The influence of carbogen breathing on tumour tissue oxygenation in man evaluated by computerised p02 histography

Falk, S.; Ward, R.; Bleehen, N. M.

doi:10.1038/bjc.1992.386

Cited by 120 publications

(45 citation statements)

References 16 publications

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“…Each individual was therefore assessed separately, and nine out of ten showed significant rises in tumour oxygen distribution. As in our previous study of carbogen breathing alone (Falk et al, 1992), we found a wide range of change in median p02 with elimination of some but not all values of p02 below 5 mmHg. The rises in median pO2 tended to be of greater magnitude than in the previous study and were sustained until 15 min and over in the majority of our patients, whereas in the previous study a fall in median tumour pO2 occurred in all patients between 12 and 18min.…”

Section: Dimsciosupporting

confidence: 58%

Carbogen breathing with nicotinamide improves the oxygen status of tumours in patients

Laurence

Ward²,

Dennis³

et al. 1995

Br J Cancer

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Section: Dimsciosupporting

confidence: 58%

Carbogen breathing with nicotinamide improves the oxygen status of tumours in patients

Laurence

Ward²,

Dennis³

et al. 1995

Br J Cancer

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“…The time-course of the response was in the range of previous studies using carbogen to oxygenate tumors (41,47), although longer breathing periods (60 min) have been reported to be required in EMT6 human tumor xenografts (47). In normal brain, a plateau in PtO 2 in response to changes in oxygen or CO 2 is reached within 5 minutes (27).…”

Section: Oxygen Response With Carbogen Breathingmentioning

confidence: 60%

Changes in oxygenation of intracranial tumors with carbogen: A BOLD MRI and EPR oximetry study

Dunn

O’Hara

Wadghiri

et al. 2002

Magnetic Resonance Imaging

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Purpose: To examine, using blood oxygen level dependent (BOLD) MRI and EPR oximetry, the changes in oxygenation of intracranial tumors induced by carbogen breathing. Materials and Methods:The 9L and CNS-1 intracranial rat tumor models were imaged at 7T, before and during carbogen breathing, using a multi-echo gradient-echo (GE) sequence to map R 2 *. On a different group of 9L tumors, tissue pO 2 was measured using EPR oximetry with lithium phthalocyanine as the oxygen-sensitive material. Results:The average decline in R 2 * with carbogen breathing was 13 Ϯ 1 s -1 in the CNS-1 tumors and 29 Ϯ 4 s -1 in the 9L tumor. The SI vs. TE decay curves indicate the presence of multiple components in the tumor. Tissue pO 2 in the two 9L tumors measured was 8.6 Ϯ 0.5 and 3.6 Ϯ 0.6 mmHg during air breathing, and rose to 20 Ϯ 7 and 16 Ϯ 4 mmHg (mean Ϯ SE) with carbogen breathing. Significant changes were observed by 10 minutes, but changes in pO 2 and R 2 * continued in some subjects over the entire 40 minutes. Conclusion:EPR results indicate that glial sarcomas may be radiobiologically hypoxic. Both EPR and BOLD data indicate that carbogen breathing increases brain tumor oxygenation. These data support the use of BOLD imaging to monitor changes in oxygenation in brain tumors.

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“…A breathing time dependence of the improvement in tumour oxygenation of clinical tumours. as measured by Po2 distribution using microelectrodes, has also been observed (Falk et al, 1992); the greatest improvement in oxygenation was seen after 8-12 min breathing and it decreased as breathing continued. This suggests that similar compensation mechanisms may be operating in human tumours.…”

Section: Resultsmentioning

confidence: 78%

Perfusion changes in the RIF-1 tumour and normal tissues after carbogen and nicotinamide, individually and combined

Honess¹,

Bleehen²

1995

Br J Cancer

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Summnu.aThe strategy of combining carbogen breathing and nicotinamide to overcome chronic and acute hypoxia respectively is being evaluated clinically. The effects of both agents individually and in combination on relative perfusion of 400-700 mm3 RIF-I tumours and normal tissues were measured by 'Rb extraction.Carbogen breathing alone for 6 min increased relative tumour perfusion by 50-700,<0 compared with control at flow rates of 50 to 200 ml min-'. but the effect was lost at 300 ml min-'. All flow rates also produced similar increases in relative perfusion of lung, of between 36% and 58%. and smaller increases in skin, of between 200 and 3400. The minimum breathing time at 150mlmin-' to produce a significant increase in relative tumour perfusion was 4.5 min. and the effect was maintained up to 9 min. Nicotinamide alone at 1000mgkg-' 60min before assay did not alter relative tumour perfusion. Comparing the combination of nicotinamide with 6 min carbogen breathing at 150 ml min-with carbogen breathing alone showed no difference in relative tumour perfusion: increases were of 36% and 42% respectively. Nicotinamide-induced alterations in microcirculation associated with reduction of acute hypoxia have therefore not been detected by 'Rb extraction. The perfusion-enhancing effect of carbogen in this tumour is probably an important component of its radiosensitising ability. in addition to its known ability to increase the oxvgen-carrving capacity of the blood. and should be taken into consideration in clinical studies.

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The influence of carbogen breathing on tumour tissue oxygenation in man evaluated by computerised p02 histography

Cited by 120 publications

References 16 publications

Carbogen breathing with nicotinamide improves the oxygen status of tumours in patients

Carbogen breathing with nicotinamide improves the oxygen status of tumours in patients

Changes in oxygenation of intracranial tumors with carbogen: A BOLD MRI and EPR oximetry study

Perfusion changes in the RIF-1 tumour and normal tissues after carbogen and nicotinamide, individually and combined

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