[P115] I-131 Patient release criteria based on dose rate measurements at the bank of cyprus oncology centre cyprus (BOCOC). (August 2018)

• Record Type: Journal Article
• Authors: Michael, Kostas; Antoniou, Georgia
• Is Part Of: Physica medica. Volume 52(2018)Supplement 1
• Page Start: 133
• Publication Date: 2018-08
• Subjects: Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2018.06.430
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract : Purpose: At the BOCOC patients who have radioiodine ablation therapy are being released from the hospital when the dose rate at 1 m is less than 40 μ Sv/h according to the European Commission's Directive 97 (RP 97). All patients are advised to avoid contact with children for the first week after administration and avoid prolonged and close contact with adults for the same period of time. This study was set out to investigate the time depended dose rate after radioiodine administration and estimate the effective half ( T eff ) life of each patient. Finally, individual restriction periods were set to limit contact to a member of the public or household to less than 300 μ Sv and comforters and carers to less than 3000 μ Sv. Methods: External whole body dose rates at 1 m from 36 patients were measured with a survey meter (Victoreen, 451P) immediately following administration and at intervals for up to 5 days after administration. Non linear regression analysis was used to plot the dose rate against time and the T eff of the decay was calculated for each patient. Assumptions for contact patterns of the patient with different groups of people were made and the cumulative doses for members of the public and comforters and carers were calculated. Restriction periods in days for each group of people were then obtained. Results: The data showed a bi-exponential decay rate with a fast clearance phase of 10.2 h that is followed by a slower clearance phase of 28.5 h. Most patients can travel in private transport for up to 10 h after discharge. Most patients can return to work (contact with adults at 1 m) 3–5 days following administration. Contact with younger children should be restricted for 5–8 days and 4–5 days for older children and adults at home. Conclusions: All patients could be released 48 h following administration as they reached the RP97 permissible dose rate. In most cases restriction periods do not exceed 7 days following administration.