Radiobiological modeling of hyperthermia combined with Gamma-Knife radiosurgery in pediatric brain cancer

Assessment of the synergistic effect of radiotherapy (RT) and hyperthermia (HT) in clinical settings is crucial for further expansion of hyperthermia. The radiobiological modeling using an extended version of the LQ model with temperature-dependent radiosensitivity parameters has been suggested in combination with external beam radiotherapy in previous studies. This study investigates the radiobiological effect of intracranial hyperthermia combined with stereotactic radiosurgery (SRS) in pediatric brain cancers.\ua0The hyperthermia treatment plan was achieved with an elliptical applicator consisting of 16 ORWG antennas working at 400 MHz and a hybrid Specific Absorption Rate (SAR) optimization procedure based on Time-Reversal and PSO. The radiotherapy plan was created by the treatment planning software of Leksell Gamma Knife\uae Icon™

Radiobiological evaluation of combined gamma knife radiosurgery and hyperthermia for pediatric neuro-oncology

Combining radiotherapy (RT) with hyperthermia (HT) has been proven effective in the treatment of a wide range of tumours, but the combination of externally delivered, focused heat and stereotactic radiosurgery has never been investigated. We explore the potential of such treatment enhancement via radiobiological modelling, specifically via the linear-quadratic (LQ) model adapted to thermoradiotherapy through modulating the radiosensitivity of temperature-dependent parame-ters. We extend this well-established model by incorporating oxygenation effects. To illustrate the methodology, we present a clinically relevant application in pediatric oncology, which is novel in two ways. First, it deals with medulloblastoma, the most common malignant brain tumour in children, a type of brain tumour not previously reported in the literature of thermoradiotherapy studies. Second, it makes use of the Gamma Knife for the radiotherapy part, thereby being the first of its kind in this context. Quantitative metrics like the biologically effective dose (BED) and the tumour control probability (TCP) are used to assess the efficacy of the combined plan