TY - JOUR T1 - Patient-Specific Dosimetry Calculations Using Mathematic Models of Different Anatomic Sizes During Therapy with <sup>111</sup>In-DTPA-<span class="sc">d</span>-Phe<sup>1</sup>-Octreotide Infusions After Catheterization of the Hepatic Artery JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1476 LP - 1482 VL - 47 IS - 9 AU - Dimitrios K. Kontogeorgakos AU - Panagiotis A. Dimitriou AU - Georgios S. Limouris AU - Lambros J. Vlahos Y1 - 2006/09/01 UR - http://jnm.snmjournals.org/content/47/9/1476.abstract N2 - The aim of the study was to provide dosimetric data on intrahepatic 111In-diethylenetriaminepentaacetic acid (DTPA)-d-Phe1-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) × 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. ER -