Patient-specific dosimetry calculations using mathematic models of different anatomic sizes during therapy with 111In-DTPA-D-Phe1-octreotide infusions after catheterization of the hepatic artery.

Abstract

UNLABELLED:

The aim of the study was to provide dosimetric data on intrahepatic (111)In-diethylenetriaminepentaacetic acid (DTPA)-D-Phe(1)-octreotide therapy for neuroendocrine tumors with overexpression of somatostatin receptors.

METHODS:

A dosimetric protocol was designed to estimate the absorbed dose to the tumor and healthy tissue in a course of 48 treatments for 12 patients, who received a mean activity of 5.4 +/- 1.7 GBq per session. The patient-specific dosimetry calculations, based on quantitative biplanar whole-body scintigrams, were performed using a Monte Carlo simulation program for 3 male and 3 female mathematic models of different anatomic sizes. Thirty minutes and 2, 6, 24, and 48 h after the radionuclide infusion, blood-sample data were collected for estimation of the red marrow radiation burden.

RESULTS:

The mean absorbed doses per administered activity (mGy/MBq) by the critical organs liver, spleen, kidneys, bladder wall, and bone marrow were 0.14 +/- 0.04, 1.4 +/- 0.6, 0.41 +/- 0.08, 0.094 +/- 0.013, and (3.5 +/- 0.8) x 10(-3), respectively; the tumor absorbed dose ranged from 2.2 to 19.6 mGy/MBq, strongly depending on the lesion size and tissue type.

CONCLUSION:

The results of the present study quantitatively confirm the therapeutic efficacy of transhepatic administration; the tumor-to-healthy-tissue uptake ratio was enhanced, compared with the results after antecubital infusions. Planning of treatment was also optimized by use of the patient-specific dosimetric protocol.

• Authors: Dimitrios K Kontogeorgakos, Panagiotis A Dimitriou, Georgios S Limouris, Lambros J Vlahos
• Journal: Journal of nuclear medicine : official publication, Society of Nuclear Medicine (J Nucl Med) Vol. 47 Issue 9 Pg. 1476-82 (Sep 2006) ISSN: 0161-5505 [Print] United States
• PMID: 16954556 (Publication Type: Controlled Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Radiopharmaceuticals
• Somatostatin
• pentetreotide

Topics

• Adult
• Aged
• Body Burden
• Body Size
• Computer Simulation
• Female
• Hepatic Artery (diagnostic imaging, metabolism)
• Humans
• Image Interpretation, Computer-Assisted (methods)
• Infusions, Intra-Arterial
• Male
• Middle Aged
• Models, Biological
• Neuroendocrine Tumors (diagnostic imaging, radiotherapy)
• Radiometry (methods)
• Radionuclide Imaging
• Radiopharmaceuticals (administration & dosage, therapeutic use)
• Radiotherapy Dosage
• Radiotherapy Planning, Computer-Assisted (methods)
• Relative Biological Effectiveness
• Reproducibility of Results
• Sensitivity and Specificity
• Somatostatin (administration & dosage, analogs & derivatives, therapeutic use)