A hybrid IMRT/VMAT technique for the treatment of nasopharyngeal cancer.
BIOMED RESEARCH INTERNATIONAL 2015;
2015:940102. [PMID:
25688371 PMCID:
PMC4320861 DOI:
10.1155/2015/940102]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 12/14/2022]
Abstract
Hybrid IMRT/VMAT technique which combined intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) was developed for the treatment of nasopharyngeal cancer (NPC). Two-full-arc VMAT (2ARC-VMAT), 9-field IMRT (9F-IMRT), and Hybrid IMRT/VMAT plans for NPC were compared in terms of the dosimetric quality, sparing of organs at risk (OARs), and delivery efficiency. The Hybrid IMRT/VMAT technique can improve the target dose homogeneity and conformity compared with 9F-IMRT and 2ARC-VMAT. It can reduce the dose delivered to the TMJ, mandible, temporal lobe, and unspecified tissue with fewer MUs compared with 9F-IMRT and dose delivered to parotids, brainstem, and spinal cord compared with 2ARC-VMAT technique. The mean delivery time of Hybrid plans was shorter than that of 9F-IMRT plans (408 s versus 812 s; P = 0.00) and longer than that of 2ARC-VMAT plans (408 s versus 179 s; P = 0.00). Hybrid IMRT/VMAT technique could be a viable radiotherapy technique with better plan quality.
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