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Luminescence imaging of water during proton‐beam irradiation for range estimation
Author(s) -
Yamamoto Seiichi,
Toshito Toshiyuki,
Okumura Satoshi,
Komori Masataka
Publication year - 2015
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4932630
Subject(s) - luminescence , imaging phantom , proton therapy , proton , materials science , irradiation , bragg peak , optics , ionization chamber , range (aeronautics) , beam (structure) , radiochemistry , ionization , chemistry , optoelectronics , physics , ion , nuclear physics , organic chemistry , composite material
Purpose: Proton therapy has the ability to selectively deliver a dose to the target tumor, so the dose distribution should be accurately measured by a precise and efficient method. The authors found that luminescence was emitted from water during proton irradiation and conjectured that this phenomenon could be used for estimating the dose distribution. Methods: To achieve more accurate dose distribution, the authors set water phantoms on a table with a spot scanning proton therapy system and measured the luminescence images of these phantoms with a high‐sensitivity, cooled charge coupled device camera during proton‐beam irradiation. The authors imaged the phantoms of pure water, fluorescein solution, and an acrylic block. Results: The luminescence images of water phantoms taken during proton‐beam irradiation showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. Furthermore, the image of the pure‐water phantom showed almost the same distribution as the tap‐water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of the fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had a 14.5% shorter proton range than that of water; the proton range in the acrylic phantom generally matched the calculated value. The luminescence images of the tap‐water phantom during proton irradiation could be obtained in less than 2 s. Conclusions: Luminescence imaging during proton‐beam irradiation is promising as an effective method for range estimation in proton therapy.