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The aim of this study was to measure the radiation exposure rate from differentiated thyroid carcinoma (DTC) patients who had received iodine-131 ((131)I) treatment, and to evaluate hospital discharge planning in relation to three different sets of regulations. We studied 100 patients, 78 females and 22 males, aged 13 to 79 years (mean 44.40±15.83 years) with DTC, in three Groups who were treated with 3.7, 5.5 or 7.4GBq of (131)I, respectively. The external whole-body dose rates following oral administration of (131)I were measured after each one of the first three hospitalization days. A multivariant linear analysis was performed, considering exposure rates as dependent variables to the administered dose for treatment, age, gender, regional and/or distant metastases, thyroglobulin (Tg), antibodies to Tg and thyroid remnant in the three dose groups. We found that the exposure rates after each of the three first days of hospitalization were 30, 50 and 70μSvh-1 at 1m. All our DTC patients had an acceptable dose rate on days 2 and 3 that allowed their hospital discharge. After only 1 day of hospitalization, just 3/11 cases showed not permissible exposure rates above 70μSvh-1. In conclusion, it is the opinion of the authors that after measuring the exposure rates, most treated, DTC patients could be discharged after only one day of hospitalization, even some of those treated with high doses of (131)I (7.4GBq). Patients, who received the higher doses of (131)I, should not be released before their individual exposure rate is measured.

Radioiodine ((131)I iodide) has long been a safe, effective and widely used treatment in the management of differentiated thyroid cancer (DTC). Concerns regarding stochastic radiogenic risks have led to regulatory criteria for the release from medical confinement of patients who receive such radionuclide therapy. Over a 6-y period, the external whole-body dose rates at 1 m from 562 DTC patients were measured with an ionisation chamber calibrated in microsieverts per hour out to 5-d post-administration. Patients were stratified into four administered activity groups: 3.7 GBq (36.8 %), 5.55 GBq (47.3 %), 7.4 GBq (12.8 %) and 9.25 GBq (3 %). Consistent with previously published data, the current study demonstrated that a bi-phasic model accurately described (131)I-iodide kinetics up to at least 5-d post-administration in DTC patients, providing data that would be useful in formulating radiation safety guidelines for staff and other individuals coming into contact with such patients after treatment.

Objective: We evaluated the potential detrimental cytogenetic effects of Tc-methoxyisobutyl isonitrile (MIBI) and I on patients who were exposed to the radiopharmaceutics for cardiac imaging or thyroid cancer therapy, respectively., Methods: Mononuclear leukocytes were isolated both before and after radiopharmaceutical administration and subsequently cultured. Micronuclei frequency was then assessed and microscopic evaluation of apoptosis was conducted., Results: Small statistically insignificant augmentation in the percentage of micronuclei from 10.9+/-3.8 to 11.3+/-2.4% was observed in the Tc-MIBI group. In contrast, I elicited a notable augmentation of micronuclei from 6.3+/-2.2 to 9.6+/-3.1 at 3.7 GBq, and 6+/-1.5 to 9.2+/-2.7 at 5.55 GBq (P<0.05)., Conclusion: Our results showed that there were no remarkable alterations either in the micronuclei incidence or in the percentage of apoptotic lymphocytes after in-vivo exposure to radiopharmaceutical imaging, which provides evidence to reduce the growing concern about the safety issue of cardiac imaging with Tc-MIBI, whereas the deleterious effects of I must be considered when it is applied to thyroid cancer treatment.

Three days following administration of radioactive iodine in 38 patients, exposure rates such as dose rate close to the dress (D0), dose rate of dress at 1 m (D1), dose rate close to the bedsheet (B0), dose rate of bedsheet at 1 m (B1), dose rate of patient at 1 m (P1) and also sum of D1 and B1 (S1) were measured using a radiation detection survey metre with a calibrated ionisation chamber. The patient population consisted of 36 females and 2 males with mean age 38.92 +/- 15.76 y. A considerable correlation was found between age and P1 (r = 0.37 and p = 0.02), and administered dose and P1 (r = 0.43 and p = 0.006). It is recommended that a document should be prepared for practitioners and also all individuals coming in contact with older patients are to be made aware of the contamination and radiation hazards.