Figure 1

We will go through a basic radiobiology review including a guide to alpha-beta ratios, biologically effective dose, and fractionation schemes. We will also review clinical dose volume histogram evaluation and the structures evaluated for radiation planning (targets vs. organs at risk). We will then apply these concepts to a few clinical radiation practice questions: What are some of the pros and cons of manual planning vs. 3D-planning and inverse planning? How does newer technology (such as positioning devices, on-board imaging, and CT-based planning with IMRT and VMAT) allow us to deliver hypofractionated radiation and/or stereotactic techniques? How does the dose to normal tissues and subsequent side effects differ with different radiation delivery and fractionation techniques? What are the capabilities of some different therapy machines on the market?