177Lu-Octreotate peptide receptor radionuclide therapy of neuroendocrine tumours: dosimetry of personnel and caregivers

Introduction The clinical application of 177 Lu-Octreotate Peptide Receptor Radionuclide Therapy (PRRTs) is well-established. The relatively long physical half life of 177 Lu, along with the fact that it is both a betta and gamma emitter, necessitates investigation of the radiation burden to the personnel and caregivers involved. Purpose The purpose of this study was to measure the effective dose to the personnel per administered dose, as well as the effective dose to the caregivers during the immediate p.i. period. Materials and Methods Dosimetry measurements were performed for both personnel and caregivers involved in 45 administrations between June ’13–December ’15. Personnel whole-body doses were recorded on a monthly basis. Dose rate measurements at 1 m distance from the patient were recorded, at time instances 0–30 min and 30–120 min p.i. TLD dosimeters were provided to caregivers to assess their exposure in the time intervals 0–3 days, 3–7 days and 0–7 days p.i. Results The personnel’s average dose was 32.7 μSv/administered dose. The average dose rate at 1 m distance from the patient 0–30 min p.i. was 47 μSv/hr (range:15–100 μSv/hr), decreasing to 26 μSv/hr 30–120 min p.i. (range:10–50 μSv/hr). The average recorded dose to caregivers was 0.065 mSv in the first 3 days p.i. (range:0–0.14 mSv), 0.035 mSv in the next 4 days p.i. (range:0–0.15 mSv) and 0.100 mSv in the whole dosimetric period (range:0–0.29 mSv). Conclusion 177 Lu-Octreotate PRRT can be safely performed on an outpatient basis, as long as individualised radiation protection instructions are provided and followed by the caregivers.