RADIATION SAFETY Phil Facey Lead Superintendent Radiographer Nuclear Medicine and PET University Hospital of Wales Honorary Lecturer University of the...
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
Cosmic 10%
Ground and buildings
14%
14%
Medical
50%
Radon gas from the ground
Medical Radiation 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 u
1 in a Million 1 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
Units u Absorbed dose – Gray (Gy) u Dose Equivalent – Sievert (Sv) u Radioactivity - Becquerel (Bq)
Radiology Department Diagnostic Radiology u X-Rays u Fluoroscopy – Barium Studies, Interventional Procedures Nuclear Medicine u V/Q scans, Bone scans, Renograms, u Therapy
Radiology Department Nuclear Medicine u Department split into 2 Areas u Supervised Area – may or may not contain radioactivity u 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 Supervisors u Supervise radiation in their own department u 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 Radiation u
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 radiation u 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
X RAYS AND RADIOTHERAPY
SOURCE OF RADIATION
Medical Radiation Nuclear Medicine Rooms u Problems can be due to: u External Radiation u Contamination u The room can be radioactive even when empty
Medical Radiation Radiation Hazards on the Ward u Portable Radiography u
Nuclear Medicine Patients
Medical Radiation Portable Radiography u X Ray examinations performed outside the department on wards/theatre u Radiation only produced when Radiographer presses exposure button u Always follow instructions u Keep a safe distance u 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 RADIONUCLIDES u Maximum Energy u Half Life (T1/2) 99mTc
(Technetium) u 140KeV u T1/2 - 6 hours
NUCLEAR MEDICINE PATIENT rays
SOURCE OF RADIATION
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.
NUCLEAR MEDICINE THERAPY PATIENT
An additional problem, ONLY for the inpatients 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 wardrobe
rays
SOURCE OF RADIATION
NOT CONTAMINATING THINGS IN ROOM
NUCLEAR MEDICINE THERAPY PATIENT wardrobe
rays
SOURCE OF RADIATION
NOT CONTAMINATING THINGS IN ROOM
NUCLEAR MEDICINE I THERAPY PATIENT wardrobe
rays
SOURCE OF RADIATION
CONTAMINATING THINGS IN ROOM
NUCLEAR MEDICINE 90Y THERAPY PATIENT
Blood Supply of Liver Cancer
SIR-Spheres in Liver Cancer
NUCLEAR MEDICINE THERAPY PATIENT 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
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 -KEEP AS SHORT AS POSSIBLE
DISTANCE near a radiation source -KEEP AS FAR AWAY AS POSSIBLE SHIELDING near a radiation source
-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 Monitoring u
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 Monitoring u
Personal Dosimeters Give an immediate dose reading and alerts you to high radioactivity
Radiation Safety u
u u u u u
Always follow instructions Observe and take note of door signs Time Distance Shielding Wear Personal Radiation Monitors if required
