Dose response of polymer gel dosimeter based on hydroxypropyl cellulose hydrogel; Toward the application on heavy ion therapy

Hiroki, Akihiro; Yamashita, Shinichi*; Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa

The polymer gel dosimeters consisting of 2-hydroxyethyl methacrylate, nonaethylene glycol dimethacrylate, and tetrakis (hydroxymethyl) phosphoniumu chloride with radiation-crosslinked hydroxypropyl cellulose gel were irradiated with 290 MeV/u C ions at HIMAC. Absorbance of the irradiated dosimeters at 660 nm increased with an increase in the dose up to 10 Gy. The dose response of the dosimeter irradiated with C ions was about 0.007 Abs. Gy, which decreased in about one-tenth of the -irradiated sample. RGB value of the image obtained by using a flat-bed image scanner also increased with increasing dose. Distribution of the dose estimated from RGB value of the scanned image was almost agreement with that of a general radiochromic film for the radiotherapy.