Cancer patients from Jammu and Kashmir in general, and the valley in particular, requiring sophisticated radiotherapy treatment, technically called Stereotactic Radio Surgery {SRS} used to go to outside institutions in other parts of the country like Tata Memorial Hospital, AIIMS New Delhi, Rajiv Gandhi Cancer Hospital, Fortis etc., where this treatment is in use for last few years, but at rates usually in the range of 03 to 05 lacs. Besides being too costly, patient and attendant stay charges put expenditure at too high a level for middle class family. Also because of communication gap between patient and treating physician patients never attain a satisfaction to the level of having same treatment option delivered at door step. Most of the times Kashmiri patients used to reschedule treatment at outside institutions because of quite different geographical conditions thus patient who should have received treatment in summer would delay till winter to accommodate to the quite different weather conditions. Covid 19 situation would never allow any patient to move to outside institutions and thus render cancer patients hopeless. A crisis for the patient, family and treating doctor, be it Surgical Oncologist, Radiation Oncologist, Medical Oncologist or any other domain of medicine dealing with cancer.
Under able guidance of Principal / Dean GMC Srinagar Prof Samia Rashid, and tireless efforts of the Department Radiation Oncology we have been able to accomplish this long awaited goal by procuring TrueBeam Linear Accelerator, to realize the dream of delivering this costly treatment at doorstep. It is through persistent strivings that we continue to offer our patients the most advanced technologies available in the treatment of cancer at international level. Our dreams saw the light of reality when Dr. Syed Arshad Mustafa (Associate Professor) along with trained teams of other faculty, Medical Physics and Radiotherapy Technologists took the biggest successful challenge in executing first SRS treatment at our center. Mr. X (name changed) a 54 year old male, suffering from metastatic brain cancer is the first patient being offered this treatment. This initiative made our esteem go heaven high, both academically and technically. Though most cancer patients and their educated attendants know about various forms of radiotherapy treatments and usually discuss on availability of this and that of each treatment facility, yet for general public awareness to prevent people from moving to outside Union Territory institutions some basic information on Stereotactic Radio surgery {SRS} is presented below:
Stereotactic Radio Surgery (SRS) is a non-surgical radiation therapy treatment used to treat functional abnormalities and small tumors of the brain. It can deliver precisely-targeted radiation in fewer high-dose treatments than traditional therapy, which helps preserve healthy tissue. In SRS treatment delivery is accurate to within one to two millimeters. Same techniques are now being applied to the treatment of body tumors with a procedure known as stereotactic body radiotherapy (SBRT). This treatment is only possible due to the development of highly advanced radiation technologies that permit maximum dose delivery within the target while minimizing dose to the surrounding healthy tissue. The goal is to deliver doses that will destroy the tumor and achieve permanent local control. Although SRS commonly refers to a one-day treatment, physicians sometimes recommend multiple stereotactic delivered treatments. This is important for tumors larger than one inch in diameter as the surrounding normal tissue exposed to the single high dose of radiation must be respected and limited, and the volume of normal tissue treated increases proportionally to the tumor size. Delivering the radiation in a few sessions as opposed to one improves safety and allows the normal tissue to heal in between treatments. SRS and SBRT are important alternatives to invasive surgery, especially for patients who are unable to undergo surgery and for tumors and abnormalities that are: difficult to reach, located close to vital organs / anatomic regions, subject to movement within the body.
SRS is used to treat many types of brain tumors including, Benign and Malignant, Primary and Metastatic, Single and Multiple, residual tumor cells following surgery, intracranial, orbital and base-of-skull tumors, arteriovenous malformations (AVMs), other neurological conditions like trigeminal neuralgia etc. SRS fundamentally works in the same way as other forms of radiation treatment. It does not actually remove the tumor; rather, it damages the DNA of tumor cells. As a result, these cells lose their ability to reproduce. Following treatment, benign tumors usually shrink over a period of 18 months to two years. Malignant and metastatic tumors shrink more rapidly, even within a couple of months. When treated with SRS, arteriovenous malformations (AVMs) may begin to thicken and close off slowly over a period of several years following treatment. Many tumors will remain stable and inactive without any change. Since the aim is to prevent tumor growth, this is considered a success. In some tumors, like acoustic neuromas, a temporary enlargement may be observed following SRS due to an inflammatory response within the tumor tissue that overtime either stabilizes, or a subsequent tumor regression is observed called pseudo progression. SBRT is currently used in treating malignant or benign small-to-medium size tumors in the body and common disease sites, including the lung, liver, abdomen, spine, prostate, head and neck.
