What is MRI Guided HiFU
1. What is the clinical indication of MRI-HIFU?
- MRI-HIFU is indicated for the ablation of uterine fibroids (leiomyomas) in pre-menopausal and peri-menopausal woman who does not want her uterus to be removed.
2. How does MRI-HIFU work?
HIFU or High-Intensity-Focused-Ultrasound uses high-intensity ultrasound waves that are focused into a small area of between 4 – 16mm, to produce heat and energy, which kills the tumor cells. To ensure that this is done accurately, MRI is used, both to localize the area for ablation as well as to monitor the temperature.
- Its Real-time, magnetic resonance image guidance (MRg) allows the treating radiologist to target the fibroid with a high-intensity focused ultrasound (FUS) energy beam.
- Process is called “SONICATION” - ultrasound beam delivered to the target is converted to heat energy.
- Technique relies on heat-induced tissue necrosis (coagulative), which is achieved when the target is heated to a temperature at or beyond 57°C tissue infarction and death
- Normal uterine muscle remains intact following the procedure.
- Principal determinants for procedure duration include size and location of the fibroid.
- Vital to deflect the ultrasound beam away from bowel loops and bone.
3. Which fibroids can be treated?
- All fibroids greater than 3 cm
This is decided on the basis of MRI findings performed when the patient first comes for counseling.
4. Any contraindications?
- The presence of scar tissue and adhesions from previous surgery may create problems and sometimes be a contraindication.
- Technical Issues primarily due to the location of the fibroid in relation to vital structures outside uterus, such as bowel loops, spine (Vertebra) Nerves.
5. Does the fibroid disappear? What happens?
- The fibroid does not disappear. It however shrinks in size leading to a significant reduction in symptoms. Approximately 30-90% ablation is aimed for.
6. What is the pre-procedure preparation?
- Shaving of the pelvic area
- Fasting for 6 hours
7. What is done at the time of the procedure?
- A catheter is placed in the bladder.
- The patient has to lie on her stomach in the MRI scanner with her head out.
- A button is given to the patient to stop the ultrasound beam whenever she feels uncomfortable.
- The team consisting of the doctor and nurse will be in constant touch with the patient.
- It takes 2-4 hours.
8. What happens after the procedure?
- The patient will be kept in the recovery area for 1-2 hours.
- The catheter will be removed.
- On a daily basis for 3 days and then weekly for a month, our doctor or nurse will be in touch with the patient to monitor the progress.
- An MRI will be performed at 1 month, 6 months and 1 year as follow-up
9. To what extent do patient symptoms improve after treatment, especially bleeding?
- As a rule, significant improvement in symptoms is expected within the first three months. This is expected to remain for 3-5 years.
10. What are the known (most common) complications of the procedure?
- It is a safe technique and non-invasive.
- Minor pelvic discomfort and a little pain may occur during the procedure and/or for about 72 hours after.
- There may be a flu-like syndrome approximately 48-72 hours after the procedure, especially if a large volume has been ablated.
- Skin burns and nerve damage are known, but these are extremely rare. We take the utmost care to make sure that these don’t occur.
11. Does the HIFU procedure preserve fertility?
- There is no formal trial that has been done for this. However there is enough anecdotal published data that has shown that women have become pregnant without any problems after the use of MRI-HIFU.
12. Is MR-HIFU cost-effective relative to hysterectomy?
- No surgery
- Back to work from the next day.
- No hospital charges and no ongoing post-surgical problems.