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Title: Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

Abstract

Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-{micro}m thick and spaced 100-300 {micro}m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-{micro}{micro}m dose falloff (80-20%) atmore » the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.« less

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
914398
Report Number(s):
BNL-78966-2007-JA
Journal ID: ISSN 0027-8424; PNASA6; TRN: US0802860
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
Proc Natl Acad Sci USA
Additional Journal Information:
Journal Volume: 103; Journal Issue: 25; Journal ID: ISSN 0027-8424
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BRAIN; CENTRAL NERVOUS SYSTEM; GEOMETRY; IMPLEMENTATION; NEOPLASMS; RADIOTHERAPY; SPINAL CORD; SURGERY; SYNCHROTRONS; TARGETS; TOLERANCE; national synchrotron light source

Citation Formats

Dilimanian, F, Zhong, Z, Bacarian, T, Benveniste, H, Romanelli, P, Wang, R, Welwart, J, Yuasa, T, Rosen, E, and Anschel, D. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential. United States: N. p., 2006. Web. doi:10.1073/pnas.0603567103.
Dilimanian, F, Zhong, Z, Bacarian, T, Benveniste, H, Romanelli, P, Wang, R, Welwart, J, Yuasa, T, Rosen, E, & Anschel, D. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential. United States. doi:10.1073/pnas.0603567103.
Dilimanian, F, Zhong, Z, Bacarian, T, Benveniste, H, Romanelli, P, Wang, R, Welwart, J, Yuasa, T, Rosen, E, and Anschel, D. Sun . "Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential". United States. doi:10.1073/pnas.0603567103.
@article{osti_914398,
title = {Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential},
author = {Dilimanian, F and Zhong, Z and Bacarian, T and Benveniste, H and Romanelli, P and Wang, R and Welwart, J and Yuasa, T and Rosen, E and Anschel, D},
abstractNote = {Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-{micro}m thick and spaced 100-300 {micro}m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-{micro}{micro}m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.},
doi = {10.1073/pnas.0603567103},
journal = {Proc Natl Acad Sci USA},
issn = {0027-8424},
number = 25,
volume = 103,
place = {United States},
year = {2006},
month = {1}
}