High Intensity Focused Ultrasound vs. Cryotherapy in the Treatment of Basal Cell Carcinomas and Bowen's Disease in Adults

HIFU vs. CRYO - High Intensity Focused Ultrasound vs. Cryotherapy in the Treatment of Basal Cell Carcinomas and Bowen's Disease - a Randomized Controlled Trial

This prospective, randomized, controlled, and single-blinded non-inferiority clinical trial compare the efficacy and tolerability of high intensity focused ultrasound (HIFU) to standard cryotherapy in the treatment of low-risk basal cell carcinomas (BCCs) and Bowen's disease (BD) in adults. The main questions it aims to answer are:

• Is HIFU an efficient treatment option for BCCs and BD?
• What medical problems do participants get after HIFU?

Researchers will compare HIFU to standard cryotherapy with liquid nitrogen to see if the ultrasound works to treat these local and low-risk non-melanosytic skin cancers.

Participants will:

• Be treated either with HIFU (intervention) or cryotherapy (control).
• Visit the clinic 4 weeks, 1-, 3- and 5 years after the treatment for check-ups, tests and survey questions.

Low-risk BCCs and BD are both local keratinocyctic skin cancers with increasing prevalence and they cause a rising burden to the health care system. In this study we assess the efficacy of HIFU compared to liquid nitrogen cryotherapy between years 2025-2030.

Alltogether 294 patients are recruited based on referrals or from patients attending the clinic, with histologically confirmed BD, superficial BCC or nodular BCC located between neck and knees. 98 tumors of each aforementioned subtypes will be recruited and randomized with 1:1 ratio to HIFU and CRYO - groups. Follow-up appointments are 4 weeks, 1-, 3- and 5 years post treatment.

Inclusion Criteria:

• age 18 years or older at the time of informed consent
• ability to give informed consent and comply with the treatment protocol and follow-up plan
• study lesion located between neck and knees
• one of following histologically confirmed diagnosis: Superficial BCC with maximum diameter of 2.0 cm / Nodular BCC with max. diameter of 1.5 cm / BD with max. diameter of 2.0 cm

Exclusion Criteria:

• Study lesion location in face, head, genitals, hands, or below the knee
• Clinical/dermoscopical/histological feature for high-risk/aggressive BCC
• Clinical/histological sign for hypertrophic BD
• Clinical/dermoscopical/histological feature for Squamous cell carcinoma
• Gorlin Golz syndrome
• Pregnancy or breastfeeding