Purpose: To compare beam characteristics of superficial X-rays with 6 MeV Electrons for the purpose of replacing superficial treatments with electron fields for skin lesions.
Methods: Electron beam cutouts were made with 12mm thickness cerrobend in diameters 2-5 cm to match superficial X-ray machine cones. Central axis depth doses and profiles were generated using 0.007 cc Exradin A-16 ion chamber, in PTW water phantom at 1mm steps, at 96 and 100cm SSD for electron beams, and at 15cm SSD for superficial X-rays. From the beam data, radiation penumbra 90-10%, 90% profile width, peripheral dose and percentage depth dose were obtained for comparison.
Results: The 90-10% radiation penumbra was ranging 7.4-13.7 mm, 12.6-17.6 mm for 6 MeV electrons at 96 and 100cm SSD respectively, and 4.2-11.4 mm for 2-5 cm superficial X-ray cones. For 90% treatment width, a margin ranging 5-7 mm, 6-9 mm is needed around the periphery of target for 6 MeV Electrons at 96 and 100cm SSD respectively, and 2-3 mm for superficial X-ray cones. For 96cm SSD, the peripheral dose from the geometrical field edge were 3.9% at 1cm and 0.5% at 2cm. It was 2.6% at 1cm and 0.7% at 2cm for 100cm SSD. For superficial, it was 6.2%, 7.5%, 9.1% at 1cm, and 3.4%, 4.3%, 5.6% at 2cm for 100 kV, 120 kV and 150 kV respectively. The electron surface dose was below 90%.
Conclusion: 6 MeV Electron beam shows high superiority with rapid fall off of dose beyond target with lower peripheral dose compared to superficial X-rays. However, the electrons need higher margin around the target and also need appropriate bolus thickness to increase skin dose. The dose at depth beyond 2cm makes very significant advantage using electrons compared to superficial X-rays.
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http://dx.doi.org/10.1118/1.4735294 | DOI Listing |
Sci Rep
January 2025
Department of Physics, TU Dortmund University, Otto-Hahn-Straße 4, 44227, Dortmund, Germany.
Time-resolved momentum microscopy is an emerging technique based on photoelectron spectroscopy for characterizing ultrafast electron dynamics and the out-of-equilibrium electronic structure of materials in the entire Brillouin zone with high efficiency. In this article, we introduce a setup for time-resolved momentum microscopy based on an energy-filtered momentum microscope coupled to a custom-made high-harmonic generation photon source driven by a multi-100 kHz commercial Yb-ultrafast laser that delivers fs pulses in the extreme ultraviolet range. The laser setup includes a nonlinear pulse compression stage employing spectral broadening in a Herriott-type bulk-based multi-pass cell.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
January 2025
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA. Electronic address:
Purpose: Proton FLASH has been investigated using cyclotron and synchrocyclotron beamlines but not synchrotron beamlines. We evaluated the impact of dose rate (ultra-high [UHDR] vs. conventional [CONV]) and beam configuration (shoot-through [ST] vs.
View Article and Find Full Text PDFCancers (Basel)
January 2025
Intense Laser Irradiation Laboratory, National Institute of Optics, National Research Council of Italy, 56124 Pisa, Italy.
The use of very high energy electron (VHEE) beams, with energies between 50 and 400 MeV, has drawn considerable interest in radiotherapy due to their deep tissue penetration, sharp beam edges, and low sensitivity to tissue density. VHEE beams can be precisely steered with magnetic components, positioning VHEE therapy as a cost-effective option between photon and proton therapies. However, the clinical implementation of VHEE therapy (VHEET) requires advances in several areas: developing compact, stable, and efficient accelerators; creating sophisticated treatment planning software; and establishing clinically validated protocols.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
National Key Laboratory of Science and Technology on Advanced Laser and High Power Microwave, Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900, China.
The Chinese Academy of Engineering Physics Terahertz Free Electron Laser Facility (CAEP THz FEL, CTFEL) has been operated as a user facility for over five years. To further meet the growing demands of modern science, an upgrade project for an infrared-terahertz free electron laser facility based on CTFEL has been proposed to broaden the frequency range from 0.1-4.
View Article and Find Full Text PDFPhys Med
January 2025
Centre for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW 2522, Australia.
Purpose: To propose comprehensive characterization methods of additive manufacturing (AM) materials for MV photon and MeV electron radiotherapy.
Methodology: This study investigated 15 AM materials using CT machines. Geometrical accuracy, tissue-equivalence, uniformity, and fabrication parameters were considered.
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