Table 1. Baseline Features of the Study Population.
| Characteristics | MR-HIFU Ablation | MR-HIFU Ablation with BRB Maneuver |
|---|---|---|
| Patients | n = 206 | n = 60 |
| Age (years) | 43.2 ± 4.8 (25–55) | 42.2 ± 5.1 (28–53) |
| Body mass index (kg/m2) | 22.2 ± 2.7 (16.2–30.8) | 21.7 ± 2.5 (16.2–28.1) |
| History of pregnancy | 66.0% (136/206) | 60.0% (36/60) |
| History of full-term delivery | 62.1% (128/206) | 63.3% (38/60) |
| History of Cesarean section | 17.5% (36/206) | 13.3% (8/60) |
| Uterine configuration | ||
| Forward-bent | 93.2% (192/206) | 81.7% (49/60) |
| Backward-bent | 6.8% (14/206) | 18.3% (11/60) |
| Uterine size on screening day (cm) | 12.2 ± 2.7 (7.8–19.5) | 10.3 ± 1.4 (7.8–13.9) |
| Uterine size on treatment day (cm) | 11.9 ± 2.7 (6.8–19.0) | 9.9 ± 1.6 (6.8–14.0) |
| Pretreatment with GnRH agonist | 16.0% (33/206)) | 28.3% (17/60) |
| History of fibroid treatment | 21.8% (45/206) | 26.7% (16/60) |
| Medical therapy* | 11.2% (23/206) | 15.0% (9/60) |
| Myomectomy | 6.3% (13/206) | 10.0% (6/60) |
| Radiofrequency ablation | 1.5% (3/206) | 1.7% (1/60) |
| Uterine fibroid embolization | 1.5% (3/206) | 0% (0/60) |
| Ultrasound-guided HIFU | 1.5% (3/206) | 0% (0/60) |
| Symptom severity score† | 46.1 ± 18.8 (9.4–125) | 49.7 ± 20.8 (9.4–93.8) |
| Number of fibroids treated | 1.9 ± 1.4 (1–8) | 1.8 ± 1.4 (1–6) |
| Fibroids | n = 401 | n = 106 |
| Diameter (cm) | 6.1 ± 3.4 (2.0–16.0) | 5.7 ± 2.1 (2.0–11.6) |
| Type | ||
| Location | ||
| Intramural | 38.7% (155/401) | 35.8% (38/106) |
| Subserosal | 24.9% (100/401) | 26.4% (28/106) |
| Submucosal | 27.7% (111/401) | 27.4% (29/106) |
| Transmural | 8.7% (35/401) | 10.4% (11/106) |
| Signal on T2-weighted MR image‡ | ||
| Type I | 59.9% (240/401) | 61.3% (65/106) |
| Type II | 32.2% (129/401) | 31.1% (33/106) |
| Type III | 8.0% (32/401) | 7.5% (8/106) |
Note.___ Values are given as the mean ± standard deviation; values in parentheses represent ranges. MR, magnetic resonance
*Other than pretreatment with a GnRH agonist
† Transformed to 0–100 [12]
‡ Type I: comparable to skeletal muscle; type II: lower than the myometrium and higher than the skeletal muscle; type III: equal to or higher than the myometrium, based on visual inspection [13]