110 O - Magnetic resonance imaging guided minimally invasive treatment of breast cancer

Abstract

Interstitial laser photocoagulation (ILP) is a recently developed, minimally invasive technique of local tumour destruction within solid organs. It current limitation is the lack of an optimal imaging technique to demonstrate treatment effects. This study was designed to assess the role of breast MR (magnetic resonance) imaging in the guidance of ILP for the minimally invasive treatment of primary breast cancer. Thirty patients with symptomatic breast cancer diagnosed by cytology underwent ILP using a single fibre (n = 20) and four fibres (n = 10) prior to surgical excision. MR imaging was performed using a contrast enhanced T1W 3D FLASH sequence before and after laser treatment. Real time MR imaging of laser treatment was performed in 7 patients. Following resection the extent of disease, size of laser burn and the extent of residual tumour were correlated with the MR images. Per-procedural and delayed MR images accurately showed the extent of laser induced necrosis and residual viable tumour. The correlation coefficent (MR v Histopathological analysis) for the laser burn diameter and residual tumour was 0.90 and 0.89 respectively. In conclusion, post-contrast MR images can accurately define the extent of both laser induced necrosis and residual viable tumour following ILP treatment of breast cancer.