Commissioning and quality assurance of single isocenter stereotactic radiotherapy for multiple brain metastasis
Single-isocentric multi-focal stereotactic radiosurgery (SIMF-SRS) for multiple brain metastasis treatments, is one of the most challenging modern radiotherapy techniques. Spatial accuracy of dose delivery to each individual metastasis and the corresponding dose accuracy are both influencing significantly the treatment efficiency and patient safety. A comprehensive End-to-End QA methodology for commissioning, acceptance and periodic QA of such treatment modality is required in clinical practice. In this work, such a methodology is presented along with its results for a single clinical case. The methodology involves the use of 3D printing technology in combination with polymer gel dosimetry. Combined geometrical uncertainties of imaging, co-registration, set-up and dose delivery are evaluated. 3D relative dose distribution accuracy evaluation is also implemented. Conclusively, the high complexity of SIMF-SRS treatments poses the need for sophisticated End-to-End QA methodologies to be incorporated in the clinic. Such a methodology and its QA results are presented.