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Intensity-modulated radiotherapy for early-stage nasopharyngeal carcinoma
A prospective study on disease control and preservation of salivary function
Article first published online: 23 AUG 2004
Copyright © 2004 American Cancer Society
Volume 101, Issue 7, pages 1584–1593, 1 October 2004
How to Cite
Kwong, D. L. W., Pow, E. H. N., Sham, J. S. T., McMillan, A. S., Leung, L. H. T., Leung, W. K., Chua, D. T. T., Cheng, A. C. K., Wu, P. M. and Au, G. K. H. (2004), Intensity-modulated radiotherapy for early-stage nasopharyngeal carcinoma. Cancer, 101: 1584–1593. doi: 10.1002/cncr.20552
- Issue published online: 17 SEP 2004
- Article first published online: 23 AUG 2004
- Manuscript Accepted: 29 JUN 2004
- Manuscript Revised: 25 JUN 2004
- Manuscript Received: 29 APR 2004
- University of Hong Kong, Committee on Research and Conference Grant (CRCG). Grant Numbers: 10202651/25065/21600/323/01, 10204855/25065/21600/302/01, 10203969/25065/21600/301/01, 20372439/11331/08007/400/01
- nasopharyngeal carcinoma;
- intensity-modulated radiotherapy;
- parotid sparing;
- salivary flow
Xerostomia is a uniform complication after radiotherapy (RT) for nasopharyngeal carcinoma (NPC). Dosimetric studies suggested that intensity-modulated RT (IMRT) can spare part of the parotid glands from high-dose radiation. Disease control and salivary function after IMRT for early-stage NPC was studied prospectively.
Thirty-three patients with T1,N0–N1,M0 NPC were treated with IMRT from 2000 to 2002. The prescribed dose was 68–70 grays (Gy) in 34 fractions to gross tumor volume, 64–68 Gy to the planning target volume, and 70 Gy to enlarged cervical lymph nodes. Nineteen patients had stimulated whole salivary (SWS) flow assessment and stimulated parotid salivary (SPS) flow assessment at baseline and at 2 months, 6 months, 12 months, 18 months, and 24 months after the completion of IMRT.
At a median follow-up of 2 years, only 1 neck failure was observed. The 2-year and 3-year local control, distant metastases-free, and overall survival rates all were 100%. The lymph node control and progression-free survival rates were 100% at 2 years and 92.3% at 3 years, respectively. The average mean dose to the parotid gland was 38.8 Gy. The SWS and SPS flow showed continuous recovery: 60% and 47.1% of patients recovered at least 25% of their baseline SPS flow and SWS flow, respectively, at 1 year after completion of IMRT, and the proportions rose to 85.7% and 71.4%, respectively, by 2 years. The pH and buffering capacity of saliva also improved with time.
Parotid-sparing IMRT achieved good locoregional control, and there was continuous recovery of salivary flow, pH, and buffering capacity in the first 2 years after IMRT in patients with NPC. Cancer 2004. © 2004 American Cancer Society.