Radiotherapy is used to destroy cancer cells or control their growth. The main purpose of radiotherapy is to protect healthy organs while destroying the tumor. Ionization radiations such as x-rays, gamma rays and proton particles are used in radiation therapy. Nowadays, advanced treatment techniques are used when applying radiotherapy to cancer patients. Advanced treatment techniques have been developed to target cancer cells and protect healthy tissues, increase the effectiveness of radiotherapy and minimize side effects. Treatment techniques applied in radiotherapy largely depend on the development of technology. With the developments in computer technology, imaging methods have improved, and parallel to these, there have been developments in radiotherapy techniques. There are many advanced treatment techniques used in radiation therapy. The main ones are intensity-modulated radiation therapy, image-guided radiation therapy, stereotactic radiosurgery and stereotactic body radiation therapy, adaptive radiotherapy, brachytherapy, hypofractionation and proton therapy. Intensity modulated radiation therapy (IMRT) is a treatment technique that uses different beams of light to the targeted volume, destroying cancer cells while sparing surrounding tissues. Image guided radiation therapy (IGRT) uses real-time image guidance during treatment. Patient position and tumor movements are observed so that the target can be treated more accurately. Stereotactic Radiosurgery and Stereotactic Body Radiotherapy are basically based on treating small lesions by focusing on them with very high doses of radiation. Adaptive radiotherapy is a radiotherapy technique that takes into account the patient's anatomical and physiological changes during cancer treatment. This technique makes it possible to update the radiotherapy plan in response to changes in the patient's body and to provide a treatment that targets the radiation dose more precisely. Brachytherapy is a treatment technique that involves placing radioactive sources directly or very closely into or near cancer cells. Hypofractionation involves giving higher doses to the patient in a shorter period of time compared to conventional radiotherapy fractionation. Proton therapy is a treatment that targets cancer cells using proton-charged particles instead of x-rays or gamma rays. Advanced treatment techniques in radiotherapy offer more options and higher success rates in cancer treatment. However, the type of cancer for each disease differs from each other, so it is very important to determine the most appropriate treatment approach for the patient.