Comparison of the efficacy of focused ultrasound at different focal depths in treating vulvar lichen sclerosus.

Objective: This study aimed to compare the efficacy and safety of focused ultrasound (FU) at different focal depths in treating vulvar lichen sclerosus (VLS).

Methods: A retrospective study was conducted on 84 patients with VLS. Among them, 43 cases were treated with FU at a focal depth of 2.5 mm and 41 cases at a focal depth of 4.0 mm. Therapeutic time, treatment energy, postoperative efficacy, complications and recurrence rates were compared.

Results: No statistically substantially differences in age, disease course, history of immune system diseases, lesion size and severity of symptoms were found between the two groups. All patients successfully received FU therapy. No significant difference in curative rate was observed between the two groups at 3, 6 and 12 months after FU therapy. At 12 months after FU therapy, the recurrence rate of the experimental group (FU treatment at 2.5 mm focal depth) was lower than the control group (FU treatment at 4.0 mm focal depth) (7.0% vs 24.4%,  = 0.027). The experimental group was treated for a shorter period of time [22.69 ± 0.64 (min) vs 24.93 ± 0.72(min),  = 0.022] and at a lower dose[5,026.05 ± 148.00(J) vs 5,484.26 ± 160.60(J)  = 0.039].

Conclusion: Compared with that at the routine focal depth (4.0 mm), FU therapy at a low treatment depth (2.5 mm) can achieve a similar therapeutic effect but lower recurrence rate, therapeutic time and treatment energy. This work provides insight into the optimization of clinical protocols.