Multi-fractionated stereotactic radiotherapy

Precision and accuracy of a patient's treatment are key advantages of single-fraction stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMS) and some small brain metastases. These advantages are equally valuable in fractionated treatment of the pituitary, brain metastases and brain boost fields. The need to implement the preciseness from stereotactic radiosurgery to fractionated treatments was recognized. Using our experience with single-fraction stereotactic radiosurgery as a model, we developed a multi-fractionated stereotactic radiotherapy technique that allows us to immobilize a patient daily and implement important existing devices such as the Brown-Roberts-Wells (BRW) angiographic localizer, CT scan localizer, and non-coplanar shaped field treatment planning. Development of this technique also allows us to achieve reproducible patient positioning based on immobilization techniques using polyurethane foam immobilization and heat moldable plastic technology without the necessity of the invasive technique of skull fixation. The development, implementation and dosimetry of this technique will be discussed in this paper.