TY - JOUR
T1 - Absorbed dose measurements from a 90Y radionuclide liquid solution using LiF:Mg,Cu,P thermoluminescent dosimeters
AU - D'Arienzo, Marco
AU - Pimpinella, Maria
AU - De Coste, Vanessa
AU - Capogni, Marco
AU - Ferrari, Paolo
AU - Mariotti, Francesca
AU - Iaccarino, Giuseppe
AU - Ungania, Sara
AU - Strigari, Lidia
PY - 2020/1
Y1 - 2020/1
N2 - In the last few years there has been an increasing interest in the measurement of the absorbed dose from radionuclides, with special attention devoted to molecular radiotherapy treatments. In particular, the determination of the absorbed dose from beta emitting radionuclides in liquid solution poses a number of issues when dose measurements are performed using thermoluminescent dosimeters (TLD). Finite volume effect, i.e. the exclusion of radioactivity from the volume occupied by the TLD is one of these. Furthermore, TLDs need to be encapsulated into some kind of waterproof envelope that unavoidably contributes to beta particle attenuation during the measurement. The purpose of this study is twofold: I) to measure the absorbed dose to water, Dw, using LiF:Mg,Cu,P chips inside a PMMA cylindrical phantom filled with a homogenous 90YCl3 aqueous solution II) to assess the uncertainty budget related to Dw measurements. To this purpose, six cylindrical PMMA phantoms were manufactured at ENEA. Each phantom can host a waterproof PMMA stick containing 3 TLD chips encapsulated by a polystyrene envelope. The cylindrical phantoms were manufactured so that the radioactive liquid environment surrounds the whole stick. Finally, Dw measurements were compared with Monte Carlo (MC) calculations. The measurement of absorbed dose to water from 90YCl3 radionuclide solution using LiF:Mg,Cu,P TLDs turned out to be a viable technique, provided that all necessary correction factors are applied. Using this method, a relative combined standard uncertainty in the range 3.1–3.7% was obtained on each Dw measurement. The major source of uncertainty was shown to be TLDs calibration, with associated uncertainties in the range 0.7–2.2%. Comparison of measured and MC-calculated absorbed dose per emitted beta particle provided good results, with the two quantities being in the ratio 1.08.
AB - In the last few years there has been an increasing interest in the measurement of the absorbed dose from radionuclides, with special attention devoted to molecular radiotherapy treatments. In particular, the determination of the absorbed dose from beta emitting radionuclides in liquid solution poses a number of issues when dose measurements are performed using thermoluminescent dosimeters (TLD). Finite volume effect, i.e. the exclusion of radioactivity from the volume occupied by the TLD is one of these. Furthermore, TLDs need to be encapsulated into some kind of waterproof envelope that unavoidably contributes to beta particle attenuation during the measurement. The purpose of this study is twofold: I) to measure the absorbed dose to water, Dw, using LiF:Mg,Cu,P chips inside a PMMA cylindrical phantom filled with a homogenous 90YCl3 aqueous solution II) to assess the uncertainty budget related to Dw measurements. To this purpose, six cylindrical PMMA phantoms were manufactured at ENEA. Each phantom can host a waterproof PMMA stick containing 3 TLD chips encapsulated by a polystyrene envelope. The cylindrical phantoms were manufactured so that the radioactive liquid environment surrounds the whole stick. Finally, Dw measurements were compared with Monte Carlo (MC) calculations. The measurement of absorbed dose to water from 90YCl3 radionuclide solution using LiF:Mg,Cu,P TLDs turned out to be a viable technique, provided that all necessary correction factors are applied. Using this method, a relative combined standard uncertainty in the range 3.1–3.7% was obtained on each Dw measurement. The major source of uncertainty was shown to be TLDs calibration, with associated uncertainties in the range 0.7–2.2%. Comparison of measured and MC-calculated absorbed dose per emitted beta particle provided good results, with the two quantities being in the ratio 1.08.
KW - Absorbed dose measurement
KW - Internal dosimetry
KW - Molecular radiotherapy
KW - TLDs
UR - http://www.scopus.com/inward/record.url?scp=85077322727&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85077322727&partnerID=8YFLogxK
U2 - 10.1016/j.ejmp.2019.11.010
DO - 10.1016/j.ejmp.2019.11.010
M3 - Article
C2 - 31901837
AN - SCOPUS:85077322727
VL - 69
SP - 127
EP - 133
JO - Physica Medica
JF - Physica Medica
SN - 1120-1797
ER -