Research progress in replanning during intensity-modulated radiotherapy for nasopharyngeal carcinoma

Intensity-modulated radiotherapy (IMRT) is the first-line treatment for nasopharyngeal carcinoma currently. Previous studies have shown that regression of primary tumor and metastatic lymph nodes or a decrease in body weight causes the contour of normal organs and head-and-neck to shrink during the course of radiotherapy, which may lead to underdose in primary tumor and overdose in organs at risk (OARs) and then adversely affect treatment outcomes. Replanning during the course of radiotherapy can maintain the dose to target volume and reduce the exposure of OARs, which improves outcomes in some patients. For replanning during the course of IMRT, however, the advantages have not been widely recognized and there is still a long way to go before widely accepted timing and frequency of replanning are set up. Further studies are needed to figure out how to identify patients appropriate for plan modification. (authors)