Radioiodine Dosimetry Protocol for Thyroid Cancer Metastases

Investigating Absorbed Radiation Dose Delivered to Differentiated Thyroid Cancer Metastases Following Administration of Fixed Activity of Radioactive Iodine

The main purpose of the study is to establish a relationship between the administered activity of the radioiodine and absorbed dose in the tumor sites.

Study Design - the assessment of patients with multiple tumour sites with metastatic thyroid cancer to correlate the administered activity to absorbed dose. Patients will receive the standard therapy dose of 5.5 GBq as per the hospital policy and there will be no change for the protocol purpose.

Inclusion Criteria:

• age above 18
• histological confirmation of the differentiated thyroid carcinoma available
• WHO performance score 0-2
• metastatic sites lung and/or bone and/or nodal (radiologically measurable disease > 1 cm)
• life expectancy > 6 months
• patient has undergone total/near total thyroidectomy
• no past history of sensitivity/reaction to 1311

Exclusion Criteria:

• non iodine concentrating tumours
• received chemotherapy or radiotherapy in 6 weeks
• pregnant or breast feeding patients
• iodine contrast injection in last 3 months