This time may vary from five to 30 seconds beyond the initial time for formation of the ice field. Liquid nitrogen spray methods for lesions of different sizes include the timed spot freeze or direct spray technique, the rotary or spiral pattern, and the paintbrush method Figure 3. Skin lesions often can be treated in a single session, although some Liquid nitrogen on precancerous facial skin several hingarian nud pics. Basal cell skin cancer. The gel is usually applied twice daily for 2 or 3 months. Cryotherapy is used most often for pre-cancerous conditions such as actinic keratosis and for small basal cell and squamous cell carcinomas. The cryoprobe is applied directly to the lesions.