Advanced Radiation DOSimetry phantom (ARDOS): a versatile breathing phantom for 4D radiation therapy and medical imaging

Abstract

A novel breathing phantom was designed for being used in conventional and ion-beam radiotherapy as well as for medical imaging. Accurate dose delivery and patient safety are aimed to be verified for four-dimensional (4D) treatment techniques compensating for breathing-induced tumor motion. The phantom includes anthropomorphic components representing an average human thorax. It consists of real tissue equivalent materials to fulfill the requirements for dosimetric experiments and imaging purposes. The different parts of the torso (lungs, chest wall, and ribs) and the tumor can move independently. Simple regular movements, as well as more advanced patient-specific breathing cycles are feasible while a reproducible setup can be guaranteed. The phantom provides the flexibility to use different types of dosimetric devices and was designed in a way that it is robust, transportable and easy to handle. Tolerance levels and the reliability of the phantom setup were determined in combination with tests on motion accuracy and reproducibility by using infrared optical tracking technology. Different imaging was performed including positron emission tomography imaging, 4D computed tomography as well as real-time in-room imaging. The initial dosimetric benchmarking studies were performed in a photon beam where dose parameters are predictable and the dosimetric procedures well established.

Tissue mimicking materials for imaging and therapy phantoms: a review

“…End-to-end tests are particularly useful for multi-centre audits (Clark et al 2015, Lambrecht et al 2019, Wesolowska et al 2019) and have shown that they are useful for comparing the magnitude of dose differences due to effects such as motion (de Jong et al 2017, Kostiukhina et al 2017, Perrin et al 2017, Pallotta et al 2018, Ehrbar et al 2019 or magnetic fields (Steinmann et al 2019a(Steinmann et al , 2020, see table 6. Reported absolute differences can be variable depending on the dosimeter employed (Kostiukhina et al 2017), although it may be challenging to disassociate errors due the treatment planning system, treatment delivery, detector limitations or the material characteristics. Careful characterization of the material properties can allow explanation of the uncertainties associated with this component of any overall differences observed (Taylor et al 2016, Steinmann et al 2018.…”

“…Steidl et al 2012 developed a series of specifications for dynamic radiotherapy phantoms, one of which was to include inhomogeneities such as rib structures. Many dynamic lung phantoms have been developed with inhomogeneities(Mann et al 2017, Pallotta et al 2018, Kostiukhina et al 2017, Perrin et al 2017 …”

Clinical implementations of 4D pencil beam scanned particle therapy: Report on the 4D treatment planning workshop 2016 and 2017

“…An independent tumor motion in all three directions as well as a thorax movement can be facilitated on the basis of arbitrary movement curves while inserts for films or ion chamber are available. Another sophisticated research phantom was developed at the Medical University of Vienna in cooperation with the Austrian Institute of Technology an Advanced Radiation DOSimetry phantom (ARDOS) in the frame of a Marie Curie project [59]. This phantom was built from three different tissue equivalent materials: high density balsa wood for lung, solid water for soft tissue and bone material.…”

Additively Manufactured Patient-Specific Anthropomorphic Thorax Phantom With Realistic Radiation Attenuation Properties

“…To precisely analyze different imaging systems, a realistic phantom should accurately simulate a true patient scan including anatomy, tissue density and X-ray attenuation characteristics in the case of X-ray or computed tomography (CT) imaging. Tissue equivalency is not only relevant for image quality assessment but also for accurate radiation dosimetry especially for charged particles where the tissue composition influences the particle interactions (Kostiukhina et al, 2017;Kostiukhina et al, 2019). Despite the ubiquitous existence of various thoracic pathologies and their imaging-based surgical and diagnostic procedures, more realistic models are required (Nardi et al, 2017;Huang et al, 2019;Montigaud et al, 2019).…”