Patient position verification in magnetic-resonance imaging only radiotherapy of anal and rectal cancers
| Autor: | Hazel McCallum, Ann Henry, Bashar Al-Qaisieh, M. Beasley, David Sebag-Montefiore, Richard Speight, Rachel A Cooper, Nathalie Casanova, Alexandra Gilbert, David L. Buckley, M. Tyyger, David Bird, M. Nix, M. Teo |
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| Rok vydání: | 2021 |
| Předmět: |
Cone beam computed tomography
Colorectal cancer medicine.medical_treatment MR-only R895-920 Rectum CBCT patient positioning Medical physics. Medical radiology. Nuclear medicine mental disorders medicine Anal cancer Radiology Nuclear Medicine and imaging Original Research Article Rectal cancer RC254-282 Radiation medicine.diagnostic_test business.industry Neoplasms. Tumors. Oncology. Including cancer and carcinogens CBCT Magnetic resonance imaging medicine.disease Anus Radiation therapy medicine.anatomical_structure MRI-only Tomography Nuclear medicine business psychological phenomena and processes |
| Zdroj: | Physics and Imaging in Radiation Oncology Physics and Imaging in Radiation Oncology, Vol 19, Iss, Pp 72-77 (2021) |
| ISSN: | 2405-6316 |
| Popis: | Highlights • MR-only patient positioning for anal and rectal cancers using CBCT. • MR-only results in systematic positioning differences to of Background and Purpose Magnetic resonance (MR)-only treatment pathways require either the MR-simulation or synthetic-computed tomography (sCT) as an alternative reference image for cone beam computed tomography (CBCT) patient position verification. This study assessed whether using T2 MR or sCT as CBCT reference images introduces systematic registration errors as compared to CT for anal and rectal cancers. Materials and Methods A total of 32 patients (18 rectum,14 anus) received pre-treatment CT- and T2 MR- simulation. Routine treatment CBCTs were acquired. sCTs were generated using a validated research model. The local clinical registration protocol, using a grey-scale registration algorithm, was performed for 216 CBCTs using CT, MR and sCT as the reference image. Linear mixed effects modelling identified systematic differences between modalities. Results Systematic translation and rotation differences to CT for MR were −0.3 to + 0.3 mm and −0.1 to 0.4° for anal cancers and −0.4 to 0.0 mm and 0.0 to 0.1° for rectal cancers, and for sCT were −0.4 to + 0.8 mm, −0.1 to 0.2° for anal cancers and −0.6 to + 0.2 mm, −0.1 to + 0.1° for rectal cancers. Conclusions T2 MR or sCT can successfully be used as reference images for anal and rectal cancer CBCT position verification with systematic differences to CT |
| Databáze: | OpenAIRE |
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