Frame-based radiosurgery of multiple metastases using single-isocenter volumetric modulated arc therapy technique
| Autor: | Konstantin V. Slavin, Bulent Aydogan, Kamil M. Yenice, Matthew Koshy, Kang-Hyun Ahn |
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| Rok vydání: | 2019 |
| Předmět: |
Frame based
Organs at Risk Patient Motion Computer science medicine.medical_treatment multiple metastases Radiosurgery Imaging phantom 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine medicine Image Processing Computer-Assisted VMAT SRS Humans Radiation Oncology Physics Radiology Nuclear Medicine and imaging Instrumentation frame‐based SRS Radiation business.industry Brain Neoplasms Radiotherapy Planning Computer-Assisted Isocenter Radiotherapy Dosage Treatment verification Prognosis Volumetric modulated arc therapy Magnetic Resonance Imaging single‐isocenter volumetric modulated arc therapy 030220 oncology & carcinogenesis Delivery efficiency Radiotherapy Intensity-Modulated Nuclear medicine business Tomography X-Ray Computed Algorithms |
| Zdroj: | Journal of Applied Clinical Medical Physics |
| ISSN: | 1526-9914 |
| Popis: | Single‐isocenter volumetric modulated arc therapy (VMAT) technique can provide stereotactic radiosurgery (SRS) treatment with improved delivery efficiency for treating multiple metastases. Nevertheless, planning is time consuming and verification of frame‐based SRS setup, especially at noncoplanar angles, can be challenging. We report on a single‐isocenter VMAT technique with a special focus on improving treatment workflow and delivery verification to exploit the minimized patient motion of the frame‐based SRS. We developed protocols for preplanning and verification for VMAT and evaluated them for ten patient cases. Preplans based on MRI were used to generate comparable treatment plans using CT taken on the day of treatment after frame placement. Target positioning accuracy was evaluated by stereoscopic in‐room kV imaging. Dosimetric accuracy of the noncoplanar plan delivery was validated using measurement‐guided 3D dose reconstruction as well as film‐based end‐to‐end test with a Rando phantom. Average absolute differences of homogeneity indices, conformity indices, and V12Gy between MR preplans and CT‐based plans were within 5%. In‐room imaging positioning accuracy of 0.4 mm was verified to be independent of the distance to the isocenter. For treatment verification, average local and global passing rates of the 3D gamma (1 mm, 3%) were 86% and 99%, respectively. D99 values were matched within 5% for individual target structures (>0.5 cc). Additional film analysis confirmed dosimetric accuracy for small targets that had large verification errors in the 3D dose reconstruction. Our results suggest that the advantages of frame‐based SRS and noncoplanar single‐isocenter VMAT technique can be combined for efficient and accurate treatment of patients with multiple metastases. |
| Databáze: | OpenAIRE |
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