Velimir Karadza, MSc, radiation therapist, lecturer University of Applied Health Sciences Zagreb Zagreb, Croatia Member of radiation oncology safety and quality committee

 

Introduction

The radiation therapy environment is constantly changing. New technology advances such as artificial intelligence and automisation are changing the activities of preparation and treatment within radiotherapy. This also influences the content and performance of the quality checks that are required of our processes.

This document aims to address how we can meet these challenges through explanations of basic tools and to highlight webinars that are on offer.  

Preface

“First, do no harm” is one of the basic principles of medicine. Considering the nature of radiation, this principle is essential in radiation therapy. Radiotherapy uses high doses of radiation to kill tumour cells as part of medical treatment for oncology patients. Since high doses are harmful to surrounding healthy tissue as well, the process of radiotherapy must provide safe and quality treatment to patients to avoid adverse events. This is achievable only through the use of a systematic approach and continuous effort through the application of quality assurance (QA) and quality control (QC) programmes that have been developed over many years by institutes, associations and societies in this field.
This document is meant to serve as a guide for radiotherapy groups to establish their own local quality management systems. It can also help them find other documents and resources that are of use in creating local QA/QC protocols and safety procedures.

 

Considerations during the setting-up of local protocols

Although every local setup is different, all guidelines/protocols should always comply with:

• (inter)national laws and regulations;
• systems in the hospital/department ;
• equipment provider instructions; and
• best practice.

Local specificity should be taken into account when the protocol is being designed:

• the equipment and resources that are available;
• staff composition and education; and
• their roles and responsibilities.

 

Prospective tools

When a new workflow is introduced, or the current workflow is changed in a way that introduces new risks, it is recommended that a prospective analysis be performed. The goal of prospective analytic tools is to anticipate, assess and manage potential risk.

If new technology is introduced, prospective analysis is mandatory according to the medical device regulations.

Different prospective tools are available with which to perform failure modes and effects analysis (FMEA).

 

Failure modes and effects analysis

A good FMEA analysis is built on two pillars: the multidisciplinary team and the FMEA scoring table. The multidisciplinary team must contain representatives of all professions that are included in each step of the process. These individuals must be experienced and able to anticipate and assess the potential risk. Their expertise combined with that of other team members must provide a complete analysis from different points of view. The quality of the input from each team member and their professional contribution has a direct impact on the quality of the analysis. First, the multidisciplinary team must list all the potential risks that can occur in the observed part of the process. Each of these risks is to be assessed through the use of an FMEA scoring table.

https://www.ihi.org/resources/Pages/Tools/FailureModesandEffectsAnalysisTool.aspx

 

Process mapping and flowcharting

The design of hardware and software that are used to deliver radiotherapy has reached a high level of commonality and it incorporates many safety mechanisms that prevent errors [2]. However, this does not automatically result in the unification of workflow design across different sites. Workflows are highly customised due to variability in the way that processes are performed, and this is a source of risk and uncertainty. Each workflow of radiotherapy treatment must be performed in a safe environment.

Fault tree analysis

The use of this tool helps practitioners to analyse and detect the root cause of potential risk. When such a risk is identified, corrective measures can be undertaken and safety mechanisms put in place.

Fault tree analysis (FTA) is a top-down approach through which an event or failure mode is analysed. It is applied to work to discover the true cause of the failure and to identify risk-control measures. FTA evolved in the aerospace industry during the 1960s. The symbols used in it were originally used in electronic logic diagrams. The use of FTA enables the application of a systematic approach that is sufficiently flexible to enable analysis of a variety of factors, including human interactions. It is used in risk analysis to provide estimates of fault probabilities and to identify single faults and common-cause faults that result in hazardous situations or failures [3].

FTA is a technique used to estimate the frequency of occurrence of a hazardous incident (called the top event) through a logic model of the failure mechanisms of the system. The analysis is initialised through the selection of an undesired top event and then the sequence of events is traced back to the possible cause, which may be one of several occurrences such as a component failure, or human error. The analysis proceeds systematically to identify the sub-events that are the immediate precursors to the top event, the immediate precursors to the sub-events, and so on, until the basic events that are the primary causes of the top event are reached [4,5].

