Validation of complex radiotherapy techniques using polymer gel dosimetry

Abstract

Modern radiotherapy delivers highly conformal dose distributions to irregularly shaped target volumes while sparing the surrounding normal tissue. Due to the complex planning and delivery techniques, dose verification and validation of the whole treatment workflow by end-to-end tests became much more important and polymer gel dosimeters are one of the few possibilities to capture the delivered dose distribution in 3D. The basic principles and formulations of gel dosimetry and its evaluation methods are described and the available studies validating device-specific geometrical parameters as well as the dose delivery by advanced radiotherapy techniques, such as 3D-CRT/IMRT and SRS treatments, the treatment of moving targets, online-adaptive MRgRT as well as proton and ion beam treatments, are reviewed. The present status and limitations as well as future challenges of polymer gel dosimetry for the validation of complex radiotherapy techniques are discussed.

Clinical applicability of Linac-integrated CBCT based NIPAM 3D dosimetry: a dual-institutional investigation

“…Polymer gel dosimetry (PGD) is a dose verification tool that is beneficial for highly complex and advanced radiation therapy treatments (Baldock et al 2010, Karger et al 2024. PGD distinguishes itself from other commonly used dosimeters, such as ionization chamber (1D) and film (2D), since it inherently records dose information in three dimensions (Ibbott 2004).…”

“…Polymer gel dosimeters are composed of radiosensitive chemicals, which upon irradiation undergo polymerization and crosslinking as a function of the absorbed dose (Karger et al 2024). The polymerization and crosslinking result in changes in the physical density of the gel dosimeter, which can be recorded with clinically available imaging modalities.…”