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Services & Information For Doctors

Physician’s Free Internet Consultation - Upload MRI/CT Images

Receive a Virtual Medical Consultation from our Board of Medical Advisors by uploading your patient’s MRI and or CT Images through our advanced Internet Imaging Software System.

Referring a Patient to the CyberKnife Center

Beyond a Medical Consultation, the Medical Staff at the CyberKnife Center is committed to serving the needs of Physicians looking to Refer a Patient for a CyberKnife procedure. We will provide your patients with the most effective treatment options available, and we will work closely with the Referring Physicians to keep them up-to-date on their patients, coordinating the entire patient experience with the Referring Doctors.

If you would like to Refer a Patient or if you have any questions, please call us at 1-800-208-5050, or email us at info@cyberknifedelhi.com.

Physician Certification and Credentialing to Practice at the CyberKnife Center

The Artemis CyberKnife Center is an Open Center, offering the opportunity to become Credentialed to all qualified Physicians, including the facilitating of a Doctor's Training and Certification in Cyberknife techniques. If you are interested in becoming a treating CyberKnife Physician, please contact us and we will outline the training, certification, and application requirements to become Credentialed as a member of the Medical Staff at the Artemis CyberKnife Center.

For complete information on Certification and Credentialing contact us at 1-800-208-5050, or email us at info@cyberknifedelhi.com.

International Doctors

International Doctors are very important to the Artemis CyberKnife Center. The CyberKnife Center provides additional support and services to International Doctors.

To find out more about these additional services that might be provided to international patients and International Doctors, please call us at 1-800-208-5050, or send us an email: info@cyberknifedelhi.com

Cyberknife Features and Advantages

Iris™ Variable Aperture Collimator

Rapidly manipulates beam geometry to deliver up to 12 beam sizes from each linac position with characteristics virtually identical to that of fixed circular collimators.


Xsight® Spine Tracking System

Eliminates the need for surgical implantation of fiducials by using the bony anatomy of the spine to automatically locate and track tumors, making radiosurgery more precise and less invasive.


Synchrony® Respiratory Tracking System

Continuously synchronizes beam delivery to the motion of the tumor, allowing clinicians to significantly reduce margins while eliminating the need for gating or breath-holding techniques.


Xsight® Lung Tracking System

Directly tracks the movement of lung tumors without fiducials while maintaining precision, reliability and self-adjusting repeatability.


Monte Carlo Dose Calculation

Often considered the gold standard when treating lung tumors, the CyberKnife System’s Monte Carlo Dose Calculation produces results in minutes compared to what commonly requires hours or days with other systems.


Conditions & Indications

Intercranial Guidelines Extracranial Guidelines

Radiosurgery is Indicated

  • As an Adjunct or planned “boost” after conventional external beam radiation therapy (XRT)
  • As an alternative to conventional XRT, especially for radioresistant tumors
  • For tumor recurrence in previously irradiated Regions. These patients usually have no other Option.
  • As an alternative to conventional surgery:
    1. Equivalent outcomes in some cases
    2. Medical condition may preclude surgery
    3. Patient preference is a large factor

Benign Tumors

  • Meningioma
  • Pituitary Adenoma
  • Acoustic Neuroma
  • Other Cranial nerve Schwannomas
  • Glomus Jugulare Tumors
  • Residual/recurrent low-grade Astrocytoma Oligodendroglioma, Hemangioblastoma

Malignant Tumors

  • Metastatic Tumors
  • Malignant Gliomas

Vascular Lesions

  • Arteriovenous Malformations (AVM)
  • Cavernous Malformations/AOVM

Functional Disorders

  • Trigeminal Neuralgia
  • Cluster Headache


  • Recurrent or residual head and neck tumors after conventional treatment


  • Selected solitary metastases without bony spinal cord compression
  • Primary treatment of classically radioresistant solitary tumors, i.e. melanoma, renal cell, and sarcoma
  • Recurrent solitary metastases after Conventional radiotherapy

Benign Tumors

  • Stage I NSCLC if medically inoperable or if patient refuses open surgery
  • Advanced state NSCLC as a boost treatment
  • Up-front treatment of obstructing endobronchial lesion with post-obstructive pneumonia
  • Metastases: solitary or limited (2-5) multiple metastases if symptomatic or enlarging on serial imaging with a favorable survival profile


  • Metastases: solitary or limited (2-5) multiple metastases if symptomatic or enlarging on serial imaging with a favorable survival profile


  • Up-front radio surgery treatment of unresectable tumor “sandwiched” between chemotherapy doses
  • Boost treatment for persistent PET-positive region after conventional chemotherapy and radiation therapy


  • Renal cell cancer in medically inoperable patients


  • Low-risk prostate cancer as an alternative to multi-week IMRT, low dose brachytherapy or high-dose brachytherapy (HDR)


  • Fro vaginal cuffs as primary or as boost
Note: Other conditions may be treatable, please consult the CyberKnife Center for a recommendation.

