Radiation oncology is a discipline of medicine that uses high-energy X-rays, gamma rays, electrons, and protons to treat cancer. The branch owes its subsistence to an exquisite blend of the scientific fields of physics and biology. Conceptual expansion in radiobiology, improvements in engineering, and advancement in computer technology have made a paradigm shift in the way radiation treatment is delivered presently.   

Radiation utilized in cancer treatment, known as ionizing radiation, is a high-energy form of radiation. As the name suggests, ionizing radiation ionizes atoms. It means that it has sufficient energy to eject electrons from the orbit of an atom forming free radicals. By doing so, these free radicals split up the DNA of cancer cells and eradicate them.  

Approximately 60% to 70% of cancer patients might receive radiation treatment at some point in their cancer treatment. It could be as a part of curative or palliative treatment of various cancers. For instance, radiation therapy is given as a curative treatment, delivered solely or along with chemotherapy, in cancers localized to the head and neck, and cervical region. The course of this type of radiation will take 5 to 7 weeks to complete. On the other hand, a short duration of palliative radiation therapy might be given to a patient who suffers from extensive cancer metastases to alleviate the symptoms brought about by the same. 

Radiation treatment has advanced radically in the previous few decades, and the tempo of change is fast. Today, we treat tumors with millimeter precision. Different techniques, such as Intensity Modulated Radiotherapy (IMRT), Image-Guided Radiotherapy (IGRT), Volumetric Modulated Arc Therapy (VMAT), Stereotactic Radiosurgery (SRS), Stereotactic Radiation Therapy (SRT), and Stereotactic Body Radio Therapy (SBRT), help us implement radiation with greater precision than ever before. Precision aside, these techniques deliver a higher dose to tumors located at anatomically challenging positions, at the same time preventing any dose spill to critical structures surrounding the tumor. 

The newer techniques conquer the problems brought about by breathing motion or even a heartbeat. Previously, it was challenging for doctors to treat tumors that move along with breathing, such as lung cancer, tumor in the liver, and breast cancer. Today, with the help of an ingenious technique called gating, this problem is solved. This technique allows the doctor to deliver radiation along with the rhythm of every breathing cycle. In this technique, an infrared camera monitors the breathing pattern of the patient. This camera aids the machine to stop the radiation once the tumor goes off focus. This innovative technique allows the clinician to deliver a higher dose to the tumor, less burdened by injuring the adjacent normal lung and heart tissues. 

The amalgamation of uninterrupted imaging, motion perception, and robotic control coalesces to allow efficient radiation treatment. These innovations promise a bright future that allows faster, effective, painless, and safer cancer treatment.