Microbeam radiation therapy

Laissue, Jean A.; Lyubimova, Nadia; Wagner, Hans-Peter; Archer, David W.; Slatkin, Daniel N.; Michiel, Marco Di; Némoz, Christian; Renier, M.; Brauer, Elke; Spanne, P.; Gebbers, Jan-Olef; Dixon, Keith; Blattmann, H.

doi:10.1117/12.368185

Cited by 81 publications

(63 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1, 2, 7, and 11), (ii) suckling rat cerebellum (150 Gy; ref. 3), (iii) piglet cerebellum (600 Gy; ref. 4), (iv) duckling embryo brain (160 Gy; ref.…”

mentioning

confidence: 99%

Interlaced x-ray microplanar beams: A radiosurgery approach with clinical potential

Dilmanian

Zhong²,

Bacarian³

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

175

214

View full text Add to dashboard Cite

Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25-to 90-m thick and spaced 100 -300 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°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 ؋ 3.4 ؋ 3.4 mm 3 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-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.

show abstract

“…1, 2, 7, and 11), (ii) suckling rat cerebellum (150 Gy; ref. 3), (iii) piglet cerebellum (600 Gy; ref. 4), (iv) duckling embryo brain (160 Gy; ref.…”

mentioning

confidence: 99%

Interlaced x-ray microplanar beams: A radiosurgery approach with clinical potential

Dilmanian

Zhong²,

Bacarian³

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

175

214

View full text Add to dashboard Cite

show abstract

“…At the ESRF the center-to-center distances between beams range from 100 to 400 µm in MRT and it is 1200 µm in MBRT. The preclinical studies in MRT indicate a remarkable healthy tissue sparing capability [10,11,12,13,14,15] and the ablation of highly aggressive tumours in several animal models [16,17,18,19,20,21,22]. In MBRT, the first preclinical studies indicate that minibeams still keep (part) of the healthy tissue sparing capability observed in MRT [9,23].…”

Section: Introductionmentioning

confidence: 96%

Synchrotron Radiation Therapy from a Medical Physics point of view

Prezado

Adam

Berkvens

et al. 2010

AIP Conference Proceedings

View full text Add to dashboard Cite

On the possibilities of x-ray phase contrast microimaging by coherent high-energy synchrotron radiation Review of Scientific Instruments 66, 5486 (1995) Abstract.Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development: Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT).The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

show abstract

“…1 Experimentally discovered at the Brookhaven National Laboratory 2 and soon afterwards studied at the European Synchrotron Radiation Facilities 3,4 it was shown to have the extraordinary ability of ablating brain tumors while sparing normal tissue in a variety of animals. 5 The absorbed dose threshold for tissue damage using micrometer-width beams was on the order of 10 3 Gy, orders of magnitude higher than that for broad beam radiation.…”

Section: A Microbeam Radiation Therapy (Mrt)mentioning

confidence: 99%

“…5 The absorbed dose threshold for tissue damage using micrometer-width beams was on the order of 10 3 Gy, orders of magnitude higher than that for broad beam radiation. [4][5][6][7] Synchrotron microbeams are generally 25-75 μm in width and spaced 100-200 μm center to center. 6 Studies have shown normal tissue sparing effect is preserved at up to ∼700 μm beam width 8 as long as the valley doses are kept under the threshold values.…”

Section: A Microbeam Radiation Therapy (Mrt)mentioning

confidence: 99%

Physiologically gated microbeam radiation using a field emission x‐ray source array

et al. 2014

View full text Add to dashboard Cite

Purpose: Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. Methods: The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic c films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only during a portion of the mouse respiratory cycle when there was minimum motion. Parallel planes of microbeams with 12.4 Gy/plane dose and 900 μm pitch were delivered. The microbeam profiles with and without gating were analyzed using γ -H2Ax immunofluorescence staining. Results: The phantom study showed that the respiratory motion caused a 50% drop in PVDR from 11.5 when there is no motion to 5.4, whereas there was only a 5.5% decrease in PVDR for gated irradiation compared to the no motion case. In the in vivo study, the histology result showed gating increased PVDR by a factor of 2.4 compared to the nongated case, similar to the result from the phantom study. The full width at tenth maximum of the microbeam decreased by 40% in gating in vivo and close to 38% with phantom studies. Conclusions:The CNT field emission x-ray source array can be synchronized to physiological signals for gated delivery of x-ray radiation to minimize motion-induced beam blurring. Gated MRT reduces valley dose between lines during long-time radiation of a moving object. The technique allows for...

show abstract

Microbeam radiation therapy

Cited by 81 publications

References 0 publications

Interlaced x-ray microplanar beams: A radiosurgery approach with clinical potential

Interlaced x-ray microplanar beams: A radiosurgery approach with clinical potential

Synchrotron Radiation Therapy from a Medical Physics point of view

Physiologically gated microbeam radiation using a field emission x‐ray source array

Contact Info

Product

Resources

About