Long-term follow-up post-cryosurgery in a sheep breast model

Area of Science:

• Oncology
• Surgical Innovation
• Regenerative Medicine

Background:

• Ongoing development of cryosurgical devices and techniques for breast cancer treatment.
• Evaluation of long-term outcomes following cryosurgery in preclinical models is crucial for clinical translation.

Purpose of the Study:

• To assess the long-term efficacy and tissue response to breast cryosurgery in a sheep model.
• To compare the healing process and tissue regeneration after cryosurgery versus surgical excision.

Main Methods:

• Utilized a sheep breast model for cryosurgery, followed by long-term observation up to 5 months.
• Employed ultrasound, mammography, and MRI for imaging assessment of the cryotreatment site.
• Conducted histological analysis to evaluate tissue damage and regeneration, comparing single and multiple freeze-thaw cycles.

Main Results:

• Cryotreatment sites were undetectable by imaging modalities (ultrasound, mammography, MRI) at 5 months post-cryosurgery.
• Histology revealed no significant differences between one and three freeze-thaw cycles; characterized by a central injured region and a surrounding transition zone.
• The final cryoinjured region was approximately half the diameter of the initial ultrasound-imaged ice ball, with a 5 mm transition zone.

Conclusions:

• Breast cryosurgery in a sheep model leads to complete tissue regeneration and scar formation within 5 months.
• Surgical excision demonstrates a faster healing process compared to cryosurgery.
• A minimum safety margin of 5 mm is recommended for ultrasound-monitored cryosurgery to account for the cryoinjured and transition zones.