Next Article in Journal
Phenolic Acids and Flavonoids in Selected Commercial Organic and Conventional Tea Products Characterized by Different Degrees of Leaf Fragmentation
Next Article in Special Issue
Design of a Novel DXA Scanner with a CdTe Photon-Counting Timepix4 Detector for Peripheral Bone Densitometry
Previous Article in Journal
ConvNeXt Meets Vision Transformers: A Powerful Hybrid Framework for Facial Age Estimation
Previous Article in Special Issue
Preclinical Validation of the iBNCT001 Accelerator System for Boron Neutron Capture Therapy: In Vitro Efficacy, Beam Quality, and Radiation Safety Evaluation
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Design and Optimization of X-Ray Collimators for Preclinical Minibeam Radiation Therapy

by
Umberto Crimaldi
1,2,
Nastassja Luongo
1,2,
Laura Antonia Cerbone
2,3,4,
Roberto Pacelli
1,5,
Paolo Russo
2,4,† and
Giovanni Mettivier
2,4,*,†
1
Azienza Ospedaliera Universitaria Policlinico Federico II, I-80131 Napoli, Italy
2
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli, Italy
3
Scuola Superiore Meridionale, I-80134 Napoli, Italy
4
Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, I-80126 Napoli, Italy
5
Dipartimento di Scienze Biologiche Avanzate, Università di Napoli Federico II, I-80131 Napoli, Italy
*
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Appl. Sci. 2026, 16(7), 3282; https://doi.org/10.3390/app16073282
Submission received: 19 February 2026 / Revised: 21 March 2026 / Accepted: 25 March 2026 / Published: 28 March 2026
(This article belongs to the Special Issue Novel Technologies in Radiology: Diagnosis, Prediction and Treatment)

Featured Application

This work provides insights into the technical details of a beam collimator design for a preclinical radiation therapy research technique with arrays of submillimeter beamlets of kilovoltage X-rays, a form of spatially fractionated radiation therapy currently investigated for possible translation to the clinical environment.

Abstract

Spatially fractionated radiotherapy with X-ray minibeams (x-MBRT) aims to increase normal-tissue tolerance by delivering alternating high- and low-dose regions. We provide a Monte Carlo-based framework to design and optimize multi-slit collimators, quantifying how geometry and material govern peak–valley modulation. A validated digital twin of the SmART X-RAD225Cx irradiator was implemented in TOPAS/Geant4. Various x-MBRT collimators were simulated with parallel or divergent slits. The parameter space covered a slit width w (0.1–0.9 mm), center-to-center spacing CTC (1–3 mm), thickness T (1–5 mm), and acceptance angle θ. Dose was scored in a 2 × 2 × 2 cm3 water phantom at a 1 cm depth. For fixed w/CTC, peak-valley dose ratio PVDR increases with larger CTC via an increase in peak dose, with the valley dose nearly constant. Peak transmission saturated at θ ≈ 3°, indicating minimal benefit from larger acceptance. Divergent slits yielded flatter lateral profiles but higher valley doses than parallel slits, reducing PVDR around the central axis. This Monte Carlo study provides insights for optimizing collimator geometries in x-MBRT using small-animal irradiators, informing the design of more effective collimation systems to enhance treatment precision and normal-tissue sparing.
Keywords: minibeam radiation therapy; Monte Carlo simulations; TOPAS; X-rays minibeam radiation therapy; Monte Carlo simulations; TOPAS; X-rays

Share and Cite

MDPI and ACS Style

Crimaldi, U.; Luongo, N.; Cerbone, L.A.; Pacelli, R.; Russo, P.; Mettivier, G. Design and Optimization of X-Ray Collimators for Preclinical Minibeam Radiation Therapy. Appl. Sci. 2026, 16, 3282. https://doi.org/10.3390/app16073282

AMA Style

Crimaldi U, Luongo N, Cerbone LA, Pacelli R, Russo P, Mettivier G. Design and Optimization of X-Ray Collimators for Preclinical Minibeam Radiation Therapy. Applied Sciences. 2026; 16(7):3282. https://doi.org/10.3390/app16073282

Chicago/Turabian Style

Crimaldi, Umberto, Nastassja Luongo, Laura Antonia Cerbone, Roberto Pacelli, Paolo Russo, and Giovanni Mettivier. 2026. "Design and Optimization of X-Ray Collimators for Preclinical Minibeam Radiation Therapy" Applied Sciences 16, no. 7: 3282. https://doi.org/10.3390/app16073282

APA Style

Crimaldi, U., Luongo, N., Cerbone, L. A., Pacelli, R., Russo, P., & Mettivier, G. (2026). Design and Optimization of X-Ray Collimators for Preclinical Minibeam Radiation Therapy. Applied Sciences, 16(7), 3282. https://doi.org/10.3390/app16073282

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop