Chemical Overview of Gel Dosimetry Systems: A Comprehensive Review

Abstract

Advances in radiotherapy technology during the last 25 years have significantly improved both dose conformation to tumors and the preservation of healthy tissues, achieving almost real-time feedback by means of high-precision treatments and theranostics. Owing to this, developing high-performance systems capable of coping with the challenging requirements of modern ionizing radiation is a key issue to overcome the limitations of traditional dosimeters. In this regard, a deep understanding of the physicochemical basis of gel dosimetry, as one of the most promising tools for the evaluation of 3D high-spatial-resolution dose distributions, represents the starting point for developing new and innovative systems. This review aims to contribute thorough descriptions of the chemical processes and interactions that condition gel dosimetry outputs, often phenomenologically addressed, and particularly formulations reported since 2017.

Dosimetric Double Network Hydrogel Based on Poly(vinyl-alcohol)/Phenylalanine-Derivatives with Enhanced Mechanical Properties

“…Gel dosimetry, as Fricke gel (FG) dosimetry, has been widely studied for radiotherapy/radiosurgery applications because of their radiological tissue equivalence, ease of molding into any desired shape and size, and therefore, it is useful for evaluating the 3D relative dose distributions. − …”

“…Besides the great advantages, some limits, such as the spatial and temporal instability of the dosimetric information, make this kind of dosimeter still inadequate for routine applications in the clinical environment. Various FG dosimeters are discussed in the literature based on different polymeric matrices and readout approaches in order to overcome these limits. − However, all the proposed hydrogel matrices still show lacks mechanical flexibility, in terms of ability of bending, folding, and stretching together with high cracking and rupture resistance. , All these properties are of primary importance considering the necessity to prepare anthropomorphic phantoms with an elasticity comparable to various soft tissues of the human body, allowing, among others, the dosimetric application in sophisticated radiotherapy treatments for organs subjected to natural movement ( i.e. , breathing). − …”

Gel Dosimetry

“…The review article entitled “Chemical Overview of Gel Dosimetry Systems: A Comprehensive Review” by Macchione et al [ 22 ] aims to contribute thorough descriptions of the chemical processes and interactions that condition the gel dosimetry outputs of ten phenomenologically addressed and particular formulations reported since 2017.…”

Development of a quasi‐3D dosimeter using radiochromic plastic for patient‐specific quality assurance

“…21 Several studies have used anthropomorphic phantoms of polymer and Frick gel dosimeters for 3D dosimetry. [22][23][24] Although the Fricke gel is easy to manufacture, the 3D dose distribution is degraded by the diffusion of ferrous and ferric ions. 25,26 A radiochromic plastic material called PRESAGE® was introduced in 2006 as a novel 3D dosimetric device.…”

“…Ferrous ions in the Fricke solution undergo proportionate oxidation to ferric ions when exposed to radiation 21 . Several studies have used anthropomorphic phantoms of polymer and Frick gel dosimeters for 3D dosimetry 22–24 . Although the Fricke gel is easy to manufacture, the 3D dose distribution is degraded by the diffusion of ferrous and ferric ions 25,26 …”