIMETRY 2023; 199:1605-1610. [PMID: 37721066 DOI: 10.1093/rpd/ncad008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 12/02/2022] [Accepted: 01/04/2023] [Indexed: 09/19/2023]
Abstract
Determination of beam quality correction factors is crucial for performing accurate alanine pellet dosimetry in non-reference fields. For some complex irradiation geometries, interpolation from literature data is more convenient than an experimental approach to establish these factors. Here we investigate the validity of extracting quality correction factors from literature data based on information on beam qualifiers such as half-value layer (HVL) or effective energy ${E}_{\text{eff}}$. A combination of Monte Carlo calculated dose ratios and a microdosimetric assessment of the relative efficiency allows for numerical evaluation of quality correction factors for a wide array of X-ray qualities. The computational analysis demonstrates that the average energy of the X-ray beam is optimal for characterizing the relative response. Special care should be taken when using the common X-ray beam qualifiers HVL or ${E}_{\text{eff}}$ to determine quality correction factors from literature data.
Collapse
Affiliation(s)
| | | | - Arne Miller
- Department of Health Technology, Technical University of Denmark, Roskilde, Denmark
| | - Claus E Andersen
- Department of Health Technology, Technical University of Denmark, Roskilde, Denmark
| |
Collapse
|
2
|
van den Elzen P, Sander T, Palmans H, McManus M, Woodall N, Lee N, Fox OJL, Jones RM, Angal-Kalinin D, Subiel A. Alanine response to low energy synchrotron x-ray radiation. Phys Med Biol 2023; 68:065011. [PMID: 36731142 DOI: 10.1088/1361-6560/acb886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 02/01/2023] [Indexed: 02/04/2023]
Abstract
Objective. The radiation response of alanine is very well characterized in the MV photon energy range where it can be used to determine the dose delivered with an accuracy better than 1%, making it suitable as a secondary standard detector in cancer radiation therapy. This is not the case in the very low energy keV x-ray range where the alanine response is affected by large uncertainties and is strongly dependent on the x-ray beam energy. This motivated the study undertaken here.Approach. Alanine pellets with a nominal thickness of 0.5 mm and diameter of 5 mm were irradiated with monoenergetic x-rays at the Diamond Light Source synchrotron, to quantify their response in the 8-20 keV range relative to60Co radiation. The absorbed dose to graphite was measured with a small portable graphite calorimeter, and the DOSRZnrc code in the EGSnrc Monte Carlo package was used to calculate conversion factors between the measured dose to graphite and the absorbed dose to water delivered to the alanine pellets. GafChromic EBT3 films were used to measure the beam profile for modelling in the MC simulations.Main results. The relative responses measured in this energy range were found to range from 0.616 to 0.643, with a combined relative expanded uncertainty of 3.4%-3.5% (k= 2), where the majority of the uncertainty originated from the uncertainty in the alanine readout, due to the small size of the pellets used.Significance. The measured values were in good agreement with previously published data in the overlapping region of x-ray energies, while this work extended the dataset to lower energies. By measuring the response to monoenergetic x-rays, the response to a more complex broad-spectrum x-ray source can be inferred if the spectrum is known, meaning that this work supports the establishment of alanine as a secondary standard dosimeter for low-energy x-ray sources.
