And why it is better than cobalt.
Medical Linear Accelerator (LINAC) is a machine used for delivering radiotherapy in cancer treatment. It delivers high-energy x-rays to the region of the patient’s tumor. This treatment can be designed in such a way that it destroys the cancer cells while sparing the surrounding normal tissue.
The LINAC is used to treat cancer of almost all body sites, either by using conventional techniques, Intensity-Modulated Radiation Therapy (IMRT), Image Guided Radiation Therapy (IGRT), Stereotactic Radiosurgery (SRS) and Stereotactic Body Radio Therapy (SBRT).
The Linear Accelerator (LINAC) at our center is one of the best machines available for high precision radiation therapy. With facilities of Three-Dimentional Radiation Planning, Intensity modulation of the radiation beam,VMAT , and electron beams, the machine is very suitable for many different types of cancers.
Advantages of a Linear Accelerator over the Cobalt machine ?
2D – vs – 3D Radiotherapy
Linear Accelerators work on a different mechanism and also these days come with 3-Dimentional Planning System making them more precise, thus tumors can be treated precisely without much toxicity to surrounding tissue. Multileaf collimators (MLC) are computerized thin blocks that are attached to LINAC treatment head, that shapes the radiation beam according to geometry of tumor.
In Cobalt machine, 2-Dimentional planning is done imagining the tumor to be in the center of the drawn rectangle, which can be readily missed.
Cobalt machines work with a Cobalt-60 radioactive source, and can be very dangerous if it gets leaked or lost. Whereas Linear Accelerators do not have radioactive isotopes. It works with x-rays and the radiation is only ‘on’ when the machine is on. Because of this, personnel safety is also maintained.
No need of Source Change
Cobalt-60 is an radioactive isotope and has to be changed every 5 to 10 years because it gets depleted with time. In LINAC, there is no radioactive source so there is no concern of source change.
Burden of cancer patients needing radiotherapy is increasing day by day. Usually Cobalt machine can treat around 40-50 patients daily. Each treatment would take about 10-15 minutes. The advantage of LINAC is that the treatment time significantly decreases to less than 5 minutes, thus decreasing the patient’s time in the radiation bunker significantly.
Because of high energy x-ray, the penetration of the LINAC is more as compared to Cobalt thus treating deep seated tumors can be done with confidence, sparing the overlying skin and the other normal tissue.
Is LINAC necessary?
LINAC is very necessary if cancer treatment has to be done properly. There are a few cobalt machines in Nepal and most of the developed countries have replaced it with LINACs many years back.
Radiotherapy is under-utilized around the world and varies widely among countries. Published peer-review literature has suggested that more than half of all cancer patients should have radiotherapy included as part of their treatment regimen. In under-developed or developing economies, radiotherapy is provided to no more than 25% of cancer patients.
IAEA recommends that each radiotherapy machine should treat on average up to 500 patients per year. It is also suggested that with current cancer incidence in the Low and Mid-Income countries, from 1–3 radiotherapy machines per one million population would be needed. That would mean in Nepal, we need atleast 30 Linear Accelerators.
Many breast cancer patients require radiation therapy during their treatment. Inside the chest wall, where radiotherapy is given, lies the heart and the lungs.
During conventional radiotherapy, both the heart and the lungs receive a fraction of the radiation that was planned for the chest wall only. Scientists have proven that a few of those patients would have issues with their heart after many years when their left chest wall is treated with radiotherapy conventionally.
We at Kathmandu Cancer Center are using a technique called the DIBH – deep inspiration breath holding technique, where the patient takes a deep breath and holds during some seconds when radiation is given. This way, the heart moves away from the chest wall reducing significantly the dose the heart receives.
Hippocampus Sparing Radiotherapy
Hippocampus are small parts of the brain that are responsible for memories. Conventional radiotherapy to the brain is given without sparing the hippocampus. With our 3D imaging and inverse planning software, we have been doing hippocampus sparing radiotherapy to the brain in selected patients of brain tumors and brain metastasis.
