Radiation therapy works by using focused high energy x-rays to destroy cancer cells and shrink tumours. The radiation kills cells by damaging their genetic structure. It consists of external beam radiation therapy and internal radiation therapy (called brachytherapy). Radiation therapy is generally more location specific compared to chemotherapy and a critical therapy to achieve local control of tumors.
Chemotherapy is a systemic treatment that stops or slows down the overall growth of cancer cells and is administered orally or intravenously.
Both radiation therapy and chemotherapy work by targeting and killing the cancer cells. Immunotherapy, on the other hand, redirects the body’s own immune system and tries to remove the camouflage of cancer cells to destroy the tumour.
Currently, the number of patients treated with immunotherapy is still small and response rates vary according to the type of cancer. Additional research is required to study why it is more effective in some patients and to increase the effectiveness of immunotherapy by combining it with other types of cancer treatment such as radiation therapy and
chemotherapy. The good news is there is increasing evidence that shows the synergistic effect of radiotherapy and immunotherapy and there are many ongoing clinical trials, which are looking deeper into this approach.