Elekta has reported positive data from a clinical study of its MR-linac magnetic resonance radiation therapy (MR/RT) system in patients with lumbar spinal bone metastases.
The MR-guided system is designed to integrate a 1.5 Tesla MR scanner with advanced linear accelerator and intelligent software.
Conducted at the University Medical Centre Utrecht (UMCU) in the Netherlands, the study showed that the system delivers high dosing with positional accuracy and enables the making of treatment decisions throughout the radiation delivery process.
The system could simultaneously capture high-quality MR images to allow visualisation of tumours at any time.
UMCU Experimental Physics professor Bas Raaymakers said: “These first clinical treatments show an outstanding level of dosimetric and geometric accuracy of the online IMRT planning and the radiation delivery based on the 1.5T MRI guidance.
“This approach enables the optimisation of dose to the tumour while reducing exposure of healthy tissue.”
During the study, four subjects were treated with a single fraction of 8Gy that was prescribed to the target volume while reducing the dose to the spinal cord and other body locations.
To determine stereotactic accuracy, delivered plan and imaging analyses were performed, along with quality assurance procedures for the pre-treatment plan.
The online MRI guidance’s geometric accuracy was validated with the comparison of portal images of the IMRT segments and MRI-based calculated projections.
Elekta Scientific Research global vice-president Kevin Brown said: “These preliminary results are exciting and support the tremendous potential of Elekta’s MR-linac to address some of the historic challenges to improving the safety and efficacy of radiation therapy.”