Gamma Knife vs. TrueBeam

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  • Competition to treat benign and malignant brain tumors, vascular malformations, and functional disorders with stereotactic radiosurgery (SRS) has increased dramatically in recent years. All-in-one linear accelerator (linac) systems like Varian TrueBeam™ are aggressively positioning themselves as being comparable to Leksell Gamma Knife® in effectiveness and efficiency.

    Consider these fundamental differences between Gamma Knife and TrueBeam:

    Gamma Knife Perfexion

    Gamma Knife Perfexion
    Designed exclusively for non-invasive brain surgery, allowing optimized performance.
    MR Imaging, planning and treatment performed on the same day, as a single session outpatient procedure.
    A lightweight stereotactic frame is affixed to the head to provide rigid stabilization for maximum accuracy. This is the technology of choice for precision neurosurgery and is the same frame used in open craniotomies.
    Dedicated design minimizes chances of treatment errors.
    Radiation beam is stationary. There is no physical movement between beam and table during treatment.
    MRI used for treatment planning, avoiding x-ray exposure.
    As the most accurate of all SRS technologies, Gamma Knife has the lowest published radiation dose to normal brain tissue as well as to the rest of a patient’s body.


    Not designed exclusively for brain surgery, necessitating performance compromises (including sacrificing accuracy and increasing radiation exposure).
    Imaging, fitting of thermoplastic face mask, and planning performed on multiple days; treatment often performed over multiple days or weeks.
    A thermoplastic face mask (that is shrink-wrapped and then attached to the table during treatment) provides non-rigid immobilization which results in measurable head movement. This compromises treatment accuracy and increases radiation dose to normal brain tissue.
    Complicated equipment adjustments are required for SRS procedures, increasing chances of hazardous radiation exposure.*
    Radiation beam rotates during treatment producing pitch, roll and yaw patient positioning errors.
    Patient exposed to x-rays from CT scan used for treatment planning and from x-ray images taken every 10 seconds during treatment to confirm target position.
    Patient exposed to x-rays from CT scan used for treatment planning and from x-ray images taken every 10 seconds during treatment to confirm target position.

    *A Pinpoint Beam Strays Invisibly, Harming Instead of Healing, NYTimes,

    Gamma Knife is the gold standard for stereotactic radiosurgery treatment of brain disorders.

    The clinical effectiveness of Gamma Knife has been documented over four decades. More than 700,000 cases have been treated worldwide, providing data for over 3,000 publications in peer-reviewed medical literature.

    Gamma Knife radiosurgery is used as the performance metric against which other technologies (such as TrueBeam) are measured. Compared to linac modalities, Gamma Knife has the most accurate dose delivery system and exposes healthy brain tissue to significantly less radiation. For the treatment of metastatic tumors, multiple brain metastases, trigeminal neuralgia, arteriovenous malformations, and the vast majority of acoustic neuromas and meningiomas, Gamma Knife is superior to other technologies.

    No matter how complex or intricate the clinical challenge, Gamma Knife radiosurgery delivers the highest levels of physician and patient satisfaction. This makes it the treatment of choice at leading hospitals and clinics around the world.

    San Diego Gamma Knife Center pioneered radiosurgery and is the most experienced radiosurgery center in the greater San Diego community.