 

 

Figure 1: Example of a fault tree. The figure shows a process with four inputs, each of which has QC to maintain the integrity of the process and QA to provide confidence that the output of the process is correct. The red and green symbols represent “OR” and “AND” gates, respectively. Source: Huq et al., TG 100 report, Medical Physics, Vol. 43, No. 7, July 2016.

 

Retrospective tools

The main purpose of the use of retrospective tools is to learn from past events in order to change current practice and improve future outcomes. They contain two phases or tools.

Incident report: this is usually in template form and is used to describe formally the adverse event. Incident reporting systems can be established at institutional or departmental level.

Analysis: an appointed commission then analyses the incident report. The main task of this commission is to analyse the event and to propose corrective measures. These measures may include changes in procedures and practice, and modification of protocols or disciplinary measures.

Concerning the last mentioned, the essential prerequisite for effective incident reporting is a “no-blame” environment. People should be encouraged and feel safe to report incidents.

Besides the risks that are identified by the multidisciplinary team on a local level, it is beneficial and therefore recommended that those who are setting up a local protocol explore the databases that contain incident reporting data on an international level, such as safety in radiation oncology database held by the International Atomic Energy Agency and the radiation oncology safety education and information system from ESTRO. This insight can help to identify previously undetected risks and errors.

 

Protocols and procedures

Protocols and procedures are formal, written documents that describe what each process in clinical practice consists of and how it is done. Their purpose is to ensure the standardisation of procedures and to minimise the risk of errors due to inharmonious activities. One should always be able to consult the written instructions to ensure that the correct action has been taken. They are commonly found in the form of standard operative procedures or working instructions. They should be updated continually to ensure that they describe the best actual practice.

During the development of protocols and procedures, it can be beneficial to look into ESTRO guidelines and the work of the ESTRO guidelines committee (formerly the Advisory Committee for Radiation Oncology Practice):

https://www.estro.org/Science/Guidelines

  

QC of machinery and equipment

Machines and equipment must undergo regular QC to ensure that all hardware and software are working properly and according to the standards. It is necessary in order to ensure that the therapy that is delivered to patients corresponds with initial treatment plans or intentions. Most of these procedures and the frequency at which they must be carried out are described by manufacturers and regulators. Some tests can be adapted to meet specific local needs.

 

Recording of QC results

The results of QC tests that are regularly performed must be preserved. These records are to be presented during audits or inspections. Early methods of record-keeping included paper forms or general-purpose software such as Microsoft Office products. Today, there are two main groups of software available for this purpose: software developed by hardware manufacturers or independent (freeware) solutions.

Proprietary software offers better connectivity with the measurement hardware than does freeware and, in general, the initial setup is simple. On the other hand, the use of such systems can bind the user to a certain manufacturer and possibilities of customisation may be more limited.

Independent or open-source software can be used with some equipment and its use enables a high level of customisation. However, extensive initial set-up is required, and the achievement of automatic data transfer may be hard or impossible.

 

Process evaluation

The use of continuous loops of plan-do-check-act/plan-do-study-act cycles to evaluate the process is recommended. This approach is a simple and effective way to solve problems and manage change.

 

Conclusion

QC and QA are necessary as part of overall quality management in radiotherapy and the wider hospital/department system. They are increasingly important to maintain and improve the services that are provided in modern, rapidly growing, and changing pathways of care for oncology patients. 

 

1. https://www.estro.org/Library/Search?s=rosqc
2. Huq, M.S., et al., The report of Task Group 100 of the AAPM: Application of risk analysis methods to radiation therapy quality management. Med Phys, 2016, 43(7): pp. 4209-62.
3. Sastri, V.R., Risk Management for Medical Devices, Plastics in Medical Devices (Third Edition), 2022, pp. 463-484, ISBN 9780323851268, https://doi.org/10.1016/B978-0-323-85126-8.00006-0
4. Borysiewicz, M.J., et al., Quantitative Risk Assessment (QRA), Institute of Atomic Energy, CoE MANHAZ, Poland (2003).
5. Brook, P.J., and Paige, R.F., Fault trees for security system design and analysis, Computers & Security, 2004, 22(3), pp. 256-264.