High resolution 3D imaging of synchrotron generated microbeams. Issue 12 (12th November 2015)

• Record Type: Journal Article
• Authors: Gagliardi, Frank M.; Cornelius, Iwan; Blencowe, Anton; Franich, Rick D.; Geso, Moshi
• Is Part Of: Medical physics. Volume 42:Issue 12(2015)
• Page Start: 6973
• Page End: 6986
• Publication Date: 2015-11-12
• Subjects: biomedical equipment -- biomedical optical imaging -- dosimeters -- dosimetry -- fluorescence -- image resolution -- laser applications in medicine -- medical image processing -- optical microscopy -- radiation therapy; Laser imaging -- Confocal -- Therapeutic applications -- Dosimetry/exposure assessment -- Biomedical imaging; Radiation therapy -- Measuring microscopes -- Biological material, e.g. blood, urine; Haemocytometers -- Dosimeters -- Digital computing or data processing equipment or methods, specially adapted for specific applications -- Image data processing or generation, in general -- Scintigraphy; MRT -- microbeam imaging -- PRESAGE® dosimeter -- IntMRT -- DynMRT; Dosimetry -- Magnetic resonance imaging -- Medical imaging -- Collimators -- Goniometers -- Three dimensional image processing -- Laser beam effects -- Fluorescence -- Confocal microscopy -- Confocal microscopes; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4935410
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: Microbeam radiation therapy (MRT) techniques are under investigation at synchrotrons worldwide. Favourable outcomes from animal and cell culture studies have proven the efficacy of MRT. The aim of MRT researchers currently is to progress to human clinical trials in the near future. The purpose of this study was to demonstrate the high resolution and 3D imaging of synchrotron generated microbeams in PRESAGE® dosimeters using laser fluorescence confocal microscopy. Methods: Water equivalent PRESAGE® dosimeters were fabricated and irradiated with microbeams on the Imaging and Medical Beamline at the Australian Synchrotron. Microbeam arrays comprised of microbeams 25–50 μm wide with 200 or 400 μm peak‐to‐peak spacing were delivered as single, cross‐fire, multidirectional, and interspersed arrays. Imaging of the dosimeters was performed using anikon a1 laser fluorescence confocal microscope. Results: The spatial fractionation of the MRT beams was clearly visible in 2D and up to 9 mm in depth. Individual microbeams were easily resolved with the full width at half maximum of microbeams measured on images with resolutions of as low as 0.09 μm/pixel. Profiles obtained demonstrated the change of the peak‐to‐valley dose ratio for interspersed MRT microbeam arrays and subtle variations in the sample positioning by the sample stage goniometer were measured. Conclusions: Laser fluorescence confocal microscopy of MRT irradiated PRESAGE® dosimeters has been validated in this study as a high resolution imaging tool for the independent spatial and geometrical verification of MRT beam delivery.