Treatment Process

Step 1: Initial Consultation

During the initial consultation, the patient will meet with several members of our highly trained staff, including the radiation oncologist, the CyberKnife coordinator, the radiation therapist, and/or a surgical specialist if needed. At this time, the procedure, treatment objectives and risks and benefits will be explained in depth; questions are welcomed and encouraged.

Step 2: Patient Treatment Preparation

Soft Tissue Fiducial Placement (not required for all cases): The CyberKnife is a completely frameless treatment system, which often utilizes bony structures in the body as landmarks to track tumor location. For some tumors or lesions, however, tiny gold seeds, called fiducials, may be implanted to accurately guide the radiation beams. These are typically used to mark tumors in the chest, the abdomen, pelvis or other soft tissue areas. If fiducial placement is needed, the CyberKnife Center will typically coordinate this procedure with an interventional radiologist or a surgeon (see Fiducial insert for more information).

Making a Mask or Body Immobilizer: In addition, either a plastic “mesh” mask (used with brain, head or neck tumors) or a comfortable foam body mold will be made to help minimize movement during treatment. This simple and painless process is done in the CyberKnife Center. The patient will then undergo imaging (CT, MRI, PET, etc.) with the mask or the body mold.

Imaging: CT Scan, MRI, PET scan, CT cisternogram / myelogram One or more of the imaging tests outlined below may be prescribed in order to provide the most detailed map possible of your treatment area. When you are consulting with your radiation oncologist, you will be informed of which imaging out of those listed below is needed to plan for your treatment.

Computed Tomography (CT) uses x-rays to capture extremely detailed cross-sectional images of your body, called slices. The image slices allow physicians to view internal organs, tissue, bones, and blood vessels at various angles.

What to expect:

  • You will be asked to remove all jewelry, hairpins, eyeglasses, hearing aids and dentures. For abdominal exams, you should refrain from eating and /or drinking after midnight prior to your exam date.
  • Let the technologist know if you have had allergic reactions to a contrast medium, iodine, or shellfish, or if you have asthma. Also inform the radiologic team if you have diabetes or take medication.
  • If contrast medium is used, it will be given either intravenously or by mouth to coat the gastrointestinal tract. Most people tolerate the contrast medium without any problems and merely feel flushed for a moment.
  • Though the images are acquired in a few seconds, the entire exam takes about 15-30 minutes – longer if contrast medium is used.

Magnetic Resonance Imaging (MRI) uses a huge magnet and radio waves to create a high resolution image of body tissues. The open design facilitates ease and comfort for each patient.

What to expect:

  • Let the technologist know if you have a pacemaker; other imaging will be substituted.
  • No special preparation is usually needed prior to your MRI. Eat normally and take medications as usual, unless your doctor or the CyberKnife nurse instructs you otherwise.
  • You will be asked to remove your eyeglasses, watch, jewelry, credit cards, dentures, hearing aids and any other metallic objects that you are carrying.
  • Generally, you lie on your back. A lightweight surface coil may be placed over the part of the body to be scanned. The exam itself usually takes 15-30 minutes.

Positive Emission Tomography (PET)/CT detects changes in cells in internal organs and living tissue, diagnosing the presence of disease at the molecular level. The CT pinpoints exact location with fine structural detail of the anatomy. For the PET you will be injected with a drug that contains a dose of radiation to localize the disease.

What to expect:

  • For six (6) hours before your test, do not eat or drink (except water), do not even chew gum. Your last meal should be high in protein and low in carbohydrates. No caffeine or exercise 24 hours before the test.
  • Take medication as prescribed, but if taken with food try to eat a few soda crackers only four to eight hours prior to your exam. If you have diabetes, call the CyberKnife nurse at least 48 hours prior to your appointment.
  • Most people receive the radiopharmaceutical (called FDG) intravenously, a procedure that is usually painless. You will then rest quietly for about 60-90 minutes to allow the FDG to distribute throughout your body. The scan itself will take approximately 2 hours.

Myelography is a type of radiographic exam of the spinal cord by the use of contrast medium injected into the space around the spinal cord and the nerves, visualization using fluoroscopy and a series of x-rays. A cisternogram is a similar exam of the cerebral (brain) spinal fluid. Both tests will show soft tissues that regular x-ray and other imaging may not show in order to develop your individualized CyberKnife treatment plan.

