A larger percentage of small tumors in the breast are being detected due to effective screening programs and improved
radiological diagnostic methods. For treatment, less invasive methods are preferred which are still radical but also
provide a better aesthetic result. Recently, several ablation techniques have become available to locally ablate tumors in
situ. In this study, the effectiveness of three ablation techniques was compared by imaging the thermal distribution and
temperature mapping in vitro.
The first system (KLS Martin, Trumpf, Germany) uses Nd:YAG laser light delivered through a single diffusing fiber tip
which is positioned direct into the tissue or in a water-cooled needle. The second system (Olympus-Celon, Germany)
uses bipolar Radio Frequency currents between electrodes in a water-cooled needle. The RF system has a temperature
feedback based on tissue impedance to prevent tissue charring. The third system is a focused ultrasound system
developed in the Hospital.
For all three the techniques, the dynamics of temperature gradients around the probe or focus point are visualized using
color Schlieren techniques in a transparent tissue model and recorded using thermocouples. The effective lesion size and
tissue temperatures were determined in in vitro bovine mamma tissue.
All systems were capable to heat tissue volumes up to 3 cm in diameter. The lesion growth dependent on the power
input, temperature gradient around the initial power source and treatment time.
Although the three systems are capable to ablate small mamma carcinoma in situ, they differ in precision, MR
compatibility, invasiveness, practical use and treatment time.
The real clinical effectiveness has to be proven in large patient studies with long term follow up.