Extremities

Treatment planning for extremities presents unique challenges due to their mobility and their positioning at the lateral extremes of the body. To ensure that the planned dose can be accurately delivered, it is essential to carefully assess setup reproducibility, the effectiveness of immobilization, and the robustness of dose distributions with respect to potential tumor changes over the course of treatment when evaluating plan quality. When clinical target volumes include the skin or subcutaneous tissue, bolus or other techniques are often required to ensure adequate dose coverage, while skin sparing may be important in preoperative settings to minimize wound healing delays. Additional considerations include minimizing dose to uninvolved parts – such as bones, the normal tissue strip, and contralateral limbs – and accounting for machine limitations when treating long anatomical regions. This chapter describes these challenges and outlines practical considerations to help mitigate them during treatment planning with the goal of ensuring high plan quality.