title: Practical time considerations for optically stimulated luminescent dosimetry (OSLD) in total body irradiation.
abstract: Total body irradiation (TBI) treatments are used to treat the whole body in preparation for hematopoietic stem cell (or bone marrow) transplantation. Our standard clinical regimen is a 12 Gy in 6 fraction, bi-daily technique using 6 MV X-rays at an extended Source-to-Surface distance (SSD) of 300 cm. Utilizing these characteristics, the beam dose rate is reduced below 7 cGy/min as is standard for TBI treatment. Dose received by the patient is monitored using optically stimulated luminescent dosimetry (OSLD). This work presents some practical calibration corrections based on time-dependant factors for OSLD calibration related to TBI procedure. Results have shown that a negligible difference is seen in OSL sensitivity for 6 MV X-rays irradiated in standard SSD (100 cm) and high dose rate (600 cGy/min) conditions compared to extended SSD (300 cm) and low TBI dose rate (6 cGy/min) conditions. Results have also shown that whilst short term signal fading occurs in the OSL after irradiation at a high dose rate (37% reduction in signal in the first 15 min), thereafter, negligible differences are seen in the OSL signal between 600 and 7 cGy/min irradiations. Thus a direct comparison can be made between calibration OSLs and clinical TBI OSLs between 15 min and 2 h. Finally a table is presented to provide corrections between calibration OSL readout and clinical TBI dose readout for a period up to 7 days. Combining these three results allows users to pre-irradiate their calibration OSLs at standard dose rate and SSD, up to 1 week prior to clinical treatment, and still provide accurate in-vivo dosimetry. This can help with time saving and work efficiency in the clinic.
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia. Martin.butson@lh.org.au.|Institute of Medical Physics, University of Sydney, Camperdown, Australia. Martin.butson@lh.org.au.
authors.forename: Martin
authors.initials: M
authors.lastname: Butson
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.|Institute of Medical Physics, University of Sydney, Camperdown, Australia.
authors.forename: Mamoon
authors.initials: M
authors.lastname: Haque
authors.affiliation: Sydney Medical School, University of Sydney, Camperdown, Australia.
authors.forename: Leon
authors.initials: L
authors.lastname: Smith
authors.affiliation: Institute of Medical Physics, University of Sydney, Camperdown, Australia.
authors.forename: Ethan
authors.initials: E
authors.lastname: Butson
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Odgers
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.
authors.forename: Dane
authors.initials: D
authors.lastname: Pope
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.
authors.forename: Tina
authors.initials: T
authors.lastname: Gorjiana
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.
authors.forename: May
authors.initials: M
authors.lastname: Whitaker
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.|School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Level 4 O Block, Garden's Point, Brisbane, QLD, 4001, Australia.
authors.forename: Johnny
authors.initials: J
authors.lastname: Morales
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.|Sydney Medical School, University of Sydney, Camperdown, Australia.
authors.forename: Angela
authors.initials: A
authors.lastname: Hong
authors.affiliation: Dept of Radiation Oncology, Chris O'Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia.|Institute of Medical Physics, University of Sydney, Camperdown, Australia.
authors.forename: Robin
authors.initials: R
authors.lastname: Hill
mesh_terms: D002138:Calibration; D006801:Humans; D062791:Optically Stimulated Luminescence Dosimetry; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D014916:Whole-Body Irradiation
keywords: Dosimetry; OSL; Radiation; Total body irradiation