78 year old Mr. A was taken aback when a small spot in the right lung on chest X ray turned out to be adenocarcinoma ( a type of cancer) after the biopsy. He had a number of associated health problems – COPD, diabetes, heart disease for which he had undergone bypass surgery 8 year back. He was considered very high anesthetic risk. He was advised surgery for the cancer, however due to the high anesthetic risk, he was not a suitable candidate and surgery was ruled out. He then heard about Cyberknife treatment for lung cancer and opted for it. He underwent 3 sessions of treatment and his PET CT scan 3 months later is showing that the tumor has reduced by about 75%.
How common is lung cancer in India?
Lung Cancer is one of the most common cancers in India and has emerged as Global Killer. According to the GLOBOCAN 2012 report – Lung cancer ranked fourth overall among the various types of cancer in India; in males, it ranked second while in females it was sixth in terms of cancer incidence. The incidence of lung cancer is increasing each year with the trends in India following its global counterpart. With time, there has been a better understanding of the biology of the disease, with screening protocols put in place to detect the signs of lung cancer at an early stage.
Most lung cancers in India are detected at a stage when it has spread beyond the lung into the lymph nodes or other organs. Statistically, only 16% are diagnosed when confined to the local site, which signals early stage disease. Lung cancer has good cure rates when detected early. This is reflected in the 5 year survival rate for lung cancer which is around 56 % for localized disease, and 30% for disease which has spread to the nodes.
Who is the main culprit?
The primary risk factor for lung cancer is smoking tobacco, which accounts for most lung cancer related deaths. Cigarette smoke contains many cancer producing chemicals like nitrosamines and benzopyrenes. The risk for lung cancer increases with the number of packs of cigrattes smoked per day, and with the number of years spent smoking. Exposed non smokers also have an increased relative risk of developing lung cancer from second hand smoke. Stopping smoking brings down the risk of developing lung cancer. The decline is overall risk following stopping of smoking (called cessation) starts within 2-5 years of stopping smoking especially in people below 50 years of age.
What are the treatment options?
Surgery remains the gold standard of treatment in early stage lung cancers. However, there has been a search for nonsurgical, but curative treatment, more so in patients who are medically inoperable (that means the cancer as such is operable, however the patient cannot undergo surgery due to anesthetic risk), and in patients with a small tumour which has recurred (come back) after prior treatment. These are patients who earlier hit the dead end – now , Cyberknife treatment ( called SBRT or SABR in lung) is an easy, non invasive therapy available with proven and equal efficacy in these patients. The effectiveness of Cyberknife treatment has made it a treatment option in early stage node negative non small cell lung cancers who are medically inoperable and has been incorporated into NCCN protocols.
Why M6 Cyberknife is preferred?
The CyberKnife system is a method of delivering radiotherapy, with the intention of targeting treatment more accurately than standard radiotherapy. It consists of two main components : Linac which produces the radiation, and a robotic arm which allows the energy to be directed at any part of the body from any direction.
CyberKnife radiation surgery is the most advanced, non invasive radiation therapy tool available to treat cancerous as well as non cancerous diseases with the help of precise beams of high-dose radiation. It is a no pain and a no risk day-care treatment wherein patients are discharged as soon as the session gets over and therefore, no hospitalisation is required. The treatment uses a sophisticated image guidance system to beam high doses of radiation directly to your tumor.
The CyberKnife radiation therapy works the best for tumors that are upto 3cm in size. Cyberknife radiosurgery is a very powerful and precise radiation technique, for patients with early stage primary, medically inoperable lung cancer. The treatment is safe to administer and also offers a new option in patients with recurrent disease or a single metastatic disease in the lung.
The Cyberknife-M6 device is uniquely designed to deliver an accurate and exact radiation dose to a moving cancer target in the chest ,while preserving the maximum possible adjacent tissue ,making it an ideal device to treat lung cancer patients.
The CyberKnife-M6 device is the only radiosurgery or radiotherapy device that tracks and treats a moving cancer throughout the entire breathing cycle. This enables an even smaller margin of normal tissue around the cancer to be treated, increasing the safety of treatment.
How does M6 Cyberknife work?
Treatment with CyberKnife is phased. Imaging is performed few days in advance in a process called planning, thereby leaving the radiation oncologist with enough time to design and finalise a customised treatment plan. Once the plan is set in place, the patient will return for a non-invasive, pain-free treatment experience. Using advanced tumor-tracking technology, the CyberKnife system is able to deliver either one single high-dose treatment, or smaller doses (upto 5) over the course of two to five days, depending on the plan generated. This approach limits side effects and enables most patients to return to their regular routine the same day.
The best part of Cyberknife treatment in the lung is the synchrony based tracking and treatment feature. This means that the tumour is tracked throughout the breathing cycle, and treated exactly at its position in the lung, even as the lung moves with respiration, thus causing the tumour also to move. Additionally, there is no necessity for complicated techniques like holding the breath in order to achieve such accuracy. The Cyberknife treatment in lung is done in the course of normal breathing cycle, yet achieving an accuracy of less than a millimeter, called sub millimetric accuracy).Nothing is required of patients during treatment with CyberKnife, except to relax and breathe as normally as possible. However, the cyberknife also has an autostop feature if your breathing is suddenly varied and heavy. The treatment will start again only when the breathing returns to normal, in order to ensure total accuracy.
Each session of treatment usually lasts for about 45 min to 1 hour. The treatment is usually completed in three to four treatment sessions, over a week’s time. It is a cost effective treatment with a 5 year local control of 92.6% in early stage lung cancers.