VMAT-like plans for magnetic resonance guided radiotherapy: Addressing unmet needs
| Autor: | Lorenzo Placidi, M. Nardini, Angela Romano, L. Boldrini, C. Votta, Davide Cusumano, Giuditta Chiloiro, V. Valentini, Luca Indovina, Marta Antonelli |
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| Rok vydání: | 2021 |
| Předmět: |
Organs at Risk
medicine.medical_specialty Magnetic Resonance Spectroscopy Imrt plan Computer science medicine.medical_treatment Biophysics Locally advanced General Physics and Astronomy 030218 nuclear medicine & medical imaging Unmet needs 03 medical and health sciences 0302 clinical medicine Daily practice medicine Radiology Nuclear Medicine and imaging Medical physics Retrospective Studies medicine.diagnostic_test Radiotherapy Planning Computer-Assisted Lateral positioning Radiotherapy Dosage Magnetic resonance imaging General Medicine Radiation therapy 030220 oncology & carcinogenesis Radiotherapy Intensity-Modulated Treatment time |
| Zdroj: | Physica Medica. 85:72-78 |
| ISSN: | 1120-1797 |
| Popis: | Purpose VMAT delivery technique is currently not applicable to Magnetic Resonance-guided radiotherapy (MRgRT) hybrid systems. Aim of this study is to evaluate an innovative VMAT-like (VML) delivery technique. Material and methods First, planning and dosimetric evaluation of the MRgRT VML treatment have been performed on 10 different disease sites and the results have been compared with the corresponding IMRT plans. Then, in the second phase, 10 of the most dosimetrically challenging locally advanced pancreas treatment plans have been retrospectively re-planned using the VML approach to explore the potentiality of this new delivery technique. Finally, VML robustness was evaluated and compared with the IMRT plans, considering a lateral positioning error of ± 5 mm. Results In phase one, all VML plans were within constraint for all OARs. When PTV coverage is considered, in the 50% of the cases VML PTV coverage is equal or higher than in IMRT plan. In the remaining 50%, the highest target under coverage difference in comparison with IMRT plan is −1.71%. The mean and maximum treatment time differences (VML-IMRT) is 0.2 min and 3.1 min respectively. In phase two, the treatment time variation (VML-IMRT), shows a mean, maximum and minimum variations of 1.3, 4.6 and −0.6 min respectively. All VML plans have a better target coverage if compared with IMRT plans, keeping in any case the OARs constraints within tolerance. VML doesn’t increase plan robustness. Conclusion VMAT-like treatment approach appeared to be an efficient planning solution and it was decided to clinically implement it in daily practice, especially in the frame of hypo fractionated treatments. |
| Databáze: | OpenAIRE |
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