BACKGROUND: Radiofrequency ablation (RFA) is an emerging minimally invasive technique for breast cancer treatment.There are two different needle designs.One is to deploy a series of arrays to allow an even distribution of heat within the tumor.A new design is a straight needle with continuous infusion of cold saline to prevent charring and ensure continuous heat delivery.We report the first comparative study using two different needles for ablation of breast cancer.METHODS: Chinese patients with breast cancer less than 2 cm were prospectively recruited.Multifocal tumor was excluded.RFA was performed under general anesthesia following sentinel node biopsy.Sequential allocation was used.In the first group, tumor was ablated by using the LeVeen needle.Cool-tip needle was used in the subsequent group.The tumor was then resected.Tumor viability was assessed by nicotinamide adenine dinucleotide-diaphorase (NADH) staining.Complete ablation rate was compared.Evidence of thermal damage to the skin was also assessed.RESULTS: Twenty patients were recruited.Mean tumor size was 14 mm.Complete ablation rate was the same (90%versus 89% for the Cool-tip and the LeVeen, respectively).Cool-tip has a shorter ablation time when compared with LeVeen (12 versus 28 min), and the Cool-tip needle was found to be easier to insert.There was no visible skin bum after RFA.CONCLUSIONS: Cool-tip and LeVeen systems had the same efficacy in ablation of breast cancer, but Cool-tip was easier to insert and had a shorter ablation time.