Influence of eye movement on lens dose and optic nerve target coverage during craniospinal irradiation
| Autor: | Gijsbert H. Bol, Matteo Maspero, Mirjam E. Bosman, Astrid L.H.M.W. van Lier, Geert O. Janssens, John H. Maduro, Enrica Seravalli, Bianca A.W. Hoeben, Amber M L Wood, W. P. Matysiak |
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| Přispěvatelé: | Guided Treatment in Optimal Selected Cancer Patients (GUTS) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
genetic structures
Optic nerve R895-920 PBS pencil-beam scanning ITVoptic disc internal target volume around optic discs VMAT sCT synthetic CT OON orbital optic nerve Craniospinal Irradiation Article COM center of mass law.invention 3D-conventional GERMINOMA Medical physics. Medical radiology. Nuclear medicine Lens CATARACT law medicine D98OON D98 orbital optic nerve Radiology Nuclear Medicine and imaging PRVlens planning organ-at-risk volume around lenses Pencil-beam scanning Proton therapy RC254-282 CTVvoxelwise min voxelwise minimum CTV business.industry SIOPE European International Society for Paediatric Oncology Eye movement Neoplasms. Tumors. Oncology. Including cancer and carcinogens Craniospinal irradiation ANGLE Gaze eye diseases Lens (optics) CSI craniospinal irradiation medicine.anatomical_structure Oncology MLD mean lens dose sense organs Proton Nuclear medicine business Optic disc RADIOTHERAPY |
| Zdroj: | Clinical and Translational Radiation Oncology Clinical and Translational Radiation Oncology, Vol 31, Iss, Pp 28-33 (2021) Clinical and Translational Radiation Oncology, 31, 28-33. Elsevier |
| ISSN: | 2405-6308 |
| Popis: | Highlights • While optic nerves are part of the CSI target volume, lenses need to be spared. • Lens and optic disc movement for different gaze directions was evaluated in MRI scans. • Eye movement influence on lens and optic nerve CSI dose distribution was analyzed. • With modern radiotherapy techniques, any eye movement increases the mean lens dose. • Maximum eye movements decrease mean orbital optic nerve D98 Purpose Optic nerves are part of the craniospinal irradiation (CSI) target volume. Modern radiotherapy techniques achieve highly conformal target doses while avoiding organs-at-risk such as the lens. The magnitude of eye movement and its influence on CSI target- and avoidance volumes are unclear. We aimed to evaluate the movement-range of lenses and optic nerves and its influence on dose distribution of several planning techniques. Methods Ten volunteers underwent MRI scans in various gaze directions (neutral, left, right, cranial, caudal). Lenses, orbital optic nerves, optic discs and CSI target volumes were delineated. 36-Gy cranial irradiation plans were constructed on synthetic CT images in neutral gaze, with Volumetric Modulated Arc Therapy, pencil-beam scanning proton therapy, and 3D-conventional photons. Movement-amplitudes of lenses and optic discs were analyzed, and influence of gaze direction on lens and orbital optic nerve dose distribution. Results Mean eye structures’ shift from neutral position was greatest in caudal gaze; −5.8±1.2 mm (±SD) for lenses and 7.0±2.0 mm for optic discs. In 3D-conventional plans, caudal gaze decreased Mean Lens Dose (MLD). In VMAT and proton plans, eye movements mainly increased MLD and diminished D98 orbital optic nerve (D98OON) coverage; mean MLD increased up to 5.5 Gy [total ΔMLD range −8.1 to 10.0 Gy], and mean D98OON decreased up to 3.3 Gy [total ΔD98OON range −13.6 to 1.2 Gy]. VMAT plans optimized for optic disc Internal Target Volume and lens Planning organ-at-Risk Volume resulted in higher MLD over gaze directions. D98OON became ≥95% of prescribed dose over 95/100 evaluated gaze directions, while all-gaze bilateral D98OON significantly changed in 1 of 10 volunteers. Conclusion With modern CSI techniques, eye movements result in higher lens doses and a mean detriment for orbital optic nerve dose coverage of |
| Databáze: | OpenAIRE |
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