Variation in Dosimeter Calibration Factor (NDW) Over a Period of 20 Years.
J Med Phys
; 46(2): 125-127, 2021.
Article
in English
| MEDLINE | ID: covidwho-1360850
ABSTRACT
Long delays in renewal of calibration of secondary standards radiation dosimeters in radiation oncology centers due to the COVID19 pandemic have aroused concerns regarding accuracy in dose delivery to patients. The concerns are mainly due to the uncertainty in the absorbed dose to water calibration factor (NDW) over a period of time. In this study, the NDWfactor for two ion chambers, thimble type (Farmer) and parallel plate type (Markus), used in most of the radiotherapy centers, were retrospectively reviewed for 20 years. The calibration on all occasions except once was carried out at the Secondary Standards Dosimetry Laboratory, Bhabha Atomic Research Centre, Mumbai. The change in the NDWfactor over this period was < ±3%. We, therefore, believe that a dosimeter with no history of repairs showed reasonable stability in the NDWfactor over a long period.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Type of study:
Prognostic study
Language:
English
Journal:
J Med Phys
Year:
2021
Document Type:
Article
Affiliation country:
Jmp.JMP_42_21
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