Refinement and Individualization of Clinical Target Volume Delineation in Nasopharyngeal Carcinoma: A 22-Year Clinical Experience

Abstract

Radiation-related toxicity in nasopharyngeal carcinoma (NPC) is common, even in the IMRT era. Little progress has been made on the refinement of target volume delineation. There is no well-established guideline for clinical target volume (CTV) delineation. A common practice is to add a fixed circumferential margin around gross tumor volume (GTV). Another common practice is to routinely include certain bony structures such as the posterior third of the maxillary sinus/nasal cavity and sphenoid sinus, irrespective of tumor extent, an approach that was used to define field borders in the 2D era.