Thermal ablation of the goat mammary gland as a model for post-lumpectomy treatment of breast cancer: preliminary observations.

Int J Hyperthermia. 2009 Feb;25(1):47-55

Authors: Alvarado R Mahon B Valadez C Caufield M Wadhwani S Hambleton C Siziopikou KP Dickler AT Gatta J Dowlatshahi K

BACKGROUND: Partial breast irradiation post-lumpectomy with a balloon bearing a radioactive source in its center is practiced as an alternative to whole breast irradiation in the treatment of breast cancer. The goal is to ablate residual malignant cells within 1 cm radius of the resected lumpectomy margin. We hypothesize that this goal may be achieved with a fluid-filled heated balloon. METHODS: Nubian-cross goats were treated under general anesthesia. The two mammary glands were sequentially bisected and a non-inflated balloon with a heating element was placed in the center of the gland which was re-sutured. Two series of experiments were conducted. In the first 22 goats (44 glands) the balloon was inflated with 5% dextrose to a pressure of 150 mmHg and heated at 87 degrees C over selected time intervals of 1-24 minutes. In the second series (16 glands) the re-programmed device operated at 50-80 mmHg over selected time intervals of 5-20 minutes. The depth of necrosis was histologically determined after sacrificing the goats and excising the glands. RESULTS: In the first series glandular necrosis was noted to extend to a depth of 3.2-9.6 mm for the above heating cycles. Corresponding figures for the second series ranged from 4.7-8.6 mm for treatment times of one minute 'warm up' to 20 minutes of heating at 90 degrees C. The animals exhibited no systemic side effects post-treatment. CONCLUSION: An experimental model describing a thermal technique causing necrosis of the goat mammary gland is described.

PMID: 19219700 [PubMed - indexed for MEDLINE]