Cancer is the deadliest disease of the century. The advancements in the medical field and years of research have resulted in developing a variety of treatments for cancer. Chemotherapy, surgery, proton therapy, cryosurgery and radiation therapy are the most common treatment methods. Radiation treatment is done in about 50-60 % of cancer patients. This method of cancer treatment is applied on almost every type of cancer like breast cancer, pancreatic, prostrate, uterine, lung, leukemia, cancer affecting lymphatic system, soft tissue sarcomas and the host of other types of cancers.
Radiation therapy is a targeted therapy where the cancerous cells are targeted specifically to destroy the cancerous tissue. This treatment damages the ability of the cancer cells to replicate and spread cancer.
What is Radiotherapy Treatment?
Radiotherapy can be defined as a cell targeted treatment using ionizing radiations to destroy the cancer cells. It causes damage to the genetic make up of the cells which in turn results in the cessation of growth and replication of these cells. These radiations may damage the nearby normal cells, but most of the normal cells can recover from this. Maximum destruction of cancer cells is the aim of the treatment. Radiation therapy is used to destroy a tumor completely or to shrink the tumor so as to relieve symptoms.
Cancer radiation therapy can be used alone or as a combination with chemotherapy or surgery. This is mostly done to increase the success of the treatment. There are cases where radiation treatment is used as symptomatic treatment or a palliative treatment to alleviate symptoms like pain and improve the condition of the patient.
Methods of Radiotherapy
Basically, there are two types of radiation therapy –the external radiotherapy and internal radiotherapy. The effectiveness of external radiation therapy can be achieved by using certain refined techniques like three-dimensional conformal radiation therapy, intensity modulated radiation therapy (IMRT) and proton beam radiation therapy (PBRT). The stereo tactic radiotherapy is a method used in the treatment of brain tumor. It can be done in three ways such as linac-based stereo tactic radio surgery, using heavy charged proton or helium ions and the gamma knife technique. Brachytherapy is another advanced method.
Effectiveness of Radiation therapy on Different Types of Cancer
Radiation therapy has prolonged the survival of cancer patients. As in every treatment, different cells respond differently to this treatment also. Radio sensitivity depicts the response of cancer cells. Radiation dose is the term used to depict the amount of radiation absorbed by the cancer cells. The currently used unit of the radiation dose is Gray (gy).
The highly sensitive cancer cells like blood cancer and germ cell tumors are rapidly destroyed by the minute doses of radiation. Moderately sensitive cells like skin cancer cells need a higher dose of radiation. There are even cells that are radio resistant. Melanoma and renal cell cancer are good examples. In such cases, a higher dose of radiation is preferred. Curative densitivity of the tumors differ from each other. Leukemia cannot be cured as the cancerous cells spread through out the body. Lymphoma can be cured if it is concentrated on one specific area. The radio responsive tumors are routinely treated with curative doses of radiotherapy.
Size also matters in cancer treatment. Small sized tumors are more responsive than large tumors. Various methodologies are adopted to nullify this effect. Surgical resection before therapy is a common method. It is widely adopted in breast cancer treatment. Using neoadjuvant chemotherapy before radical radiotherapy is another method. Various drugs like Cetuximab and Cisplatin are usually administered before radiotherapy. All these are radio-sensitizing drugs which help increase the effectiveness of the cancer radiation therapy.