Collapse
Affiliation(s)
- P van den Elzen
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
- University of Manchester, Department of Physics and Astronomy, Manchester, United Kingdom
- The Cockcroft Institute of Accelerator Science and Technology, Daresbury, United Kingdom
| | - T Sander
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
| | - H Palmans
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - M McManus
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
| | - N Woodall
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
| | - N Lee
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
| | - O J L Fox
- Diamond Light Source Ltd, Harwell Science Innovation Campus, Didcot, United Kingdom
| | - R M Jones
- University of Manchester, Department of Physics and Astronomy, Manchester, United Kingdom
- The Cockcroft Institute of Accelerator Science and Technology, Daresbury, United Kingdom
| | - D Angal-Kalinin
- University of Manchester, Department of Physics and Astronomy, Manchester, United Kingdom
- The Cockcroft Institute of Accelerator Science and Technology, Daresbury, United Kingdom
- Science and Technology Facilities Council, Accelerator Science and Technology Centre, Daresbury, United Kingdom
| | - A Subiel
- National Physical Laboratory, Medical Radiation Science Group, Teddington, United Kingdom
- University College London, UCL Cancer Institute, London, United Kingdom
| |
Collapse
|
3
|
Characterization and implementation of the L-alanine detector for quality control of lung SBRT treatments with the VMAT technique. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2022. [DOI: 10.1016/j.jrras.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
4
|
Rech AB, Kinoshita A, Donate PM, Baffa O. ESR dosimetry with lithium, potassium, and sodium compounds. Appl Radiat Isot 2022; 181:110105. [DOI: 10.1016/j.apradiso.2022.110105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 12/10/2021] [Accepted: 01/07/2022] [Indexed: 11/02/2022]
|
5
|
Lima IS, Guidelli EJ, Baffa O. Dose enhancement factor caused by gold nanoparticles: influence of the dosimetric sensitivity and radiation dose assessed by electron spin resonance dosimetry. Phys Med Biol 2021; 66. [PMID: 34592720 DOI: 10.1088/1361-6560/ac2bb2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 09/30/2021] [Indexed: 11/12/2022]
Abstract
Gold nanoparticles have been extensively used to increase the sensitivity of radiation dosimeters. In this work, nanocomposites of alanine (Ala), 2-methylalanine (2MA), asparagine (Asn) and monosodium glutamate (MSG) containing gold nanoparticles were prepared. The influence of the mass percentage of gold (0.1% up to 3%), absorbed dose (2 Gy-10 kGy) and the intrinsic sensitivity of these materials on the dose enhancement factor (DEF) were investigated. The prepared nanocomposites were characterized by UV-vis absorption spectroscopy and dynamic light scattering technique. Electron spin resonance spectroscopy was employed to assess the dosimetric response. The results revealed that the gold nanoparticles aggregated in the nanocomposites of MSG and Asn but not in the Ala and 2MA samples. Higher DEFs were observed for materials with lower intrinsic sensitivities (Asn and MSG) and for lower doses of radiation, suggesting that the dosimetric response of the nanocomposite dosimeters is governed by the probability of radical recombination. The higher the radiation dose, gold mass percentage and/or intrinsic sensitivity of the dosimetric material, the higher the production of radiation-induced free-radicals, enhancing the probability of radical recombination and resulting in lower DEFs. These results bring new insights about the use of gold nanoparticles to the construction of more sensitive radiation dosimeters.
Collapse
Affiliation(s)
- Iara S Lima
- Departamento de Física, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Eder J Guidelli
- Departamento de Física, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Oswaldo Baffa
- Departamento de Física, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| |
Collapse
|
6
|
Lima IS, Guidelli EJ, Baffa O. Potential properties of L-Asparagine for ESR dosimetry applications. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.109204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
7
|
Geso M, Ackerly T, Lim SA, Best SP, Gagliardi F, Smith CL. Application of the ‘Spiking’ method to the measurement of low dose radiation (≤ 1 Gy) using alanine dosimeters. Appl Radiat Isot 2018; 133:111-116. [DOI: 10.1016/j.apradiso.2018.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/19/2017] [Accepted: 01/09/2018] [Indexed: 12/01/2022]
|
8
|
Investigation of IRGANOX®1076 as a dosimeter for clinical X-ray, electron and proton beams and its EPR angular response. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
9
|
Marrale M, Abbene L, d'Errico F, Gallo S, Longo A, Panzeca S, Tana L, Tranchina L, Principato F. Characterization of the ESR response of alanine dosimeters to low-energy Cu-target X-tube photons. RADIAT MEAS 2017. [DOI: 10.1016/j.radmeas.2017.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
10
|
Alves GG, Kinoshita A, Oliveira HFD, Guimarães FS, Amaral LL, Baffa O. Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry. ACTA ACUST UNITED AC 2015; 48:644-9. [PMID: 26017344 PMCID: PMC4512104 DOI: 10.1590/1414-431x20154367] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/05/2015] [Indexed: 11/22/2022]
Abstract
Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses.
Collapse
Affiliation(s)
- G G Alves
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - A Kinoshita
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - H F de Oliveira
- Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - F S Guimarães
- Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - L L Amaral
- Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - O Baffa
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| |
Collapse
|
11
|
Baffa O, Kinoshita A. Clinical applications of alanine/electron spin resonance dosimetry. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2014; 53:233-240. [PMID: 24398918 DOI: 10.1007/s00411-013-0509-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Accepted: 12/22/2013] [Indexed: 06/03/2023]
Abstract
This paper discusses the clinical applications of electron spin resonance (ESR) dosimetry focusing on the ESR/alanine system. A review of few past studies in this area is presented offering a critical overview of the challenges and opportunities for extending this system into clinical applications. Alanine/ESR dosimetry fulfills many of the required properties for several clinical applications such as water-equivalent composition, independence of the sensitivity for the energy range used in therapy and high precision. Improvements in sensitivity and the development of minidosimeters coupled with the use of a spectrometer of higher microwave frequency expanded the possibilities for clinical applications to the new modalities of radiotherapy (intensity-modulated radiation therapy and radiosurgery) and to the detection of low doses such as those present in some radiological image procedures.
