Is High-Intensity Focused Ultrasound (HIFU) a viable treatment option for a female patient of reproductive age with an intramural myoma?

HIFU for Intramural Myoma in Reproductive-Age Women

MR-guided High-Intensity Focused Ultrasound (MRgFUS/HIFU) is a viable but limited treatment option for intramural myomas in reproductive-age women, though myomectomy remains the preferred first-line surgical approach when fertility preservation is desired. 1

Treatment Efficacy and Limitations

HIFU achieves approximately 50% fibroid volume reduction at 1 year and 40% reduction at 24 months, but viable tumor cells persist in 26% of specimens after treatment. 1 This incomplete ablation represents a significant limitation compared to complete surgical excision.

Current Restrictions on HIFU Use

HIFU is currently restricted to patients meeting specific criteria: 1

• Fewer than 6 leiomyomas
• Total fibroid volume <900 cm³
• Intramural location is technically feasible but requires careful patient selection

The procedure is noninvasive but time-intensive, with each treatment session taking several hours to complete. 1

Fertility Considerations: Critical Limitations

The evidence for HIFU in women desiring pregnancy is severely limited and concerning. 1

Pregnancy Outcome Data

Registry data from 54 pregnancies in 51 women who underwent HIFU shows: 1

• Only 41% resulted in live births
• 28% ended in spontaneous abortion (nearly double the general population rate)
• 43% of pregnancies had associated complications
• 93% of deliveries that occurred were at term (only 1 preterm birth at 36 weeks)

These outcomes are substantially worse than myomectomy, which shows pregnancy rates of 85% with live birth rates of 65%. 1

Guideline Recommendations for Fertility Preservation

The ACR 2024 guidelines state that for reproductive-age patients with fibroids desiring pregnancy, laparoscopic or open myomectomy should be offered as the first therapeutic choice. 1 HIFU is listed as "usually appropriate" but with the critical caveat that there is insufficient medical literature to definitively support its use in this population. 1

The panel noted controversy regarding HIFU for fertility preservation, and the evidence quality is far inferior to that supporting myomectomy. 1

Comparative Treatment Options

Myomectomy (Preferred for Fertility)

• Pregnancy rates: 85% 1
• Live birth rates: 65% 1
• Miscarriage rate: 14% (comparable to general population) 1
• Recurrence risk: 27% at 10 years 2
• Requires 2-3 month healing period before attempting pregnancy 2

Uterine Artery Embolization (UAE)

• Should NOT be first-line in women seeking pregnancy 1
• Increased miscarriage rate of 35% 1
• Increased cesarean section rate of 66% 1
• Increased postpartum hemorrhage rate of 13.9% 1

When HIFU May Be Considered

HIFU can be considered in specific scenarios: 1

• Poor surgical candidates who cannot tolerate myomectomy
• Patients who refuse surgery despite counseling
• As adjunctive therapy before hysteroscopic resection for large submucosal components 3, 4
• When combined with hysteroscopic procedures for Type 2 myomas >4cm 4

Documented Complications

Serious complications have been reported with HIFU, particularly in unmarried women with large fibroids: 5

• Rapid myoma enlargement post-treatment (2 cases)
• Heavy vaginal bleeding (1 case)
• Skin burns requiring further research 6

Clinical Algorithm for Decision-Making

For reproductive-age women with intramural myomas:

1. If fertility desired: Offer laparoscopic or open myomectomy as first-line 1

   • HIFU only if patient refuses surgery or has prohibitive surgical risk
   • Counsel extensively on limited pregnancy data (41% live birth rate) 1

2. If fertility NOT desired: Multiple equivalent options 1

   • Medical management trial first (OCPs, tranexamic acid, SPRMs) 2
   • HIFU, UAE, or myomectomy are all "usually appropriate" 1
   • Hysterectomy for definitive treatment 2

3. HIFU-specific requirements before proceeding: 1

   • Confirm <6 fibroids total
   • Confirm total volume <900 cm³
   • Ensure patient understands incomplete ablation risk (26% viable cells remain)
   • Counsel on limited long-term efficacy data

Critical Pitfalls to Avoid

• Do not offer HIFU as equivalent to myomectomy for fertility preservation - the pregnancy outcomes are significantly inferior 1
• Do not use HIFU for large fibroid burdens (>6 fibroids or >900 cm³ volume) 1
• Recognize that 50% volume reduction does not equal complete treatment - viable cells persist in 26% of cases 1
• Avoid HIFU in patients with unrealistic expectations about single-treatment cure rates
• Screen carefully for huge fibroids - complications including rapid enlargement have been documented 5