Letrozole as premedication of high intensity focused ultrasound treatment of uterine fibroids: A retrospective observation study

Wei-Chun Chen; Chia-Chen Hsu; Huei-Jean Huang; Wei-Jen Cheng; Ting-Chang Chang; Hung-Hsueh Chou

doi:10.3389/fmed.2022.1069654

Letrozole as premedication of high intensity focused ultrasound treatment of uterine fibroids: A retrospective observation study

Front Med (Lausanne). 2022 Dec 6:9:1069654. doi: 10.3389/fmed.2022.1069654. eCollection 2022.

Authors

Wei-Chun Chen^{1

2

3

4

5}, Chia-Chen Hsu², Huei-Jean Huang^{2

4}, Wei-Jen Cheng^{6

7

8}, Ting-Chang Chang^{2

4

5}, Hung-Hsueh Chou^{2

4

9}

Affiliations

¹ Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
² Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
³ Department of Obstetrics and Gynecology, New Taipei City Municipal Tucheng Hospital, New Taipei City, Taiwan.
⁴ High Intensity Focused Ultrasound (HIFU) Treatment Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
⁵ College of Medicine, Chang Gung University, Taoyuan, Taiwan.
⁶ Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
⁷ Center for Traditional Chinese Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
⁸ School of Traditional Chinese Medicine, Chang Gung University, Taoyuan, Taiwan.
⁹ School of Medicine, National Tsing Hua University, Hsinchu, Taiwan.

Abstract

Background: No reports on Letrozole as a pretreatment before ablation of uterine fibroid with high intensity focused ultrasound (HIFU), so a retrospective observation study was performed to evaluate the response of different pre-HIFU medication.

Methods: We collected patients with single uterine fibroid receiving HIFU ablation from January 2018 to April 2021. All enrolled patients were classified into three group: group A (no pre-HIFU medication use), group B (Pre-HIFU letrozole use), group C (pre-HIFU gonadotrophin releasing hormone analog, GnRHa). Further associated clinical data and treatment response after HIFU treatment were reviewed and evaluated.

Results: A total of 39 patients including 21, 7, and 11 in group A, B, and C were collected respectively. After pre-HIFU medication, no difference of fibroid volume was found (A: 251.4, B: 360.6, C: 409.4 cm³, p = 0.250), and GnRHa group had significantly larger volume reduction than Letrozole users (38.6% vs. 16.4%, p = 0.007). The incidence of hypoestrogenic symptoms was higher in GnRHa group than in letrozole users (27.3% vs. 0, p = 0.170). GnRHa group had more sonication time (p = 0.001), treatment duration (p = 0.002), and ablated energy (p = 0.001) than group A and B. The treatment efficiency was higher in letrozole group than that in other 2 groups (4.52 vs. 2.39 vs. 2.34 cm³/min, p = 0.050). For patients with fibroid over 10 cm in diameter, letrozole group had even better energy efficiency (p = 0.067), treatment speed (p = 0.007), treatment efficiency (p = 0.001), NPV per energy (p = 0.005), and NPV per sonication (p = 0.004) than other 2 groups.

Conclusion: Letrozole as a pretreatment medication before HIFU treatment might increase the energy efficiency and treatment efficiency of its ablation of uterine leiomyoma, especially for fibroid over 10 cm. Future study of larger patient number is needed to confirm our results.

Keywords: HIFU; gonadotrophin releasing hormone analog; high intensity focused ultrasound; letrozole; uterine fibroid.