Targeting Deep Tumors with Microwaves

The Technology
Adaptive Phased Arrays


The Missile Defense Connection
In the early days of SDIO, Dr. Alan Fenn of the Massachusetts Institute of Technology Lincoln Laboratory designed and developed an adaptive phased-array (APA) microwave antenna in an electromagnetically quiet, non-reflecting chamber to simulate space-based radar transmission. The APA algorithms are similar to those used for adaptive optics in astronomy. Augustine Cheung, an engineer interested in the medical capabilities of the APA technology, licensed the APA technology and set out to test its capabilities in the treatment of cancer.

The Commercial Application
Dr. Cheung’s company, Cheung Laboratories, eventually became Celsion Corporation, which developed a device, the Microfocus 1000™, for the purposes of eradicating tumors by deep, focused microwave heating. This device received a pre-market approval from the Food and Drug Administration in 1997. The principal advantage of APA-based heating is that the clinician can focus microwave energy on tumors and avoid unwanted heat in normal tissue, because APA technology can “null” or cancel out microwave radiation of normal, healthy tissue.

Thermal ablation of tumors is not new, but only surface or near-surface tumors can be treated with currently available devices. The APA approach is unique in being able to heat deep inside the body without heating the skin or surrounding healthy tissue. Celsion went on to develop other heating platforms, using radio frequency instead of microwaves, but kept APA on the back burner while it pursued new thermal therapies for prostatic hyperplasia and liver cancer. Throughout the development of these related thermal technologies, Dr. Cheung also explored the possibility of using APA in the treatment of breast cancer, both alone and in combination with chemotherapy.

In 2006, Dr. Cheung bought the APA-related assets of Celsion Corporation and created a new company, Celsion (Canada), to pursue microwave heating of breast tumors. His new company, Celsion (Canada), will continue this pursuit. Clinical trials were set to begin in late 2006 at centers in the United States, Canada, and possibly China. Locations lined up in the United States include the University of Oklahoma Health Sciences Center (Oklahoma City, OK), Harbor-UCLA Medical Center (Torrance, CA), and St. Joseph Comprehensive Breast Center (Orange, CA).

Two studies have been published detailing the safety and efficacy of APA microwave heating of breast tumors, both appearing in the Annals of Surgical Oncology. These studies verified the basic utility of APA microwave heating.

* For more information, please visit the Summer '06 Issue of the MDA TechUpdate.