High-Intensity Focused Ultrasound (HIFU) Versus Observation for Low-Grade Squamous Intraepithelial Lesions of Cervix: A Randomized Controlled Trial

The majority of low-grade pre-invasive lesions of cervix (low-grade squamous intraepithelial lesions, LSIL).will regress spontaneously over 2 years and immediate treatment may not be necessary. According to the Hong Kong College of Obstetricians and Gynaecologists (HKCOG), if a low-grade lesion is confirmed by colposcopy and biopsy, the patient can be observed and followed up with HPV testing or co-testing at 12 months, irrespective of age. This randomized controlled study is to determine whether high-intensity focused ultrasound (HIFU) treatment of low-grade pre-invasive lesions of cervix, can cause regression of these lesions in more patients within a specific time when compared to observation as a standard management according to HKCOG Guidelines. All eligible patients will be randomized in a 1:1 ratio into 2 groups: high-intensity focused ultrasound (HIFU) or Observation group. Background information of the patients such as age, parity, body mass index, smoking status and the presence of chronic medical disease will be collected. All patients with cervical HR-HPV status will be tested. Patients randomized into HIFU group will receive HIFU treatment within 2 weeks after randomization. Those randomized into Observation group will have no intervention. All patients will attend follow-up at 6 and 12 months after randomization, during which cervical smear for cytology (with cytopathologists blinded to the treatment group) and HR-HPV testing will be performed. The rate of cytological LSIL regression and HR-HPV clearance rates at 6 and 12 months in both groups will be analyzed. Patients will be referred back to colposcopy clinic for repeat colposcopy if needed according to HKCOG Guidelines. At the 12-month follow-up visit, if referral to repeat colposcopy is not needed, patients will be referred back to their primary care physicians, Department of Health Family Health Service, Family Planning Association or other primary care centres for follow-up cervical smears.