Radiation Protection

Question 1

For RT bunker calculations or assessment of bunker material in shielding, what sort of factors would you need to consider in your calculations and assessment?

Answer 1

1) types of material that are/could be in the barriers
2) thickness of barriers
3) distances from isocentre to calculation points (e.g. control room)
4) dose rates at isocentre - FFF treatments, VMAT, hypofractionation, energy of beam (inc future-proofing, e.g. higher energies than currently used) - note which machine used (Varian vs Elekta, Varian using 10MV most of time, Elekta 6MV most of time; also flatting filter just taken out in Varian for FFF, therefore softer beam - more like 4MV; Elekta modify the beam to give 6MV).
5) practicality of installation of materials
6) cost of materials (linked to (5))
7) staff time in areas/calculation points
8) TDR2000 rates
9) actual beam on time when beam or scatter on barriers
10) for scatter, 0.1% * output dose rate at isocentre (or 1/1000)

Question 2

Who (locally) may be notified of an incident (not necessarily by you)?

Answer 2

Patient/patient representative
Patient's referrer and practitioner
Clinical Director
RT Head of Service
Head of RT Physics
MPE
Lead Radiographer
Directorate Manager
Physics Service Lead
RPA (if appropriate, e.g. equipment issue, public/staff at risk)
Risk Department
Hospital Incident Database (this records who is informed, when and by whom; also specifies principle investigator)
Trust Exec?

Question 3

When you recieve a phone call/communication indicating a patient may have been overdosed and you are the most senior clinical scientist present, what do you do?

Answer 3

Record everything!!!!

1) What happened?
a) describe what happened
b) has patient been overdosed?
c) one fraction or many?
d) is the incident correctable?
e) is it an equipment fault? Does equipment need taking out of clinical use?

2) What should happen now?
a) stop treatment?
b) stop treatment until we can calculate what to do?
c) continue under current treatment plan/regime?
d) continue as originally intended?
e) continue with modified dose?

Question 4

How should an incident be reported to the CQC (for incidences in England)? Who should report incidences?

Answer 4

1) via an electronic form online
2) report should be timely, immediate preliminary investigation and if SAUE is not ruled out, immediately notify!
3) notify outcome of the full investigation within 12 weeks of the incident date

It is not usually the responsibility of the physicist to report incidences to the CQC, it is the employers “Risk Office” usually but a physicist (e.g. you) could be asked by them to carry it out.

The CQC document “Significant Accidental & Unintended Exposures under IR(ME)R - Guidance for employers and duty holders” provides advice on reporting.

Question 5

When a potential incidence occurs, what specific things should you do (this relates to practical investigation guidance)?

Answer 5

1) Collect peoples recollections ASAP (what went on before, during and after, who was involved, who can provide information; i.e. try to prevent agreement of story)
2) Collect electronic logs ASAP

Question 6

Name two online resources regarding RT incident learning.

Answer 6

1) IAEA SAFRON

2) IAEA Safety and Quality in RT

Question 7

Learning from incidents - what should come out of an incident report?

Answer 7

1) what needs to change to avoid a repeat of the incident:
a) is a review of procedures needed? e.g. are they clear enough
b) extra/re-training required?
c) do new procedures need putting in place?
d) does the safety culture need improving?

Question 8

When investigating incidences, what tools could you use to analyse incidents?

Answer 8

Incidences show weak points in processes/culture; therefore, tools such as:
1) Process Trees
2) Failure Mode Effect Analysis
can be used.

AAPM TG100 is a good source of advice and guidance.

Question 9

List some reports/documents that can provide guidance for radiation safety in RT.

Answer 9

(not a comprehensive list)

1) Medical and Dental Guidance notes (old but update imminent, not cited to inspectors but can be used a general good practice guide)
2) Towards Safer RT (introduces classification system, this is used at Leeds, see WI)
3) PHE TSR Reports (good to identify common areas of safety failure)