RADIATION SAFETY
Phil Facey Lead Superintendent Radiographer Nuclear Medicine and PET University Hospital of Wales Honorary Lecturer University of the South West of England
RADIATION IS AROUND US ALL THE TIME
Medical
Cosmic 10%
Radon gas from the ground
Ground and buildings14%
50%14%
Medical Radiation
u Ionizing radiation even at low doses is potentially capable of causing serious and lasting biological damage
u There is great care to control the amount of radioactivity used in diagnostic imaging
1 in a Million1 chest x-ray 1 in a million chance of radiation induced cancer
Equivalent fatal risks (1 in a million)u 1.5 cigarettes (lung cancer)u 300miles in a car (fatal accident)u 10 miles on a bike (fatal accident)u 6 minutes in a canoe (fatal accident)u 1000miles in an aeroplane (fatal accident)
NRCP 1978
Unitsu Absorbed dose – Gray (Gy)u Dose Equivalent – Sievert (Sv)u Radioactivity - Becquerel (Bq)
Radiology Department
Diagnostic Radiologyu X-Raysu Fluoroscopy – Barium Studies,
Interventional Procedures
Nuclear Medicineu V/Q scans, Bone scans, Renograms, u Therapy
Radiology Department
Nuclear Medicineu Department split into 2 Areasu Supervised Area – may or may not
contain radioactivityu Controlled Area – contains a radioactive
source
Radiology Department
You should never walk through a Nuclear Medicine Department as a short cut to other departments
You can enter only under instructions from staff
Radiology Department
Radiation Protection Supervisorsu Supervise radiation in their own
departmentu Their names will be displayed on the
doors marked with radiation signs
Medical Radiation
Radiation could be present in rooms marked with warning signs
Medical Radiationu Or by illuminated signs over doors
u If the words DO NOT ENTER are lit DO NOT ENTER under any circumstances
Medical Radiation
Problems working in Radiation areas can be split into 2 categories
u Due external radiationu Due to contamination
Medical Radiation
In the X Ray rooms and Radiotherapy rooms
u The problem is due to External Radiation
u The rooms are not left radioactive and neither is the patient
SOURCEOFRADIATION
X RAYS AND RADIOTHERAPY
Medical Radiation
Nuclear Medicine Roomsu Problems can be due to:u External Radiationu Contaminationu The room can be radioactive even when
empty
Medical Radiation
Radiation Hazards on the Wardu Portable Radiography
u Nuclear Medicine Patients
Medical Radiation
Portable Radiographyu X Ray examinations performed outside the
department on wards/theatre u Radiation only produced when Radiographer
presses exposure buttonu Always follow instructions u Keep a safe distanceu Wear lead protection if involved in holding
patients
Medical Radiation
Nuclear Medicine u Patients returning to the ward after
being administered with a radiopharmaceutical
u Ward information sheet only given when a patient has been administered with a dose above
Medical Radiation
Nuclear Medicine patients are given u a) an injection of radioactivity or u b) asked to breathe in a gas or u c) asked to eat prepared food
Medical Radiation
RADIONUCLIDESu Maximum Energy
u Half Life (T1/2)
99mTc (Technetium)u 140KeV
u T1/2 - 6 hours
NUCLEAR MEDICINE PATIENT
SOURCE OF RADIATION
rays
BUT AS WELL AS THE EXTERNAL RADIATION THERE IS ALSO A RISK OF CONTAMINATION
The main way the radioactivity leaves the body is in the urine.
Hence a spill of urine can make the room radioactive.
A spilt vial in the Nuclear Medicine labs can make the room radioactive.
An additional problem, ONLY for the in-patients treated with high amounts of radioactivity for Radiotherapy, is that the radioactive contamination can come from their sweat as well as their urine. Hence anything they touch or anywhere they walk can become radioactive
NUCLEAR MEDICINE THERAPY PATIENT
NUCLEAR MEDICINE THERAPY PATIENT
SOURCE OF RADIATION
rays
NOT CONTAMINATING THINGS IN ROOM
wardrobe
NUCLEAR MEDICINE THERAPY PATIENT
SOURCE OF RADIATION
rays
NOT CONTAMINATING THINGS IN ROOM
wardrobe
NUCLEAR MEDICINE I THERAPY PATIENT
SOURCE OF RADIATION
rays
CONTAMINATING THINGS IN ROOM
wardrobe
NUCLEAR MEDICINE 90Y THERAPY PATIENT
Blood Supply of Liver CancerBlood Supply of Liver Cancer
SIR-Spheres in Liver CancerSIR-Spheres in Liver Cancer
This is why patients are admitted so that they do NOT contaminate their own home.
Even when they leave, the rooms will be radioactive. It is not safe for people to go into these rooms unless they know what they are doing or until notified by the Nuclear Medicine Department
NUCLEAR MEDICINE THERAPY PATIENT
There are 3 basic steps you can take to ensure the Radiation dose you receive while working is as low as possible
TIME near a radiation source
DISTANCE near a radiation source
SHIELDING near a radiation source
-KEEP AS SHORT AS POSSIBLE
-KEEP AS FAR AWAY AS POSSIBLE
-USE IF ADVISED TO DO SO
You may also be advised to wear Protective clothing
Gloves,
Plastic apron,
Overshoes,
Lead apron
This will prevent the radioactive material from getting on your skin or clothes or radiation from reaching your body
Personal Radiation Monitoringu Film Badges You may be required to wear a film
badge. It is important you wear it throughout the examination
Personal Radiation Monitoring
u Film Badges Under the Health and Safety at Work Act 1974 You can be prosecuted if you fail to wear, look after or return your film badge
Personal Radiation Monitoring
u Finger Badges
Records radiation dose to hand and fingers
Personal Radiation Monitoringu Personal Dosimeters
Give an immediate dose reading and alerts you to high radioactivity
Radiation Safety
u Always follow instructionsu Observe and take note of door signsu Time u Distance u Shieldingu Wear Personal Radiation Monitors if
required
PRESENT DAY RADIATION EXPERTS
Any Questions ?