Hybrid computational phantoms offer unique advantages for the construction of diverse anthropomorphic models. In this paper, a methodology is presented for the construction of patient-dependent phantoms built around anthropometric distributions of the U.S. adult and pediatric populations. The methodology relies on the flexibility of hybrid phantoms to match target anthropometric parameters as determined from National Center for Health Statistics databases. Target parameters as defined in this paper include the primary parameters such as standing height, sitting height, and total body mass; and secondary parameters such as waist, buttocks, arm, and thigh circumference. As a demonstration of this methodology, the UF hybrid adult male (UFHADM) and UF hybrid 10-year-old female (UFH10F) were selected as representative anchor phantoms for this study and were subsequently remodeled to create 25 different adult male and 15 different pediatric female patient-dependent phantoms. The phantoms were evaluated based on appearance and internal organ masses. Aesthetically, the phantoms appear correct and display characteristics of a diverse population including variability in body shape and standing/sitting height. Organ masses display several general trends, including a gradual increase with both standing height and subject weight. Selected organ masses from the UFHADM series were also compared with published correlations taken from a 2001 French-based autopsy study. The organ masses were located well within the statistical deviation presented in the autopsy study and followed similar trends when correlated with both standing height and body mass index.

The presence of lymphatic nodes within computational human phantoms is critical to the evaluation of tissue doses in lymphoma patients treated with targeted radionuclide therapy. Furthermore, the International Commission on Radiological Protection (ICRP) now considers the lymphatic nodes to be a radiosensitive tissue of the remainder tissues of the effective dose as defined in ICRP Publication 103. Lymphatic nodes have previously not been included within the structure of stylized phantoms and are only present within a few voxel-based phantoms through manual retagging of voxels of the residual soft tissues. In this paper, an automated methodology is introduced whereby lymphatic nodes are placed-in an anatomically realistic fashion-within the University of Florida adult male reference hybrid phantom. First, a total of 16 lymphatic node anatomical sites are defined within the phantom. These include the extrathoracic, cervical, thoracic (upper and lower), breast (left and right), mesentery (left and right), axillary (left and right), cubital (left and right), inguinal (left and right), and popliteal (left and right) nodal regions. Secondly, individual lymphatic node positions are randomly sampled within spherical tissue regions centered at each previously selected lymphatic node site. Thirdly, smaller voxelized tissue spheres representing individual lymphatic nodes are then created to populate each nodal region of the phantom using a nominal nodal diameter. This process is repeated until a total lymphatic node mass is achieved to match age-dependent total reference masses derived from ICRP Publication 66 and 89 data. An illustrative set of radionuclide S-values for131I are presented whereby regional lymphatic nodes are considered to be independent source and target regions of a reference lymphoma patient. As nodal size can easily be changed within individual nodal regions, the lymphatic node model suggested in this paper can be used to obtain realistic dosimetry for lymphoma patients treated with radionuclide therapy.