What Equipment is used? There are three basic kinds of equipment, each of which uses different instruments and sources of radiation: (1)The Gamma Knife®, which uses 192 or 201 beams of highly focused gamma rays all aiming at the target region. The Gamma Knife is ideal for treating small to medium size intracranial lesions.(2) Linear Accelerator (LINAC) machines, prevalent throughout the world and available at SMHS Hospital, deliver high-energy X-Rays also known as photons. The linear accelerator can perform SRS on larger tumors in a single session or during multiple sessions, which is called fractionated stereotactic radiotherapy. (3) Proton beam or heavy-charged-particle radio surgery is in limited use in North America, and some centers.
Stereotactic Radiosurgery Using the TrueBeam Linear Accelerator: Stereotactic Radiosurgery (SRS) using Linear Accelerator (LINAC), is similar to the Gamma Knife (SRS) procedure and its four phases: i) head frame placement, ii) imaging, iii) computerized dose planning and iv) radiation delivery. Worldwide LINAC technology is much more common than Gamma Knife technology and has been in practice for a similar length of time. Unlike the Gamma Knife, which remains motionless during the procedure, part of the LINAC machine called a gantry rotates around the patient, delivering the radiation beams from different angles. A CT with the frame in place is commonly acquired. A robotic arm moves the compact LINAC around the patient under image-guidance. The LINAC-based SRS is also based on delivering SRS without using an invasive head frame as needed for Gamma Knife treatment. We use simple non invasive plastic head mask to keep the head from moving during delivery which improves patient comfort. The development of frameless SRS is possible due to the incorporation of image-guidance in the delivery of treatment. Now, most LINAC based SRS technology is moving towards frameless SRS. The Gamma Knife is also developing frameless technology in order to spare the patient from presently using invasive frame placement procedure. Frameless SRS also allows for fractionated SRS, or SBRT, which give an advantage for large tumors or those tumors located in particularly critical locations. On board imaging during treatment allows for 100% precision with machine operating in robotic mode without allowing manual adjustments.
Who will be involved in this procedure and who operates the equipment? The treatment team is comprised of a number of specialized medical professionals, typically including a radiation oncologist, medical physicist, radiologist, Dosimetrist, radiation therapist, and radiation therapy nurse. The radiation oncologist and, in some cases, a neurosurgeon lead the treatment team and oversee the treatment; they outline the target(s) to be treated, decide on the appropriate radiation dose, approve the treatment plan, and interpret the results of radio surgical procedures. A radiologist interprets imaging that identifies the target(s) to be treated in the brain or body. The medical radiation physicist ensures the delivery of the precise dose of radiation. The physicist, or a Dosimetrist under the supervision of the physicist, uses special computer software to devise a treatment plan; he or she calculates the exposures and beam configuration to conformally treat the target(s) to the prescribed dose.
A highly trained radiation therapist positions the patient on the treatment table in line with planned treatment and operates the machine from an adjacent protected area {control panel}. The radiation therapist can observe the patient through a closed-circuit television and is able to communicate with the patient throughout the procedure. The radiation therapy nurse assesses the patient, provides the patient with information about the treatment, monitors the patient during treatment, and helps answer questions after treatment.
What does a patient feel during treatment? External radiation is a lot like getting a regular x-ray or C T Scan. The radiation beams are invisible and patient does not feel anything. The treatment itself is painless and takes only a few minutes. But each session can last 15 to 30 minutes because of the time it takes to set up the equipment and put patient in the right position. Depending on the area being treated, patient may need to undress, so one must wear clothes that are easy to take off and put on. Before starting treatment the radiation therapist controls the movements and checks to be sure machine is working properly. If patient feels concerned about anything that happens in the treatment room, he/she can ask the therapist to explain.
Starting Stereotactic Radiosurgery (SRS) and SBRT technology puts SMHS Hospital parallel to many renowned institutions of country like Tata Memorial Hospital, AIIMS New Delhi, Rajiv Gandhi Cancer Hospital, Fortis etc and thus represents yet another feather added to the crown of facilities already in use including IMRT, IGRT and VMAT
Prof Sanaullah Kuchay is Head of Department, Radiation Oncology , SMHS Hospital, GMC Srinagar