CyberKnife – A Boon to Cancer Patients
CyberKnife®: State of the Art Equipment
CyberKnife® is state-of-the-art radiotherapy equipment for robotic radiosurgery, which allows the radiation oncologists to treat pathologies painlessly, without requiring any surgery. CyberKnife® uses pencil beams of radiation, which can be directed to any part of the body from any direction with the help of a robotic arm. The system tracks the tumour, detects any movement of the tumour or patient, and automatically corrects its positioning. It then targets the tumour with multiple beams of high-energy radiation and destroys abnormal tissue without causing any damage to the surrounding areas. The tumour position is verified before each beam delivery for accuracy.
The treatment is so accurate that it is now possible to treat tumours previously thought to be inoperable. Although the results of the treatment always do not show immediately, in most of the cases the procedure will initially stop the growth of tumours, before gradually reducing their size. As there is no open surgery in this treatment, the normal risk complications associated with surgery are eliminated, as is the need for a long recovery time. This makes the treatment suitable even for those who are not well enough to cope with surgery.
The Way It Works
CyberKnife® gives patients new hope for treating tumours that are previously diagnosed as inoperable or untreatable. As mentioned earlier, CyberKnife® uses pencil beams of radiation, which can be directed to any part of the body from any direction, through a robotic arm. The vast array of different angles/trajectories from which pencil beams of radiation converge upon the tumour lead to a high cumulative dose of radiation at the convergence point (the target/tumour), and yet a very fast ‘fall-off’ of dose towards the periphery of the carefully mapped target. The surrounding normal tissues/organs receive only a small fraction of the high central dose of the treatment.
The indications for which cyberknife treatment could be useful is indicated below : Dr.Rathna devi, Senior consultant, Radiation oncology
Intra Cranial Tumours – Indications
• Skull base Tumours
• Brain Metastases
• Acoustic Schwannoma
• Pituitary adenoma
• Low/Hi grade Glioma
Boost Re- irradiation
• Trigeminal Neuralgia
• Spinal Tumors – Primary
Re irradiation – Metastases
• Harmangio blastoma
• Glomus Jugular Tumor
• Boost for Nasopharynx carcinoma
EXTRA CRANIAL SITES – INDICATIONS
. Lung – Primary
• Liver – Primary
• Head & Neck – Tonsil
(Re Irradiation) – Larynx
– Lacrimal Gland
• Sino Nasal Carcinoma – Boost
– Re –irradiation
• Carcinoma Pancreas
• Carcinoma Gall Bladder
• Para arotic lymph nodes
• Carcinoma prostate
• Recurrent Orbital Tumours Renal Tumours
• Soft tissue sarcoma
Scanning: Prior to the treatment with CyberKnife® System, the patient undergoes imaging procedures, which may include CT/MRI/PET CT, to determine the exact size, shape and location of the tumour. The CyberKnife® Treatment Planning Software helps to integrate CT scans and other imaging data into the pretreatment planning process.
Planning: After scanning, the image data are then digitally transferred to the CyberKnife® System’s dedicated treatment planning workstation, where the treating physician identifies the exact size, shape and location of the tumour to be targeted and the surrounding vital structures to be avoided.
A qualified physician and/or radiation oncologist or physicist then uses the CyberKnife® software to generate a treatment plan to provide the desired radiation dose to the identified tumour location. As part of the treatment plan, the CyberKnife® System’s proprietary planning software automatically determines the number, duration and angles of the delivery of radiation beams.
Treatment: A patient lies comfortably on the treatment table during the CyberKnife® procedure. Anesthesia is not required, as the procedure is painless and noninvasive.
The treatment, which generally lasts between 30 and 90 minutes, typically involves administration of about 100 to 200 radiation beams delivered from different directions, each lasting 10 to15 seconds. Prior to the delivery of each radiation beam, the CyberKnife® System simultaneously takes a pair of X-ray images and compares them with the DRR generated from the planning system.
Hypofractionated Radiation Therapy
Short-course radiation therapy is one of the most talked about subject in recent years and also a fascinating research zone. Hypo-fractionated radiation therapy is an old concept, but only in recent years, with tremendous improvement in radiation therapy delivery technologies, there is a significant visible surge in its applicability in clinical practice.
Modern radiation therapy technology is capable of delivering high doses to the target while sparing majority of the adjacent critical structures. Hence, it is possible to deliver a short course of treatment regimen with higher dose per fraction without increase in toxicity.
Apart from the intracranial lesions, there are emerging evidences about short-course treatment schedule in ‘extracranial’ sites such as lung, prostate, breast, and pancreas and also in various ‘oligo metastasis’. Short-course treatment regimens are comfortable for patients and caregivers. These regimens are more acceptable to the patients who have higher compliance rate and a definite positive influence in the quality of life.
However, planning the hypo-fractionated treatment is demanding, highly skill dependent and requires strict quality assurance. Appropriate training to the treating physicians, physicists and radiation technologists is critical to have a desired treatment outcome. Hypo-fractionated radiation therapy still have many unanswered questions, some of them may be sought out in such platforms.
Courtesy : Apollo Specialty Hospitals, Chennai
Apollo Speciality Cancer Hospital,
New No:6(Old No 24),
Chennai – 600 035
For more information call Cyberknife Helpline
Tel: 044 – 24334455
Fax : 91-44-24336089