Radiation Therapy Essay

Radiation therapy (RT) is an essential component in the interdisciplinary treatment of brain tumors. Independently of histology, radiation plays a central role and has shown to increase local tumor control.
Developments in radiation oncology are always aiming at an increase precision of dose delivery: More conformal coverage of target volumes, steep dose gradients to surrounding tissues, and sparing of organs at risk (OAR). In photon therapy, based on 3D-RT, stereotactic radiotherapy was a big step in the direction of more precision. Tightly conformal dose distributions and a sharp dose fall-off to normal tissue were the main benefits. With this, high single doses can be applied in a single fraction, as radiosurgery, or, in larger volumes as fractionated stereotactic radiotherapy (FSRT) (1). The search for increased conformality in more complex shaped volumes and the need to spare specific regions, such as parotid glands or other functional organs, have facilitated the development of intensity modulated radiotherapy (IMRT). With this, broadening of the theapeutic window has taken place, and for certain indications, such as skull base tumors, head-and-neck tumors or prostate cancers, this technique can be considered the treatment standard (1-4). Taken both techniques together, RT has gained a central role in the treatment
The strongest rationale lies not primarily in increase in local tumor control, but in reduction of side effects, i.e. neurocognitive side effects or secondary malignancies. Albeit many calculations have demonstrated the potential of protons to meet these criteria, generation of evidence is still underway; the end points however are intricate to meet, and long-term follow-up in large populations may be necessary to demonstrate the hypothetical benefits with clinical