Answer Justification is the answer Dose limits are

Answer: �Justification is the answer. �Dose limits are not applicable only recommened.

Class Activity 4 While caring for his spouse Mr. Joseph got exposed to 2 m. Sv. As a member of the public with 1 m. Sv dose limit, he can not get any radiation dose this year.

Answer: �The average dose limit for a member of the public should not exceed 1 m Sv/y over 5 y.

Personal Monitoring � Regulations require that workers occupationally exposed to ionizing radiation wear devices called dosimeters so that accumulated doses can be monitored over a period of time. � There are several types but commonly used are Thermoluminescent dosimeters (TLDs)

Personal Monitoring � Is necessary to measure the radiation doses received by the radiation workers in the course of their work to verify that these doses are within the recommended limits. � The medical physicist, RSO will identify individuals who have higher does and counsel them before their neglectfulness reaches serious proportions. � Methods of personal monitoring: film badges, TLD, pocket dosimeters.

Different types of personal dosemeters for monitoring external exposure Film • Thermoluminescence • dosemeters (TLD) ”electronic” dosemeters •

TLDs Applications in Nuclear medicine • personal dosemeters (body, fingers…) • special measurements •

TLDs whole body extremity

WHAT IS A TLD � Device used to measure and record the exposure of individuals to ionizing radiation outside the body (external dose). � Compared to photographic film dosimeters (film badges), TLD’s are more sensitive, reusable, often more nearly tissue-equivalent, cover a wider range of doses, allows us to measure deep and shallow doses, and most TLD materials are less subject to fading

What are the different types of TLDs? � Several types of TLD depending on the type of radiation and energies and the nature of work of the users. � Types: • • Whole Body (Personal), Environmental, Neutron Extremity Dosimeters.

Who Should Wear Them: � Persons who are routinely exposed to radiation should wear (monitoring device). � Occasionally exposed workers need not to be monitored but removed from the exposure area/lead aprons when required. � Health care members who assist patients with radiographic procedures should be rotated.

How to wear a TLD: � TLD badge should be worn at the level of the waist or at the collar/neck region UNLESS pregnant. � Pregnant radiation workers should wear 2 TLD’s one on each location. � Radiologists/ Radiographers rarely wear ring badges; most often, they are worn by nuclear medicine technologists because of their exposure from handling radioisotopes.

Shielding: Bench top shield Vial shields Syringe shields

SHIELDING OF SOURCES: Factors affecting the design: radionuclide • activity • shielding material •

MONITORING EQUIPMENT Personal (effective dose, extremity dose & contamination) Workplace (external dose rate & contamination)

A Survey Meter

Detector material Any material that exhibits measurable radiation related changes can be used as detector for ionising radiation. Change of colours • Chemical changes • Emission of visible light • Electric charge • Active detectors: immediate measurement of the change. Passive detectors: processing before reading.

Safety equipment Shields • Protective clothing • Tools for remote handling • of radioactive material Containers for radioactive • waste Dose rate monitor with • alarm Contamination monitor • Decontamination kit • Signs, labels and records • 18

FORCEPS AND TONGS Part 4. Design 19

Signs, labels and records Tc 99 m-MDP Activity: 4312 MBq Volume: 12 ml Activity concentration; 359 MBq/ml Date: 2001 -10 -18 Time: 07. 45 Signature: SC Tc. generator no: A 2376 Reference activity: 30 GBq Reference date: Oct 12 12. 00 GMT Date Time Activity Volume Signature Oct 15 07. 30 22572 MBq 15 ml SC

White-I Label < 5. 0 Sv/h @ surfacel < 0. 05 Sv/h @ 1. 0 ml

Yellow-II Label < 500 Sv/h, > 5 Sv/hl @ surface < 10 Sv/h @ 1. 0 ml

Yellow-III Label > 500 Sv/h, < 2000 Sv/h l @ surface > 10 Sv/h, < 100 Sv/hl @ 1. 0 m

My resident doctor has got 12 m. Sv in her last badge report as she was wearing the badge while getting her barium study. She wants off from radiation work. ? ? ?

Medical Physics: �What is medical physics: The application of physics to medicine. It generally concerns physics as applied to medical imaging and radiotherapy, although a medical physicist may also work in many other areas of healthcare.

Role of Medical Physicist in radiology: � Responsible for equipment performance (Quality Assurance Program) to maintain optimal diagnostic imaging quality with minimum radiation hazard to the patient and workers. � Maintain and develop quality control tests that would detect changes in imaging systems’ function and keep measurable records of all parameters. � Involved in technical specification writing and acceptance testing of new equipment acquired. � Establish and maintain a radiation safety program within the department.

� Supervise the preparation and handling, disposal of radionuclide. � Take part in monitoring, record keeping of staff exposure levels and insure all occupational radiation exposures are monitored. � Interact with vendors of medical equipment regarding safety concerns of the department’s imagines systems. � Review and implement all policies and procedures related to radiation safety. � Involved in training and awareness of hospital staff concerning radiation safety and radioactive waste.

Summary:

Summary

Post lecture survey: �As done before please answer the following MCQs.

Contact details: �Via Email: Mawya@hotmail. com �In-person: basement next to the MRI. �For lectures and previous exams check my web page: www. kau. edu. sa/mkhafaji