The Xoft® Electronic Brachytherapy (eBx®) System® is designed to simplify the radiation therapy process and make it more accessible to patients who are suitable candidates for vaginal brachytherapy. While reducing the number of required treatments, eBx® delivers a targeted prescribed dose of radiation directly to the site where cancer recurrence is most likely, minimizing exposure to healthy tissue such as the bladder and rectum (Reduced Dose to Bladder and Rectum).
As an alternative to radionuclide-based HDR brachytherapy, the Xoft, Inc. technology will meet the standard of care set by Iridium 192. The standard of care begins with the surgical resection of the primary tumor through hysterectomy and bilateral salpingo-oophorectomy (TAH/BSO) (removal of the uterus, ovaries and tubes on both sides) whenever technically feasible. The procedure is often combined with complete surgical staging, including lymphnode removal or sampling to determine if the cancer has spread to pelvic or para-aortic lymphnodes. This additional surgical step can be performed when the health status of the patient allows a more invasive procedure and the facility can provide the extent of care postoperatively.
About 75% of endometrial cancer patients are considered early stage patients in which the cancer is still confined to the uterus and in which the majority of recurrences can be found in the vaginal cuff area (adjacent to the surgical site). Adjuvant radiotherapy has contributed to a three- to four-fold reduction in recurrence rates in early stage endometrial cancer patients. Postoperative radiotherapy typically consists of external beam radiation therapy, vaginal brachytherapy or a combination thereof.
If surgical staging reveals no involvement of lymphnodes or if the cancer is considered low-risk, the treatment regimen can be less aggressive and external radiation can be replaced by vaginal cuff brachytherapy in selected cases. Additionally, external beam radiation therapy requires daily doses over a course of 3–5 weeks, whereas vaginal brachytherapy consists of a total of 3–5 fractions, typically delivering 4–7 Gy once per week.
eBx® is administered under the direction of a radiation oncologist who will determine the amount of radiation needed. It is delivered on an outpatient basis once a week for 3–5 weeks in a non-shielded room. During radiation therapy, the portion of the vaginal applicator that remains outside the vagina will be connected to an Xoft controller. The patient is prepared with a flexible X-ray shield that is draped over the abdomen. A miniaturized X-ray source will travel through the applicator into the vagina, administering radiation. The X-ray source will remain in the applicator and deliver radiation for about 3–10 minutes. The positioning of the X-ray source and the dose per fraction are determined in the treatment plan. The X-ray source can easily then be turned off and withdrawn. No radiation device will remain in the vagina between treatments or after the final treatment.
All statistics in this report are based on SEER incidence and NCHS mortality statistics: http://seer.cancer.gov/statfacts/html/corp.html?statfacts_page=corp.html