Differences in biodistribution between 99mTc-depreotide, 111In-DTPA-octreotide, and 177Lu-DOTA-Tyr3-octreotate in a small cell lung cancer animal model.
Cancer Biother Radiopharm
; 20(2): 231-6, 2005 Apr.
Article
em En
| MEDLINE
| ID: mdl-15869461
ABSTRACT
AIM:
(177)Lu-DOTA-Tyr(3)-octreotate is a candidate radiopharmaceutical for the therapy of somatostatin receptor (sstr)-positive small cell lung cancer (SCLC). Scintigraphy of lung tumors is made with 2 alternative somatostatin analogs, (111)In-DTPA-octreotide or (99m)Tc-depreotide. The aim of this study was to compare the biodistribution of these 3 radiopharmaceuticals in SCLC xenografted to nude mice.METHODS:
Nude mice, bearing tumors from the human SCLC cell line NCI-H69, were intravenously injected with 10 MBq (2.4 microg) (99m)Tc-depreotide and 2 MBq (0.5 microg) (111)In-DTPA-octreotide simultaneously. The activity concentration (%IA/g) was measured in tumor and normal tissue at 2, 4, and 24 hours postinjection (hpi). The results were compared with earlier published biodistribution data of 3 MBq (0.7 microg) (177)Lu-DOTA-Tyr(3)-octreotate in the same animal model.RESULTS:
The activity concentration of (111)In-DTPAoctreotide in tumor was higher than the activity concentration of (99m)Tc-depreotide at 2-24 hpi, p < 0.05. The highest tumor uptake at 24 hpi was, however, found for (177)Lu-DOTA-Tyr(3)-octreotate. The activity concentration of (99m)Tc-depreotide was significantly higher in the heart, lungs, liver, the salivary glands, spleen, and bone marrow than for (111)In-DTPA-octreotide at 2-24 hpi. Saturation of the somatostatin receptors may have influenced the uptake in tumor and sstr-positive normal tissues.CONCLUSION:
The low tumor-to-lung and tumor-to-liver activity concentration ratios for (99m)Tc-depreotide could result in a lower detection rate of SCLC with this compound versus (111)In-DTPA-octreotide. (177)Lu-DOTA-Tyr(3)-octreotate gave the highest tumor-activity concentration, and has, thus, the best properties for therapy.
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Base de dados:
MEDLINE
Assunto principal:
Compostos Organometálicos
/
Somatostatina
/
Octreotida
/
Compostos de Organotecnécio
/
Carcinoma de Células Pequenas
/
Ácido Pentético
/
Neoplasias Pulmonares
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article