Program Information

Dosimetric Evaluation of Tissue Equivalent Gel Dosimeter Using Saccharide in Radiotherapy System

Y Cho¹, D Lee² , H Jung³ , Y Ji⁴ , K Kim⁵ , U Chang⁶ , S Kwon⁷* , (1) Korea institute of Radiological and Medical Sciences (KIRAMS), Seoul, Korea (2) Korea Institute of Radiological and Medical Sciences, Seoul, Korea (3) Korea Institute of Radiological and Medical Sciences, Seoul, Korea (4) Korea Institute of Radiological and Medical Sciences, Seoul, Korea (5) Korea Institute of Radiological and Medical Sciences, Seoul, Korea (6) Korea Institute of Radiological and Medical Sciences, Seoul, Korea (7) Kyonggi University, Suwon-si, Gyeonggi-do, Korea

Presentations

SU-E-T-130 Sunday 3:00PM - 6:00PM Room: Exhibit Hall

Purpose:
In this study, the dose responses of the MAGIC gel with various concentrations and type of saccharide are examined to clarify the roles of mono and disaccharide in the polymerization process. Then we focused on the tissue equivalence and dose sensitivity of MAGIC gel dosimeters.

Methods:
The gel is composed of HPLC, 8% gelatin, 2 x 10-3 M L-ascorbic acid, 1.8 x 10-2 M hydroquinone, 8 x 10-5 M copper(II)sulfate and 9% methacrylic acid, new polymer gels are synthesized by adding glucose(monosaccharide), sucrose(disaccharide) and urea in the concentration range of 5~35%. For irradiation of the gel, cesium-137 gamma-ray irradiator was used, radiation dose was delivered from 5~50 Gy. MRI images of the gel were acquired by using a 3.0 T MRI system.

Results:
When saccharide and urea were added, the O/C, O/N and C/N ratios agreed with those of soft tissue with 1.7%. The dose-response of glucose and sucrose gel have slope-to-intercept ratio of 0.044 and 0.283 respectively. The slope-to-ratio is one important determinant of gel sensitivity. R-square values of glucose and sucrose gel dosimeters were 0.984 and 0.994 respectively. Moreover when urea were added, the slope-to-intercept ratio is 0.044 and 0.073 respectively. R-square values of mono and disaccharide gel were 0.973 and 0.989 respectively. When a saccharide is added into the MAGIC gel dosimeter, dose sensitivity is incrâ½â½eased. However when urea were added, dose sensitivity is slightly decreased.

Conclusion:
In this study, it was possible to obtain the following conclusions by looking at the dose response characteristics after adding mono-, di-saccharide and urea to a MAGIC gel dosimeter. Saccharide was a tendency of increasing dose sensitivity with disaccharide. SaÎœccharide is cost effective, safe, soft tissue equivalent, andâ½ â½can be used under various experimental conditions, making it a suitable dosimeter for some radiotherapy applications.

Funding Support, Disclosures, and Conflict of Interest: This work was supported by National Foundation of Korea Grant funded by the Korean Government (2011-0030597).

Contact Email: