Monochromatic Minibeams Radiotherapy: From Healthy Tissue-Sparing Effect Studies Toward First Experimental Glioma Bearing Rats Therapy

Journal Article · Thu Mar 15 00:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.09.013· OSTI ID:22056196

Deman, Pierre ^[1]; Vautrin, Mathias ^[1]; DOSIsoft, Cachan ^[2]; Edouard, Magali ^[1]; Stupar, Vasile ^[1]; Bobyk, Laure; Farion, Regine ^[1]; Elleaume, Helene ^[1]; Remy, Chantal; Barbier, Emmanuel L ^[1]; Esteve, Francois ^[1]; Adam, Jean-Francois ^[1]

---

1. INSERM, Grenoble (France)
2. France

Purpose: The purpose of this study was to evaluate high-dose single fraction delivered with monochromatic X-rays minibeams for the radiotherapy of primary brain tumors in rats. Methods and Materials: Two groups of healthy rats were irradiated with one anteroposterior minibeam incidence (four minibeams, 123 Gy prescribed dose at 1 cm depth in the brain) or two interleaved incidences (54 Gy prescribed dose in a 5 Multiplication-Sign 5 Multiplication-Sign 4.8 mm{sup 3} volume centered in the right hemisphere), respectively. Magnetic resonance imaging (MRI) follow-up was performed over 1 year. T2-weighted (T2w) images, apparent diffusion coefficient (ADC), and blood vessel permeability maps were acquired. F98 tumor bearing rats were also irradiated with interleaved minibeams to achieve a homogeneous dose of 54 Gy delivered to an 8 Multiplication-Sign 8 Multiplication-Sign 7.8 mm{sup 3} volume centered on the tumor. Anatomic and functional MRI follow-up was performed every 10 days after irradiation. T2w images, ADC, and perfusion maps were acquired. Results: All healthy rats were euthanized 1 year after irradiation without any clinical alteration visible by simple examination. T2w and ADC measurements remain stable for the single incidence irradiation group. Localized Gd-DOTA permeability, however, was observed 9 months after irradiation for the interleaved incidences group. The survival time of irradiated glioma bearing rats was significantly longer than that of untreated animals (49 {+-} 12.5 days versus 23.3 {+-} 2 days, p < 0.001). The tumoral cerebral blood flow and blood volume tend to decrease after irradiation. Conclusions: This study demonstrates the sparing effect of minibeams on healthy tissue. The increased life span achieved for irradiated glioma bearing rats was similar to the one obtained with other radiotherapy techniques. This experimental tumor therapy study shows the feasibility of using X-ray minibeams with high doses in brain tumor radiotherapy.

• OSTI ID: 22056196
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 82, Issue 4; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BLOOD
BLOOD FLOW
BLOOD VESSELS
BRAIN
DIFFUSION
DOSIMETRY
GLIOMAS
IRRADIATION
LIFE SPAN
MONOCHROMATIC RADIATION
MONTE CARLO METHOD
NMR IMAGING
PERMEABILITY
RADIATION DOSES
RADIOTHERAPY
RATS
SURVIVAL TIME
X RADIATION