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Title: Stereotactic targeting and dose verification for age-related macular degeneration

Abstract

Purpose: Validation of the targeting and dose delivery of the IRay low voltage age-related macular degeneration treatment system. Methods: Ten human cadaver eyes were obtained for this study and mounted in the IRay system. Using gel and vacuum, an I-Guide immobilization device was coupled to the eyes and radiochromic film was affixed to the posterior aspect of the globes. Three narrow x-ray beams were delivered through the pars plana to overlap on the predicted nominal fovea. A needle was placed through the center of the film's beam spot and into the eye to register the film and the inner retina. The process was performed three times for each of the ten eyes (30 simulated treatments; 90 individual beams). The globes were dissected to assess the targeting accuracy by measuring the distances from the needles to the fovea. The dose to the fovea was calculated from the radiochromic film. Results: X-ray targeting on the retina averaged 0.6{+-}0.4 mm from the fovea. Repeated treatments on the same eye showed a reproducibility of 0.4{+-}0.4 mm. The optic nerve was safely avoided, with the 90% isodose edge of the beam spot between 0.4 and 2.6 mm from the edge of the optic disk. Measuredmore » dose matched that prescribed. Conclusions: This study provides confidence that the IRay, with an average accuracy of 0.6 mm and a precision of 0.4 mm, can reliably treat most AMD lesions centered on the fovea. With the exception of motion, all sources of error are included.« less

Authors:
; ; ; ; ;  [1];  [2];  [2]
  1. Oraya Therapeutics, Inc., Newark, California 94560 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22096623
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 37; Journal Issue: 2; Other Information: (c) 2010 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ACCURACY; GELS; RADIATION DOSES; RADIOTHERAPY; RETINA; SIMULATION; VALIDATION; VERIFICATION; X RADIATION

Citation Formats

Gertner, Michael, Chell, Erik, Pan, Kuang-Hung, Hansen, Steve, Kaiser, Peter K., Moshfeghi, Darius M., Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44915, and Department of Ophthalmology, Stanford University, Stanford, California 94305. Stereotactic targeting and dose verification for age-related macular degeneration. United States: N. p., 2010. Web. doi:10.1118/1.3291648.
Gertner, Michael, Chell, Erik, Pan, Kuang-Hung, Hansen, Steve, Kaiser, Peter K., Moshfeghi, Darius M., Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44915, & Department of Ophthalmology, Stanford University, Stanford, California 94305. Stereotactic targeting and dose verification for age-related macular degeneration. United States. doi:10.1118/1.3291648.
Gertner, Michael, Chell, Erik, Pan, Kuang-Hung, Hansen, Steve, Kaiser, Peter K., Moshfeghi, Darius M., Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44915, and Department of Ophthalmology, Stanford University, Stanford, California 94305. 2010. "Stereotactic targeting and dose verification for age-related macular degeneration". United States. doi:10.1118/1.3291648.
@article{osti_22096623,
title = {Stereotactic targeting and dose verification for age-related macular degeneration},
author = {Gertner, Michael and Chell, Erik and Pan, Kuang-Hung and Hansen, Steve and Kaiser, Peter K. and Moshfeghi, Darius M. and Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44915 and Department of Ophthalmology, Stanford University, Stanford, California 94305},
abstractNote = {Purpose: Validation of the targeting and dose delivery of the IRay low voltage age-related macular degeneration treatment system. Methods: Ten human cadaver eyes were obtained for this study and mounted in the IRay system. Using gel and vacuum, an I-Guide immobilization device was coupled to the eyes and radiochromic film was affixed to the posterior aspect of the globes. Three narrow x-ray beams were delivered through the pars plana to overlap on the predicted nominal fovea. A needle was placed through the center of the film's beam spot and into the eye to register the film and the inner retina. The process was performed three times for each of the ten eyes (30 simulated treatments; 90 individual beams). The globes were dissected to assess the targeting accuracy by measuring the distances from the needles to the fovea. The dose to the fovea was calculated from the radiochromic film. Results: X-ray targeting on the retina averaged 0.6{+-}0.4 mm from the fovea. Repeated treatments on the same eye showed a reproducibility of 0.4{+-}0.4 mm. The optic nerve was safely avoided, with the 90% isodose edge of the beam spot between 0.4 and 2.6 mm from the edge of the optic disk. Measured dose matched that prescribed. Conclusions: This study provides confidence that the IRay, with an average accuracy of 0.6 mm and a precision of 0.4 mm, can reliably treat most AMD lesions centered on the fovea. With the exception of motion, all sources of error are included.},
doi = {10.1118/1.3291648},
journal = {Medical Physics},
number = 2,
volume = 37,
place = {United States},
year = 2010,
month = 2
}
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