CURRENT ISSUES IN COMPUTATIONAL METHODS-ROUNDTABLE: COMPUTATIONAL HUMAN PHANTOMS

摘要

The objective of this panel is to assemble several world renowned experts to discuss the pros and cons of a number of technologies that Computational human phantoms are models of the human body used in radiation transport codes. Since the 1960s, these models have been used in both deterministic and Monte Carlo transport codes to determine organ doses for applications in shielding, health physics, and medical physics. As computer capabilities have evolved over the years, so have the detail and sophistication of phantoms. Early phantoms were simplified solid body models; today's phantoms include detailed voxels, non-uniform B-splines, and unstructured meshes, and have been extended to 4D (space+time) for simulations involving respiratory and cardiac motions. A very recent development is classes of deformable phantoms that can be tailored to body stature, age, pregnancy, height, obesity, and other individual characteristics. The phantom posture can be adjusted to simulate nuclear accidents and deep space exploration. While about 10 phantoms were available prior to the 1980s, we now have more than 200. Phantoms developed over the last 5 years are extremely demanding of today's computer resources and transport codes. Even codes used for large-scale, detailed reactor analysis are pushed to or beyond their limits in terms of the type and size of the geometrical information in the latest and future phantoms. Many research groups worldwide are developing highly parallel GPU- or MIC-based transport codes for radiation treatment planning to analyze these phantoms in less than 1 minute, rather than the hours or days needed by conventional codes.