Effects of PVA-GTA-I radiochromic gel dosimeter components on optical dose-response

Abstract

In recent years, a novel radiochromic gel dosimeter was developed that utilizes the color development of a polyvinyl alcohol-iodide (PVA-I) complex. In this study, we explore the effects of different iodide salts (LiI, NaI, KI, CsI, NH4I, CaI2, and ZnI2) and PVAs with different degrees of polymerization (500, 1000, and 1500) and saponification (80, 88, and 98 mol%) were investigated on a PVA-GTA-I gel dosimeter using PVA that was chemically crosslinked with glutaraldehyde (GTA) as a matrix. The results showed that these substitutions had negligible effect on dose-responses, such as sensitivity and dose-rate independence.

Thermally Controllable Decolorization of Reusable Radiochromic Complex of Polyvinyl Alcohol, Iodine and Silica Nanoparticles (PAISiN) Irradiated with γ-rays

“…For the application of PAISiN to routine monitoring in a variety of workplaces, further investigations to improve its accuracy, stability and reproducibility are desirable to be performed in reference to the preceding approaches using other materials [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. Those studies should include experiments to examine the UV absorbance, higher dose-response, longer-term stability, changes in dosimetric properties after more repetitive irradiation and preventive measures against degradation during storage, in parallel with comprehensive theoretical analyses on the thermally dynamic kinetics of coloration/decolorization and molecular interactions with varying compositions.…”

“…According to the fact that a red color was induced by irradiation of PAISiN, it was presumed that the red component was less sensitive to radiation than other color components. Actually, it was reported that a higher-degree saponification of PVA lowered the absorbance of the red color (around 490 nm) [35,36], which implies that the red component of a PAISiN image is attributable to the formation of the residual acetyl group of polyvinyl acetate in PVA. With this consideration, the inverted images were split into three color components: blue, green and red; then, the dose responses of each component were examined using the same data of Figure 2.…”

Optimizing the feasibility of polyvinyl alcohol-potassium iodine gel for medical dosimeter

“…The absorbance as well as sensitivity of the dosimeters are shown in figures 4(a), and (b) which show a very poor stability of PVA-KI dosimeter, due to the continuous oxidation of iodide ions with time. Indeed, the weak stability of iodine gel dosimeter was reported recently [49], which limit the feasibility of using it in routine radiotherapy dosimetry.…”

“…The developed gel with GTA was more transparent and sensitive compared with PVA-I dosimeters. Then, the PVA-GTA-I gel dosimeter was combined with glucono-δ-lactone (GDL) acid and fructose [47][48][49]. The resultant sensitivity became higher with increasing the rate of autooxidation (i.e.…”

Bare spherical gel dosimeter with optical computed tomography scanning

“…Recently a formulation of a radiochromic polyvinyl alcohol-iodide (PVA-I) hydrogel dosimeter with crosslinking by glutaraldehyde (GTA) was introduced by Hayashi et al [1]. The dosimeter has several advantages for optical computed tomography (CT) readout.…”