Image Guided Radiation Therapy Strategies for Pelvic Lymph Node Irradiation in High-Risk Prostate Cancer: Motion and Margins

Image guided radiation therapy based on bony anatomy requires larger prostate and SV margins, and guidance on prostate requires larger LN margins. Neither guidance strategy is optimal, and a combination of the 2 or treatment adaptation after a number of fractions might be preferable. Calculation of the total margin should also include delineation uncertainties.