Ovarian function during and after curative intracavitary high dose-rate irradiation: steroidal output and morphology

The endocrinological function of the ovary during and after curative intracavitary high dose-rate irradiation has been studied by determining the peripheral plasma levels of P, E₁, E₂, FSH, LH and PROL in 8 patients aged 37 ± 7 yr (± SD). In addition, the concentrations of E₁ and E₂ in ovarian venous blood during the estimated ovulatory phase after irradiation were determined. The functional structure of the ovary was studied histochemically using 3β-hydroxysteroid dehydrogenase (HSD) and ultrastructurally and histologically with routine methods. The results during and after irradiation were compared to those before irradiation. In addition, 28 postmenopausal patients were used as controls.At the end of the irradiation course, which lasted from the premenstrual to the ovulatory phase, 3 out of 4 patients with cervical carcinoma had normal plasma P levels; the menstrual cycles of these patients was previously ovulatory. The normal P levels as well as a rise in E₁ and E₂ concentrations indicate ovulation. During the next menstrual cycle these values and the $\text{E}{}_2\text{E}{}_1$ ratio in peripheral venous blood decreased and the levels of FSH and LH rose to the postmenopausal values. In patients with endometrial carcinoma, the menstrual cycle was anovulatory both before and after radiotherapy; in estrogen and gonadotrophin levels, similar changes were observed as in patients having ovulatory cycles.In ovarian venous blood, the E₂ plasma levels and the $\text{E}{}_2\text{E}{}_1$ ratios were in both groups significantly higher at the time of the second potential ovulatory phase than the corresponding postmenopausal values. As in the postmenopausal women, both E₁ and E₂ levels in irradiated patients were higher in ovarian effluent blood than peripherally. The ovarian/cubital E₁ ratios did not differ between these groups. For E₂, this ratio was, however, significantly higher in irradiated patients than in postmenopausal controls.The morphological findings — both by light and electron microscopy — as well as the enzymehistochemical studies support the chemical results reflecting a decreased yet significant estrogen production in the ovaries after irradiation.