The response of human tumors to carbogen breathing, monitored by Gradient-Recalled Echo Magnetic Resonance Imaging

Int J Radiat Oncol Biol Phys. 1997 Oct 1;39(3):697-701. doi: 10.1016/s0360-3016(97)00326-x.


Purpose: Gradient-Recalled Echo (GRE) Magnetic Resonance Imaging (MRI), which detects changes in blood vessel deoxyhaemoglobin content, has been investigated as a noninvasive monitor of changes in human tumor oxygenation and blood flow, in response to carbogen (95% O2, 5% CO2) breathing.

Methods and materials: GRE images (TE = 60 ms, TR = 200 ms, alpha = 40 degrees, 256[2] matrix) were acquired from 31 patients with primary and metastatic disease, prior to and during carbogen breathing. Three patients underwent a follow-up examination after radiotherapy.

Results: Seventeen out of 34 tumors showed enhanced image intensity, consistent with an improvement in tumor oxygenation and blood flow, while 11 showed no response; 6 studies were technical failures. In one patient a metastatic node that had eluded orthodox investigation was visualized. A reduction in response was observed in the three patients studied postradiotherapy.

Conclusion: This method, which can be performed on a standard clinical MRI instrument, provides a noninvasive measurement of tumor response to oxygenation/blood flow modification. In principle, this should enable the clinician to optimize treatment protocols, such as carbogen breathing, for individual radiotherapy patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Carbon Dioxide / administration & dosage*
  • Carcinoma, Squamous Cell / blood supply
  • Carcinoma, Squamous Cell / metabolism
  • Humans
  • Lymphatic Metastasis / diagnosis
  • Magnetic Resonance Imaging / methods*
  • Neoplasms / blood supply*
  • Neoplasms / metabolism*
  • Oxygen / administration & dosage*
  • Oxygen / metabolism*


  • Carbon Dioxide
  • carbogen
  • Oxygen