Collapse
Affiliation(s)
- Oswaldo Baffa
- Departamento de Física, Faculdade de Filosofia Ciências e Letras, USP, Av. Bandeirantes, 3900, Ribeirão Prêto, SP, 14040-901, Brazil,
| | | |
Collapse
|
12
|
Guidelli EJ, Ramos AP, Zaniquelli MED, Nicolucci P, Baffa O. Synthesis and characterization of gold/alanine nanocomposites with potential properties for medical application as radiation sensors. ACS APPLIED MATERIALS & INTERFACES 2012; 4:5844-51. [PMID: 23067227 DOI: 10.1021/am3014899] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Radiation dose assessment is essential for several medical treatments and diagnostic procedures. In this context, nanotechnology has been used in the development of improved radiation sensors, with higher sensitivity as well as smaller sizes and energy dependence. This paper deals with the synthesis and characterization of gold/alanine nanocomposites with varying mass percentage of gold, for application as radiation sensors. Alanine is an excellent stabilizing agent for gold nanoparticles because the size of the nanoparticles does not augment with increasing mass percentage of gold, as evidenced by UV-vis spectroscopy, dynamic light scattering, and transmission electron microscopy. X-ray diffraction patterns suggest that the alanine crystalline orientation undergoes alterations upon the addition of gold nanoparticles. Fourier transform infrared spectroscopy indicates that there is interaction between the gold nanoparticles and the amine group of the alanine molecules, which may be the reason for the enhanced stability of the nanocomposite. The application of the nanocomposites as radiation detectors was evaluated by the electron spin resonance technique. The sensitivity is improved almost 3 times in the case of the nanocomposite containing 3% (w/w) gold, so it can be easily tuned by changing the amount of gold nanoparticles in the nanocomposites, without the size of the nanoparticles influencing the radiation absorption. In conclusion, the featured properties, such as homogeneity, nanoparticle size stability, and enhanced sensitivity, make these nanocomposites potential candidates for the construction of small-sized radiation sensors with tunable sensitivity for application in several medical procedures.
Collapse
Affiliation(s)
- Eder José Guidelli
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901 Ribeirão Preto, São Paulo, Brazil.
| | | | | | | | | |
Collapse
|
13
|
Guidelli EJ, Ramos AP, Zaniquelli MED, Nicolucci P, Baffa O. Synthesis and characterization of silver/alanine nanocomposites for radiation detection in medical applications: the influence of particle size on the detection properties. NANOSCALE 2012; 4:2884-2893. [PMID: 22441754 DOI: 10.1039/c2nr30090g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Silver/alanine nanocomposites with varying mass percentage of silver have been produced. The size of the silver nanoparticles seems to drive the formation of the nanocomposite, yielding a homogeneous dispersion of the silver nanoparticles in the alanine matrix or flocs of silver nanoparticles segregated from the alanine crystals. The alanine crystalline orientation is modified according to the particle size of the silver nanoparticles. Concerning a mass percentage of silver below 0.1%, the nanocomposites are homogeneous, and there is no particle aggregation. As the mass percentage of silver is increased, the system becomes unstable, and there is particle flocculation with subsequent segregation of the alanine crystals. The nanocomposites have been analyzed by transmission electron microscopy (TEM), UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy and they have been tested as radiation detectors by means of electron spin resonance (ESR) spectroscopy in order to detect the paramagnetic centers created by the radiation. In fact, the sensitivity of the radiation detectors is optimized in the case of systems containing small particles (30 nm) that are well dispersed in the alanine matrix. As the agglomeration increases, particle growth (up to 1.5 μm) and segregation diminish the sensitivity. In conclusion, nanostructured materials can be used for optimization of alanine sensitivity, by taking into account the influence of the particles size of the silver nanoparticles on the detection properties of the alanine radiation detectors, thus contributing to the construction of small-sized detectors.
