An innovative solution for recurrent cancers.

Cesium-131 has been introduced as a novel treatment option for patients with recurrent gynecological cancer.  The use of Cesium-131 has demonstrated sustained local control in limited studies. 

The short half-life and high energy delivery to the tumor treatment bed allows for efficient targeting of radiation therapy to the tumor and bed, while limited radiation dose to surrounding tissues.

The Cesium-131 radiation treats the tumor directly, with sources that are implanted directly into the tumor, in a single session.  The efficient delivery of radiation at the time of surgery provides the patient with a complete treatment is a single treatment regimen, allowing a fast return to activity.

The treatment is delivered by a multi-disciplinary team that includes surgeons, radiation specialists and a physics team to support the proper radiation dosing and delivery.

Finally, the availability of Cesium 131 provides patients with recurrent disease an additional treatment option when previous treatments may approach limits of acceptable radiation dose following prior radiation treatments.


In the United States, gynecological cancer accounts for an estimated 105,890 cases and 30,890 deaths annually, this is the fourth highest incidence and mortality from cancer in women, according to the American Cancer Society.  Historically, the standard of care for these malignancies included pelvic radiation therapy (RT), either a definitive therapy or in combination with surgery, chemotherapy and/or brachytherapy.  The position of many gynecologic tumor to sensitive surrounding organs (such as the rectum small bowel) requires precise delivery of the radiation to limit toxicity to the nearby organs.  For initial treatment this should not impact patient therapeutic options, however in the case of recurrence, there are limited options for additional radiation.  This often results in radical surgeries or palliative therapies as the only treatment options for recurrent disease.

As an alternative, some clinicians are considering permanent interstitial brachytherapy as an alternative to these more radical approaches.  The targeted nature of the treatment allows for treatment strategies that provide curative treatment for accessible, small volume, recurrent tumors, while minimizing dose to surrounding, health tissues.

Early experience with permanent brachytherapy involved the use of Au198 implants, however, adoption of the technique was limited by concerns about radiation exposure and comfort with implant techniques.  Recently, experiences with Cesium 131 are raising new interest in the use of permanent brachytherapy implants.  Cesium-131 has multiple favorable dosimetric properties for interstitial brachytherapy compared to the initial isotope (Au-198) used for gynecological cancer. (1)

Permanent interstitial brachytherapy with Cesium 131 is an ideal, yet underutilized treatment modality for accessible, small volume gynecological malignancies.

Permanent Cesium-131 interstitial implants are relatively easy to perform and can be used as a safe, effective and potentially curative option in patients with primary disease and in those with locally recurrent disease, whether or not the patient has had previous radiation therapy.

Jonathan Feddock

Assistant Professor, University of Kentucky


1. Wooten CE, Randall M, Edwards J, Aryal P, Luo W, Feddock J. Implementation and early clinical results utilizing Cs-131 permanent interstitial implants for gynecologic malignancies. Gynecol Oncol. 2014 May;133(2):268-73. doi: 10.1016/j.ygyno.2014.02.015. Epub 2014 Feb 17.

2. Feddock J, Aryal P, Wooten C, Randall M.Outpatient Interstitial Implants – Integrating Cesium-131 Permanent Interstitial Brachytherapy into Definitive Treatment for Gynecologic MalignanciesMay–June, 2016, Volume 15, Supplement 1, Pages S93–S94.

3. Okazawa K, Yuasa-Nakagawa K, Yoshimura R, Shibuya H. Permanent interstitial reirradiation with Au-198 seeds in patients with post-radiation locally recurrent uterine carcinoma. J Radiat Res. 2013 Mar; 54(2): 299–306.

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