CT-resolution regional hyperthermia treatment planning

• Published in: International journal of hyperthermia Vol. 18; no. 2; pp. 104 - 116
• Main Authors: Kamer, J. B. van de, Vulpen, M. van, Leeuw, A. A. C. de, Kroeze, H., Lagendijk, J. J. W.
• Format: Journal Article
• Language: English
• Published: London Informa UK Ltd 2002; Taylor & Francis
• Subjects: Biological and medical sciences; High-RESOLUTION Sar Modelling; Hyperthermia, Induced; Medical sciences; Quasistatic Zooming; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Regional Hyperthermia Treatment Planning; Technology. Biomaterials. Equipments. Material. Instrumentation; Therapy, Computer-Assisted; Tomography, X-Ray Computed; Human; Regional treatment; High resolution; Temperature; Radiodiagnosis; Hot spot; Instrumentation therapy; Low resolution; Biophysics; Thermotherapy; Distribution; Medical imagery; Computerized axial tomography; Treatment planning; Computer aid; Comparative study; Induced hyperthermia
• ISSN: 0265-6736; 1464-5157
• DOI: 10.1080/02656730110092620

Recent development of quasistatic zooming has enabled the computation of mm-resolution SAR distributions within reasonable computation times. These high-resolution SAR distributions proved to be completely dissimilar from the cm-resolution distributions. To study the impact of high-resolution SAR modelling on regional hyperthermia treatment planning (HTP), a conventional, low-resolution treatment plan is compared to an high-resolution plan. This comparison shows that the high-resolution plan yields totally different SAR and temperature distributions when compared to the conventional plan. Both SAR and temperature maxima predicted by the low-resolution plan are not predicted by the high-resolution plan and, even worse, the low-resolution plan fails to predict maxima that are predicted by the high-resolution plan. Furthermore, it appears that small-scale SAR maxima can result in temperature maxima which may cause treatment-limiting hot spots. These small-scale SAR maxima appear to be highly determined by the dielectric geometry of the patient. This demonstrates the need for an accurate, high-resolution description of this dielectric geometry. Moreover, it suggests that it may be very difficult to reduce potential treatment-limiting hot spots in clinical practice. This study demonstrates the need for high-resolution regional hyperthermia treatment planning.