Spain’s Fundación Instituto Valenciano de Oncología (IVO) has conducted its first simulated therapy for brain metastases using RTsafe’s PseudoPatient. This patient-specific quality assurance process comprises an anatomically faithful model of each patient’s head aligned to dosimetric evaluation services. The technology
enables medical physicists and clinicians to verify the entire treatment process before the patient is subjected to radiotherapy.
RTsafe founder and chief scientific officer Evangelos Pappas commented: “We are delighted that IVO has embraced the concept of assuring patient safety and treatment efficiency through human-like simulation of the stereotactic radiosurgery [SRS] process.”
The simulation was carried out ahead of IVO’s first patient treatment using the new TrueBeam linear accelerator from Varian Medical Systems, a Siemens Healthineers company, that integrates radiotherapy and image-guided radiosurgery on the same platform.
A case study published by medical technology distribution company Aplicaciones Tecnológicas de la Física points out that due to the complexity of administering SRS plans, periodic quality control protocols and pretreatment dose verification procedures based on actual patient anatomy are advisable and could improve treatment efficiency.
The PseudoPatient treatment verification process begins with the construction of a 3D-printed phantom based on the patient’s CT scan, accurately reproducing the bone anatomy. The phantom is then filled with a polymer gel that acts as both a soft tissue equivalent material and a 3D dosimeter. The end-to-end radiosurgery procedure is then performed just as it would be on the real patient. The irradiated phantom is MRI scanned and changes in the gel’s magnetic properties reveal the treated areas. RTsafe then provides a comprehensive quantitative and qualitative report in order to assist the clinical team in verifying the treatment plan or making adjustments to it.
“Brain metastases can occur in more than 30 per cent of all cancer patients and, while SRS is a good treatment option for many patients, its complexity means that accurate pretreatment dose verification could make a difference to treatment outcomes should an adjustment to dosage or targeting be indicated by the simulation process,” Pappas added.
Picture: RTsafe’s PseudoPatient is used to verify radiotherapy dosage and accuracy ahead of treatment.
Published on page 10 of the March 2023 issue of RAD Magazine.