Author
Sueyasu, S., Kasamatsu, K., Takayanagi, T., Chen, Y., Kuriyama, Y., Ishi, Y., Uesugi, T., Rohringer, W., Ünlü, Mehmet Burçin, Kudo, N., Yokokawa, K., Takao, S.
Publication Date
2023-12
Publication Place
-
Wiley
Subject
Ionoacoustics, Range verification, Spot-scanning proton therapy
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
0094-2405
Record ID
d792a1f1-be95-4288-a902-146cc4e596f9
Library Location
Natural and Mathematical Sciences
Date
2023-12
Notes
JST FOREST ; JSPS KAKENHI
Sample Text
Background: Ionoacoustics is a promising approach to reduce the range uncertainty in proton therapy. A miniature-sized optical hydrophone (OH) was used as a measuring device to detect weak ionoacoustic signals with a high signal-to-noise ratio in water. However, further development is necessary to prevent wave distortion because of nearby acoustic impedance discontinuities while detection is conducted on the patient's skin.Purpose: A prototype of the probe head attached to an OH was fabricated and the required dimensions were experimentally investigated using a 100-MeV proton beam from a fixed-field alternating gradient accelerator and k-Wave simulations. The beam range of the proton in a tissue-mimicking phantom was estimated by measuring gamma-waves and spherical ionoacoustic waves with resonant frequency (SPIRE).Methods: Four sizes of probe heads were fabricated from agar blocks for the OH. Using the prototype, the gamma-wave was detected at distal and lateral positions to the Bragg peak on the phantom surface for proton beams delivered at seven positions. For SPIRE, independent measurements were performed at distal on- and off-axis positions. The range positions were estimated by solving the linear equation using the sensitive matrix for the gamma-wave and linear fitting of the correlation curve for SPIRE; they were compared with those measured using a film.Results: The first peak of the gamma-wave was undistorted with the 3 x 3 x 3-cm(3) probe head used at the on-axis and 3-cm off-axis positions. The range positions estimated by the gamma-wave agreed with the film-based range in the depth direction (the maximum deviation was 0.7 mm), although a 0.6-2.1 mm deviation was observed in the lateral direction. For SPIRE, the deviation was <1 mm for the two measurement positions.Conclusions: The attachment of a relatively small-sized probe head allowed the OH to measure the beam range on the phantom surface.
DOI
10.1002/mp.16892
