Is there a 'mucosa-sparing' benefit of IMRT for head-and-neck cancer?
- Department of Radiation Oncology, University of Texas Medical Branch, Galveston, TX (United States)
- Department of Medical Physics, University of Texas Medical Branch, Galveston, TX (United States)
Purpose: To investigate whether intensity-modulated radiation therapy (IMRT) allows more mucosal sparing than standard three-field technique (3FT) radiotherapy for early oropharyngeal cancer. Methods and Materials: Whole-field IMRT plans were generated for 5 patients with early-stage oropharyngeal cancer according to Radiation Therapy Oncology Group 0022 (66 Gy/30 fractions/6 weeks) guidelines with and without a dose objective on the portion of mucosa not overlapping any PTV. 3FT plans were also generated for the same 5 patients with two fractionation schedules: conventional fractionation (CF) to 70 Gy/35 fractions/7 weeks and concomitant boost (CB) to 72 Gy/40 fractions/6 weeks. Cumulative dose volume histograms (DVHs) of the overall mucosal volume (as per in-house definition) from all trials were compared after transformation into the linear quadratic equivalent dose at 2 Gy per fraction with a time factor correction. Results: Compared with IMRT without dose objective on the mucosa, a 30-Gy maximum dose objective on the mucosa allows {approx}20% and {approx}12% mean absolute reduction in the percentage of mucosa volume exposed to a dose equivalent to 30 Gy (p < 0.01) and 70 Gy (p < 0.01) at 2 Gy in 3 and 7 weeks, respectively, without detrimental effect on the coverage of other regions of interest. Without mucosal dose objective, IMRT is associated with a larger amount of mucosa exposed to clinically relevant doses compared with both concomitant boost and conventional fractionation; however, if a dose objective is placed, the reverse is true, with up to {approx}30% reduction in the volume of the mucosa in the high-dose region compared with both concomitant boost and conventional fractionation (p < 0.01). Conclusions: Intensity-modulated radiation therapy can be potentially provide more mucosal sparing than traditional approaches.
- OSTI ID:
- 20850182
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 66, Issue 3; Conference: 48. annual meeting of the American Society for Therapeutic Radiology and Oncology, Pennsylvania, PA (United States), 5-9 Nov 2006; Other Information: DOI: 10.1016/j.ijrobp.2006.05.060; PII: S0360-3016(06)00987-4; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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