Figure 1.

Study design for assessing effects of injection rate and ethyl cellulose concentration on therapeutic efficacy in vivo. Squamous cell carcinomas were induced in the hamster cheek pouch through topical application of DMBA 3X per week until tumors formed and reached a volume of 100 mm³ (approximately 20 weeks). Tumors were then injected with 50 µL of either ethanol or 3% ethyl cellulose-ethanol solution at a rate of 0.1, 1.0, 10 or 100 mL/hr. After ablation, tumor volume was measured at 1, 2, 4, and 7 days after treatment. For tumors that were still present after 7 days, repeat ablations were performed; these were treated as independent ablations if tumor volume had increased for two consecutive days after day 7.