Ovarian transposition before radiotherapy in cervical cancer patients: functional outcome and the adequate dose constraint

BACKGROUND: The data regarding a transposed ovary in intensity-modulated radiotherapy (IMRT) are not sufficient. Here we aim to investigate the adequate dose constraint of ovarian transposition before radiotherapy in cervical cancer patients. METHODS: This was a retrospective analysis of 118 patients with cervical cancer who received a radical hysterectomy and ovarian transposition before pelvic irradiation from April 2012 to July 2017. A total of 105 patients underwent IMRT with a limited radiation dose to the ovaries; 48 of these patients received unilateral ovary limitation, while 57 received bilateral ovary limitations. Patient follow up regarding sex hormone levels (estrogen [E2], follicle stimulating hormone [FSH]) and menopausal symptoms was completed one year after their radiation therapy. RESULTS: A total of 41 out of 105 patients (39.0%) who underwent IMRT with a limited radiation dose to the ovaries preserved their normal ovarian function. The cutoff dose of comparatively lower side ovarian maximum dose was 9.985Gy and the cutoff of mean dose was 5.32Gy. The optimal dose–volume constrains to ovaries was V5.5 < 29.65%. Age ≤ 38 (P = 0.001) was an independent predictors of ovarian function, while limited ovarian side numbers were excluded. CONCLUSION: Using IMRT, preservation of ovarian function was possible when the limited dose was as low as possible to the ovaries regardless of bilateral or unilateral limitation to the ovaries. The ovarian maximum dose of less than 9.985Gy, the mean dose less than 5.32Gy and V5.5 < 29.65% could be better at preventing ovarian dysfunction. Patients younger than 38 years old were more likely to keep normal ovarian function while limited ovarian side numbers did not appear to exert an obvious effect.