RADYONÜKLİD TEDAVİLERDE DOZ HIZI ÖLÇÜMLERİ VE HASTA TABURCU EDİLME KOŞULLARININ DEĞERLENDİRİLMESİ

Abstract

Objective: The aim of this study is to measure radiation dose rate from hospitalized patients and to determine release dose for discharge time after radionuclide therapy. Materials and Methods: Our study included 840 patients undergoing radionuclide therapy in which 576 patients were treated by different doses of iodine: 3700, 5550 ve 7400 MBq, 144 patients weere treated with variable amounts of 177Lu-DOTATATE : 3700 and 7400 MBq, 245 patients were subjected to 177Lu-PSMA therapy with activity range 1500-4500 MBq and 19 patients were arbitraryly selected for 90Y microsphere therapy. Dose rates were measured at a distance of 1 meter from patients via Geiger- Müller (GM) probe. Dose rate readings >30 μS/h were repeated at 48 hours. Results: The average dose rate measured at 24 hours after administration of 3700, 5550 and 7400 MBq 131I was 24.6±7 μSv/h, 52.3±17 μSv/h and 66.7±15 μSv/h respectively, the average dose rate was 3.7±1, 5.1±2 and 7.1±3 µSv/h after administration of 3700, 5550 and 7400 MBq 177Lu-DOTATATE respectively; whereas the dose rate was 4±0.3 μSv/h in 90Y microsphere treatment and 7.2±3 µSv/h after administration of 7400 MBq 177Lu-PSMA. The mean dose rate after 48 hours following radioiodine therapy using activity of 3700, 5550 ve 7400 MBq 131I was 13±6, 13.2±5 ve 17.2±4 µSv/h repectively. Conclusion: We concluded that patients treated with 3700 MBq 131I must stay in lead-shielded rooms at least 24 hours and patients treated with 5550 and 7400 MBq 131I should stay up to 48 hours to assure dose rate less than 30 µSv/h as recommended by TAEK, while in 177Lu and 90Y treatment maximum 24 hours is found adequate for discharge of patients.