TY - JOUR

T1 - Inverse Techniques in Hyperthermia

T2 - A Sensitivity Study

AU - Clegg, Scott T.

AU - Samulski, Thaddeus V.

AU - Murphy, Katherine A.

AU - Rosner, Gary L.

AU - Dewhirst, Mark W.

N1 - Funding Information:
Manuscript received April 2, 1992; revised December 13. 1993. This work was supported by NIH/NCI Grant 2P0I CA42745-05. S. T. Clegg, T. V. Samulski, G. L. Rosner, and M. W. Dewhirst are with the Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 USA. K. A. Murphy is with the Department of Mathematics, Universily of North Carolina, Chapel Hill, NC 27599 USA. IEEE Log Number 9401228.

PY - 1994/4

Y1 - 1994/4

N2 - Numerical modeling methods and hyperthermia treatment temperature measurements have been used together to reconstruct steady-state tumor temperature distributions. However, model errors will exist which may in turn produce errors in the reconstructed temperature distributions. A series of computer experiments was conducted to study the sensitivity of reconstructed two-dimensional temperature distributions to perfusion distribution modeling errors. Temperature distributions were simulated using a finite element approximation of Pennes’ bioheat transfer equation. Relevant variables such as tumor shape, perfusion distribution, and power deposition were modeled. An optimization method and the temperatures “measured” from the simulated temperature distributions were used to reconstruct the tumor temperature distribution. Using this procedure, the sensitivity of the reconstructed tumor temperature distribution to model-related errors, such as the perfusion function, was studied. It was found that: 1) if the problem is conduction dominated, large errors in the perfusion distribution produce only small errors in the reconstructed temperature distribution (maximum error <1.0° C), and 2) when the actual perfusion distribution contains a small random variation (±15%) which is neglected by the model, the reconstructed temperature distribution will be in good agreement with the actual temperature distribution (maximum error ≤ 0.3°.

AB - Numerical modeling methods and hyperthermia treatment temperature measurements have been used together to reconstruct steady-state tumor temperature distributions. However, model errors will exist which may in turn produce errors in the reconstructed temperature distributions. A series of computer experiments was conducted to study the sensitivity of reconstructed two-dimensional temperature distributions to perfusion distribution modeling errors. Temperature distributions were simulated using a finite element approximation of Pennes’ bioheat transfer equation. Relevant variables such as tumor shape, perfusion distribution, and power deposition were modeled. An optimization method and the temperatures “measured” from the simulated temperature distributions were used to reconstruct the tumor temperature distribution. Using this procedure, the sensitivity of the reconstructed tumor temperature distribution to model-related errors, such as the perfusion function, was studied. It was found that: 1) if the problem is conduction dominated, large errors in the perfusion distribution produce only small errors in the reconstructed temperature distribution (maximum error <1.0° C), and 2) when the actual perfusion distribution contains a small random variation (±15%) which is neglected by the model, the reconstructed temperature distribution will be in good agreement with the actual temperature distribution (maximum error ≤ 0.3°.

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U2 - 10.1109/10.284965

DO - 10.1109/10.284965

M3 - Article

C2 - 8063303

AN - SCOPUS:0028420008

VL - 41

SP - 373

EP - 382

JO - IRE transactions on medical electronics

JF - IRE transactions on medical electronics

SN - 0018-9294

IS - 4

ER -