Imaging luminescent tattoo inks for direct visualization of linac and cobalt irradiation
| Autor: | Samuel S. Streeter, Leonardo Barrios, Jason R. Gunn, Brian W. Pogue, Marysia Guzmán, Suyapa Bejarano, Ethan P. M. LaRochelle, Jennifer Soter |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Luminescence Ultraviolet Rays Tattoo ink Imaging phantom Article 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Optics Fiducial Markers Dosimetry Image sensor Image resolution Tattooing business.industry Phantoms Imaging General Medicine Cobalt 030220 oncology & carcinogenesis Ink Monochromatic color Particle Accelerators business Fiducial marker Radiotherapy Image-Guided |
| Zdroj: | Med Phys |
| Popis: | Purpose Tattoo fiducials are commonly used in radiotherapy patient alignment, and recent studies have examined the use of UV-excited luminescent tattoo ink as a cosmetic substitute to make these visible under UV illumination. The goal of this study was to show how luminescent tattoo inks could be excited with MV radiation and imaged during beam delivery for direct visualization of field position. Methods A survey of nine UV-sensitive tattoo inks with various emission spectra were investigated using both UV and MV excitation. Images of liquid solutions were collected under MV excitation using an intensified-CMOS imager. Solid skin-simulating phantoms were imaged with both surface-painted ink and in situ tattooing during dose delivery by both a clinical linear accelerator and cobalt-60 source. Results The UV inks have peak fluorescence emission ranging from approximately 440 to 600 nm with lifetimes near 11-16 μs. The luminescence intensity is approximately 6x higher during the x-ray pulse than after the pulse, however, the signal-to-noise is only approximately twice as large. Spatial resolution for imaging was achieved at 1.6 mm accuracy in a skin test phantom. Optical filtering allows for continuous imaging using a cobalt source and provides a mechanism to discriminate ink colors using a monochromatic image sensor. Conclusions This study demonstrates how low-cost inks can be used as fiducial markers and imaged both using time-gated and continuous modes during MV dose delivery. Phantom studies demonstrate the potential application of real-time field verification. Further studies are required to understand if this technique could be used as a tool for radiation dosimetry. |
| Databáze: | OpenAIRE |
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