What to expect:

  • Some medications such as aspirin, ibuprofen or Plavix will need to be held for one week prior. Others should be held for only 48 hours prior to the exam. Be sure to review all prescribed and over-the-counter medications with the CyberKnife nurse prior to your exam date.
  • You will need to abstain from eating after midnight on the night before the imaging appointment. You may drink clear liquids (clear broth, tea, clear juice, coffee w/out dairy products) up to the time of your examination. You are encouraged to drink 2- 3 glasses of fluid prior to the test.
  • On the morning of your imaging, you should take a bath/shower and dress in comfortable clothing and leave all jewelry (metal) at home.
  • Before going to the Radiology department you will be asked to empty your bladder and you may be given a prescribed medication that may make you drowsy or your mouth dry.
  • You will be taken to the x-ray area via stretcher. Your family should wait in the waiting room. You will be placed on your abdomen on an x-ray table and the Radiologist explains the treatment to you. The Radiologist will then anesthetize (numb) the part of your spine where the needle will be inserted. With the needle, he/she will inject the dye into the spinal canal. The x-ray table may be tilted at one point so that the dye moves to the part of your spine to be x-rayed and a series of x-rays will be taken. The procedure may take about one hour. After the procedure you will be watched for several hours with your head elevated before going home. Further instructions will be given to you upon discharge.

Step 3: Treatment Planning

The CyberKnife physician(s) and the medical physicist will use the high resolution imaging conducted above to identify the exact size, shape and location of the tumor, along with the surrounding health tissues to be avoided. The imaging data is downloaded to the CyberKnife treatment planning computer where physicians use advanced software to customize the number, intensity, and direction of radiation beams the robot will send to the target. This may take a few days depending upon the complexity. The patient is not present during this step. When the planning is complete, a date and time for treatment(s) will be scheduled.

Step 4: CyberKnife Treatment

When you are preparing for your first treatment, you may want to enlist the help of a close friend, family member or driver in case you should require sedation for treatment. Wear comfortable clothes and avoid wearing jewelry. A blanket will be provided for warmth if needed. Take all medication as usual unless specifically told otherwise – avoid diuretics.

CyberKnife treatment will be given once or up to 5 times depending on your unique situation. When the treatment begins, the patient lies flat on the treatment couch while the imaging system acquires the first set of x-rays. The treatment table then moves to the correct position for accurate alignment with the robotic arm. The robotic arm then moves around the patient to deliver the radiation beams—often greater than 100 times. This process takes anywhere from 20 to 130 minutes; so patients need to prepare to lie still for this time frame. Plan on spending two hours at the center on the first day of treatment to allow for variability, though if more than one treatment is given, this time will be more firm after the first treatment.

There are cameras in the treatment room so the CyberKnife team can monitor the entire process. A microphone allows the patient, who is alone in the treatment room, to communicate directly with the radiation therapist at all times. The entire process is painless, but if the patient becomes uncomfortable during treatment, the patient should tell the radiation therapist.

If the treatment plan calls for more than one treatment session, the radiation therapists will schedule all appointment times with you.

Follow Up

The proximity of these tumors to vital nerve and vascular structures makes them surgically problematic. Risk of injury, infection and residual tumor growth make CyberKnife a leading treatment.

Fiducial Placement

Fiducial markers are gold seeds or stainless steel screws that are implanted in and/or around a soft tissue tumor, or within the bony spine, to act as a radiologic landmark, to define the target lesion's position with millimeter precision. They are typically placed using a CT or other image-guided percutaneous method. There may be other appropriate fiducial placement methods as well, including endoscopic or surgical approaches, if determined best by the participating physicians. To track lesions in 6 degrees (translational and rotational movements), fiducials may be recommended, depending upon the exact circumstance and lesion. Fiducials must be fixed relative to other fiducials and relative to the tumor to ensure targeting accuracy.

Approved Fiducials

Stainless Steel Screw (2.0 x 5.0mm) embedded within bone. Self-drilling and self-tapping screws provide optimal contrast against the bone and minimize migration. These are typically used for spine applications.

