This linear accelerator (linac) represents the state of the art in external beam radiation treatment delivery.  The Trilogy system includes all of the features of the Varian Clinac 23EX series of linacs, plus several additional features that make it the first system capable of delivering all forms of external beam radiation therapy:  3D conformal radiotherapy, intensity modulated radiation therapy (IMRT), stereotactic radiosurgery (SRS), fractionated stereotactic radiotherapy (FSR), and intensity-modulated stereotactic radiosurgery (IM-SRS).

     The Trilogy system also provides several features that represent new advances in radiation treatment delivery.  The most important of these are accessories for image-guided radiation therapy (IGRT) and respiratory gating.  The on-board imager (OBI) provides highly detailed images of the patient in the treatment position at the time of treatment delivery, allowing rapid fine adjustments to improve accuracy.  The respiratory gating system is useful for many patients with tumors in the chest or abdomen that move with the patient's breathing cycle.  This system allows our radiation oncologists to track the tumor motion, thereby reducing radiation field size and minimizing radiation dose delivered to normal tissues.

     The Emory Clinic's Trilogy system is equipped with the Millenium 120-leaf dynamic multi-leaf collimator, and has a higher maximum dose rate and a more restrictive isocenter tolerance.  The maximum excursion of the isocenter on all three rotational axes (gantry, couch, and collimator) is a 1.5 mm diameter sphere.  The Trilogy system provides a range of photon (X-ray) and electron energies for treating various malignancies.

Varian Clinac 2300 CD Linear Accelerator

     At the Emory Clinic, we use this modern medical linac to achieve the best outcome and to maximize patient convenience.

     This dual-energy machine has the capability of producing a high energy X-ray beam (18 million electron volts) and a lower energy X-ray beam (6 million electron volts).  The linac also can produce an assortment of electron beams with energies varying between 6 and 22 million electron volts.  Thus, it can be used for a wide range of clinical conditions, from superficial skin lesions to prostate cancer deep in the pelvis.

     This linac also is equipped with a modern 120-leaf Millenium collimating system (Dynamic Multi-leaf Collimator, or DMLC).  Heavy, manually-mounted shielding blocks are no longer necessary, making the treatment more accurate and faster.  Often, the Millenium collimator system reduces the time necessary to treat a particular patient by two thirds.  Each treatment field can be programmed to achieve a highly conformal delivery of radiation doses to the target lesion using the DMLC.  Furthermore, the DMLC collimator may be used to deliver intensity modulated radiation therapy (IMRT), in which the intensity at different points within the radiation beam is finely adjusted to suit each treatment volume for individual patients.  The target lesion can be programmed to receive a higher radiation dose while radiation doses to neighboring organs can be reduced. 

Varian Clinac 600 CD Linear Accelerator

     At Emory, this linear accelerator is used to achieve the best clinical results for most of our patients with cancers of the brain or head/neck.

     This linac produces a single lower energy X-ray beam (6 million electron volts) which is used to treat lesions relatively close to the skin surface.  This unit has a new Dynamic Multi-leaf Collimator with 120 individual leaves. This Millenium collimator allows detailed shaping of the radiation field for treating areas of the body with many important structures in close proximity.