Biokinetics and dosimetry in patients administered with 111In-DOTA-Tyr3-octreotide: Implications for internal radiotherapy with 90Y-DOTATOC

摘要: Recent advances in receptor-mediated tumour imaging have resulted the development of a new somatostatin analogue, DOTA-dPhe1-Tyr3-octreotide. This compound, named DOTATOC, has shown high affinity for receptors, ease labelling and stability with yttrium-90 favourable biodistribution animal models. The aim this work was to evaluate dosimetry DOTATOC radiolabelled indium-111, anticipation therapy trials 90Y-DOTATOC patients. Eighteen patients were injected (10 µg), labelled 150–185 MBq 111In. Blood urine samples collected throughout duration study (0–2 days). Planar single-photon emission tomography images acquired at 0.5, 3–4, 24 48 h time-activity curves obtained organs tumours. A compartmental model used determine kinetic parameters each organ. Dose calculations performed according MIRD formalism. Specific activities >37 GBq/ µmol routinely achieved. Patients showed no acute or delayed adverse reactions. residence time 111In-DOTATOC blood 0.9±0.4 h. activity excreted first 73%±11%. agent localized primarily spleen, kidneys liver. times source were: 2.2±1.8 1.7±1.2 kidneys, 2.4±1.9 liver, 1.5±0.3 urinary bladder 9.4±5.5 remainder body; mean 0.47 (range: 0.03–6.50 h). Based on our findings, predicted absorbed doses would be 7.6±6.3 (spleen), 3.3±2.2 (kidneys), 0.7±0.6 (liver), 2.2±0.3 (bladder), 0.03±0.01 (red marrow) 10.1 1.4–31.0) (tumour) mGy/MBq. These results indicate that can administered low risk myelotoxicity, although potentially radiation spleen kidneys. Tumour enough most cases make it likely disired therapeutic response desired obtained.