Assessment of Renal Dosimetry and Nephrotoxicity in Patients with Neuroendocrine Tumors Treated with 177Lu-DOTATATE

Aim: This study aimed to conduct dosimetry and evaluate renal toxicity based on calculated kidney doses and glomerular filtration rates (GFR) in 22 patients diagnosed with neuroendocrine tumors following the administration of 5550 MBq (150 mCi) of 177Lu-DOTATATE radiopharmaceutical. Materials and Methods: Patients, aged between 35 and 80, including 14 males and 8 females, underwent 68Ga-DOTATATE PET/CT scans to identify lesions and subsequently received treatment planning. Dosimetry of ¹⁷⁷Lu-DOTATATE was performed using whole-body imaging based on scans acquired at 4, 24, 48, and 72 hours post-administration. Results: According to our results, the average number of treatment cycles was 5±1, with an average total kidney dose of 24.32±3.5 (Gy), average total BED dose of 27.9±2.5 (Gy), average whole-body dose of 1.83±0.4 (Gy), and average GFR of 69.95±12.2. The correlation between kidney doses and GFR was calculated as R2=0.7945. The significance of the relationship between total kidney doses and total kidney BED doses was evaluated using the Mann-Whitney U test (p=0.0244). Conclusion: The study found that as the number of treatment cycles increased, the total kidney dose also increased; however, rapid declines in GFR were not observed, and none of the treated patients reached toxic doses in the kidneys.