SU‐GG‐T‐367: Fast Hyperthermia Temperature Optimization for Pelvic Carcinoma Patient Treated in Sigma‐Eye Applicator

Purpose: Though hyperthermia shows promising features being used with radiation and chemotherapy, it requires accurate spatial power focusing, which leads a workload proportional to square of number of antennas in an applicator. This motivates this investigation of model reduction method for pelvic‐carcinoma patient treated in Sigma‐Eye applicator. Method and Materials: A patient placed in the middle ring of this 100 MHz 3‐ring 12‐antenna applicator was used to validate our approach. A ‘similar’ patient with different thermal property values, perfusion values and was placed between the middle and low ring was used to determined virtual source (VS) basis vectors. A VS vector is a weighted combination of magnitudes and phases of 12 antennas and was determined to maximize averaged tumor temperature. Physical variables were projected to a reduced VS subspace spanned by a few VS vectors. Temperature response functions of tumor and normal tissues were determined in this reduced subspace and then used in temperature optimization iteration process. Results: By comparing the optimized temperature elevation distributions, we found it is indeed feasible to use a few chosen (best) VS basis vectors to optimally treat a pelvic carcinoma patient in Sigma‐Eye applicator; even when we determined those virtual source basis vectors from an existing “similar” patient. Conclusion: This success suggests a faster and easier pre‐treatment temperature optimization approach that relives workloads of physicians. © 2008, American Association of Physicists in Medicine. All rights reserved.

Duke Scholars

Author Mark Wesley Dewhirst Radiation Oncology

Author Shiva Kumar Das Radiation Oncology