Microwave ablation to treat bone tumors by using a double slot antenna: A modelling study

This work present a new microwave double slot antenna designed specifically to treat, with thermal ablation, bone tumors. Different levels of input power were analyzed to know its performance. 5 W and 10 W of constant power and a variable input power (8 W - 3 W) were applied for 15 min. A 3D model, solved by the finite element method, was developed to analyze the effectiveness of the antenna. First, the electromagnetic simulations were done and the specific absorption rate (SAR) was calculated. The SAR was used as an input to the thermal models. The volumes of tissue under hyperthermia, ablation and vaporization, and other parameters were calculated to know the performance of the antenna. 5 W and a variable input power show the highest volumes of tissue under hyperthermia (26.79 cm
³
and 38.14 cm
³
, respectively) and ablation ranges (19.12 cm
³
and 15.11 cm
³
, respectively); while the vaporization volumes were keep as low as possible (0.007 cm
³
and 1.56 cm
³
). 10 W generates up to 4.03 cm
³
of tissue under vaporization which can produce a mismatch in the MW equipment. The effectiveness of the antenna to treat bone tumors was proved by using either low or variable input power applied for times up to 15 min.