Study Finds CyberKnife Provides Safe, Effective Treatment to Control Brainstem Metastases

Accuray Incorporated announced an international retrospective multicenter analysis found that radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT), delivered with the CyberKnife System, can provide an effective and time-saving treatment option for brainstem metastases (BSM). The nine institution study results, published in the International Journal of Cancer, “underscore the long-term benefits in local control and the robust safety profile despite the delicate location of the treated metastases1.”

“The brainstem is an integral part of the central nervous system, and metastatic spread to this part of the brain is a potentially life-threatening situation. Since surgical resection is rarely an option, stereotactic radiosurgery and fractionated stereotactic radiotherapy are both effective and safe treatment options when thoroughly planned and executed. The available literature, along with our multicenter study, clearly underscores the central role of radiosurgery for affected patients,” said Felix Ehret, MD, Department of Radiation Oncology, Charité - Universitätsmedizin Berlin and European Radiosurgery Center Munich, Munich, Germany. 

SRS and FSRT – also referred to as fractionated radiosurgery – are advanced forms of radiation therapy. SRS delivers a high dose of radiation in one session, while FSRT divides the total treatment dose into multiple, smaller doses given over several days. Both techniques provide medical care teams with the ability to deliver extremely precise, very targeted doses of radiotherapy, typically to small, specific areas within the body, usually in the brain. In the reported analysis, 136 patients who received treatment in one to five sessions were analyzed; 69.4% received radiotherapy in just one treatment dose1.

"The brain's tissues and structures are incredibly delicate and are essential to everything from basic functions to the very essence of who we are as individuals. That's why we developed the CyberKnife System to deliver radiation with the utmost accuracy and precision, and why we remain committed to innovating for better clinical outcomes for people with brain tumors, lesions, and benign neurological conditions," said Seth Blacksburg, MD, MBA, Chief Medical Officer at Accuray.

The CyberKnife System can be used to treat brain tumors and neurological conditions with sub-millimeter accuracy and precision in just one to five sessions over one to two weeks. With the CyberKnife System, patients aren’t required to have a metal frame attached to their head to undergo treatment, enabling a wide range of people, including those with recurrent tumors and young patients who can’t be treated with a fixed head frame, to benefit from a shorter overall course of care that may positively impact their quality of life. The CyberKnife System can also be used at various stages in the treatment journey – from first line to adjuvant therapy and palliation – reinforcing its benefits in daily practice.

The objective of this analysis was to provide further evidence for the use of radiosurgery in the treatment of patients with BSM. The retrospective evaluation compared the safety and efficacy results achieved by nine institutions delivering radiotherapy in single (SRS) and up to five sessions (FSRT) with the CyberKnife® System to available published literature on these techniques. The multicenter study assessed 136 patients with 144 BSM who received treatment from 2005 to 2022. One hundred BSM were treated with SRS, and the remaining 44 received FSRT. The results showed one-year, two-year, and three-year local BSM control rates were 82.9%, 71.4%, and 61.2%. This study helps to underscore the long-term benefits in local control despite the delicate position of the treated metastases. SRS and FSRT treatments were well tolerated and the incidence of treatment-related side effects was low.