Technical Assistance Request, Washington University Medical Center, St. Louis, MO; Authorization to Manipulate Low-Dose Afterloading Brachytherapy Devices

HPPOS-310 PDR-9306250064

See the memorandum from J. E. Glenn to J. A. Grobe dated January 14, 1991.

This memo responses to a TAR from Region III, dated September 26, 1990, regarding an amendment request by Washington University Medical Center, St. Louis, Mo. The licensee requests authorization to perform various operations that require manipulation of cesium-137 sealed sources from a Low-Dose Afterloading Brachytherapy Devices by or under the supervision of a licensee brachytherapy physicist. The request described in a letter from the licensee, dated August 16, 1990, has been reviewed and the following direction is given.

Request 1. The licensee requests that the license be amended to no longer reference a single individual as having authorization to perform installation, replacement and/or exchange of iridium-192 sources, but rather the institutional RSC be authorized to designate a qualified physicist as a brachytherapy physicist and permit this individual to perform or oversee these activities. The licensee also suggests that these activities might be performed by a full-time brachytherapy technologist under the supervision of a brachytherapy physicist.

Response 1. Qualified physicists authorized by the licensee's RSC as brachytherapy physicists must receive training from the manufacturer in the safe performance of the proposed activities. Policy and Guidance Directive FC 86-4, "Information Required for Licensing Remote Afterloading Devices", requires the licensee to submit training for those individuals who perform source exchanges in addition to the training described in 10 CFR 19.12. The license may be amended to authorize the RSC to designate qualified physicists as brachytherapy physicists, authorizing only these individuals to perform the proposed activities, and in conjunction, prohibiting the delegation of these responsibilities to anyone else except brachytherapy physicists.

Request 2. The licensee requests that the license be amended to permit manual removal of cesium-137 sources from the MicroSelectron storage container by a brachytherapy physicist for the purpose of performing quality assurance tests, dose measurements, and visual inspection of the sources as needed to guarantee safe, dosimetrically accurate and mechanically reliable patient treatments.

Response 2. NMSS believes that the request should be denied. We are aware that this institution performs innovative methods of treatment that might require special source configurations which sometime result in increased device "failure" rates; however, troubleshooting on this unit by the licensee should not be authorized. Based on the information submitted, it is not clear what basis the licensee has for proposing activities other than those currently recommended and described by the manufacturer for the purpose of quality assurance. The licensee should not be authorized access to the afterloader device and radioactive sealed sources, other that recommended by the manufacturer for routine calibration and quality control.

Request 3. The licensee requests modification of the license to allow for emergency manual afterloading of MicroSelectron cesium-137 sources into patients whose treatment has been interrupted by failure of the afterloading device.

Response 3. The license may be amended to authorize emergency manual afterloading of MicroSelectron cesium-137 sources into patients whose treatment has been interrupted by machine failure. In addition, in cases where the afterloader device has failed during a patient treatment, the licensee should be required to perform routine operational checks on the unit prior to initiating subsequent patient treatments. This preventative measure may help to identify and reduce the frequency of generic device failures, or those failures not attributed to individual geometric configurations.

It should be emphasized that the emergency manual afterloading procedures proposed by the licensee only be used in patients whose treatment has been interrupted by failure of the remote afterloading device. Since the licensee's emergency nursing procedures require that the brachytherapy physicist and implant resident be called in the event of a detached source in the patient, it is assumed that it is the brachytherapy physicist or implant resident that would perform the manual afterloading of the remote afterloader sources in the event of a machine malfunction. In addition, this responsibility must not be delegated to nurses.

The emergency manual use of remote afterloader sources as proposed by the licensee is being authorized for the medical benefit of the patient. As will be discussed in the following item, we do not propose to authorize the manual use of these remote sources on a routine basis.

Request 4. The licensee requests that the license be amended to permit the use of MicroSelectron Heyman-Simon sources as manual afterloading sources on a routing basis. The licensee states that the sources are restricted to use in the Heyman-Simon applicator supplied by Nucletron and would utilize manual afterloading restraining caps that are also supplied by Nucletron. The justification submitted by the licensee appears to be financially motivated, in that, if they were authorized to use the remote afterloader sources for this purpose, they would be able to avoid purchasing replacement manual brachytherapy sources.

Response 4. NMSS believes that the request should be denied. After discussing the proposed use with the Sealed Source Safety Section of this branch, it is our belief that the licensee intends on routinely using the sources in a manner for which they were not designed. Therefore, in order to evaluate the integrity of the sources and device when used in a manual rather than remote mode, the licensee must submit a request containing the appropriate information necessary for the Sealed Source Safety Section to perform a Custom Source Review.

Regulatory references: 10 CFR 19.12, 10 CFR 35

Subject codes: 1.3, 1.7, 11.1

Applicability: Byproduct Material