RapidArc Planning and Delivery in Patients With Locally Advanced Head-and-Neck Cancer Undergoing Chemoradiotherapy
- Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)
Purpose: Volumetric modulated arc therapy (RapidArc, Varian Medical Systems) permits the delivery of highly conformal dose distributions. We studied planning and delivery in patients who underwent RapidArc for locally advanced head-and-neck cancer (HNC). Methods and Materials: A total of 35 consecutive patients who completed RapidArc with concurrent chemotherapy for Stages III-IV tumors of the oro- and hypopharynx/larynx in our center were identified. All underwent bilateral neck irradiation and 21 patients had at least N2 disease. A simultaneous integrated boost (SIB) delivered 70 Gy (in 2 Gy/fraction) to the planning target volume (PTV){sub boost} and elective nodal regions (PTV{sub elect}) received 57.75 Gy. A standard planning constraint set was used and constraints for parotid glands were individually adapted. Treatments were delivered using two arcs after all plans were verified in a solid water phantom using GafChromic External Beam Therapy films. Results: RapidArc planning generally took 1.5-2 h, which was faster than with our previous seven-field intensity-modulated radiotherapy sliding window technique. Film dosimetry revealed that 0.6% of films exceeded a combination of dose differences {>=}3% or distance to agreement {>=}2 mm. More than 99% of both PTVs received {>=}95% of the prescription dose. Average plan conformity index was 1.13 and mean dose to ipsilateral and contralateral parotid glands were 31.4 Gy and 26.1 Gy, respectively. The mean beam-on time was <3 min and mean number of monitor units was 426. Conclusions: RapidArc achieved excellent target coverage and normal tissue sparing, with delivery completed in less than 3 min. RA is currently our standard intensity-modulated radiotherapy approach for advanced HNC.
- OSTI ID:
- 21491581
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 79, Issue 2; Other Information: DOI: 10.1016/j.ijrobp.2009.11.014; PII: S0360-3016(09)03539-1; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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