We treated 2 patients using a new generation of microwave ablation (MWA) system.
This new product received regulatory approval last November 2016, but this is the first clinical use in Japan.
It is technically almost the same to insert a MWA antenna into the tumor under ultrasound guidance as to place an RFA electrode.
However, the fiberglass antenna shaft, despite a 13 gauge diameter, is a little flexible, making applying force difficult at the time of insertion. In addition, the antenna can move easily during patient breathing because its surface is slick. Thus, we must be more careful to monitor the position of the antenna during the ablation.
On the other hand, being able to ablate a large ablation zone with a single insertion is a major benefit. With RFA, we would puncture 3 to 4 times to completely ablate a tumor of 2.5 cm in diameter. With the new generation of MWA, however, we may achieve complete ablation with a single antenna placement in the central line of the target. Setup and operation of the generator is also simple and there is the advantage with MWA of not having to use return electrodes.
In the future, treatment for tumors greater than 2 cm in size may shift from RFA technology to this new generation of microwave technology.