Archived Policies - Surgery

Microwave Thermotherapy (MTT) for Primary Breast Cancer


Effective Date:02-01-2005

End Date:09-14-2007


Focused microwave phase array thermotherapy (MTT) is considered experimental, investigational and unproven as a treatment of breast cancer.


Focused microwave phase array thermotherapy (MTT) has been investigated as a type of heat therapy for treating either (1) primary breast cancer in conjunction with lumpectomy in patients with early stage breast cancer, or (2) as a cytoreductive technique in conjunction with preoperative chemotherapy in patients with advanced breast cancer.

Microwave applicators are placed on either side of the compressed breast that, when activated, illuminate a large volume of breast tissue. A probe is placed within the breast to monitor the interstitial temperature. The technique is based on the preferential microwave heating that occurs in high-water content breast carcinoma compared to the surrounding lower-water content healthy breast tissues. If successful, the microwave therapy could function similarly to the role of whole breast irradiation therapy after breast-conserving surgery, i.e., by destroying microscopic residual cancer cells. In patients with locally advanced primary breast cancer, MTT may reduce the size of the tumor sufficiently to allow a less invasive surgical procedure to be performed.

Currently, no MTT device that is indicated for the treatment of breast cancer has received approval for marketing from the U.S. Food and Drug Administration (FDA). The Microfocus™ APA 1000 System (Celsion, Columbia, MD) is a device that is currently undergoing clinical trials through the FDA investigational device exemption process (IDE).


A literature search based on the MedLine database revealed limited published data regarding microwave thermotherapy. Gardner and colleagues reported on the results of a phase I and II clinical trial including 10 patients that reported that the technique is technically feasible. The following randomized clinical trials are now ongoing:

Study 102-00-202:  A total of 222 female patients with early-stage primary breast cancer will be randomized (ratio 1:1) either to thermotherapy (at one of two different doses) plus surgery, or surgery alone. The primary endpoints include reduction of tumor cells at surgical margins and reduction of second incision rates due to unclean surgical margins.

Study 102-00-201:  A total of 228 female patients with locally advanced primary breast cancer will be randomized (ratio 1:1) either to chemotherapy plus thermotherapy or chemotherapy alone. The primary endpoints include downsizing from mastectomy to partial mastectomy, and determining the percentage of patients with ≥85% pathological cell death.

This procedure is not supported by evidence in the peer-reviewed medical literature that demonstrates that improvement attainable by MTT for primary breast cancer is attainable outside investigational settings.


Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply. If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.



Medicare Coverage:

Medicare does not have a national position on this service. It is subject to local carrier discretion. Please refer to the local carrier for more information.


Gardner, R.A., Vargas, H.I., et. al. Focused microwave phased array thermotherapy for primary breast cancer. Annals of Surgical Oncology (2002 May) 9(4): 326-32.

Celsion News Release – Breast Cancer 2004. Celsion’s News Releases (2004 November 10) <>.

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