Purpose: To explore 3D printing for rapid development of prototype thin slab low-Z/density ionization chamber arrays viable for custom needs in radiotherapy dosimetry and quality assurance (QA).
Materials And Methods: We designed and fabricated parallel plate ionization chambers and ionization chamber arrays using an off-the-shelf 3D printing equipment. Conductive components of the detectors were made of conductive polylactic acid (cPLA) and insulating components were made of acrylonitrile butadiene styrene (ABS). We characterized the detector responses using a Varian TrueBeam linac at 95 cm SSD in slab solid water phantom at 5 cm depth. We measured the current-voltage (IV) curves, the response to different energy beam lines (2.5 MV, 6 MV, 6 MV FFF) for various dose rates and compared them to responses of a commercial Exradin A12 ionization chamber. We measured off-axis ratio (OAR) for several small field static multi-leaf collimators field sizes (0.5-3 cm) and compared them to OAR data obtained for commissioning of stereotactic radiotherapy.
Results: We identified the printing capability and the limitations of a low-cost off-the-shelf 3D printer for rapid prototyping of detector arrays. The design of the array with sub-millimeter size features conformed to the 3D printing capabilities. IV-curve for the array showed a strong polarity effect (8%) due to the design. Results for the parallel plate and the array compared well with A12 chamber: monitor unit (MU) dependence for the array was within a few % and the response to different energy beam lines was within 1%. Off-axis dose profiles measured with the array were comparable to dose profiles obtained in water tank and stereotactic diode after accounting for the size of the chambers. Dose error was within 2% at the center of the profile and slightly larger at the penumbra.
Conclusions: Rapid prototyping of ion chambers by means of low-cost 3D printing is feasible with certain limitations in the design and spatial accuracy of the printed details.
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http://dx.doi.org/10.1002/mp.13841 | DOI Listing |
Int J Part Ther
March 2025
Institute of Medical Physics and Radiation Protection, University of Applied Sciences, Giessen, Germany.
Purpose: The spot size of scanned particle beams is of crucial importance for the correct dose delivery and, therefore, plays a significant role in the quality assurance (QA) of pencil beam scanning ion beam therapy.
Materials And Methods: This study compares 5 detector types-radiochromic film, ionization chamber (IC) array, flat panel detector, multiwire chamber, and IC-for measuring the spot size of proton and carbon ion beams.
Results: Variations of up to 30% were found between detectors, underscoring the impact of detector choice on QA outcomes.
Tech Innov Patient Support Radiat Oncol
March 2025
Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Tokushima 770-8503, Japan.
Purpose: This study aims to compare treatment plans created using RapidPlan and PlanIQ for twelve patients with prostate cancer, focusing on dose uniformity, dose reduction to organs at risk (OARs), plan complexity, and dose verification accuracy. The goal is to identify the tool that demonstrates superior performance in achieving uniform target dose distribution and reducing OAR dose, while ensuring accurate dose verification.
Methods: Dose uniformity in the planning target volume, excluding the rectum, and dose reduction in the OARs (the rectum and bladder) were assessed.
J Neurosci Methods
January 2025
Cognitive Neuroscience Laboratory, German Primate Center - Leibniz Institute for Primate Research, Goettingen, Germany; Faculty of Biology and Psychology, University of Goettingen, 37077 Goettingen, Germany.
Background: Neuronal activity is modulated by behavior and cognitive processes. The combination of several neurotransmitter systems, acting directly or indirectly on specific populations of neurons, underlie such modulations. Most studies with non-human primates (NHPs) fail to capture this complexity, partly due to the lack of adequate methods for reliably and simultaneously measuring a broad spectrum of neurotransmitters while the animal engages in behavioral tasks.
View Article and Find Full Text PDFIndian J Nucl Med
November 2024
Center for Research and Production of Radioisotopes, Dalat Nuclear Research Institute, Vietnam Atomic Energy Institute (VINATOM), Da Lat City, Lam Dong Province, Vietnam.
Aims: This study aimed to evaluate the principal technical characteristics of a well-type gas-filled ionization chamber dose calibrator used in measuring radiopharmaceutical activity, namely accuracy, repeatability, and linearity. Furthermore, this work also explored the correlation between the device's response and the position and volume of the radiopharmaceutical I-131.
Materials And Methods: Experimental measurements were conducted on the ATOMLAB 500 dose calibrator using NIST traceable Cs-137 source to determine the accuracy and repeatability.
Anal Chim Acta
January 2025
University Regensburg, Institute of Analytical Chemistry, Universitätsstrasse 31, 93053, Regensburg, Germany. Electronic address:
Background: The demand for lithium-ion cells in the automotive industry is rapidly growing due to the increasing electrification of the transportation sector. The electrolyte composition plays a critical role in determining the lifetime and performance of these large-format cells. Additionally, advancements in this field are leading to frequent changes in both electrode materials and electrolyte formulations.
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