Radical Treatment of Nasopharyngeal Carcinoma
Abstract
Nasopharyngeal carcinoma (NPC) is endemic in southern China and Southeast Asia. It is distinctly different from other head and neck cancers in terms of etiology, clinical behavior and response to treatment. There have been marked improvements in treatment outcome in the past decades, partly the result of early presentation and diagnosis, and partly the result of improvements in treatment. Radiotherapy is the standard treatment for NPC, its success depending on accurate delineation of target volume, determination of optimal radiation dose, and the means to deliver the desired radiation dose to this target volume. The advent of cross-sectional imaging of CT and MR has allowed more accurate delineation of tumor extent. The recent advent of intensity-modulated radiotherapy (IMRT), as a means of 3D conformal radiotherapy, allows conforming high radiation dose to target volume, and at the same time conforming low radiation dose to sensitive structures. For the more advanced cases, adding chemotherapy can in theory partly help through sensitizing tumor cells to radiotherapy, and partly through direct effect on the occult micro-metastases. Randomized prospective controlled trials of concurrent chemoradiotherapy had demonstrated benefits in terms of improving relapse-free and overall survival; studies using neoadjuvant or adjuvant chemotherapy had not been able to demonstrate such benefits.
