THE EVALUATION OF BREAST LESIONS USING LEVOVIST.

Louise Baillon(1), Simon Gruenewald(1), Owen Ung(2), George Larcos1.
Departments of Nuclear Medicine & Ultrasound(1) and Surgery(2), Westmead Hospital, Westmead NSW

ASUM'99 - Winner of the ATL Ultrasound Best Sonographer's Research Presentation Award

AIM
The aim of this study was to assess the ability of Levovist (an ultrasound contrast agent) and colour/power Doppler to enhance diagnostic accuracy in breast masses of indeterminate significance on mammography and ultrasound. A particular group of interest were patients with previously treated breast cancer who presented with a recurrent mass.

METHODS
Our study comprised two subgroups. Subgroup A consisted of 11 patients with newly diagnosed lesions while subgroup B consisted of 16 patients with post surgical and radiotherapy lesions. Patients were studied on an Acuson XP-10 or ATL 3000 using a 7MHz or 10MHz linear array transducers. Lesions were measured and their appearance and vascularity determined. An intravenous bolus injection of 8ml Levovist (300mg/ml) was administered whilst scanning the breast lesion in real time using B Mode imaging and colour Doppler. Studies were performed by experienced sonographers and sonologists. An increase in vascularity post Levovist administration was considered suspicious of malignancy. All patients had a fine needle aspiration and/or a core biopsy to obtain a definitive diagnosis.

RESULTS
In subgroup A the 11 patients with a mean age of 57 years (33-78 years) had 13 lesions with a mean lesion size of 1.7cm (1.1-3.0cm). In subgroup B the 16 patients with a mean age of 53 years (36-73 years) had 17 lesions with a mean lesion size of 1.3cm (0.4-2.5cm). In subgroup A, following Levovist, 8 of the 8 benign lesions showed no increase in vascularity. Four of the 5 malignant lesions showed increased vascularity. The one false negative study was histologically diagnosed as a mucinous carcinoma.

In subgroup B, 2 of the 2 malignant lesions demonstrated an increase in vascularity post Levovist injection (Figures 1 & 2). Twelve of the 15 benign lesions showed no change in vascularity, while 3 showed increased vascularity. At histology these 3 false positives were found to be radiation inflammation and fat necrosis.

Figure 1: Malignant lesion before Levovist injection

Figure 2: The same lesion after Levovist injection demonstrating increased vascularity

Subgroup A has -

Subgroup B has -

CONCLUSION
This preliminary data shows that the use of the ultrasound contrast agent Levovist has encouraging results in newly diagnosed breast lesions. However, it is less promising in patients who have previously been treated for breast cancer since radiation inflammation and fat necrosis may mimic cancer recurrence. Newer developments in imaging technology such as harmonic imaging and pulse inversion harmonics may improve the diagnostic accuracy in the future.