In this study we evaluated for a realistic head model the 3D temperature rise induced by a mobile phone. This was done numerically with the consecutive use of an FDTD model to predict the absorbed electromagnetic power distribution, and a thermal model describing bioheat transfer both by conduction and by blood flow. We calculated a maximum rise in brain temperature of 0.11 degrees C for an antenna with an average emitted power of 0.25 W, the maximum value in common mobile phones, and indefinite exposure. Maximum temperature rise is at the skin. The power distributions were characterized by a maximum averaged SAR over an arbitrarily shaped 10 g volume of approximately 1.6 W kg(-1). Although these power distributions are not in compliance with all proposed safety standards, temperature rises are far too small to have lasting effects. We verified our simulations by measuring the skin temperature rise experimentally. Our simulation method can be instrumental in further development of safety standards.

strong enhancement of the electric-field values in SC-2 as compared with the ones obtained without the eyeglasses (that is, SC-1). The results obtained from the two scans (corresponding to the left and right eye lines, respectively) are reported in Figure 5. For the right eye (the one closer to the antenna), which is supposed to be positioned about 20 mm from the lens plane, we have measured a field value of 78.3 V/m, corresponding to 2.12 times the value observed without the eyeglasses. The left eye, on the contrary, exhibits a value of 48.4 V/m, which is more than 2.86 times above the value in the absence of eyeglasses. These values are expected to be different from those which can be measured in the real scenario, where the user's head is considered. However, also in this case, we anticipate a field increase in the ocular region, induced by the presence of the eyeglasses with metallic frames. CONCLUSIONThe enhancement induced by metallic eyeglasses on the e.m. field emitted by a cellular telephone has been investigated numerically and experimentally in a simplified scenario, where we neglect any e.m. effect arising from the presence of the user's head tissues. A significant local increase of the electric field has been detected. This can be especially relevant in the eye region, where hazardous situations can be envisaged. ACKNOWLEDGMENTPart of this work has been sponsored by MIUR.

The Technical Committee and the Clinical Committee of the ESHO evaluated the experience of the institutes which are active in clinical regional hyperthermia using radiative equipment. Based on this evaluation, QA guidelines have been formulated. The focus of these guidelines lies on what must be done not on how it should be done. Subjects covered are: treatment planning, treatment, treatment documentation, requirements and characterization of equipment, safety aspects, hyperthermia staff requirements and instrumentation for quality assurance.

A flexible and fast regional hyperthermia treatment planning system for the Coaxial TEM System has been devised and is presented. Using Hounsfield Unit based thresholding and manually outlining of the tumour, a 40 cm CT data set (slice thickness 5 mm) is segmented and down scaled to a resolution of 1 cm, requiring only 30 min. The SAR model is based on the finite-difference time-domain (FDTD) method. The number of time steps to achieve numerical stability has been determined and was found to be 7000. Various optimizations of the SAR model have been applied, resulting in a relatively short computation time of 3.7 h (memory requirements 121 MB) on a Pentium III, 450 MHz standard personal computer, running GNU/Linux. The model has been validated using absolute value(Ez) measurements in a standard phantom inserted in the Coaxial TEM Applicator under different conditions and a good agreement was found. Hyperthermia treatment planning in combination with the homemade visualization tools have provided much insight in the regional hyperthermia treatment with the Coaxial TEM Applicator.

Today most treatments with regional hyperthermia are applied using radiofrequency systems with 'focus' steering by amplitude and phase control. This paper deals with quality assurance procedures developed to ensure controlled and safe treatments in such systems. Our results show how the deviations between requested and observed phase and amplitude vary with frequency, and how these deviations depend on both the geometry of the object (phantom) inside the system and the power level applied. The results also indicate that the investigated systems' internal quality assurance procedures were inadequate and that additional procedures should be applied. Since the system parameters depend on patient and treatment specific conditions it is concluded that there is a need for QA measurements before or during treatment. This paper deals specifically with the commercial BSD-2000 system from BSD Medical Corp. in Salt Lake City, Utah, as installed in Bergen, but the procedure outlined can be applied to other phase and amplitude-controlled RF-RHT systems with only minimal adjustments.