Verification of electron beam parameters in an intraoperative linear accelerator using dosimetric and radiobiological response methods

Abstract

Background The availability of linear accelerators (linac) for research purposes is often limited and therefore alternative radiation sources are needed to conduct radiobiological research. The National Centre for Radiation Research in Poland recently developed an intraoperative mobile linac that enables electron irradiation at energies ranging from 4 to 12 MeV and dose rates of 5 or 10 Gy/min. The present study was conducted to evaluate the electron beam parameters of this intraoperative linac and to verify the set-up to evaluate out-of-field doses in a water phantom, which were determined through dosimetric and biological response measurements. Materials and methods The distribution of radiation doses along and across the radiation beam were measured in a water phantom using a semiconductor detector and absolute doses using an ionisation chamber. Two luminal breast cancer cell lines (T-47D and HER2 positive SK-BR-3) were placed in the phantom to study radiation response at doses ranging from 2 to 10 Gy. Cell response was measured by clonogenic assays. Results and Conclusion The electron beam properties, including depth doses and profiles, were within expected range for the stated energies. These results confirm the viability of this device and set-up as a source of megavoltage electrons to evaluate the radiobiological response of tumour cells.

A pragmatic approach to analyze the ability of ethylene‐octene copolymer in the long chain branching of polypropylene in molten and solid state

“…To investigate the impact of electron beam (EB) irradiation on the long‐chain branching (LCB) process in ethylene‐octene copolymers (EOC), it is crucial to minimize degradation reactions. To achieve this, the samples were exposed to a fixed dose of 12.5 kGy 49–51 . After irradiation, the samples underwent the following annealing process: Initial annealing under a nitrogen atmosphere for 30 min at 80°C to facilitate the mobility of free radicals. Subsequent annealing for 90 min at 130°C to deactivate the remaining free radicals. …”

“…To achieve this, the samples were exposed to a fixed dose of 12.5 kGy. [49][50][51] After irradiation, the samples underwent the following annealing process:…”