IR(ME)R for Radiotherapy Flashcards Preview

Y3: Radiation Safety in Radiotherapy > IR(ME)R for Radiotherapy > Flashcards

Flashcards in IR(ME)R for Radiotherapy Deck (25)
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What does MGTI stand for?

Much Greater Than Intended


What are the 2 classes of MGTI errors?

Equipment or procedural failure of a normally safe practice
Systematic failure at commissioning stage


On average, how many MGTI incident occur per department per year?



In 2014, how many radiotherapy therapeutic errors were reportable?

72 (49%)
Treatment error: 32%, (47)
Planning error: 13% (19)
Referror error: 3% (5)
Other: 1% (1)


In 2014, how many radiotherapy imaging errors were reportable?

76 (51%)


What is the multiplication factor for reporting imaging overdoses?



What is the purpose of IR(ME)R?

Defines working rules to reduce chance of unnecessary exposures.


Which regulation defines the IR(ME)R referrer, and what does it state?

The referrer should supply sufficient medical data to the practitioner relevant to the exposure reuested to enable the practitioner to determine that there is a net benefit from the exposure.
Sometimes the referrer and practitioner is the same person.


Who decides who can be an IR(ME)R referrer?

A local level decision should be made between the employer and healthcare professionals.


Name 2 types of exposures in radiotherapy.

Diagnostic, staging, verification, review, planning, therapeutic.


Which IR(ME)R regulation relates to justification of an exposure, and what does it state?

The practitioner shall be responsible for the justification of a medical exposure and such other aspects of a medical exposure as is provided for in these Regulations.


What are the two possible outcomes of the inital investigations when justifying therapy?

Therapy will be appropriate if result of investigative exposures shows positive.
Therapy already indicated but planning exposures show up something unexpected which causes therapy to be cancelled.


Who decides who can be an IR(ME)R practitioner?

A local level decision should be made between the employer and healthcare professionals involved in medical exposure.


Name 2 operators.

Clinical oncologist, treatment planner, radiographer, technologist, etc.


How is it decided which operator is suitable for a task?

Operators are identified by the employer, e.g: in SOPs, lists (of grades, names or profession), job description, training records, etc.


Why is authorisation required if an exposure has already been justified?

There may be a range of exposures that meet the criteria of the justification, and seperate authorisation allows operators to make technical decisions about individual exposures when a practitioner is not present.


What optimisation principle applies to non-target tissues?



What is the practitioner responsible for?

Selecting appropriate planning for target volume.
Considering normal tissue ALARP, consistent with intent.


What is the operator responsible for?

Selecting appropriate methods/equipment.
Ensuring adherence to dose constraints.
Ensuring appropriate QC.
Assessment of dose.


Why is optimisation more important for children?

Children have a longer period to show latent effects, and have organs that are closer together and may be more sensitive.


How is optimisation acheived for children in radiotherapy?

Paediatric specialists may use specialist protocols for therapy and for scanning.
Child specific OAR constraints may be used.


When should an incident be reported?

If it is over 20% of an intended fraction.
If it is over 10% of an intended course.

MGTI if:
Partial or complete geometric miss of target.
Partial or complete imaging of wrong site.
Total CT dose > 1.5 intended caused by procedural error.


Which regulations in IR(ME)R relates to research exposures, and what do they state?

6 -- In the case of [research exposures] it has been approved by a Local Research Ethics Committee;
7 -- The employer's procedures shall provide that - 
(a) the individuals concerned participate voluntarily…
(b) the individuals concerned are informed in advance about the risks…
(c) the [research] dose constraint … is adhered to
(d) individual target levels of doses are planned by the practitioner for …therapeutic practice from which the patients are expected to receive a diagnostic or therapeutic benefit.


Do DRL's apply to radiotherapy? If so, which part?

Yes - to planning procedures.


Does IR(ME)R state anything about QA?

Yes - QA should be done for SOPs. e.g: VMAT QA, peer review, Iso 9000 quality management system.