TG-100 Risk Management

What is TG-100 covering

Application of Risk Analysis Methods to Radiation Therapy Quality Management

How is risk defined in TG-100

1. Occurrence: How can something go wrong?

2. Detectability: How likely is that to happen?

3. Severity: What consequences would result?

How is quality defined in TG-100

1. Aspects which serve to meet the needs of patients considering:

   1. Medical,

   2. Psychological, and

   3. Economic goals.

2. Meeting standards of practice.

3. Freedom from errors and mistakes.

What failure modes are define din TG-100

1. Errors:

   1. Acts of Commission - doing something that should not have been done.

   2. Acts of Omission - not doing something that should have been done.

2. Mistakes - failures that result from incorrect plans (that is, even if the plan was followed perfectly, a failure would result).

3. Violations - intentional failure to follow proper procedure.

   1. Well-intentioned shortcuts and/or

   2. Sabotage.

4. Events - the propagation of the failure through the entire process.

5. Near event - a detected failure which would have resulted in a compromised treatment (close calls, near misses, and good catches).

9 major causes of failure in RT

1. Human Failure

2. Lack of Standardized Procedures

3. Inadequate Training

4. Inadequate Communication

5. Hardware/Software Failure

6. Lack of Resources

7. Design Failure

8. Inadequate Commissioning

9. Defective Materials/Tools

Quality control

procedures that help achieve a desired level of quality.

Quality Assurance

procedures that help demonstrate that the desired level of quality has been achieved and maintained.

reactive approaches to safety

1. These approaches are employed once a failure is identified.

2. Helps minimize risk of patient harm for future patients.

3. The process of identifying the failure mode in a reactive approach is the root cause analysis (RCA).

proactive approaches to safety

1. Attempt to detect failure modes before they manifest.

2. The following sections go into further detail on the TG-100 philosophy of prospective risk assessment.

general proactive procedure for safety

1. Detailed process mapping is carried out.

2. Failure Modes and Effects Analysis (FMEA) is performed by a team.

   1. Weak points are identified.

   2. Weak points are scored for:

      1. Occurrence,

      2. Severity, and

      3. Detectability.

   3. A Risk Priority Number (RPN) is obtained.

3. Fault Tree Analysis.

4. Mitigation strategies are developed.

   1. The RPN is used to prioritize QA/QC tasks.

   2. Process improvement is performed, first, for those areas with higher RPN numbers.

   3. This is continued through all identified areas of quality improvement.

Explain what a Risk priority number is and how it is scored

1. During the FMEA for a failure mode, a numerical value is assigned to three major parameters:

   1. O (Occurrence) - This describes the probability that a specific cause will result in the failure mode.

   2. S (Severity) - This describes the degree of the impact of the failure mode if it was not detected and/or corrected.

   3. D (Lack of Detectability) - This describes the likelihood that a failure would not be detected (not to be confused with detectability).

2. For these parameters, a value is assigned ranging from 1 to 10.

3. These three parameters are then multiplied together to give the so-called Risk Priority Number (RPN).

4. How to Score O:

   1. A score of 1 means that failure is unlikely (< 1 in every 10,000).

   2. A score of 10 means that failure likelihood is large (~ 1 in every 20).

5. How to Score S:

   1. A score of 1 means no danger (example: minor inconveniences).

   2. A score of 10 means catastrophic consequences (example: patient death resulting from failure).

6. How to Score D:

   1. A score of 1 means that the failure mode is very detectable (only 1 in every 10,000 failures would go unnoticed).

   2. A score of 10 means that the failure mode is very difficult to detect (4 out of 5 failures would go unnoticed).

 

In general what is FEMA

1. The FMEA process goes through each step and attempts to determine:

   1. What could fail.

   2. How it could fail.

   3. The likelihood of failure.

   4. How detectable is the failure.

   5. Impact of the failure.

2. In general, FMEA is useful for developing quality management strategies to help counter specific failure modes.

In general what is fault tree analysis

1. Evaluates how failures propagate through a process.

2. Helps identify mitigating strategies.

3. In general, the FTA is useful for determining the relative importance of certain steps of the radiotherapy process

what order should you tackle faults according to TG-100

  TG-100 recommends beginning this task by tackling the faults with the highest RPN score first as these will give you the highest return on your investment.