Regional tumor oximetry: 19F NMR spectroscopy of hexafluorobenzene.

Abstract

PURPOSE:

An accurate method for monitoring oxygen tension (pO2) of individual tumors could be valuable for optimizing treatment plans. We have recently shown that 19F nuclear magnetic resonance (NMR) spin-lattice relaxometry of hexafluorobenzene (HFB) provides a highly sensitive indicator of tumor oxygenation. We have now refined the methodology to provide enhanced precision, and applied the method to investigate dynamic changes in tumor oxygenation.

METHODS AND MATERIALS:

Dunning prostate adenocarcinoma R3327-AT1 was grown in the form of pedicles on the foreback of male Copenhagen rats. When the tumors reached approximately equal to 1 cm diameter, HFB (20 microl) was administered, either centrally or peripherally, by direct intratumoral (i.T) injection. Local pO2 was determined using pulse-burst saturation recovery (PBSR) 19F NMR spectroscopy on the basis of the spin-lattice relaxation rate, R1.

RESULTS:

Interrogation of the central region of tumors provided typical values in the range pO2 = 1.4-6.4 mmHg, with a typical stability of +/-2 mmHg over a period of 20 min, when rats breathed 33% O2. Altering the inhaled gas to oxygen or carbogen (95% O2/5% CO2) produced no significant change. In contrast, interrogation of tumor periphery indicated baseline pO2 in the range 7.9-78.9 mmHg. Altering inspired gas produced significant changes (p < 0.0001) with O2 or carbogen, although the change was generally greater with carbogen. In each case, pO2 returned to baseline within 16 min of returning the inhaled gas to baseline.

CONCLUSION:

We believe this method provides a valuable new approach with the requisite precision and accuracy to investigate tumor pO2.

• Authors: S Hunjan, R P Mason, A Constantinescu, P Peschke, E W Hahn, P P Antich
• Journal: International journal of radiation oncology, biology, physics (Int J Radiat Oncol Biol Phys) Vol. 41 Issue 1 Pg. 161-71 (Apr 01 1998) ISSN: 0360-3016 [Print] United States
• PMID: 9588931 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Fluorocarbons
• Carbon Dioxide
• Fluorine
• carbogen
• hexafluorobenzene
• Oxygen

Topics

• Animals
• Carbon Dioxide
• Fluorine
• Fluorocarbons (metabolism)
• Magnetic Resonance Spectroscopy (methods)
• Male
• Oxygen (metabolism)
• Partial Pressure
• Prostatic Neoplasms (metabolism)
• Rats