Hippocampal sparing radiotherapy is gaining positive responses world wide and we are glad to be able to deliver the same treatment for our patients.
Scalp Sparing VMAT.
Hair-loss is a common side effect in patient who receive radiotherapy in brain. But now ,these patients can avoid typical hair-loss (alopecia) when treated with newer radiation techniques
In many cancers, radiotherapy to the brain is necessary. Be it brain tumors, or cancers from other organs growing in the brain as metastasis – radiotherapy to the brain is warranted.
With conventional radiotherapy, there are high chances that there will be hairfall – usually patchy, affecting the areas of the entry of the radiation beams.
With this newer technique where radiotherapy is planned in such a way that a certain part of scalp only doesn’t receive the high dose of radiotherapy. With this technique of volumetric arc therapy (VMAT) sparing the scalp, there is very minimal hair loss.
Talk to your doctor about this hair-saving technique and if this is suitable for you.
Students from Ambition Academy visited us today. We showed them around. There were a few who were really keen about the science behind the radiotherapy.
Students were eager to see how patients are managed .Some of them showed keen interest in the physics aspect of radiotherapy. When we asked them what they liked about cancer hospital, most of them talked about treatment planning system. Doctors creating model of patients in computer before treatment was very interesting for them.
We hope we could inspire some to get into wonderful field of radiotherapy.
काठमाडौं क्यान्सर सेन्टरले बिरामीहरूकोलागी अस्पतालबाट जगातीसम्म र जगाती देखि अस्पताल सम्म निशुल्क गाडीको व्यवस्था गरेको छ ।
जगाती मुख्य सडकमा रहेको चोक हो, जहाँबाट उपत्यकाका विभिन्न ठाउँका सार्वजनिक गाडीहरू पाइन्छन् । यसले गर्दा बिरामीहरूलाई अस्पताल आउन र जान निकै सजिलो हुन्छ ।
यहाँलाई यो सुविधा चाहिएको भए ९८१८२२६२३७ मा फोन गर्न सक्नुहुनेछ । यो सुविधा बिहान ७ बजे देखि बेलुका ६ बजे सम्म मात्र उपलव्ध हुनेछ ।
४ बर्षका एक बालकमा आज हामीले टोटल बडी रेडियोथेरापी गरेका छौं । उनलाई अप्लास्टिक एनिमिया भन्ने रोग लागेको र त्यसको लागी बोन म्यारो ट्रान्स्प्लान्ट गर्ने योजना छ । यसरी टोटल बडी रेडिएसन गर्दा बिरामीको बोन म्यारो ट्रान्स्प्लान्ट सफल हुने सम्भावना बढ्छ ।
अहिले सम्म हामीले दस जना बिरामीको यो उपचार गरेका छौं र धेरै जनामा यो उपचार सफल भएको छ। अहिलेको समयमा नेपालमा यो उपचार हाम्रो अस्पतालमा मात्र हुने गरेको छ ।
KATHMANDU: Kathmandu Cancer Center, a hospital in Bhaktapur established with the joint efforts of cancer specialists in the country, has started Brachytherapy services from today.
Previously, the hospital used the Linear Accelerator from Elekta, which treated cancer patients with external beam radiation, besides chemotherapy.
With the introduction of Brachytherapy (or Internal Radiation Therapy), doctors can treat a focused part of the body more quickly with a higher total dose of radiation as compared to the conventional external beam radiation therapy.
Brachytherapy is used for the treatment of cancers throughout the body, including cancers of the cervix, breast, oesophagus cancer, among others.
The precision of 3D-reconstruction based Brachytherapy to destroy the cancer cells only, sparing the tissue nearby leading to lesser side effects.
The cost of treatment has been heavily subsidised, the technology being established with the support from an American organisation – Radiating Hope.