Non-small cell lung cancer (NSCLC) is one of the most common types of lung cancer and a reported 85% of cases belong to this type. There are various treatment options for NSCLC, which depend on the extent of the cancer. Radiation therapy is one of the recommended treatment options. Radiation therapy is a process of using high-energy radiation, similar to X-ray, which helps in killing the cancer cells and prevents them from further growth.

The various types of radiation therapies to treat NSCLC include the following:

1. External radiation
In external radiation, the machine directs high radiation at the cancer cells. It is the most preferred radiation therapy. The process of delivering high-energy radiation with a machine is called a linear accelerator.

External radiation can be given in various ways:

• Three-dimensional (3D) conformal radiation
  This type of radiation is a type of external radiation, where the radiation is directed toward the tumor from outside the body. This radiation therapy uses computers to be accurate in targeting the tumor with radiation.
• Intensity-modulated radiation treatment (IMRT)
  IMRT is a type of external radiation which uses the help of computers to target the tumors accurately and delivers high dose radiation exactly at the tumor from different angles. This treatment not only delivers radiation to the tumor but also delivers low doses of radiation to the nearby healthy tissues.
• Stereotactic radiosurgery
  Stereotactic radiosurgery is also a type of external radiation in which the radiation is delivered outside the body. It uses special equipment to precisely deliver a single heavy dose of radiation to lung cancer tumors. This type of treatment is performed in NSCLC when the tumor has also spread to the brain and spinal cord.
• Stereotactic body radiation therapy (SBRT)
  SBRT is a type of external radiation therapy which is also known as stereotactic ablative radiotherapy (SABR). SBRT is used to treat the initial stages of lung cancers. This therapy is preferred when a patient is not eligible for the surgery or if the patient doesn’t want surgery. SBRT uses a high dose of radiation targeting the tumor from different angles.

2. Internal radiation treatment or brachytherapy
Brachytherapy is performed during surgery by placing an implant into or near the tumor. The implant holds the radioactive material through which radiation is delivered to reduce the possibility of cancer returning. Brachytherapy also delivers a dose of radiation to the airways using a special approach known as endobronchial brachytherapy.

3. Photodynamic therapy (PDT)
Photodynamic therapy is a combination of a medicine called a photosensitizer which uses a specific type of light to destroy cancer cells. Photosensitizers when exposed to certain wavelengths of light, produce a form of oxygen which helps in killing the nearby cells. This therapy also helps in destroying tumors by damaging blood vessels in the tumor. Destroying blood cells will prevent cancer from receiving nutrients that are helpful for cancer to grow and spread. This therapy also activates the immune system to fight against the tumor cells.

4. Proton therapy
Proton therapy is an advanced form of radiation therapy which is precise in targeting cancer while causing minimum damage to the healthy tissues. In this therapy, the cancer-fighting radiation is directed to the precise locations within the body which allows delivering the necessary dose only to the tumor. This precise treatment prevents side effects since it protects the normal tissues from unnecessary radiation.