Potential for contamination during removal of radioactive seeds from surgically excised tissue.

The purpose of this study was to determine whether the use of a scalpel or electrocautery to remove radioactive sealed sources ("seeds") from surgically excised tissue could damage the seed and cause it to leak its radioactive contents. Attempts were made to cut or burn Oncura Model 6711 non-radioactive seeds while in pig muscle or on a stainless steel plate. Additionally, one active 125I seed was purposely charred using pressure with an electrocautery knife to see whether the casing could be damaged. Electron microscopy scanning was performed on the dummy seeds to determine if the integrity of the metal casing had been compromised. Two types of leak tests were performed on the active seed to verify the presence or absence of loose contamination. The seed casing was not damaged from either use of a scalpel or electrocautery when the seed was in tissue. The active seed was not found to be leaking after applying pressure with an electrocautery knife while the seed was on a stainless steel plate. We conclude that removal of active Model 6711 seeds from surgically excised tissue can be done safely with a scalpel or electrocautery because constant, firm pressure cannot be applied to the seed. This is likely true for seeds made of similar materials.

Protection of research subjects with emphasis on protocols involving radiation.

Approval by an institutional review board (IRB) or human studies committee must be obtained prior to conducting human subject research. Historically this was not the case, and human subjects were injured as a result. Because there has been and still remains an inevitable conflict of interest for researchers, instititions that perform human research must follow regulations designed to protect human subjects contained in the Code of Federal Regulations, if the research is federally funded. Two federal agencies provide oversight for IRB activities: the Food and Drug Administration (FDA) and a National Institutes of Health Office for Human Research Protection (OHRP), formerly the Office for Protection from Research Risks (OPRR). These agencies are charged with the implementation of rules related to ethical and legal obligations of researchers and their institutions. The institution's role, by means of an IRB, is to adhere to principles of the Belmont Report and to set forth ethical principles, policies, and procedures for protecting the rights and welfare of human subjects. The researchers' role is to conduct their research ethically while maximizing benefits and minimizing harm. Studies involving radiation exposure of human subjects add another level of risk that must be evaluated by an IRB with assistance of a radiation expert or radiation safety committee (RSC). This paper will look at regulatory aspects of human research, IRB responsibilities overall and as they relate to radiation exposure of subjects, and the role of the RSC.

Benefits and safety of CT fluoroscopy in interventional radiologic procedures.

PURPOSE: To determine the benefits and safety of computed tomographic (CT) fluoroscopy when compared with conventional CT for the guidance of interventional radiologic procedures. MATERIALS AND METHODS: Data on 203 consecutive percutaneous interventional procedures performed with use of CT fluoroscopic guidance and 99 consecutive procedures with conventional CT guidance were obtained from a questionnaire completed by the radiologists and CT technologists who performed the procedures. The questionnaire specifically addressed radiation dose measurements to patients and personnel, total procedure time, total CT fluoroscopy time, mode of CT fluoroscopic guidance (continuous versus intermittent), success of procedure, major complications, type of procedure (biopsy, aspiration, or drainage), site of procedure, and level of operator experience. RESULTS: The median calculated patient absorbed dose per procedure and the median procedure time with CT fluoroscopy were 94% less and 32% less, respectively, than those measurements with conventional CT scanning (P <.05). An intermittent mode of image acquisition was used in 97% of the 203 cases. This resulted in personnel radiation dosimetric readings below measurable levels in all cases. CONCLUSION: As implemented at the authors' institution, use of CT fluoroscopy for the guidance of interventional radiologic procedures markedly decreased patient radiation dose and total procedure time compared with use of conventional CT guidance.

Radiation safety role in institutional disaster planning.

United States Nuclear Regulatory Commission (NRC) materials license applicants (non-nuclear power) must submit spill procedures with their application. While our counterparts in the nuclear power industry historically have concerned themselves with disaster drills and evacuation plans as a result of fire, explosion, or an act of terrorism, other licensees are looking only at minor spills of unsealed radioactive material and only at tile radiation hazard. Beyond NRC regulations, various oversight and accrediting organizations require, or at a minimum encourage, a written disaster plan outlining actions to be taken for events likely to occur in the region of the institution. Some of these organizations require drills to practice implementation of the written plan. On 5 May 1999, Mayo Clinic performed a wide-scale disaster drill involving Rochester City and Olmsted County response organizations, and several Mayo Clinic departments. Planning took several months; the drill took approximately three hours. Participants gathered at several meetings post-drill for "debriefing" sessions to discuss successes, areas for improvement, and lessons learned. There were three overriding lessons learned: critical responders need special identification to allow access to the disaster site; initial victim surveys are for gross contamination only; and access to the potentially contaminated disaster site might take weeks or months following a real event.

Reorganization and consolidation of a safety program.

Prior to 1990, the Mayo Safety Program consisted of several autonomous functions, one of which was Radiation Safety. Consolidation and enhancement of these programs began in 1990 with safety coordinators (e.g., health physicists, industrial hygienists, ergonomists) reporting to one safety director who reports to a vice president level administrator. In 1995, the hierarchical structure was replaced with self-directed work teams. These teams have team leaders who replaced conventional work unit supervisors and a Human Resources (HR) Liaison who is responsible for HR issues including time keeping and 360 degrees performance reviews. A Steering Team, consisting of team leaders was established to create a strategic plan, set program goals, and hold teams accountable. In 1997, processes were evaluated and redesigned through an operational restructuring method called process mapping; process mapping is a tool used in reengineering. Value added to the safety program as a result of these efforts includes more program ownership by Safety staff as demonstrated by increased motivation, increased interest in success of the entire safety program, and increased participation in team planning and management. In addition, some economies of scale have been achieved through cross-functional teams.

Hand dose measurements in interventional radiology.

Measurements of radiation dose to the hand were conducted using TLD ring badges for individual interventional radiology cases. Results from over 30 examinations (including transhepatic cholangiograms and biliary and nephrostomy procedures) conducted by four radiologists using identical equipment show an average hand dose of 1.5 mGy (150 mrad) per procedure. Hand dose varied inversely with distance from the patient. Due to variable hand positions during clinical examinations, fluoroscopic time was not found to be a good indicator of hand dose.

Bioassay and laboratory survey scheduling based on radioisotope inventory.

Bioassay and laboratory survey schedules can be generated using a radioisotope inventory program. This paper discusses the use of laboratory activity, past performance and operational factors for laboratory survey frequency determination, and use of laboratory activity for bioassay scheduling. Mayo Clinic has recently instituted both applications with the use of a computer. Initial results indicate general acceptance of the concept by our radiation workers, an 18% increase in laboratory surveys performed, and a 21% decrease in the total number of bioassays performed annually.