Effect of Hyperoxygenation on Tissue pO{sub 2} and Its Effect on Radiotherapeutic Efficacy of Orthotopic F98 Gliomas

Journal Article · Mon Nov 15 00:00:00 EST 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2010.05.045· OSTI ID:21438057

Khan, Nadeem ^[1]; Mupparaju, Sriram M.S. ^[1]; Hekmatyar, Shahryar K ^[2]; Huagang, Hou; Lariviere, Jean P; Demidenko, Eugene ^[1]; Gladstone, David J ^[3]; Kauppinen, Risto A ^[2]; Swartz, Harold M ^[1]

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1. EPR Center for Viable Systems, Dartmouth Medical School, Hanover, New Hampshire (United States)
2. Biomedical NMR Research Center, Dartmouth Medical School, Hanover, New Hampshire (United States)
3. Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States)

Purpose: Lack of methods for repeated assessment of tumor pO{sub 2} limits the ability to test and optimize hypoxia-modifying procedures being developed for clinical applications. We report repeated measurements of orthotopic F98 tumor pO{sub 2} and relate this to the effect of carbogen inhalation on tumor growth when combined with hypofractionated radiotherapy. Methods and Materials: Electron paramagnetic resonance (EPR) oximetry was used for repeated measurements of tumor and contralateral brain pO{sub 2} in rats during 30% O{sub 2} and carbogen inhalation for 5 consecutive days. The T{sub 1}-enhanced volumes and diffusion coefficients of the tumors were assessed by magnetic resonance imaging (MRI). The tumors were irradiated with 9.3 Gy x 4 fractions in rats breathing 30% O{sub 2} or carbogen to determine the effect on tumor growth. Results: The pretreatment F98 tumor pO{sub 2} varied between 8 and 16 mmHg, while the contralateral brain had 41 to 45 mmHg pO{sub 2} during repeated measurements. Carbogen breathing led to a significant increase in tumor and contralateral brain pO{sub 2}; however, this effect declined over days. Irradiation of the tumors in rats breathing carbogen resulted in a significant decrease in tumor growth and an increase in the diffusion coefficient measured by MRI. Conclusions: The results provide quantitative measurements of the effect of carbogen inhalation on intracerebral tumor pO{sub 2} and its effect on therapeutic outcome. Such direct repeated pO{sub 2} measurements by EPR oximetry can provide temporal information that could be used to improve therapeutic outcome by scheduling doses at times of improved tumor oxygenation. EPR oximetry is currently being tested for clinical applications.

• OSTI ID: 21438057
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 78, Issue 4; Other Information: DOI: 10.1016/j.ijrobp.2010.05.045; PII: S0360-3016(10)00788-1; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ANOXIA
BRAIN
CARBON DIOXIDE
ELECTRON SPIN RESONANCE
GLIOMAS
GROWTH
INHALATION
MIXTURES
NMR IMAGING
OXYGEN
PARTIAL PRESSURE
RADIOTHERAPY
RATS
RESPIRATION
ANIMALS
BODY
CARBON COMPOUNDS
CARBON OXIDES
CENTRAL NERVOUS SYSTEM
CHALCOGENIDES
DIAGNOSTIC TECHNIQUES
DISEASES
DISPERSIONS
ELEMENTS
INTAKE
MAGNETIC RESONANCE
MAMMALS
MEDICINE
NEOPLASMS
NERVOUS SYSTEM
NERVOUS SYSTEM DISEASES
NONMETALS
NUCLEAR MEDICINE
ORGANS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIOLOGY
RESONANCE
RODENTS
THERAPY
THERMODYNAMIC PROPERTIES
VERTEBRATES