Superiority of intensity-modulated radiotherapy over three-dimensional conformal radiotherapy combined with brachytherapy in nasopharyngeal carcinoma: a planning study
- 1 May 2008
- journal article
- research article
- Published by Oxford University Press (OUP) in The British Journal of Radiology
- Vol. 81 (965), 397-405
- https://doi.org/10.1259/bjr/36110151
Abstract
A planning study was performed in order to investigate the potential benefits of intensity-modulated radiotherapy using a simultaneous integrated multi-target treatment technique (SIMT-IMRT) over highly optimized three-dimensional conformal radiotherapy combined with intracavitary brachytherapy (3D-CRT + IBT) for the treatment of nasopharyngeal carcinoma (NPC). The subjects were eight patients with Stages I-IV NPC. For each case, two sets of plans were prepared after delineation of gross tumour volumes, three planning target volumes (PTVs) and 17 organs at risk (OARs). Dose prescriptions for PTVs were 72.6 Gy, 66 Gy and 52.8 Gy in 33 fractions for SIMT-IMRT vs 72 Gy (66 Gy in 33 fractions for 3D-CRT and 3 Gy twice for IBT), 66 Gy (in 33 fractions) and 46 Gy (in 23 fractions) for 3D-CRT + IBT plans. Compared with the combined plans, SIMT-IMRT provided superior results for the primary tumour (PT) in terms of mean equivalent uniform dose (67 Gy vs 63.7 Gy, p = 0.016). IMRT plans increased the mean tumour control probability (TCP) values (both uncorrected and corrected for accelerated tumour repopulation after 28 days) for PT when compared with 3D-CRT + IBT (98% and 94.3% vs 95.8% and 89.9%, respectively, p = 0.016). Mean doses to middle/external ears, parotid glands and temporomandibular joints were significantly lower in IMRT plans. Our conclusion is that, for all stages of NPC, SIMT-IMRT was superior to highly optimized 3D-CRT + IBT in terms of tumour coverage, increased local TCP, and dose reduction to some OARs. We recommend that SIMT-IMRT should be considered as a first-line radiotherapy technique for NPC.Keywords
This publication has 28 references indexed in Scilit:
- Long-term treatment results for nasopharyngeal carcinoma: The Sahlgrenska University Hospital experienceActa Oncologica, 2007
- Sensorineural hearing loss in combined modality treatment of nasopharyngeal carcinomaCancer, 2006
- Intensity-modulated radiation therapy (IMRT) for nasopharynx cancer: Update of the Memorial Sloan-Kettering experienceInternational Journal of Radiation Oncology*Biology*Physics, 2006
- Comparing 3DCRT and inversely optimized IMRT planning for head and neck cancer: Equivalence between step-and-shoot and sliding window techniquesRadiotherapy and Oncology, 2005
- Unnecessary laryngeal irradiation in the IMRT eraHead & Neck, 2004
- Comparison of intensity modulated radiation therapy (IMRT) treatment techniques for nasopharyngeal carcinomaInternational Journal of Cancer, 2001
- Mathematical Models of Tumour and Normal Tissue ResponseActa Oncologica, 1999
- Reporting and analyzing dose distributions: A concept of equivalent uniform doseMedical Physics, 1997
- Improved dose distributions for 3d conformal boost treatments in carcinoma of the nasopharynxInternational Journal of Radiation Oncology*Biology*Physics, 1991