Planning target volume margin in head and neck cancer patients undergoing radiation therapy: Estimations derived from own data and literature.

Planning target volume (PTV) to deliver the desired dose to the clinical target volume (CTV) accounts for systematic (∑) and random (σ) errors during the planning and execution of intensity modulated radiation therapy (IMRT). As these errors vary at different departments, this study was conducted to determine the 3-dimensional PTV (PTV) margins for head and neck cancer (HNC) at our center. The same was also estimated from reported studies for a comparative assessment.