Radiation therapy (also called radiotherapy) may be a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. At low doses, radiation is employed in x-rays to ascertain inside your body, like x-rays of your teeth or broken bones.Radiation therapy (also called radiotherapy) may be a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. At low doses, radiation is employed in x-rays to ascertain inside your body, like x-rays of your teeth or broken bones.Cancer remains leading explanation for death globally. The International Agency for Research on Cancer (IARC) recently estimated that 7.6 million deaths worldwide were thanks to cancer with 12.7 million new cases per annum being reported worldwide. a big proportion of this burden is borne by developing countries; 63% of cancer deaths are reported to be from developing countries 1, 2, 3. Cancer may be a multigenic and multicellular disease which will arise from all cell types and organs with a multi-factorial etiology. Hanahan and Weinberg 4 have identified six neoplastic cell phenotypes or hallmarks of cancer: cells with unlimited proliferative potential, environmental independence for growth, evasion of apoptosis, angiogenesis, invasion and metastasis to different parts of body. If uncontrolled cell growth or metastatic spread occurs it'll end in death of the individual 5. The past decade has witnessed a substantial progress towards the treatment and understanding of the sooner proposed hallmarks of cancer 6 and along side advances in early detection and within the various treatment modalities, many cancers became curable 7.After the invention of X-rays in 1895, by Wilhelm Conrad Röntgen from Germany its clinical usefulness, as a way of cancer treatment was first appreciated. it's also 100 years ago that Curie won a second Nobel prize for her research into radium, establishing her position as a pioneer within the field of radiotherapy . To mark this, 2011 has been designated the Year of radiotherapy within the UK, celebrating a century of advances. Since that point , radiotherapy has developed into a recognized medicine with Radiation Oncology being a discipline during which various health and science professionals from numerous disciplines work together. along side surgery and chemotherapy, radiotherapy or radiotherapy remains a crucial modality utilized in cancer treatment being a highly cost effective single modality treatment accounting about only 5% of the entire cost of cancer care 8. Furthermore, approximately 50% of all cancer patients will receive radiotherapy during their course of illness 9, 10 with an estimation that radiotherapy contributes to around 40% towards curative treatment 11. Rapid progress during this field continues to be boosted by advances in imaging techniques, computerized treatment planning systems, radiation treatment machines (with improved X-ray production and treatment delivery) also as improved understanding of the radiobiology of radiotherapy