The mean oxygen saturation for deep (A) and superficial (B) tumours. No significant time-dependent changes or differences in oxygen saturation between muscle and tumour tissues in the deep tumour group (A) were observed. In the superficial tumour group (B), there was a constant oxygen saturation level, with a significant difference between tumour and muscle tissues 30 min after TM-ILP. At this point, the oxygen saturation of the tumour was significantly less than that of the muscle; this difference was highly significant (P=0.001). This effect was already gone by the next measurement (4 h after TM-ILP), and the values returned to the baseline values within the first 24 h after TM-ILP. In terms of the time-dependent changes, the decrease in tumour oxygenation from before TM-ILP to 30 min after TM-ILP did exhibit a trend; however, because of the high variance in the values before ILP, this decrease was not significant (P=0.139). The increase from 30 min after TM-ILP to 1 day after ILP was highly significant (P=0.001).