Collapse
Affiliation(s)
- Eder José Guidelli
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil.
| | | | | | | | | |
Collapse
|
14
|
Guidelli EJ, Ramos AP, Zaniquelli MED, Nicolucci P, Baffa O. Synthesis of silver nanoparticles using dl-alanine for ESR dosimetry applications. Radiat Phys Chem Oxf Engl 1993 2012. [DOI: 10.1016/j.radphyschem.2011.10.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
15
|
Waldeland E, Malinen E. Review of the dose-to-water energy dependence of alanine and lithium formate EPR dosimeters and LiF TL-dosimeters – Comparison with Monte Carlo simulations. RADIAT MEAS 2011. [DOI: 10.1016/j.radmeas.2011.03.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Gómez JA, Marques T, Kinoshita A, Belmonte G, Nicolucci P, Baffa O. Influence of dental restorative materials on ESR biodosimetry in tooth enamel. Radiat Res 2011; 176:259-63. [PMID: 21631287 DOI: 10.1667/rr2503.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Using an experimental model and PENELOPE Monte Carlo simulations, the effects of resin and amalgam on the absorbed doses in tooth enamel were studied to evaluate the feasibility of using restored teeth in electron spin resonance (ESR) dose reconstruction. The model consisted of a phantom containing a plate of these restorative materials placed between powered enamel layers exposed to X rays and a ⁶⁰Co beam. The experimental results and simulations agreed, showing that the attenuation produced by amalgam and resin with a thickness of 1, 2, and 4 mm is similar to that produced by the enamel itself in the case of the radiation sources employed. For X rays and ⁶⁰Co γ radiation the attenuation reached almost 100% and 40%, respectively. These results show that for ESR dose reconstruction, the use of all available enamel of a tooth leads to errors in the estimated dose due to attenuation effects in both healthy and restored teeth. Thus the importance of an enamel selection from different sides of the tooth surface to apply ESR dose reconstruction in the case of a practical situation is shown.
Collapse
Affiliation(s)
- J A Gómez
- Departmento de Física, Faculdade de Filosofia Ciências e Letras, Universidade de São Paulo, Av. Bandeirantes 3000, 14040-901 Ribeirão Preto, SP, Brazil.
| | | | | | | | | | | |
Collapse
|
17
|
Waldeland E, Hole EO, Sagstuen E, Malinen E. The energy dependence of lithium formate and alanine EPR dosimeters for medium energy x rays. Med Phys 2010; 37:3569-75. [DOI: 10.1118/1.3432567] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
18
|
Chen F, Ramirez JV, Nicolucci P, Baffa O. Sensitivity comparison of two L-alanine doped blends to different photon energies. HEALTH PHYSICS 2010; 98:383-387. [PMID: 20065709 DOI: 10.1097/01.hp.0000348003.11889.68] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Blends of L-alanine (85% weight proportion) with KI (10%) and with PbI2 (10%), these last two compounds acting as dopants, and with PVA (5%) acting as binder, were prepared in water at 80 degrees C. A blend of pure L-alanine (95%) with PVA (5%) was also prepared. The three blends were irradiated with photon beams of different energies (120 kV, Co, and 10 MV) to a unique dose of 30 Gy to compare their sensitivities for those three energies. EPR spectra of the three irradiated blends were recorded in a K-Band spectrometer (24 GHz) taking aliquots of about 4 mg for each blend. The energy sensitivity of a blend was defined as the peak-to-peak amplitude of its EPR spectrum central line. For the Co energy (1.25 MeV) the blends presented practically the same sensitivity, indicating that the presence of the dopants does not affect the sensitivity of L-alanine. For 10 MV x-rays, there was an increment (around 10%-20%) in sensitivity for the two L-alanine doped blends compared with the pure L-alanine blend (not doped). In the case of 120 kV x-rays, the blends ala+KI and ala+PbI showed increments of 10 and 20 times more sensitivity than the pure L-alanine blend. It is concluded that the dopants KI and PbI2 produce a great enhancement of the L-alanine sensitivity to low-energy photons. For the same dopant's content (10%) in the blend, PbI2 showed a better performance. Increasing the PbI2 proportion (30%) in the blend allows the detection of radiation dose as low as 10 mGy for 120 kV x-rays. These results encourage the authors to try to enhance the sensitivity of L-alanine even more by increasing the dopant's content in the blend and diminishing the lower limit detection. Application of these L-alanine doped blends in the dosimetry in diagnostic radiology could be possible.
Collapse
Affiliation(s)
- Felipe Chen
- Departamento de Física e Matemática, FFCLRP-Universidade de São Paulo, 14040-901, Ribeirão Preto-SP, Brasil.
| | | | | | | |
Collapse
|