Quality indicators for hyperthermia treatment: Italian survey analysis.

AIM: Nowadays, no Quality Indicators (QI) have been proposed for Hyperthermia treatments. Starting from radiotherapy experience, the aim of this work is to adapt radiotherapy indicators to Hyperthermia and to propose a new specific set of QI in Hyperthermia field. MATERIAL AND METHODS: At first, radiotherapy quality indicators published in literature have been adapted to hyperthermia setting. Moreover, new specific indicators for the treatment of hyperthermia have been defined. To obtain the standard reference values of quality indicators, a questionnaire was sent to 7 Italian hyperthermia Institutes with a list of questions on physical and clinical hyperthermia treatment in order to highlight the different therapeutic approaches. RESULTS: Three structure, five process and two outcome QI were selected. It has been possible to adapt seven indicators from radiotherapy, while three indicators have been defined as new specific indicators for hyperthermia. Average values used as standard reference values have been obtained and proposed. CONCLUSION: The survey performed on 7 Italian centres allowed to derive the standard reference value for each indicator. The proposed indicators are available to be investigated and applied by a larger number of Institutes in which hyperthermia treatment is performed in order to monitor the operational procedures and to confirm or modify the reference standard value derived for each indicator.

NOD-SCID mice irradiation with medical accelerators: Dosimetric and radiobiological results.

PURPOSE: Preclinical studies normally requires dedicated instruments due to the small anatomical scales involved, but the possibility of using clinical devices for this purpose may be of economical, scientific and translational interest. In the present work the accurate description of treatment planning, dosimetric results, radiotoxicity and tumor response of the irradiation of NOD-SCID mice were presented. Two medical linear accelerators, TrueBeam STx and Tomotherapy Hi-ART, were compared. NOD-SCID mice irradiation with Tomotherapy is a novelty, as well as the comparison of different irradiation techniques, devices and dose fractionations. METHODS: Human derived glioblastoma multiforme neurospheres were injected in immunocompromised NOD-SCID mice to establish xenograft models. Mice were anaesthetized and placed in a plexiglas cage pieboth to perform CT scan for treatment planning purposes and for the irradiation. Three fractionation schedules were evaluated: 4Gy/1 fraction, 4Gy/2 fractions and 6Gy/3 fractions. Tomotherapy planning parameters, the presence of a bolus layer and the irradiation time were reported. After irradiation, mice were examined daily and sacrificed when they showed signs of suffering or when tumor volume reached the established endpoint. Outcomes regarding both radiotoxicity and tumor response were evaluated comparing irradiated mice as respect to their controls. RESULTS: Survival analysis showed that Tomotherapy irradiation with 6Gy/3 fractions with a bolus layer prolong mice survival (log-rank test, p<0.02). Tumor volume and mice survival were significantly different in irradiated xenografts as compared to their controls (t-test, p<0.03; log-rank, p<0.05). CONCLUSION: The radiobiological potential of Tomotherapy in inducing tumor growth stabilization is demonstrated.