Staff eye doses in a large medical centre in Saudi Arabia: are they meeting the new ICRP recommendations?

A 5-y retrospective analysis of the cardiology staff eye doses was performed on 34 staff from different categories (cardiologists, nurses and technologists) at King Faisal Specialist Hospital and Research Centre (KFSHRC) in Riyadh, Saudi Arabia. KFSHRC is a tertiary medical centre with 800-bed capacity having more than 5000 cardiac catheterisation procedures performed annually. The aim of the study is to derive staff doses to the lens of the eyes using the personal dose equivalent Hp(0.07) values from the annual TLD dose report for the years 2008-2012 and determine the category of staff with high estimated eye doses. The study also aims to investigate the causes for high doses and recommend dose-reduction techniques. The dose to the lens of the eye was estimated by using the ratio Hp(0.07)slab/Hlens of 1.1 where Hp(0.07) values are the reported doses read from TLD badge worn at the collar level. The average annual eye dose of each category for the 5-y monitoring period was determined. Cardiologists tend to receive higher doses than the nurses by a factor of 2-4 and can exceed 5 mSv y(-1). No correlation exists between the eye doses of nurses and the cardiologists. There is a need to use a conversion coefficient in terms of eye lens dose per dose-area product for faster estimation of eye lens doses. However, there is a limitation on the use of the conversion coefficient because it will depend on the clinical procedure and the X-ray tube angulation. Further investigation on this limitation is needed.

Radioactive waste handling and disposal at King Faisal Specialist Hospital and Research Centre.

King Faisal Specialist Hospital & Research Centre (KFSHRC) is the largest specialized medical center in Saudi Arabia. It performs highly specialized diagnostic imaging procedures with the use of various radionuclides required by sophisticated dual imaging systems. As a leading institution in cancer research, KFSHRC uses both long-lived and short-lived radionuclides. KFSHRC established the first cyclotron facility in the Middle East, which solved the in-house high demand for radionuclides and the difficulty in importing them. As both user and producer of high standard radiopharmaceuticals, KFSHRC generates large volumes of low and high level radioactive wastes. An old and small radioactive facility that was used for storage of radioactive waste was replaced with a bigger warehouse provided with facilities that will reduce radiation exposure of the staff, members of the public, and of the environment in the framework of "as low as reasonably achievable." The experiences and the effectiveness of the radiation protection program on handling and storage of radioactive wastes are presented.

Deriving staff and public doses in a PET/CT facility from measured radiation levels using thermoluminescent dosimetry.

The introduction of PET/CT at King Faisal Specialist Hospital and Research Centre for whole body and brain imaging has become favourable for diagnosis of cancer. There is no data available on the PET/CT dose to staff and members of the public for different activities of (18)F [fluorodeoxyglucose (FDG)] and for longer patient holding time. The study aims to determine and evaluate staff and public doses by using thermoluminescent dosemeters monthly readings for a 7-month deployment period and by using direct measurements of dose rates at 30 cm and 1 m distances from the patients after injection. The whole body doses per procedure and per administered activity of (18)F (FDG) were estimated. A dose map inside the PET/CT was generated to provide information of the dose levels in different locations. The Pearson correlation showed a strong correlation (r(2) = 0.71) between the dose per activity and the number of patients. Optimisation of radiation protection of staff and members of the public was investigated and recommendations were given.

Variation in radiation doses in paediatric cardiac catheterisation procedures.

Paediatric cardiac catheterisation involves diagnostic and therapeutic procedures that range from simple to complex and can subject paediatric patients to varying radiation doses. The study aims to determine the variation in entrance doses in patients in terms of dose-area product (DAP) values and to investigate the methods for optimising radiation protection. A total of 190 paediatric patients belonging to age groups 0, 1, 5 and 10 y who underwent diagnostic and six selected therapeutic procedures at King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia were included in the study. Therapeutic procedures include coarctation (COA), patent ductus arteriosus (PDA), radiofrequency ablation, pulmonary, embolisation and septostomy. Fluoroscopy and cine radiography were used in all procedures. Patient demography (weight, age, gender and height), radiographic technique factors, fluoroscopy and cine time, frame rate, and DAP values were taken from patients records. Effective doses for each procedure were estimated from the DAP values. The mean DAP per procedure were analysed for correlation with patient equivalent cylindrical diameter, weight, fluoroscopy time and number of frames. Factors influencing the variation in doses were investigated. Initial results show that PDA occlusion has the highest mean DAP value of 23.21 Gy-cm2, while the diagnostic and septostomy procedures have the lowest value of 7.77 and 6.95 Gy-cm2, respectively.

Patient parameters and other radiation safety issues in 131I therapy for thyroid cancer treatment.

Patients administered with a therapeutic dose of I for thyroid cancer treatment are potential sources of unacceptably high radiation exposure to other individuals, particularly the patient's immediate family members. Generally, patients are hospitalized until such time that the retained radioactivity in the body or the measured dose rate at 1 m from the patient's body surface fall to within acceptable levels. Patient release criteria are set to ensure that no individual shall be liable to receive exposures above the regulatory dose limit for the public or dose constraints for the patient's relatives or caregivers.