Background:Treatments for thyrotoxicosis and carcinoma thyroid are carried out by oral administration of radioactive iodine (131I) in the form of liquid or capsules. The liquid form of 131I has higher risk factors such as vapourization, spillage and need for management of higher activity wastes. Use of 131I in capsule form simplify procedures of handling compared to liquid form of 131I. The guidelines of safe handling and quality assurance aspects for therapeutic use 131I are well outlined by International Atomic Energy Agency (IAEA) reports.Aim:A few unusual incidents with I-131 capsules encountered in the past need to be highlighted from health physics point of view.Materials and Methods:In Royal Hospital, Oman, I-131 is imported in capsules, and the total activity handled/year steadily increased over 10 years. Discrete activities range from 185 MBq (5 mCi) up to 7.4 GBq (200 mCi). In four incidents deviations in standard operational procedures were recorded.Results:Nature of incidents is described as follows: (1) After assay of activity, the capsule was directly put in the lead container with missing of inner cap. (2) Patient poured water in the Perspex tube, when the capsule was handed over to her, making an emergency situation. (3) In 3 high activity capsules (2 nos 2.96 GBq, 1 no. 4.26 GBq), observed sticky behavior in capsule holder on the 2nd day post receipt, which were in order on the 1st day. (4) A capsule could not be swallowed by a patient, which was taken back from the mouth. Monitoring of patient later did not show residual ingested activity.Conclusions:The report documents some of the unusual incidents for information to other centers engaged in such radioactive administrations.
The aim of this observational cross-sectional study with retrospective review of the data is to evaluate the efficacy of using technetium-99m-octreotide (Tc-99m-OCT) in imaging neuroendocrine tumors (NETs) in our tertiary care hospital. A total of 58 patients had Tc-99m-OCT were identified in our database, from January 2013 to December 2016. Forty-one patients (age range of 15–75 years) meet our inclusion criteria, namely histopathology proven NETs, Tc-99m-OCT scan, computed tomography (CT), or magnetic resonance imaging (MRI) done in our institute for correlation. Twenty-three patients had true positive Tc-99m-OCT scan. In addition to the primary tumors, the octreotide scan revealed metastasis in the lung, liver, and retroperitoneal lymph nodes. The smallest lesion detected on octreotide scan was a 4-mm pulmonary nodule that was missed on lung window CT scan. The Tc-99m-OCT had 17 true negative, one false negative, and no false positive. The CT and MRI scans had 18 true positive, 17 true negative, 5 false negative, and one false positive. The overall sensitivity, specificity, accuracy, positive, and negative predictive values of Tc-99m-OCT scan were 96%, 100%, 97%, 100%, and 94%, respectively. Whereas those of CT and MRI were 78%, 94%, 85%, 94%, and 77%, respectively. Our diagnostic accuracy of Tc-99m-OCT is high. We recommend that, in addition to the conventional radiological investigations, Tc-99m-OCT scan, or other somatostatin receptor imaging (SSR) is a mandate for better and accurate staging of patients with NETs.
For administration of radioactive iodine for the treatment of differentiated cancer thyroid patients, activities ranging between 1.85GBq and 7.0GBq are used. The construction of concrete rooms cleared by national regulatory authorities do not recommend the presence of windows on the walls or advise same lead equivalence of wall for the lead glass if they are put on the walls. To avoid phobia of patients to give consent for I-131 treatment and to stay in isolation rooms, a necessity was felt to introduce glass window on the opposite side wall of entrance door, which had a service corridor with restricted entry, opening toward garden area. Commercially available lead glass used for X-ray computed tomography scanner was fixed on the 0.35 m thick concrete wall in two rooms. The adequacy of protection offered by the lead glass was determined. A I-131 capsule 600 MBq was moved at a distance 50 cm away from the wall inside the room, and transmitted radiation was measured outside the room. An end window pancake type, beta-gamma survey meter was used. The measured values were normalized for 3.7 GBq at 2 m bed position in μSv/h. The obtained maximum exposure rate was 1.48 μSv/h transmitted from the glass window, against 0.44 μSv/h transmitted at full concrete wall level. As the patients provide shielding to the administrated activity, also the activity is progressively decreasing fast with an effective half-life, the stray radiation levels will be decreasing outside, reducing the mean radiation level to 0.74 μSv/h, and increasing the efficacy of protection. The patient's bed position is at lower level by 0.5 m from the lower edge of the lead glass, so that during patient is in bed the stray radiation levels reduce further. As there are no reports about such facility for isolation rooms, this report may be of value in health physics literature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.