Stereotactic Radiosurgery (SRS) is the use of high doses of radiation delivered to small volumes within the brain with high precision.  Treatment may be delivered in a single fraction or a limited number of treatment sessions. 

SRS is delivered at UCSD on a Varian Trilogy linear accelerator.  Trilogy provides the ability to deliver SRS with a variety of approaches, including intensity modulated radiation therapy (IMRT).  Such flexibility allows the Radiation Oncologist to choose the treatment approach most appropriate for the individual patient.

Varian Trilogy

Unlike other SRS approaches (GammaKnife, CyberKnife), Trilogy uses a sophisticated optically-based image-guided treatment system, whereby infrared cameras in the treatment room are used to track the position of the patient in real-time during treatment. 

Real-time tracking SRS to be delivered without the need for a frame attached to the patient’s skull, as is commonly used in other SRS systems.  Frameless SRS is the preferred method of SRS delivery at UCSD and is used on the great majority of patients.

Interested in a comparison of competing SRS technologies?  Click here for a lecture delivered by Dr. Kevin Murphy of this issue.

Patient undergoing frameless SRS treatment on the Trilogy

An example treatment plan in a patient with a solitary brain metastasis undergoing SRS is shown below:

SRS Treatment of a Solitary Brain Metastasis The tumor completed resolved and the patient developed no adverse toxicity

An exciting and novel use of the Trilogy SRS system is the treatment of multiple metastases in a single session using intensity modulated SRS (IM-SRS).  Unlike conventional approaches which require several hours to deliver, IM-SRS can be used in patients with multiple metastases to quickly and safely deliver treatment.

Multiple clinical studies have demonstrated that SRS is a highly effective approach, particularly in many patients with brain metastases (view paper) and benign meningiomas (view paper 1 and paper 2). 

Ask your physician whether SRS is appropriate for the treatment for you. 

Click here to see a detailed overview of the frameless SRS Trilogy planning and treatment process.

Stereotactic Radiosurgery (Brain) Tumor Publications by UCSD Radiation Oncology Faculty         

Schomas DA, Roeske JC, Macdonald RL, Mehta N, Sweeney PJ, Mundt AJ. Predictors of tumor control in patients treated with linac-based stereotactic radiosurgery for metastatic disease to the brain. Am J Clin Oncol 2005;28:180

Ioffe V, Miller M, Sandhu APS, et. al. Radiosurgical treatment of brain metastases in a community oncologic practice. Commun Oncol 2004;1:149

Biswas T, Sandhu APS, et al. Low dose radiosurgery for benign intracranial lesions. Am J Clin Oncol. 2003;26:325

Saunders WM, Winston KR, Siddon RL, Svensson GH, Kijewski PK, Rice RK, et al. Radiosurgery for arteriovenous malformations of the brain using a standard linear accelerator: rationale and technique. Int J Radiat Oncol Biol Phys 1998;15:441