Gold Seeds ( 0.8 mm x 5 mm) are typically used for soft tissue lesions

Specific Clinical Situations Potentially Requiring Fiducial Placement

  • Spine lesions – In cases where spine fiducials are required, we will normally recommend 3-6 Stainless Steel Screws, placed by a neurosurgeon or interventional radiologist. In some cases, only one screw may be required, and in still other cases, due to an advanced CyberKnife software feature known as X-Sight, there may be no fiducials required. The patient’s attending doctors will individualize the recommended fiducial approach for each CyberKnife spine case. If neurosurgical spine stabilization is required, any required fiducial screws may be integrated into that same surgical procedure, eliminating a separate fiducial placement step for the patient.
  • Head and Neck soft tissue lesions – In these cases, 3-6 fiducial seeds may be placed under anesthesia by the participating head and neck surgeon, or percutaneously by a radiologist under CT or other radiologic guidance. Depending upon the initial clinical presentation, it may be feasible for the head and neck surgeon or radiologist to place the CyberKnife targeting fiducials at the time of the patient’s original biopsy, if clinical suspicion is high and potential CyberKnife use is anticipated, avoiding the need for a separate fiducial placement procedure.
  • Intrathoracic lesions (e.g. NSCLC) – The majority of Intrathoracic lesions will be lung cancers but the specific fiducial requirement will vary according to the specific clinical presentation.
  • Peripheral pulmonary nodules – Typically, these lesions will be targeted using 3-6 transthoracically placed CT-guided fiducials. In certain clinical situations where the nodule is small and the medical risk high, it may be acceptable to place a single fiducial for translational motion tracking only. Because there is a pneumothorax risk with the transthoracic CT-guided approach, this will ordinarily be done in a hospital setting, and the patient observed for a period of time. If no pneumothorax ensues the patient will be discharged the same day and treatment planning will ensue approximately one week later.
  • Central or recurrent lesions – Central intrathoracic lesions such as endobronchial or mediastinal presentations may be effectively targeted for fiducial placement bronchoscopically or transesophageally, greatly reducing the pneumothorax risk. Depending upon the initial clinical presentation, it may also be feasible for the pulmonologist or thoracic surgeon to place the CyberKnife targeting fiducials at the time of the patient’s original biopsy, if clinical suspicion is high and potential CyberKnife use is anticipated, avoiding the need for a separate fiducial placement procedure. CT +/- PET based CyberKnife treatment planning will then ensue approximately 7 days after fiducial placement.
  • Liver, Pancreatic, Retroperitoneal and Kidney Lesions – These will ordinarily be marked using CT-guided fiducial placement technique, delivering 3-6 seed fiducials in and around the target lesion. If surgical exploration is otherwise indicated then open or laparoscopic fiducial placement may also be accomplished at the time of surgical exploration in lieu of scheduling a separate invasive CT procedure. CT +/- PET based CyberKnife treatment planning will then ensue approximately 7 days later.
  • Prostate Cancer – Typically, 3-6 seed fiducials will be placed in the prostate using ultrasound guidance, either transrectally or transperineally, by the urologist or radiation oncologist. CT +/- co-registered MRI CyberKnife treatment planning will then ensue approximately 7 days later.
  • Miscellaneous – Invariably, there will arise some sort of tumor situation that is not specifically addressed by any of the fiducial placement protocols described above. In such a case the patient’s participating physicians will decide the most effective fiducial placement and treatment planning approach.
  • Technology note – Over time, as the CyberKnife device continues to evolve, improved software and image-processing capability may eliminate the need for fiducials in some cases, though at present, fiducials are required for all non-cranial lesions, except for X-Sight targeted spine lesions.

Key Fiducial Placement Principles

  • Implant 3 - 6 fiducials with a minimum of 2.0 cm spacing between fiducials to minimize uncertainty in measuring rotation. They should be placed no more than 5 -6 cm from lesion (20 cm FOV for live images)
  • There must be at least a 15° angle between any grouping of 3 fiducials - not collinear - encompassing the tumor volume
  • In soft tissue, use gold seeds and place 3 - 6 fiducials around the perimeter of the tumor, 2 -3 cm apart.
  • If hardware or other radio-opaque materials are present, place the fiducial above, below or lateral to and not along the axis of the X-ray tracking system (i.e. - Do not place fiducial(s) at or near 45 degrees axial orientation from the potentially obstructing hardware).

Fiducial Migration

Any fiducial migration will degrade the accuracy of fiducial-based targeting. If CyberKnife targeting fiducials migrate more than 1.5 mm from time of CyberKnife CT planning to actual CyberKnife treatment, it may render the patient untreatable without repeating the entire CyberKnife treatment planning process.

As there may be some migration or “settling” of fiducials for up to 7 days following their placement into soft tissue, it is recommended that the CyberKnife planning CT study be obtained approximately 7 days after fiducial placement for soft tissue lesions, to allow them to settle into stable position. For spine lesions, where fiducials are anchored into bone, the planning CT may be accomplished as soon as the following day. Once the CyberKnife planning CT has been accomplished, the time to the actual CyberKnife treatment itself should be minimized, to reduce the probability of fiducial mis-registration between the planning and treatment stage due to additional potential fiducial migration.

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