Evaluation of deformable image registration (DIR) methods for dose accumulation in nasopharyngeal cancer patients during radiotherapy
| Autor: | Vicharn Lorvidhaya, Taweap Sanghangthum, Imjai Chitapanarux, Hudsaleark Neamin, Somsak Wanwilairat, Wannapha Nobnop |
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| Rok vydání: | 2017 |
| Předmět: |
medicine.medical_specialty
medicine.medical_treatment nasopharyngeal cancer R895-920 Image registration Tomotherapy 030218 nuclear medicine & medical imaging Medical physics. Medical radiology. Nuclear medicine 03 medical and health sciences 0302 clinical medicine medicine Initial treatment Radiology Nuclear Medicine and imaging deformable image registration Nasopharyngeal cancer Dose accumulation dose accumulation business.industry Cumulative dose mvct helical tomotherapy Target dose Radiation therapy Oncology 030220 oncology & carcinogenesis Radiology Nuclear medicine business Research Article |
| Zdroj: | Radiology and Oncology, Vol 51, Iss 4, Pp 438-446 (2017) Radiology and Oncology |
| ISSN: | 1581-3207 2017-0033 |
| DOI: | 10.1515/raon-2017-0033 |
| Popis: | Introduction Deformable image registration (DIR) is used to modify structures according to anatomical changes for observing the dosimetric effect. In this study, megavoltage computed tomography (MVCT) images were used to generate cumulative doses for nasopharyngeal cancer (NPC) patients by various DIR methods. The performance of the multiple DIR methods was analysed, and the impact of dose accumulation was assessed. Patients and methods The study consisted of five NPC patients treated with a helical tomotherapy unit. The weekly MVCT images at the 1st, 6th, 11th, 16th, 21st, 26th, and 31st fractions were used to assess the dose accumulation by the four DIR methods. The cumulative dose deviations from the initial treatment plan were analysed, and correlations of these variations with the anatomic changes and DIR methods were explored. Results The target dose received a slightly different result from the initial plan at the end of the treatment. The organ dose differences increased as the treatment progressed to 6.8% (range: 2.2 to 10.9%), 15.2% (range: -1.7 to 36.3%), and 6.4% (range: -1.6 to 13.2%) for the right parotid, the left parotid, and the spinal cord, respectively. The mean uncertainty values to estimate the accumulated doses for all the DIR methods were 0.21 ± 0.11 Gy (target dose), 1.99 ± 0.76 Gy (right parotid), 1.19 ± 0.24 Gy (left parotid), and 0.41 ± 0.04 Gy (spinal cord). Conclusions Accuracy of the DIR methods affects the estimation of dose accumulation on both the target dose and the organ dose. The DIR methods provide an adequate dose estimation technique for observation as a result of inter-fractional anatomic changes and are beneficial for adaptive treatment strategies. |
| Databáze: | OpenAIRE |
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