Radiation therapy (Radiotherapy), is the use of various types of radiation to effectively and safely treat cancer and other diseases. Radiation is used to cure cancer, to control the growth of cancer or to relieve symptoms, such as pain and bleeding (palliative radiation). Radiation therapy acts by damaging cells. Normal cells are capable to repair themselves, whereas cancer cells cannot. Radiation can be used by alone or with other treatments, such as chemotherapy or surgery. If radiation is delivered from outside, its called external radiation therapy. Suppose it is delivered from inside the body, its called internal radiation or brachytherapy. Based on the site if the tumour and the type of cancers, appropriate techniques are used.
For the best radiation therapy in India consult the best cancer hospital near you.
Radiotherapy with the aim of cure in cancer usually lasts between 1 to 7 weeks. For radiotherapy to relieve symptoms, duration might be anything between a single treatment to 2 weeks of treatment. Most people have daily treatment from Monday to Friday, with rest at weekends.
After the patient is examined and is decided for external radiation therapy, then the following procedures are done:
Immobilization – Depending on the type, size and location of the tumours, the patient undergoes appropriate immobilization. For example, in head & neck cancers, a thermoplastic mould is used, which takes the shape of the face and neck. A vacuum cushion can also be used in certain conditions. The purpose of immobilization is to assure correct position in day to day treatment.
Simulation – After the immobilization, the patient is subjected to CT simulator. Here the patient undergoes CT scan with or without contrast in the treatment position along with immobilization. The acquired images are transferred to the Treatment Planning System (TPS) for planning. Sometimes when required, MRI and or PET CT is also done during the simulation.
Planning –The images are transferred to the Treat Planning System (TPS) for planning. The first step involves contouring or drawing the target structures and normal tissues. After contouring, the radiation beams are decided. Complex computer software is used, the radiation planning is done, which virtually shows the way radiation is delivered. It also shows the dose received by the target volumes and to the normal tissues. Based on the dose distribution, the oncologist approves the plan. After this treatment delivery is done.
Treatment delivery - There are different type of treatment delivery techniques, like 3DCRT, IMRT, IGRT, SRS, SBRT, TBI, TSEB Therapy
Cancer Therapy India offers the best radiation therapy in Bangalore and the best treatment and cares you need.
3D conformal radiation therapy is a type of radiation therapy for cancer treatment that shapes the radiation beams to match the tumour.
In the past, when there was minimal technological advancement, the radiation beam was in fixed geometrical shapes and both the cancerous and normal tissue used to get the same radiation. With the rise of technology, we can safely target the cancerous regions and avoid normal organs.
This exact targeting allows us to use higher levels of radiation in treatment. More radiation is more effective in shrinking and killing tumours.
IMRT is an advanced form of 3DCRT. It is of particular value for tumours with concave or complex shapes with proximity to normal structures. IMRT uses advanced technology to manipulate radiation beams to conform to the shape of a tumour.
Each beam is subdivided into hundreds of beamlets, each with an individual intensity level, enabling a very complicated pattern. The use of several beams can build up a highly conformal dose distribution, allowing precise shaping and thus further sparing of the normal tissues.
Advantages of IMRT
Improved target conformity, particularly for concave tumours
Can produce dose-painting
Increases normal tissue sparing – less toxic both immediate and long term
Enables increase in dose safely – Thus better cure rates.
When we are delivering radiation every day to the tumour, which is very near critical structures, possibility is that we may miss the tumour and deliver high doses to the normal structures. This can be avoided by using daily imaging before delivery of radiation. This process is Image-Guided Radiation Therapy (IGRT).
The definition of IGRT is "Frequent imaging in the treatment room during a course of radiotherapy to guide the treatment process"
IGRT is delivered using a linear accelerator. At Cancer Therapy, we are equipped with the state of the art linear accelerator, TruBeamStx. This machine is equipped with special imaging technology (Cone beam CT scan) that allow us to image the tumour just before or even during the time radiation is delivered, while the patient is positioned on the treatment table. Using the specialized computer software compares these images with reference images taken at the time of simulation. Any necessary adjustments are done to the patient's position and/or radiation beams and hence safely deliver the treatment. This procedure is done every day before treatment.
IGRT is often used in conjunction with intensity-modulated radiation therapy (IMRT), Volumetric arc therapy (VMAT), stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT), which are advanced modes of high-precision radiotherapy.
The main advantage of IGRT
It is very precise in delivary.
It does makes it possible to use higher doses of radiation to kill the cancer
Avoid harm to healthy tissue
To keep side effects to a minimum
TBI is a special type of radiation technique. TBI is radiation therapy that's given to the entire body. This type of radiation is a priming technique before bone marrow transplantation. TBI may be given for the following reasons:
To kill cancer cells in areas where chemotherapy can't easily reach (such as nervous system, bones, skin, or testes).
Provide sufficient immunosuppression in the recipient to prevent rejection of the graft
Create space in the bone-marrow for the donor cells
Thus help in the better success of the transplant
The treatment could be one fraction or a maximum of 8 fractions given twice a day over four days. The number of sittings depends on the disease conditions.
We at Cancer Therapy are one of the few centres who specialize in this technique.
