[Studies on oxygen partial pressure in tumor tissue under radiotherapy and thermoradiotherapy].

PURPOSE

Detection of radiation resistant hypoxic cells in poorly vascularized regions of tumors could facilitate selection of therapeutic schedules for the combination of radiotherapy and hyperthermia.

PATIENTS AND METHODS

In 29 patients (9 breast carcinomas, 8 soft tissue sarcomas, 8 lymph node metastases of head and neck cancers and 4 different other tumors) the oxygenation status was examined before, during and after radio- and partially thermoradiotherapy. It was registered using a needle electrode under local anesthesia. The pO2-values obtained from about 100 to 200 sites of an individual tumor were displayed as histograms (Eppendorf-pO2-Histograph, Hamburg).

RESULTS

Hypoxic tissue areas (pO2 < 5 mm Hg) was found more in sarcomas (10.2%) than in lymph node metastases of head and neck cancers (5.8%) and breast carcinomas (3.3%). We observed in the course of therapy increasing pO2 values (reoxygenation) only partially in the groups of breast carcinomas and cervical lymph node metastases, decreasing in the soft tissue sarcomas.

CONCLUSIONS

In future the selection of patients for hyperthermia could be done on the base of pO2-measurements.