What is radiation therapy?
What are the types of radiation therapy?
Radiation therapy is mainly of 2 types:
1. External beam radiation
- Most commonly used type of radiotherapy
- Radiation is provided from a source outside the body. If necessary, it can be applied to treat large portions of the body.
The different types of external beam radiation include-
- Three-dimensional conformal radiation therapy (3D-CRT)
– Uses computed tomography (CT) or magnetic resonance imaging (MRI) scans, to create precise 3-dimensional images of the malignancy.
– These pictures are then used as a guide for precisely delivering the radiation beam with minimal damage to the healthy tissue.
- Intensity-modulated radiation therapy (IMRT)
– Compared to standard 3D-CRT, IMRT more effectively targets the tumour while avoiding healthy tissue.
- Image-guided radiation therapy (IGRT)
– The images of the malignancy are taken before and during the treatment, while the machine is delivering radiation.
– Hence, radiation is delivered more accurately
– Highly useful for radiotherapy of cancers located close to vital structures and on structures that move during or between treatments.
- Proton beam treatment
– Proton beam therapy uses protons in place of x-rays
– Proton is a positively charged particle with high energy
– Studies have shown that it poses fewer adverse effects to adjacent healthy tissues
- Stereotactic radiation therapy (SRT)
– In this therapy, a small tumour area receives a strong, focused dosage of radiation
– The patient needs to be stable throughout therefore, moving parts are limited by a head frame.
– SRT is frequently administered in a single session or in less than ten sessions.
2. Internal radiation therapy (Brachytherapy)
– During this treatment radioactive material is inserted or placed within or close to the cancerous tissues.
– The seeds, capsules or implants thus placed, emit radiation which destroys the cancerous tissue with minimal damage to the surrounding healthy tissues.
Internal radiation therapy includes-
- Permanent implants are small radioactive steel seeds that come in the size of capsules similar to a rice grain. They provide the majority of the radiation therapy around the implant area.
- Temporary internal radiation therapy is a kind of radiation therapy that can be administered via a needle, a catheter, or specialised applicators. The duration of the radiation’s presence in the body range from a few minutes to a few days.
What are the other types of radiation therapy?
The other forms of treatment include:
- Intraoperative radiation therapy (IORT)
– Delivers radiation to the tumours during surgery using an external or internal beam.
– The procedure also allows moving the healthy tissues so that they are not damaged.
- Systemic radiation therapy
– Is a therapy in which radioactive material is injected or ingested by patients.
– Urine, saliva, and perspiration are three ways that radioactive material leaves the body.
– Uses monoclonal antibodies which are proteins that get attracted to specific markers present in the cancer cells, to deliver radiation to the tumours.
What are Radiosensitizers?
- These are chemicals that make radiation therapy more effective at removing malignancies.
- Healthy tissues near the treatment region are shielded by radioprotectors.
- Fluorouracil (5-FU, Adrucil) and cisplatin are two examples (Platinol) of radiosensitizers and amifostine (Ethyol) is a radioprotector.
What is the role of radiation therapy in the treatment of cancer?
At various points in your cancer treatment and for a variety of reasons, your doctor may offer radiation therapy as an option, including
- As the primary (main) method of cancer therapy
- In order to reduce the size of a malignant tumour prior to surgery (neoadjuvant therapy)
- To inhibit the growth of any cancer cells that may still be present after surgery (adjuvant therapy)
- Used with other therapies, such as chemotherapy, to eradicate cancer cells
- Help reduce cancer symptoms in cases of advanced malignancy
What types of cancer does radiation therapy treat?
External beam radiation usually treats the following types of cancer:
- Breast cancer
- Lung cancer
- Prostate cancer
- Colon cancer
- Cancers of the head or neck
Internal radiation usually treats body parts like:
- Head and neck
Also recommended for cancers like:
How to prepare before radiation therapy?
A doctor will evaluate the patient, inquire about their health, and discuss the treatment plan with the patient:
- A doctor will evaluate the patient, inquire about their health, and discuss the treatment plan.
- A planning meeting between a radiation oncologist and radiation therapist for a patient who agrees to receive external beam radiation is called a simulation.
- To indicate where to direct the energy beams, the radiation therapist may leave tiny scars on the patient’s skin. These stains may be tattoos or temporary marks.
- In order to make sure that a patient is receiving radiation therapy in the proper position, medical experts may also make a body mould.
- It may be necessary for someone getting radiation therapy to the head or neck to employ a face mask to keep their head in position during treatment.
What are the procedures done during radiation therapy?
External radiation beam
- Usually, a patient receives external beam radiation therapy while lying on a table underneath a huge machine.
- The radiation therapist will place the patient in the machine before leaving the room and enter into another room.
- Patients are required to remain still throughout the procedure but need not hold their breath. There will be whirring, clicking, and vacuum cleaner-like noises coming from the device.
- The patient can communicate with the radiation therapist while receiving treatment by a speaker system in the room.
Internal radiation therapy
- The radioactive implant is inserted by the medical team during brachytherapy using a catheter or a larger instrument called an applicator.
- The physician will arrange the catheter or applicator and then insert the radiation source inside of it.
- Before the doctor removes the implant, it may occasionally stay inside the body for a few days.
- In certain cases, the implant may be placed in the body for 10 to 20 minutes and the subsequent treatments will be over a period of several weeks.
- The physician will take out the catheter or applicator once the prescribed course of treatment is finished.
- An implant may occasionally stay in the body indefinitely but they stop producing radiation after some time.
What are the side effects of chemotherapy?
Side effects may include:
- Skin irritation.
- Dry, itchy scalp.
- Hair loss.
- Mouth sores.
- Pain when you swallow.