Program Information
Cellular Level Microdosimetry Using Raman Spectroscopy
J Mirza1*, S Park2 , W Sung1 , J Lee1 , S Ye1 , (1) Seoul National University, Seoul, Seoul, (2) Seoul National University Hospital, Seoul
Presentations
SU-I-GPD-T-530 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: To measure radiation doses in sites of radiochromic film comparable to sizes of living cells by using Raman spectroscopy.
Methods: Gafchromic™ EBTXD film pieces of 3 × 3 cm² were irradiated with doses of 0 to 5 Gy by CLINAC (6 MV and 15 MV for calibration curves). The films were readout by using Raman spectroscope in conjunction with a microscope. The maximum Raman intensity peak of C≡C stretching band of diacetylene polymer at 2060 cm⁻¹ was used to quantify doses on each film by applying Raman mapping technique in a region of interest of 10×10 μm² with a scanning resolution of 2 μm. The preprocessing of each Raman spectrum was carried out to determine a dosimetric relationship with the amount of diacetylene polymerization.
Results: Relative standard deviations among the mapping points in a region of interest of 10×10 μm² at various dose levels were less than ±6% and the dose uniformity of the film was found close to 7%. The dose vs band height plot was fitted by an exponential function with R2 = 0.997. The Raman spectroscopy of EBTXD film showed that the film was nearly energy-independent in the MV energy range.
Conclusion: The preliminary results of this work indicate that with the Raman mapping technique, it is possible to overcome the inhomogeneity of the film and noise of the single point spectra on an area equal to 10 × 10 µm².
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