What is radiotherapy?
Radiotherapy or RT is ionizing radiation therapy for the treatment of cancer in different parts of the body like prostate, breast, skin, pelvis and brain. It hinders the growth of cells which cause cancerous tumours without damaging healthy cells.
What is radiotherapy used for?
Radiotherapy kills cancerous cells of the body with a high dose of radiation. It treats germ cells of tumours, leukaemia and lymphomas. Most cancers of epithelial require a high dose of radiation for treatment. Though cancer of melanoma and renal cells are radio-resistant, radiotherapy is still a reliable option for cure.
Different types of radiotherapy
Radiotherapy or radiation therapy is broadly three types namely:
- Sealed source radiation therapy also called brachytherapy.
- Unsealed source radiotherapy, also called a systemic radioisotope.
- External beam radiation therapy or teletherapy.
Brachytherapy: it is mainly used in the treatment of skin, prostate, cervical and breast cancer. Brachytherapy is conducted by employing a source of radiation adjacent to or within the affected area. It can be done for curing tumours in the body. Since it is placed very close to a tumour, it reduces the chance of radiation exposure on the healthy tissue and limits the radiation to a certain point. This feature makes it more preferred than external beam radiation therapy (teletherapy). Brachytherapy takes less time as compared to other therapies which help in the reduction of division and growth of cancer cells between dose intervals.
Unsealed source radiotherapy: popularly known as systemic radioisotope therapy is a targeting therapy. The targeting process occurs as a result of the properties of the radioiodine isotope which gets absorbed in the thyroid gland. It is also done by guiding it towards target tissue in attachment with other antibodies. Radioisotopes are passed through ingestion in the bloodstream. It is mainly used in the treatment of cancer of bone metastasis. The common isotopes employed for treatment are samarium lexidronam, radium 223 and strontium 89.
External beam radiation therapy: this category is further divided into many parts that are conventional external beam therapy, stereotactic radiation therapy, intensity-modulated radiation therapy, volumetric modulated arc therapy and three-dimensional conformal radiation therapy.
- Conventional external beam therapy- this therapy uses two-dimensional x-rays with the help of a closed radioactive source. It comprises a single beam of radiation which operates in many directions. Its purpose is to accurately aim the area to be treated. Though it limits the capacity of surrounding unaffected tissues for other high dose surgeries. It is also not suitable for prostate cancer treatment as damage may occur to the rectum.
- Three-dimensional conformal radiation therapy- it is an advanced therapy that uses MRI and CT scan for better scanning. This virtual simulation allows a more accurate beam radiation target than conventional therapy. Multileaf collimator is used along with several beams for hitting only affected tissues while protecting others. After detecting the shape and size of the tumour, radiation toxicity is lessened around normal tissues.
- Volumetric modulated arc therapy- this method was introduced in 2007. Modification of three parameters during a procedure is a unique feature of this method. Using a multileaf collimator, shape and speed of the beam are changed while radiation is delivered by VMAT. VMAT ensures the least radiation flow in treating oropharyngeal, nasopharyngeal and hypopharyngeal.
- Intensity-modulated radiation therapy- it is considered best for treating tumours surrounded by blood vessels, organs and spinal cord as it is effective in shaping concave tumours. Computer-assisted x-rays spread a significant amount of radiation to cancerous tissues inside the tumour. In this method, the intensity of radiation is raised near the tumour while it is reduced to near-normal tissues. It showed better results as compared to three-dimensional therapy and fewer side effects.
- Stereotactic radiation- it is mostly performed for treating tumours of spine and brain. It is of two types- stereotactic radiosurgery and stereotactic body radiation therapy. Stereotactic radiosurgery uses several radiations for spinal cord and brain whereas the other is used for treating tumours of body parts like lungs.
What is the difference between chemotherapy and radiotherapy?
