ABSTRACT
This chapter makes to get students familiar with radiobiological issues introduced in modern radiotherapy techniques and the application and use of clinical radiobiology in radiotherapy treatment planning. Brachytherapy may be delivered at high dose rate (HDR), medium, or low dose rate (LDR) or in the form of pulsed brachytherapy. Radiobiological issues involved in new treatment modalities such as intensity modulated radiation therapy (IMRT)/stereotactic radiotherapy (SRT)/intraoperative radiotherapy (IORT), which involve high doses delivered in a few or even a single fraction. The topic of hypofractionation for nonpalliative therapy includes treatment modalities such as IORT, stereotactic radiosurgery (SRS), and stereotactic body radiation therapy (SBRT). Proton therapy has been administered for various tumor entities and malignancies which require precise, highly conformal dose deposition. The farther the normal-tissue complication probability (NTCP) curve is to the right of the tumor control probability (TCP) curve, the larger the therapeutic index, that is, the tumor response for a fixed level of normal tissue damage.
