Jump to content



Recommended Posts


Here is what I found when i did a search, hope this helps.



The Cyberknife is a new high-technology system that delivers LINAC radiosurgery using a robotic arm controlled by an image-guided computer technology similar to that used by the military in cruise missiles. The Cyberknife was approved by the FDA in July 1999.

Unlike conventional radiotherapy systems where the treatment machine is not able to verify the position of the tumor, the Cyberknife can define and confirm critical information concerning the position of the tumor during the treatment. Through the use of this "smart bream" technology, the accuracy of targeting is improved. According to latest research results (see Chang et al, Neurosurgery, page 140, January 2003), the accuracy of Cyberknife targeting is comparable to that of fixed (attached) frames such as in Gamma Knife treatments, and more accurate than for relocatable frames based on either bite blockes or masks, such as used for FSR.

Dr. John R. Adler (Professor of Neurosurgery, Stanford University) has provided more details about the increase in accuracy:

the RMS error measured was 1.2 mm in this paper [by Chang et al], which is in fact considerably less than the 1.8-2.0 mm errors reported for skeletally attached stereotactic frames.

This improvement comes at the price of exposure to additional radiation, in the form of X-rays. There are two ceiling mounted X-ray cameras that target the regional anatomy around the tumor, and a high speed computer that analyzes the images. The data is converted into information about the location of the patients' features, such as bone structure. The computer can account for any small changes in the position of the patient during treatment, and can deliver the radiation dose to the target with high precision.

According to Dr. John R. Adler, this additional X-ray exposure is not a concern:

the exposure to the head during a standard single treatment or even the more typical 3 stage procedure used at Stanford for acoustic neuroma, adds up to no more than the x-ray dose administered in 1 or 2 CT scans. Such a dose is much less than scatter given off by a treating linear accelerator for example, and is widely considered by most radiosurgical practioners, to be inconsequential.

It is important to note that Cyberknife differs from FSR in more than just the method of positioning. A crucial difference is that the robotic arm delivering radiation during Cyberknife treatment does not perform a continuous motion, as for standard FSR treatment with LINAC. Rather, it makes many short stops; the X-ray based targeting as well as the radiation shots are only applied during these stops rather than throughout the motion. Conceptually, this is more akin to Gamma Knife, where the radiation comes in individual beams that intersect at the tumor.

While the Cyberknife is a great new technology for those parts of the body which cannot be accurately repositioned by other means, it is not yet clear that there is a benefit to using it on the head, where the skull allows for other repositioning technologies. While the Cyberknife's targeting may be more accurate than FSR, the combination of additional X-rays and the change in radiation pattern from a continuous sweeping arc to discrete shots may offset the benefits. This issue can only be resolved after we have treatment outcome data for large samples of Cyberknife and FSR patients.

Those who wish to know more about the Cyberknife technology are referred to the website of the CyberKnife Society, located at www.cksociety.org This is a non-profit organization is dedicated to patient education and scholarly exchange regarding the Cyberknife.

Gamma Knife

Gamma Knife surgery is recognized worldwide as the preferred treatment for metastatic brain tumors and has successfully treated primary brain tumors and arteriovenous malformations. The Gamma Knife offers a non-invasive alternative for many patients for whom traditional brain surgery is not an option and removes the physical trauma and the majority of risks associated with conventional surgery. This effective treatment only requires an overnight hospital stay with periodic follow-up. It is proven safe over the long term and is recognized and covered by most insurance plans.

The Gamma Knife allows noninvasive cerebral surgery to be performed with extreme precision, sparing tissues adjacent to the target. Based on preoperative radiological examinations, such as CT-scans, MR-scans, or angiography, the unit provides for highly accurate irradiation of deep-seated targets, using a multitude of collimated beams of ionizing radiation.

Gamma Knife surgery represents a major advance in brain surgery, changing the landscape within the field of neurosurgery. Its development has enhanced neurosurgeical treatments offered to patients with brain tumors and vascular malformations by providing a safe, accurate and reliable treatment option. Gamma Knife enables patients to undergo a non-invasive form of brain surgery without surgical risks or a long hospital stay.

Gamma Knife surgery is unique in that no surgical incision is made to expose the inside of the brain, thereby reducing the risk of surgical complications and eliminating the side effects and dangers of general anethesai. The "Blades" of the Gamma Knife are the beams of gamma radiation programmed to target the lesion at the point where they intersect. In a single treatment session, 201 beams of gamma radiation focus precisely on the lesion. Ove time, most lesions slowly decrease in size and dissolve. The exposure is brief and only the tissue being treated receives a significant radiation dose, while the surrounding tissue remains unharmed.

There are numerous brain lesions for which treatment, either surgical or with radiation, is associated with considerable mortality or morbidity due to factors such as depth and inaccessibility of the lesion, its proximity to arteries, nerves and other vital structures, and the radiosensitivity of adjacent normal tissues. Even if access is possible, surgery still involves risks of hemorrhage, infection and other post-operative complications. In addition, a lengthy hospital stay is usually required.

With the Gamma Knife, a surgical incision is not required; the attendant risks of open neurosurgical procedures (hemorrhage, infection, CSF leakage, etc.) are therefore avoided.

Published reports indicate that the Gamma Knife may be used as an alternative to standard neurosurgical operations or as an adjunctive therapy in the treatment of residual or recurrent lesions left unresected by conventional surgery. Radiosurgery can be especially useful for those patients who are not suitable for standard surgical techniques due to illness or advanced age. In many neurosurgical cases, the Gamma Knife is the only feasible treatment.

Conditions for which application of the Gamma Knife is considered most effective are:

1. Intracranial tumors such as:

acoustic neuromas, pituitary adenomas, pinealomas, craniopharynigiomas, meningiomas, chordomas, chondrosarcomas, metastases and glial tumors.

2. Vascular malformations including arteriovenous malformations.

In addition to the above mentioned indications, clinical experiences exists in the treatment of functional disorders such as trigeminal neuralgia, intractable pain, Parkinson's desease and epilepsy.


* Gamma Knife is a neuro-surgical tool designed exclusively for the treatment of brain disorders.

* The lesion being treated receives a high dose of radiation with minimum risk to nearby tissue and structures.

* The cost of Gamma Knife procedure is often 25 to 30 percent less than traditional neurosurgery.

* Patients experience little discomfort.

* The absence of an incision elimates the risk of hemorrhage and infection.

* Hospitalization is short, typically an overnight stay. Patients can immediately resume their previous activities.

* Gamma Knife technology allows treatment of inoperable lesions. The procedure offers hope to patients who were formerly considered untreatable or at very high-risk for open-skull surgery.

Leksell Gamma Knife is a registered trademark of Elekta Instruments, Inc.

Link to comment
Share on other sites

Hi Stephanie:

My wife Deb had a Gamma Knife procedure done a couple of weeks ago at Hoag - they mounted a frame on her head (sounds worse than it was for her) and the procedure took a few hours. There are no robotics or concurrent X-Ray, but they did do a double contrast high density MRI prior to the procedure, then used computer positioning with the MRI to perform the Gamma Knife procedure.

She had difficulty with being held in a particular position for some time, and a side effect was heavy swelling over her eyes for about 5 days after the procedure.

Hope this helps for comparison,


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.