Trial Information

A Safety and Efficacy Study of Intra-Operative Radiation Therapy (IORT) Using the Xoft® Axxent® eBx™ System at the Time of Breast Conservation Surgery for Early Stage Breast Cancer

The rationale for IORT as the sole radiation therapy is:

Favorable preliminary results in feasibility, safety and efficacy outcomes: Accelerated
Partial Breast Irradiation (APBI) is an accepted alternative to whole breast irradiation
following breast-conserving surgery for early stage breast cancer. Intra-Operative
Radiation Therapy (IORT) is a form of APBI that allows radiation to be delivered directly to
the open tumor bed following Breast Conservation Surgery (BCS). After 4 years of follow-up,
IORT has shown equivalent disease control rates as whole breast irradiation.

Direct and timely radiation to the tumor bed: Radiation is delivered at to the target
tissue (adjacent to the resection margins at the time of lumpectomy). It avoids treatment
delays and eliminates weeks or months of post-surgical radiation therapy during which
residual cancer cells might proliferate. An in vitro study showed that un-irradiated wound
fluid stimulated the growth of breast cancer cells while irradiated wound fluid did not.
Each month of delay in radiation treatment is associated with a 1% increase in the
recurrence rate. Huang, et al., found a 5.8% recurrence rate in patients who received WBRT
within 8 weeks of BCS compared with a 9.1% recurrence rate in patients who started
radiotherapy 9-16 weeks after BCS.

Increased patient treatment compliance compared to conventional radiation therapy: Suitable
early stage breast cancer patients are able to complete their breast cancer radiotherapy
treatment at the time of BCS, which offers a convenient and potentially life-saving benefit
to patients who might otherwise omit radiation therapy if it required lengthy travel or time
commitments. In addition, healthcare resources, including both personnel and facilities,
will be conserved by eliminating the overhead cost of multiple patient visits, eliminating
waiting time for patients, and consolidating therapy to one visit combined with the surgical
procedure.

Available Technology: The Xoft Axxent controller, x-ray source, and balloon applicator are
cleared by the United States Food and Drug Administration (FDA) to deliver brachytherapy
treatments using high dose rate x-ray radiation. The Xoft Axxent System has been used to
treat breast cancer subjects using a multi-fraction APBI technique on an outpatient basis as
part of two multi-center studies. The Xoft Axxent System enables the Radiation Oncologist to
administer electronic brachytherapy without the use of a radioactive isotope in minimally
shielded rooms. Characteristics of the Xoft System that make it well-suited for IORT include
its portability and low energy photons, allowing for minimal shielding during the radiation
therapy.

This protocol has been developed to further study the use of the Xoft Axxent eBx System in
the delivery of IORT for subjects with early-stage breast cancer. The Xoft Axxent eBx
System will be used according to the United States Food and Drug Administration (FDA) 510(k)
cleared labeling; therefore, the use of the technology in this study is considered on-label
and within the scope of the FDA cleared indication.