Evaluation of Lancet Blood Sampling for Radioiodine Dosimetry in Thyroid Cancer

Recently published European guidance recommends the evaluation of the radiation dose to the bone marrow in patients undergoing radioiodine therapy for thyroid cancer. The methods described in these guidelines require serial blood samples to be taken from the patient, followed by a sophisticated analysis to determine the radiation dose. However, radiation risk assessments carried out locally have indicated that a relatively high radiation exposure will be received by the operator taking the blood samples, which may prohibit this procedure being carried out routinely. The radiation dose to the operator will be lowered if the duration of the blood sampling procedure were reduced. The investigators hypothesize that the use of a lancet and pipette to collect blood from the finger tip will greatly reduce the time spent in proximity to the patient, significantly reducing the operator exposure and allowing this procedure to be performed routinely. The proposed method is also less invasive for the patient compared to the intravenous sampling recommended in the guidelines. A proof-of-principal pilot project using radioiodine diluted to the expected concentration in blood has indicated that using very small volumes of blood (such as from a lancet) does not compromise the accuracy of the dosimetry measurement when compared to large-volume standard blood samples. The primary aim of this study is to investigate whether sampling a small volume of blood using a lancet and pipette can replace standard intravenous blood samples for bone marrow dosimetry in patients undergoing radioiodine treatment for thyroid cancer. Statistical tests will determine whether there is a significant difference between the doses calculated using each blood sampling method. In addition, the investigators will measure the radiation exposure received by the operator during each procedure using Electronic Portable Dosimeters. The results of these measurements will be used to quantify the reduction in operator radiation exposure afforded by the new technique.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* Patients undergoing inpatient radioiodine therapy for thyroid cancer

Exclusion Criteria:

* Pregnant or breastfeeding women
* Paediatric patients
* Patients with known trypanophobia