Oxygen Tension of Cervical Carcinoma during the Early Phase of External Irradiation

Abstract

The oxygen tension of tumor tissue and normal surrounding tissue was measured during the early phase of fractionated external irradiation, in 76 patients with carcinoma of the uterine cervix in the clinical stage II. Beckman's modifed Clark micro electrode was used.

The first examination was performed before treatment, the second and third examinations after a mean tumor dose of 775 and 1,700 R (Victoreen), respectively, the radiation being delivered by 31 and 33 MeV betatrons. A group of 29 patients without invasive cancer served as controls. Measurements at several sites were performed at each examination, and average values for tumor and normal tissue were calculated. In normal tissue the mean oxygen tension at each examination was about 2.5 times higher than in tumor tissue. During therapy there was a slight rise in mean oxygen tension, statistically significant between the first and third examinations, both for tumor and normal tissue.

Key Words:

• Oxygen tension
• Clark micro electrode
• cervix cancer
• radiotherapy
• oxygen effect
• radiosensitivity