From above radiotherapy is defined as the treatment through high radiation whereas chemotherapy uses high powered special drugs which shrink and eventually destroy cancer cells. Chemotherapy is delivered either orally or injected in veins at regular intervals. It is used to reduce symptoms of cancer and decreases the spreading of cancer to other parts. Side effects of chemotherapy loss of appetite, fever, diarrhoea, anaemia, constipation and weight loss.
Side effects of radiotherapy
Mild side effects include nausea, vomiting, epithelial surface damage, soreness of stomach, mouth and throat, intestine discomfort, swelling and infertility. Some major symptoms are hair loss, dryness, fibrosis, cancer, lymphedema, cardiovascular disease, diarrhoea and cognitive decline. During pregnancy, radiation can cause anomalies, disability, leukaemia and retarded growth and mental development.
Radiotherapy for breast cancer
Different types of radiation therapy can be employed for treating breast cancer depending on 0-4 stages of cancer. The treatment comprises several procedures over specific intervals like 5-6 days for 4-5 weeks. Radiotherapy lowers the risk of return of cancer in breasts. This therapy is done before and after neoadjuvant and adjuvant radiation therapy respectively. Radiotherapy is preferred after mastectomy in case of large tumours, lymph nodes cancer and other cancer cells of chest or skin. Partial breast irradiation applies radiation directly over tumour rather than the whole breast. Symptoms of breast cancer are redness, thickening of the skin, lumps, swelling of lymph nodes and inverted nipples.
Side effects of radiotherapy for breast cancer are breast swelling, variations in skin sensation, irritation from sun, loss of hair, soreness of mouth and acute to severe fatigue though most of them disappear over time.
Radiotherapy for prostate cancer
Radiotherapy involves radiation generated from a device and directed towards the prostate gland using a thin flexible tube inside the infected tissue. The most common type of radiation therapy for prostate cancer is brachytherapy and external beam radiation. X-rays are generated to ensure the correct position during the procedure. Accelerator device rotates around the body to target the beam into the tumour from various directions. Small freckles like marks are present after treatment which is generally temporary.
Side effects of radiotherapy for prostate cancer are sunburn, hair loss, swelling around the treated area, redness, slight pain, slightly dark-coloured skin, enhanced pores, high or low skin sensitivity, tissue or skin thickening, bleeding and erectile dysfunction.
Radiotherapy for brain tumour
For treatment for a brain tumour, external beam radiation is mostly done. Other therapies are also suitable depending on a health condition. Before treatment, MRI and CT scan are conducted for proper aiming and accurate dose of radiation. Radiotherapy is the main method for curing metastatic brain tumours. Side effects of radiotherapy for a brain tumour are headaches, fatigue, hearing loss, skin change, scalp change and forgetfulness.
Benefits of radiotherapy
Radiotherapy is suitable at any age, normal their side effects are minor which often vanish with time, they are very effective in controlling the growth of cancer cells, take less, proper and detailed examining, no major scarring of the skin, easily available and life expectancy is high as compared to other therapies. No longer stays required in hospital and only slight discomfort with no pain at all. Another benefit includes medical insurance cover which makes it affordable.
What is the cost of radiotherapy?
It is an expensive treatment which costs around $7,300-$10,000, $7,500-$11,000 and $11,000-$26,000 for breast cancer, lung cancer and prostate cancer respectively.
Does radiotherapy cure cancer?
Yes, it cures cancer through various times of radiation penetration in the body by targeting tumour cells.
How long does radiotherapy take?
The procedure does not take long in all cases. It hardly takes 30 minutes for completing detailed imaging of the body and it detects all cancer cells in one exam.
How long does it take to recover from radiotherapy?
Usually two weeks is enough for recovery. Recovery also depends on lifestyle and diet as oily and spicy food will reduce the pace of recovery and side effects are frequent in such conditions.
How to prepare for radiotherapy?
Avoid eating and drinking for some time before treatment, do not eat spicy, fried and oily food, stop previous medicines and ask a doctor for a proper diet before and after surgery.