ROBOTIC RADIOSURGERY; Gamma Knife vs. Cyberknife

ROBOTIC RADIOSURGERY; Gamma Knife vs. Cyberknife

What is steriotactic radiosurgery?

Stereotactic radiosurgery (SRS) is a non-surgical (no incision) treatment that delivers an ultra-precise high doses of focused radiation from multiple locations outside of the body to destroy a tumor or lesion inside the body. Worldwide, this non-invasive procedure has been used successfully in more than 400,000 patients the past 4 decades. This treatment does not remove the tumor or lesion but destroys the tumor cells or stops the growth of abnormally hyperactive tissue. Patients with otherwise inoperable or inaccessible brain lesions are now benefiting from this noninvasive SRS procedure.

What is Gamma Knife?

Not a knife at all, the 22-ton Gamma Knife is an SRS mode of treatment to 'cut out' (actually destroy) tumors or arterio-venous malformations in the brain, without cutting the skull open, as in the conventional brain surgery. This is now the treatment of choice for these pathologies, a great supplement to standard neurosurgical therapy, or an alternative when traditional surgery is not feasible or appropriate.

What is cyberknife stereotactic radiosurgery?

Mounted on a robotic arm, the cyberknife system (also an SRS) is a radiosurgery device with a linear accelerator that produces focused radiation. With the aid of image guidance cameras, the cyberknife locates the exact position of the tumor. The Linac then delivers multiple beams of radiation that converge at the tumor, which receives a concentrated does of radiation and destroys the target, while sparing the surrounding normal tissues.

How different are Gamma Knife(GK) and Cyberknife (CK)?

Gamma Knife is considered the gold standard for SRS management of intracranial (brain) lesions, and used as the 'performance meter against which other SRS technologies are measured,' according to Wake Forest University Baptist Medical Center, the first one in the United States to have the Gamma Knife in 1999. GK uses 201 source cobalt unit designed exclusively for non-invasive brain surgery, with radiologic accuracy better than 0.3mm, while CK is a single source linear accelerator, and not exclusively for intracranial SRS, with 1 mm accuracy and dose outside the target area is 2x-6x greater than with GK. Treatment with GK is delivered during one session; single or multiple sessions with CK, possible over days. Target position with GK is confirmed 10 times per second, whereas with CK, it is confirmed every 10 seconds.

Is radiation therapy in general effective for all cancers?

No, each type of cancer behaves differently and reacts to radiation, chemotherapy, or surgery differently. Not all forms of cancer are radio-sensitive or chemo-sensitive. With the available global clinical data from decades of experiences in the management of the various types of malignant tumors, today's cancer specialists know which particular type of cancers respond to which specific therapy or to which combination of these regimens.

Does SRS cure the cancer?

Using SRS even in the case of radiosensitive malignancy may or may not cure the cancer. The prognosis (outcome) will highly depend on the stage (extent and gravity) of the cancer, the presence or absence of distant metastasis (spread), and other technical and medical factors. Patients considering this modality of treatment should confer with their attending cancer specialists (oncologist, radiotherapist), to find out if SRS is an option for the management of their condition, the details of the procedure, possible complications, realistic expectations, and prognosis.

What are the advantages of SRS?

The advantages of the stereotactic radiosurgery are (1) it is non-surgical, non-invasive; (2) it takes about an hour or two for the initial treatment and usually does not require hospitalization, or a short one, if needed; (3) there is no head or body incision to cause discomfort and prolonged recovery, thus preserving better quality of life, during or after treatment; (4) SRS could be used for cancers or lesions otherwise deemed inoperable and hopeless by surgery or by plain standard radiation therapy; and (5) SRS reduces complications such as bleeding, infection, etc., since there is no incision.

What specific conditions is SRS used for?

Some of the specific diseases this noninvasive stereotactic radiosurgery procedure is used for are (1) Cancers of the brain, like astrocytomas, gliomas, carcinomas, cancers of the lungs and pancreas, metastatic cancers (tumor spread from other organs); (2) Benign or non-cancerous tumors, like acoustic neuromas, hemangioblastomas, pituitary adenomas, meningiomas, schwannomas, etc.; (3) Vascular malformations, like arterio-venous malformations, cavernous malformations; (4) Functional disorders, like trigeminal neruralgias; and (5) Extracranial (outside of the brain) tumors, like those in the base of the skull, neck, cervical, thoracic, and lumbar (neck, chest and low back) spines, liver, and other organs in the body. (Email: scalpelpen@gmail.com)