Introduction: Hyperthermia efficacy depends on the temperatures achieved in the target area. Therefore, hyperthermia systems must deliver both controlled and conformal heating. This study presents a comprehensive multi-institutional quality assurance (QA) evaluation of deep hyperthermia devices. Methods: Six European institutions equipped with BSD- Sigma 60 and Sigma Eye deep hyperthermia applicators participated in the study. Up to six measurements per applicator were performed in each institution. The thermal distribution in cylindrical homogeneous phantoms after 10 minutes of heating with a total power delivered of 1000 watts was assessed using the applicator’s integrated mapping thermometry system. Evaluated quality parameters included temperature increase, focus location, and focus symmetry. Results: A total of 54 measurements were conducted, with 43 included in the analysis. All applicators, except one, achieved a temperature increase of 6 °C in 10 minutes. Central heating capabilities were demonstrated, with mean deviations from the intended location of −1.4 ± 1.6 cm for Sigma 60 and 1.5 ± 1.4 cm for Sigma Eye. Symmetry evaluations showed differences in radial temperature profiles of 6.2 ± 4.5 % for the Sigma 60 and 5.9 ± 4.4 % for the Sigma Eye. We propose minimum acceptable values for each quality parameter based on these results. Conclusion: The measurements were reproducible with acceptable values for the various quality parameters. Potential deviations might be attributed to inaccuracies in the mapping thermometry system rather than the heating system. The presented protocol and practical recommendations should be applied for future QA measurements in deep hyperthermia.

Purpose: This study aimed to assess the quality of the lucite cone applicator (LCA), the standard applicator for superficial hyperthermia at the Erasmus MC Cancer Institute, using the most recent quality assurance guidelines, thus verifying their feasibility. Materials and methods: The assessment was conducted on each of the six LCAs available for clinical treatments. The temperature distribution was evaluated using an infrared camera across different layers of a fat-muscle mimicking phantom. The maximum temperature increase, thermal effective penetration depth (TEPD), and thermal effective field size (TEFS) were used as quality metrics. The experimental results were validated through comparison with simulated results, using a canonical phantom model and a realistic phantom model segmented from CT imaging. Results: A maximum temperature increase above 6 °C at 2 cm depth in the fat-muscle phantom for all the experiments was found. A mean negative difference between simulated and experimental data was of 1.3 °C when using the canonical phantom model. This value decreased to a mean negative difference of 0.4 °C when using the realistic model. Simulated and measured TEPD showed good agreement for both in silico scenarios, while discrepancies were present for TEFS. Conclusions: The LCAs passed all QA guidelines requirements for superficial hyperthermia delivery when used singularly or in an array configuration. A further characterization of parameters such as antenna efficiency and heat transfer coefficients would be beneficial for translating experimental results to simulated values. Implementing the QA guidelines was time-consuming and demanding, requiring careful preparation and correct setup of antenna elements.