Stereotactic radiotherapy--an approach to improve local control of nasopharyngeal carcinoma.

Radiotherapy is the primary curative treatment of nasopharyngeal carcinoma (NPC) with the dose-response relationship. Local recurrence is one of the major treatment failure patterns. With high accuracy, high tumor dose, high therapeutic enhancement ratio and low normal tissue dose, stereotactic radiotherapy (SRT) is used as boost irradiation for residual lesions and is able to improve the local control rate. Residual lesions involving the carotid artery or cavernous sinus, or with tumor necrosis are treatment contraindications to SRT boost irradiation; while the old patients, patients with hypertension, diabetes mellitus, and severe nasopharyngeal infection are relative treatment contraindications to SRT boost irradiation. Fractionated SRT can spare vessels and nerves better than stereotactic radiosurgery (SRS). SRT can definitely improve the outcome for the boost of NPC residual lesions. Proper patient selection, individualized fractionated regimen, and balance of the benefit of tumor control and the risk of normal tissue damage are of paramount importance to ensure the satisfactory clinical outcome and quality of life.