Radioprotection No 59-3 | Page 79

222 R . Y . Nasr et al .: Radioprotection 2024 , 59 ( 3 ), 220 – 224

Table 1 . Average eye lens dose ( H-lens ) in millisievert among different subjects .

* SD : Standard Deviation . * N : Number .

NM Tech : Nuclear Medicine technologist . NIC Tech : Noninvasive Cardiac technologist .

Table 2 . Average eye lens dose ( H lens ) in millisievert by occupation

* SD : Standard Deviation . NM Tech : Nuclear Medicine technologist . NIC Tech : Non-Invasive Cardiac technologist .

what was observed in a similar study conducted in the UK , which found that nuclear medicine staff receive an average annual eye dose of 4.5 mSv . The marked difference in these findings could potentially be attributed to variations in workload or the inconsistent use of OSL dosimeters during procedures . However , a UK study reported that their participants did not exceed the average dose limit ( Thome , 2018 ).

Additionally , we identified notable variations in eye dose exposure across different roles in the nuclear medicine department . The lens dose , represented by the H-lens value , was significantly elevated in hot lab technicians compared to both non-nuclear medicine technicians involved in cardiac stress tests ( p < 0.001 ) and other nuclear medicine technicians ( p < 0.0001 ). This discrepancy in exposure levels can be chiefly attributed to the different duties of the staff . In particular , hot lab technicians face higher ambient dose rate values owing to the handling and preparation of radiopharmaceuticals and the specific techniques used in their procedures . This aligns with previous studies suggesting that technicians involved in radionuclide therapy or PET scans typically experience higher radiation exposure than other staff members ( Seierstad , 2007 ; Summers , 2012 ; Antic , 2014 ; Adliene , 2020 ).

While most studies examining radiation dose exposure among nuclear medicine staff have found that exposure levels typically do not exceed recommended limits , the same cannot be said for other radiology specialties ( Mettler , 2008 ; Antic , 2014 ; Thome , 2018 ). In a nuclear medicine practice serving high volume of patients , a study reported eye lens doses for 19 staff members ( Demeter , 2019 ). They work with high loads of cardiac PET imaging and run the cyclotron center . Their reported maximum eye lens doses did not exceed 3.68 mSv for the 3-month period of the study .

Meanwhile , a Spanish study assessed eye lens dose for staff in Interventional Cardiology ( IC ) and demonstrated that doses exceeded ICRP limits in 4 out of 9 IC physicians while nurses received 2 to 4 mSv ( Principi , 2015 ). The number of procedures for each of the 9 physicians had ranged from 77 to 385 per year . In addition , physician ’ s measured eye lens doses ranged from 8 to 61 mSv due to the variability in radiation protection tools used by each of them .

These findings emphasize the need for further research and evaluation of interventional facilities to identify staff members most vulnerable to high radiation dose exposure and to implement rigorous protective measures .

Moreover , a study conducted in the field of interventional radiology compared the radiation doses measured by dosimeters worn close to the eyes with those worn around the neck ( Al-Haj , 2015 ). The results indicated that neck-worn dosimeters tended to overestimate the radiation dose compared to eye dosimeters , which is a potential limitation of our study . Therefore , further evaluation using dosimeters positioned near the eyes is recommended , and dosimeters should be worn as close to the eye as possible for the most accurate monitoring of the eye lens dose ( Al-Haj , 2015 ).

In summary , while our study confirms that radiation exposure among nuclear medicine staff generally remains within the recommended limits , it also sheds light on the differences in exposure across different roles and specialties . This highlights the need for continued vigilance , ongoing research , and implementation of role-specific protective measures to maintain highest level of radiation protection all staff members working in environments where ionizing radiation is present . This study also recommends reconsidering the positioning of dosimeters for more accurate dose monitoring .

Funding

This research did not receive any specific grant from funding agencies in the public , commercial , or not-for-profit sectors .