TY - JOUR
T1 - Time-Activity data fitting in molecular Radiotherapy
T2 - Methodology and pitfalls
AU - Ivashchenko, Oleksandra V.
AU - O'Doherty, Jim
AU - Hardiansyah, Deni
AU - Cremonesi, Marta
AU - Tran-Gia, Johannes
AU - Hippeläinen, Eero
AU - Stokke, Caroline
AU - Grassi, Elisa
AU - Sandström, Mattias
AU - Glatting, Gerhard
N1 - Publisher Copyright:
© 2023 Associazione Italiana di Fisica Medica e Sanitaria
PY - 2024/1
Y1 - 2024/1
N2 - Absorbed radiation doses are essential in assessing the effects, e.g. safety and efficacy, of radiopharmaceutical therapy (RPT). Patient-specific absorbed dose calculations in the target or the organ at risk require multiple inputs. These include the number of disintegrations in the organ, i.e. the time-integrated activities (TIAs) of the organs, as well as other parameters describing the process of radiation energy deposition in the target tissue (i.e. mean energy per disintegration, radiation dose constants, etc). TIAs are then estimated by incorporating the area under the radiopharmaceutical's time-activity curve (TAC), which can be obtained by quantitative measurements of the biokinetics in the patient (typically based on imaging data such as planar scintigraphy, SPECT/CT, PET/CT, or blood and urine samples). The process of TAC determination/calculation for RPT generally depends on the user, e.g., the chosen number and schedule of measured time points, the selection of the fit function, the error model for the data and the fit algorithm. These decisions can strongly affect the final TIA values and thus the accuracy of calculated absorbed doses. Despite the high clinical importance of the TIA values, there is currently no consensus on processing time-activity data or even a clear understanding of the influence of uncertainties and variations in personalised RPT dosimetry related to user-dependent TAC calculation. As a first step towards minimising site-dependent variability in RPT dosimetry, this work provides an overview of quality assurance and uncertainty management considerations of the TIA estimation.
AB - Absorbed radiation doses are essential in assessing the effects, e.g. safety and efficacy, of radiopharmaceutical therapy (RPT). Patient-specific absorbed dose calculations in the target or the organ at risk require multiple inputs. These include the number of disintegrations in the organ, i.e. the time-integrated activities (TIAs) of the organs, as well as other parameters describing the process of radiation energy deposition in the target tissue (i.e. mean energy per disintegration, radiation dose constants, etc). TIAs are then estimated by incorporating the area under the radiopharmaceutical's time-activity curve (TAC), which can be obtained by quantitative measurements of the biokinetics in the patient (typically based on imaging data such as planar scintigraphy, SPECT/CT, PET/CT, or blood and urine samples). The process of TAC determination/calculation for RPT generally depends on the user, e.g., the chosen number and schedule of measured time points, the selection of the fit function, the error model for the data and the fit algorithm. These decisions can strongly affect the final TIA values and thus the accuracy of calculated absorbed doses. Despite the high clinical importance of the TIA values, there is currently no consensus on processing time-activity data or even a clear understanding of the influence of uncertainties and variations in personalised RPT dosimetry related to user-dependent TAC calculation. As a first step towards minimising site-dependent variability in RPT dosimetry, this work provides an overview of quality assurance and uncertainty management considerations of the TIA estimation.
KW - Dosimetry
KW - Radiopharmaceutical therapy
KW - TAC
KW - TIA
KW - Time-activity curve
KW - Time-integrated activities
UR - http://www.scopus.com/inward/record.url?scp=85179106720&partnerID=8YFLogxK
U2 - 10.1016/j.ejmp.2023.103192
DO - 10.1016/j.ejmp.2023.103192
M3 - Article
C2 - 38052710
AN - SCOPUS:85179106720
SN - 1120-1797
VL - 117
JO - Physica Medica
JF - Physica Medica
M1 - 103192
ER -