Program Information
Development of Novel Radiochromic Films for Radiotherapy Dosimetry
M Alqathami1*, H Lee2 , G Won Choi3 , A Blencowe4 , Z Wen5 , J Adamovics6 , G Ibbott7 , (1) UT MD Anderson Cancer Center, Houston, TX, (2) UT MD Anderson Cancer Center, Houston, TX, (3) UT MD Anderson Cancer Center, Houston, TX-Texas, (4) The University of South Australia, South Australia, SA, (5) MD Anderson Cancer Center, Houston, TX, (6) Department of Chemistry and Biology, Rider University, Skillman, NJ, (7) UT MD Anderson Cancer Center, Houston, TX
Presentations
SU-G-TeP2-6 (Sunday, July 31, 2016) 4:30 PM - 5:00 PM Room: ePoster Theater
Purpose: To develop and evaluate novel radiochromic films for quality assurance in radiotherapy dosimetry.
Materials and methods: Novel radiochromic film compositions were formulated using leuco crystal violet (LCV) as a reporting system and tetrabromoethane as a free radical source. The film matrix used consisted of polyurethane polymer mixed with dibutyl phthalate plasticizer (20 wt%). The concentration of the radical initiator was kept constant at 10 wt% and the concentration of the LCV dye varied (1 and 2 wt%). To ensure uniform thickness of the film, its precursors were sandwiched between two pieces of glass separated by a 1 mm gap between during the curing process. The films were cut into pieces and were irradiated with a 6 MV X-ray beam to selected doses. The change in optical density was measured using a flatbed scanner and a spectrophotometer.
Results: The results showed that all film formulations exhibited a linear response with dose and an absorption maximum at ~ 590 nm. The formulation with 2 wt% LCV was ~ 30% more sensitive to dose than the formulation with 1 wt% LCV. Both films were very deformable. In addition, the radiochromic response of the film was found to bleach over a short period of time (few weeks) allowing the film to be reused for dose verification measurements.
Conclusion: Both film formulations displayed excellent sensitivity and linearity to radiation dose and thus can be used for the 2D dosimetry of clinical megavoltage and kilovoltage X-ray beams. In addition, the thickness of the film could easily be increased allowing for their potential use as a deformable bolus material. However, thicker films would need more optimization of the manufacturing procedure to ensure consistent material uniformity and sensitivity are recommended.
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