Kwong DLW et al. (2006) Preliminary results of radiation dose escalation for locally advanced nasopharyngeal carcinoma. Int Radiat Oncol Biol Phys 64: 374–381

Radiation-dose escalation has the potential to reduce local disease recurrence rates in patients with locally advanced nasopharyngeal carcinoma. Previous studies using conventional radiotherapy, however, have been largely unsuccessful, with considerable levels of radiation toxicity. Kwong and colleagues have addressed the need for more-precise treatment by studying dose escalation using the simultaneous modulated accelerated radiation therapy (SMART) boost technique with intensity-modulated radiotherapy (IMRT) in 50 patients with stage T3–T4 nasopharyngeal carcinoma.

All patients received a 70 Gy dose to the planning target volume and a 76 Gy dose to the gross tumor volume delivered in 35 fractions over 7 weeks. Thirty-four patients also received concurrent cisplatin chemotherapy. Patients were assessed by regular CT or MRI scans, and underwent nasopharyngoscopy and biopsy at 6 and 8 weeks after completion of IMRT. After a median follow-up of 25 months, two patients had local disease recurrence and two had distant recurrence; all four patients had undergone IMRT without concurrent chemotherapy. The 2-year disease-free survival, overall survival, distant-metastases-free survival and locoregional control rates were 93.1%, 92.1%, 94.2%, and 95.7%, respectively. Toxicities were common, but manageable, and 92% of patients completed IMRT without interruption. Notable late complications included two cases of carotid pseudoaneurysm. The authors conclude that this chemoradiotherapy regimen controls local disease recurrence effectively and improves survival rates in patients with locally advanced nasopharyngeal carcinoma, and therefore recommend the regimen in this setting.