Investigation of alanine dosimeter for output measurement in radiotherapy: Results from multicenter in Thailand

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Aungsumalin Intang
Puntiwa Oonsiri
Sakda Kingkaew
Nichakan Chatchumnan
Puangpen Tangboonduangjit
Nauljun Stansook
Pimolpun Changkaew
Suphalak Khachonkham
Amporn Funsian
Warinthorn Rattanaareeyakorn
Suriyaporn Turathong
Komkrit Krongkietlearts
Adcharee Seenukhroah
Rusdchai Chaisuttee
Chompunek Sirichotwatcharakit
Sornjarod Oonsiri


Background: Alanine dosimeters are generally used in high-dose industrial applications (kGy). Later, research into employing alanine as a dosimeter in radiotherapy (1-20 Gy) has increased, since alanine may be an alternative transfer dosimeter for quality control, postal audit, and intercomparison between laboratories. However, several factors such as the dosimeter’s characteristic should be investigated while utilizing alanine in radiotherapy. In addition, the optimal electron paramagnetic resonance (EPR) reader should be configured to match the absorbed dose range.

Objectives: This study aims to optimize the EPR setting parameters, study the characteristics of alanine dosimeters, and estimate the uncertainty of the 6MV-FFF linear accelerator in a dose ranging from 1 to 20 Gy. The output measurements from different facilities were also investigated.

Materials and methods: The alanine dosimeters were irradiated with a 6MV-FFF beam using linear accelerator, Varian TrueBeam (Varian Medical Systems, Inc, CA, USA), 100 cm SSD, with a field size of 10x10 cm2 at 1 to 30 Gy. The EPR operation parameter has been optimized for these dose ranges. The characteristics of alanine dosimeters were then investigated, along with the estimation of uncertainty in using alanine. Finally, the alanine dosimeter proficiency was validated using 9 distinct linear accelerator machines.

Results: The EPR parameters were found to be optimized at 1.589 mW of MP, 7.018 G of MA, and 40.96 ms of TC. The expanded uncertainty (k=2) was reported at 2.68% in the 1-20 Gy dose range. The alanine dosimeters’ characteristics were found to have good uniformity and reproducibility, low fading, and angle-and dose-independence. Although the investigation was performed in 9 different linear accelerator machines, the difference of delivered dose output was measured and reported with difference percentages within ±1%.

Conclusion: This study reports the feasibility of using alanine dosimeters in radiotherapy. The important EPR parameter setting, and alanine dosimetry characteristics were investigated, whose results suggest that alanine can be used at a dose range of 1-30 Gy. This especially benefits the SRS treatment which uses a high dose per fraction, and this dosimeter can be an alternative transfer dosimeter. Nonetheless, various factors should be explored using an appropriate phantom prior to clinical application.


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Intang, A., Oonsiri, P., Kingkaew, S., Chatchumnan, N. . ., Tangboonduangjit, P., Stansook, N., Changkaew, P., Khachonkham, S., Funsian, A., Rattanaareeyakorn, W., Turathong, S. ., Krongkietlearts, K. ., Seenukhroah, A. ., Chaisuttee, R. ., Sirichotwatcharakit, C. ., & Oonsiri, S. (2023). Investigation of alanine dosimeter for output measurement in radiotherapy: Results from multicenter in Thailand. Journal of Associated Medical Sciences, 56(2), 106–116. Retrieved from
Research Articles


Zeng GG, McEwen MR, Rogers DW, Klassen NV. An experimental and Monte Carlo investigation of the energy dependence of alanine/EPR dosimetry: I. Clinical x-ray beams. Phys Med Biol. 2004; 49(2): 257-70.

Garcia T, Lin M, Pasquié I, Lourenço V. A methodology for choosing parameters for ESR readout of alanine dosimeters for radiotherapy. Radiat Phys Chem. 2009; 78(9): 782-90.

Goodman BA, Worasith N, Ninlaphruk S, Mungpayaban H, Deng W. Radiation Dosimetry Using Alanine and Electron Paramagnetic Resonance (EPR) Spectroscopy: A New Look at an Old Topic. Appl Magn Reson. 2017; 48(2): 155-73.

Regulla D and Deffner U. Dosimetry by ESR spectroscopy of alanine. Int J Appl Radiat Isot. 1982; 33(11): 1101-14.

Mclaughlin WL and Desrosiers MF. Dosimetry systems for radiation processing. Radiat Phys Chem. 1995; 46(4, Part 2): 1163-74.

Sharpe PHG, Rajendran K, Sephton JP. Progress towards an alanine/ESR therapy level reference dosimetry service at NPL. Appl Radiat Isot. 1996; 47(11): 1171-5.

Buatti JM, Friedman WA, Meeks SL, Bova FJ. RTOG 90-05: the real conclusion. Int J Radiat Oncol Biol Phys. 2000; 47(2): 269-71.

Sharpe PHG, Sephton JP. Alanine dosimetry at NPL – the development of a mailed reference dosimetry service at radiotherapy dose levels. International Atomic Energy Agency (IAEA); 1999. Report No.: 1011-4289 Contract No.: IAEA-TECDOC--1070.

Gago-Arias A, González-Castaño DM, Gómez F, Peteiro E, Lodeiro C, Pardo-Montero J. Development of an alanine dosimetry system for radiation dose measurements in the radiotherapy range. J Instrum. 2015; 10(08): T08004-T.

JCGM member organizations. Evaluation of measurement data - Guide to the expression of uncertainty in measurement. JCGM guidance document. JCGM 100: 2008.

Mansour I. Development of mailed dosimetric audit for external beam radiation therapy using alanine dosimeters [dissertation]. Cannada: Carleton University; 2018.