Details

Autor(en) / Beteiligte

• Indik, Robert A.
• Indik, Julia H.

Titel

A new computer method to quickly and accurately compute steady‐state temperatures from ferromagnetic seed heating

Ist Teil von

• Medical physics (Lancaster), 1994-07, Vol.21 (7), p.1135-1144

Ort / Verlag

United States: American Association of Physicists in Medicine

Erscheinungsjahr

1994

Quelle

MEDLINE

Beschreibungen/Notizen

• A new, very fast, yet accurate program, m g s e e d, has been developed that computes steady‐state temperatures from the three‐dimensional bioheat transfer equation due to heating by a ferromagnetic seed. Seeds have a self‐regulating power absorption characteristic such that their temperatures remain within a few degrees of their Curie transition point. The code is also very flexible, being able to model a seed of any orientation embedded in a tissue domain that can be inhomogeneous with respect to blood perfusion or thermal conductivity. m g s e e d uses multigrid (or multilevel) programming techniques as well as a finite volume discretization that exploits knowledge of the approximate shape of the temperature solution very near to a seed. These techniques allow the code to sample the seed very coarsely, requiring only one or two nodes to cross the seed. With these coarse samplings m g s e e d calculated very accurate temperatures in under 3 min of CPU time on a Sun Sparcstation 2. The accuracy of m g s e e d is demonstrated at different levels of perfusion by comparing its solution in a perpendicular plane that bisects the seed with the known analytical solution. The speed of m g s e e d is compared to other methods of solution and it is found that m g s e e d performs 14 times faster than successive over relaxation and conjugate gradient methods, and 2.5 times faster than a preconditioned (modified block incomplete Cholesky) conjugate gradient method. It is concluded that the techniques for discretization and solution incorporated into m g s e e d can greatly improve the flexibility and speed of hyperthermia treatment planning, which could ultimately lead to an increased level of control over treatment outcome.