Dosimetric comparison between helical tomotherapy and volumetric modulated arc-therapy for non-anaplastic thyroid cancer treatment
| Autor: | Sabrina Boyrie, Laure Vieillevigne, Jonathan Khalifa, Thomas Filleron, M. Ouali, Anne Laprie, Michel Rives |
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| Rok vydání: | 2014 |
| Předmět: |
Organs at Risk
Medullary cavity medicine.medical_treatment Planning target volume Tomotherapy Helical tomotherapy medicine Humans Radiology Nuclear Medicine and imaging Thyroid Neoplasms External beam radiotherapy Anaplastic thyroid cancer Radiometry Thyroid cancer Volumetric modulated arctherapy business.industry Research Radiotherapy Planning Computer-Assisted medicine.disease Volumetric modulated arc therapy Radiation therapy Oncology Radiology Nuclear Medicine and imaging Radiotherapy Intensity-Modulated Non-anaplastic thyroid cancer Dosimetric comparison Nuclear medicine business |
| Zdroj: | Radiation Oncology (London, England) |
| ISSN: | 1748-717X |
| DOI: | 10.1186/s13014-014-0247-x |
| Popis: | Background To evaluate and compare dosimetric parameters of volumetric modulated arctherapy (VMAT) and helical tomotherapy (HT) for non-anaplastic thyroid cancer adjuvant radiotherapy. Methods Twelve patients with non-anaplastic thyroid cancer at high risk of local relapse received adjuvant external beam radiotherapy with curative intent in our institution, using a two-dose level prescription with a simultaneous integrated boost approach. Each patient was re-planned by the same physicist twice using both VMAT and HT. Several dosimetric quality indexes were used: target coverage index (proportion of the target volume covered by the reference isodose), healthy tissue conformity index (proportion of the reference isodose volume including the target volume), conformation number (combining both previous indexes), Dice Similarity Coefficient (DSC), and homogeneity index ((D2%-D98%)/prescribed dose). Dose-volume histogram statistics were also compared. Results HT provided statistically better target coverage index and homogeneity index for low risk PTV in comparison with VMAT (respectively 0.99 vs. 0.97 (p = 0.008) and 0.22 vs. 0.25 (p = 0.016)). However, HT provided poorer results for healthy tissue conformity index, conformation number and DSC with low risk and high risk PTV. As regards organs at risk sparing, by comparison with VMAT, HT statistically decreased the D2% to medullary canal (25.3 Gy vs. 32.6 Gy (p = 0.003)). Besides, HT allowed a slight sparing dose for the controlateral parotid (Dmean: 4.3 Gy vs. 6.6 Gy (p = 0.032)) and for the controlateral sub-maxillary gland (Dmean: 29.1 Gy vs. 33.1 Gy (p = 0.041)). Conclusions Both VMAT and HT techniques for adjuvant treatment of non-anaplastic thyroid cancer provide globally attractive treatment plans with slight dosimetric differences. However, helical tomotherapy clearly provides a benefit in term of medullary canal sparing. |
| Databáze: | OpenAIRE |
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