Dosimetry audits and intercomparisons in radiotherapy: A Malaysian profile

Dosimetry audit for megavoltage photon beams applied in non-reference conditions

“…Issues of complacency, of inexperience in conduct of the postal dosimetry audit under non-reference conditions, and a lack of advanced dosimetry audit training are potential contributory factors to the failings determined herein [27,29]. Comprehensive training and constant updates are requirements expected for all medical physicists, as suggested by Noor et al [20]. Moreover, it is important to strengthen quality assurance facilities in radiotherapy departments, enabling in-house dosimetry audits to be conducted following globally recommended guidelines.…”

“…A number of recommendations have been made: i) A national audit and intercomparison dosimetry network should be established [20]; ii) The dosimetry audit program needs to be conducted on a regular basis, obligating radiotherapy centers to participate in the dosimetry audit as part of their license renewal requirement; iii) The Malaysian dosimetry audit program should be expanded to include more complex auditing levels [20], for instance dose audits for photon beams shaped with multileaf collimators and in the presence of heterogeneities to encompass the advanced treatment delivery techniques now coming online in radiotherapy.…”

“…The number has since grown markedly, with in 2018 22 centres participating in the IAEA/WHO reference conditions postal dosimetry audit [18]; 72.7% of the radiotherapy centres complied within ± 5% of stated dose. Malaysian centres have also been involved in audits by others; nine participated in a 2002 TLD audit organized by the University of Malaya Medical Centre and University of Wisconsin, Radiation Calibration Laboratory [19], while in 2017 eight participated in a TLD audit based on the use of optical fibres [20], resulting in a passing rate of 87.5%. In each, a small number of centres deviated from stated dose by more than ± 5%, miscalculation of absorbed dose, lack of adherence to irradiation protocol, and errors in reporting absorbed dose being cited.…”

Dosimetric characteristics of fabricated germanium doped optical fibres for a postal audit of therapy electron beams

“…As a member state of the IAEA/WHO Network of Secondary Standard Dosimetry Laboratories (SSDLs), over the past 36 years Malaysia has participated in the IAEA/WHO TLD Postal Dose Quality Audit Service (Abdullah & Dolah, 2021;Samat et al, 2009). In 2011 the IAEA designated the Malaysian SSDL a moderator in coordinating the IAEA/WHO TLD Postal Dose Quality Audit Service for radiotherapy centres within Malaysia (Noor et al, 2017;Abdullah et al, 2018). Malaysia has also conducted national postal dosimetry audits for reference condition dosimetry for high energy photon beams based on IAEA Technical Report Series (TRS) No.…”