Ultrasound guided pO 2 measurement of breast cancer reoxygenation after neoadjuvant chemotherapy and hyperthermia treatment

Abstract

The objective of this study was to determine whether neoadjuvant chemotherapy in combination with hyperthermia (HT) would improve oxygenation in locally advanced breast tumours. The study describes a new optimized ultrasound guided technique of pO 2 measurement using Eppendorf polarographic oxygen probes in 18 stage IIB-III breast cancer patients. Prior to treatment, tumour hypoxia (median pO 2 < 10 mmHg) was present in 11/18 patients (average median pO 2 = 3.2 mmHg). Seven patients had well oxygenated tumours (median pO 2 of 48.3 mmHg). Eight patients with hypoxic tumours prior to treatment had a significant improvement ( p = 0.0008) in tumour pO 2 after treatment (pO 2 increased to 19.2 mmHg). In three patients, tumours remained hypoxic (average median pO 2 = 4.5 mmHg). The advantages of the ultrasound guided pO 2 probe are in the accuracy of the Eppendorf electrode placement in tumour tissue, the ability to monitor electrode movement through the tumour tissue during the measurement and the ability to avoid electrode placement near or in large blood vessels by using colour Doppler imaging. The results of this preliminary study suggest that the combination of neoadjuvant chemotherapy and hyperthermia improves oxygenation in locally advanced breast tumours that are initially hypoxic.