EP27.05: Sonographic changes in the size of endometriotic nodules and endometriomas during hormonal therapies

To compare the sonographic changes in the size of endometriotic nodules and endometriomas after 12-month treatment with dienogest (DNG) or norethisterone acetate (NETA). This prospective study included patients with rectovaginal endometriotic nodules (RVN), RVN infiltrating the rectosigmoid, endometriotic nodules infiltrating the bladder or endometrioma, who received one of the following therapies: DNG (2 mg/day; Visanne, Bayer Pharma AG, Berlin, Germany) or NETA (2.5 mg/day; Primolut-Nor, Bayer Pharma AG, Berlin, Germany). The volume of the endometriotic nodules or of the endometriomas was measured by virtual organ computer-aided analysis (VOCAL, GE Healthcare, USA) at baseline and after 6 and 12 months of treatment. 41 and 49 women with RVN, 24 and 35 with RVN infiltrating the rectosigmoid, 6 and 9 with endometriotic nodules infiltrating the bladder, and 74 and 82 with endometriomas received a 12-month treatment with DNG or NETA, respectively. The volume of all the types of nodules and of the endometriomas significantly decreased at 6- and 12-month follow-up with both the therapies (p < 0.001 for all the comparisons). No difference was reported in the percentage decrease in the volume of the nodules and of the endometriomas between patients treated with DNG compared with those treated with NETA (p > 0.05 for all the comparisons). Both 6- and 12-month administration of DNG or NETA reduced the volume of RVN, RVN infiltrating the rectosigmoid, endometriotic nodules infiltrating the bladder and endometriomas. Furthermore, the two compounds caused a similar percentage decrease in the volume of the different type of endometriotic lesions and of the endometriomas.