Misadministrations in diagnostic nuclear medicine

Frequently asked questions by the health professionals

» What types of misadministration could occur? 
» What are the main causes of misadministration of radiopharmaceuticals? 
» What primary actions should be taken in case of a misadministration? 
» Shall I report an incident of misadministration even if it did not hurt the patient? 
» An example of accidental exposure in diagnostic nuclear medicine. 

» What types of misadministration could occur?

Misadministration means giving the radiopharmaceutical to the wrong patient, giving the wrong radiopharmaceutical or wrong activity to the patient, or unjustified examination of pregnant or lactating female patients. Another type of misadministration is to use the wrong route of administration, which includes complete extravascular injections that can result in very high absorbed exposure at the injection site especially if the volume is small, the activity is high, and the radiopharmaceutical has a long retention time. The definition of wrong activity should be made locally. In general, a variation of ±25% from the prescribed activity is regarded as acceptable in diagnostic applications.

» What are the main causes of misadministration of radiopharmaceuticals?

• Communication problems (e.g. insufficient communication, improper labelling of vials and syringes); 
• Busy environment, distraction; 
• Not knowing local rules; 
• Lack of training in emergency situations; 
• Responsibilities not clearly defined; 
• Inefficient or missing quality assurance (including audits to reveal deficiencies and procedures to deal with emergency situations). 

In order to avoid future accidents it is important to learn from previous ones. The initiating event and the contributing factors can always be identified. This information provides material that should be used to prevent future accidents. This is achieved by having an efficient reporting system and a programme for continuous education and training.

» What primary actions should be taken in case of a misadministration?

• Immediately use all available means to minimize any adverse effects; 
• Inform responsible nuclear medicine physician; 
• Inform patient and referring physician; 
• Calculate dose; 
• Indicate corrective measures; 
• Implement measures; 
• Submit report to the head of the department, to the radiation protection committee and, if required, to the regulatory authority; 
• Inform all staff of the accident/incident and the corrective measures implemented. 

» Shall I report an incident of misadministration even if it did not hurt the patient?

Yes. In order to avoid future accidents, it is important to learn from previous ones. The initiating event and the contributing factors can always be identified. It is necessary to have an efficient reporting system and a programme for continuous education and training. Furthermore, according to the IAEA International Basic Safety Standards, registrants and licensees shall promptly investigate an incident. The investigation should be done as soon as possible and a written description of the incident should be prepared including:

• a description of the incident by persons involved; 
• methods used to estimate the radiation absorbed doses and organ doses received; 
• the subsequent medical consequences for those exposed; 
• conclusions drawn from the evaluation of the incident and recommendations on how to prevent a recurrence. 

» An example of accidental exposure in diagnostic nuclear medicine.

A 43-year-old female patient was scheduled for a thyroid scan. She called the department in the morning and told the technologist that she was trying to get pregnant but there was no evidence at the moment that she was. She also wanted to discuss radiation risks and the justification of the examination. The technologist misunderstood the patient and thought she did not want to have the examination due to radiation risks in general. The technologist read the request and persuaded the patient to have the examination. Later, it appeared that the patient was in a very early stage of pregnancy.

According to the local rules of the department, this patient should be regarded as pregnant until otherwise proven. The technologist was not aware of this rule. It is beyond the responsibility of the technologist to discuss justification of an examination. That should be done by the nuclear medicine specialist.