Know The Different Types of Radiation
One of the most important techniques used for the treatment of cancer is radiation therapy. This involves the usage of high-energy rays in the form of x-rays, gamma rays and highly charged particles for destruction of cancer cells through elimination and shrinkage of tumours, thereby offering protection against cancer metastasis. Besides this, another reason for radiation treatment is Palliative Treatment provided with the sole intent of alleviating painful symptoms of cancer that is beyond cure. Radiation treatment is generally provided as a standalone treatment or in certain cases in correlation with other systemic therapy or surgery.
Effectiveness of Radiation Therapy
Radiation therapy combats cancerous tissues by destruction of DNA. The DNA molecules within the tissues carry and transport genetic traits to the ensuing generation.
Radiation therapy has the ability to cause DNA destruction directly or by causing free radical elements within the tissues, which in turn causes DNA damage as a side effect. Moreover, following DNA destruction, there occurs an inability for the cancerous cells to further divide and multiply which means they die. Furthermore, through the body’s natural mechanism, these dead cancerous cells break down and undergo the elimination process.
Cancers for Radiation Therapy
Radiation therapy proves effectual for certain kinds of cancer such as leukemia, bone, lung, uterine, ovarian, breast, colorectal, larynx, throat, skin, prostate, brain, head and neck.
Preferences for Radiation
The preference of the therapy recommended by the oncologist depends upon a number of factors as given below….
- Type of cancer
- Cancer site
- Size of the cancerous tumour
- Stage of cancer
- Medical history of the patient
- General health of the patient
- Types of treatments previously received
Types of Radiation for Cancer
There are different types of radiation for effectual treatment of cancer. They fall under two categories namely External Beam Radiation and Internal beam radiation.
External Beam Radiation (EBRT)
This is one of the most prevalent forms of radiation with an ability to treat seek out large areas of the body. This type of radiation involves the usage of a linear accelerator or linac machine from the outside of the body. The unique software installed in the computer helps adjust the size and shape of the beam. The beam targets the tumour without encroaching on the normal healthy tissues.
Types of External Beam Radiation
The different types of external beam radiation are as follows…
Three Dimensional Conformal Radiation Therapies (3D CRT)
This uses specialised computers to produce detailed 3D images of cancer. This treatment hunts for the tumours with great accuracy. At times, to achieve this effect, high intensity radiation is often utilised while cutting down the risk of damage to the healthy tissues Furthermore studies confirm the fact that this therapy decreases the prospect of side effects. For instance, those individuals who undergo this treatment for head and neck cancer show least possibilities of developing symptoms of dry mouth.
Intensity Modulated Radiation Therapy (IMRT)
A more effective treatment than 3D CRT, IMRT uses multiple small shaping devices called collimators for one dose of radiation. This radiates the beam directly and more effectively on the tumour by adjustment of the intensity of the radiation beams. Besides, IMRT prevents radiation damage to the healthy tissues much better than 3DCRT by varying the radiation doses.
Proton Beam Radiation
Rather than x-rays, this utilises protons for cancer treatment. Being parts of an atom these when highly charged enable destruction of cancer tissues. However, it reduces the amount of radiation exposure to the healthy cells nearby and protects them from any damage.
Stereotactic Radiation Therapy
This treatment is commonly used to treat tiny tumours with well defines edges presumably in the spine of brain metastasis. This aims at radiation precisely at a small area of a tumour. Due to the accuracy of this therapy, the patient is required to lie immobile and static. To ensure patients immobility head frames or any other kind of body frames are used for effective precision of radiation.
Stereotactic Body Radiation
This treatment gives radiation in limited sessions utilising small areas. This employs the use of higher radiation doses when compared to 3DCRT. Despite being a single therapy, some kinds of cancer may require more sessions. This is mostly commonly used for tumours lying outside the spinal cord and the brain. Hence, unlike the tumours that lie within the locations these cannot be targeted with precision. However, this has proved effective for treatment of tiny isolated cancerous tumours in the liver and lung.
Internal Beam Radiation Therapy
Another type of radiation is the internal beam radiation, otherwise known as brachytherapy. This makes use of radioactive isotopes embedded into the cancerous or the surrounding tissues. This procedure requires hospitalisation. These radioactive implants may however be temporary or permanent depending upon the severity of the disease.
For permanent brachytherapy, radioactive isotopes are enclosed in tiny steel seeds or pellets. These are about the same size of a rice grain and embedded within the tumour. Eventually with decay, these embedded steel seeds start emitting maximum radiation in and around the tumour. Besides radiation directly from the pellets, there occurs a certain amount of radiation from the patient’s body. During such times, it is extremely crucial to protect others from radiation activity of the seeds. However, the tiny pellets remain within the body even post decay and the discontinuation of the radiation activity.
Temporary brachytherapy impart radiation either inside or outside the body by means of special dispensers and catheters. Nevertheless, unlike permanent beam therapy, the radioactive isotopes either remain for a few days or few minutes/ hours. In c as e of extended period, the patient might require hospitalisation, monitored from private room to avert radiation exposure to other people around.
Other Options for Radiation Therapy
Apart from External and internal radiation therapy there are other options for therapy. They are…
Intra Operative Radiation Therapy (IORT)
This serves as an effective technique for surgeons during a surgical procedure to pass radiation to the tumour using both external and internal methods of radiation therapy. Powerful methods for keeping the healthy cells at bay before the surgery, particularly in tumours that grow exist extremely close to the key organs of the body.
Systemic Radiation Therapy
Systemic therapy is a treatment for the whole body. This utilises radioactive substances that are either ingested or injected in to the body to target cancerous tissues. These radioactive isotopes nevertheless excrete via urine, sweat, saliva that becomes radioactive. Nevertheless, it is critical to take precautionary method for those who are exposed to the patient to avert hazards of radiation.
A type of systemic therapy this provides low dose radiation directly to the cancer cells, leaving behind the normal tissues through monoclonal antibodies. Examples of these radioactive molecules are Zevalin (ibritumomal) and Bexxar (tositumomab).
Radio Sensitizers Radio Protectors
Radio sensitizers are substances that enable better radiation for tumour destruction. Examples (fluorouracil) 5-FU, Adrucil and platinol (cisplatin)
Radio protectors are compounds that help protect the healthy cellular tissues that exist near the cancerous tissues being treated. Example -ethyol (amifostine).
Safety and Precautions
- During radiation procedure, it is imperative for expectant mothers and children below 18 years to avoid visiting the patient
- It is essential for the visitors to sit at least six feet away from the patient’s bed
- It is advisable for the visitors to limit their stay for less than half an hour
- After discharge from the hospital, the permanently embedded capsules continue to remain radioactive. Hence, it is important for the patient to minimise contact with infants, expectant mothers and children for a couple of months.
- For the first few days after systemic therapy in order to reduce radiation exposure to near and dear ones
- Washing hands after a visit to the washroom proves safe
- Plenty of fluid consumption is crucial as the radioactive materials get flushed out from the system via body sweat, urine and salivary glands
- Personal use of toiletries and cutlery is important to avert radiation exposure to others