The effect of deep inspiration breath-hold on tumour oxygenation.
OBJECTIVE
To investigate the influence of deep inspiration breath-hold on the oxygen tension of in-vivo tumours measured using an Eppendorf pO2 histograph.


METHODS
Patients with accessible primary or metastatic tumours > or = 2 cm diameter were entered into a protocol measuring tumour oxygenation with an Eppendorf pO2 histograph during normal breathing (NB) and deep inspiration breath-hold (DIBH). Change in oxygen tension was assessed using the Wilcoxon Signed Ranks test.


RESULTS
Thirty patients were entered in to this protocol. The median maximum tumour dimension was 4 cm. The median of the median pO2 of these tumours was 18 mmHg. Tumours were assessed during NB and DIBH. Oxygen tension measurements along 1-3 pairs of tracks per tumour (median of 2) were obtained. The median number of measurements per track was 30 for NB and 29 for DIBH (range 17-59). In six tumours, the values during NB were significantly higher than during DIBH, whereas, for six other tumours, the relationship was the opposite; for the remaining 18 patients, no significant difference was observed.


CONCLUSIONS
These data show heterogeneity of tumour oxygenation seen with in-situ tumours both at baseline and as a result of DIBH. No systematic change in the Eppendorf pO2 measurements was seen as a result of DIBH; however, the individual tumour responses to DIBH varied dramatically.
Department of Radiation Oncology, Vancouver Cancer Clinic, BC Cancer Agency, University of British Columbia, Vancouver Canada. cparsons@bccancer.bc.ca
C
C
Aquino-Parsons
C R
CR
Ries
A I
AI
Minchinton
Y
Y
D'yachkova
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D001239:Inhalation; D008875:Middle Aged; D009369:Neoplasms / Q000378:metabolism* / Q000532:radiotherapy; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption
D010100:Oxygen