The use of tumour markers in oesophageal cancer to quantify setup errors and baseline shifts during treatment. (January 2021)

• Record Type: Journal Article
• Authors: Thomas, Melissa; De Roover, Robin; van der Merwe, Schalk; Lambrecht, Maarten; Defraene, Gilles; Haustermans, Karin
• Is Part Of: Clinical and translational radiation oncology. Volume 26(2021)
• Page Start: 8
• Page End: 14
• Publication Date: 2021-01
• Subjects: 2D two-dimensional -- 3D three-dimensional -- 4D four-dimensional -- AP anterior-posterior -- CBCT cone-beam computed tomography -- CC cranio-caudal -- CT computed tomography -- CTV clinical target volume -- CTVtotal total clinical target volume -- DoF degree-of-freedom -- EUS endoscopic ultrasound -- FDG-PET/CT fluorodeoxyglucose positron emission tomography with integrated computed tomography -- GM grand mean -- GTV gross tumour volume -- iCTV internal clinical target volume -- IMRT intensity modulated radiation therapy -- kV kilovoltage -- LR left-right -- MRI magnetic resonance imaging -- nCRT neoadjuvant chemoradiation -- OAR organ at risk -- PTV planning target volume; Esophageal cancer -- Fiducial gold markers -- Inter-fractional motion -- Intra-fractional baseline shifts -- Radiotherapy treatment margins -- Matching strategies; Cancer -- Radiotherapy -- Periodicals; Oncology -- Periodicals; Cancer -- Radiotherapy; Oncology; Radiation Oncology; Neoplasms -- radiotherapy; Translational Medical Research; Periodicals; Electronic journals; Periodicals; 616.9940642
• DOI: 10.1016/j.ctro.2020.11.001
• Languages: English
• ISSNs: 2405-6308

Abstract

Highlights: Implantation of solid gold markers safe. Inter-fractional motion for markers in distal oesophagus largest cranio-caudally. Reduced radiotherapy treatment margins with soft-tissue vs. bony-anatomy matching. Impact of intra-fractional baseline shifts on margin calculation rather small. Abstract: Purpose: To prospectively evaluate the feasibility of solid gold marker placement in oesophageal cancer patients and to quantify inter-fractional and intra-fractional (baseline shift) marker motion during radiation treatment. Radiotherapy target margins and matching strategies were investigated. Materials/methods: Thirty-four markers were implanted by echo-endoscopy in 10 patients. Patients received a planning 4D CT, daily pre-treatment cone-beam CT (CBCT) and a post-treatment CBCT for at least five fractions. For fractions with both pre- and post-treatment CBCT, marker displacement between planning CT and pre-treatment CBCT (inter-fractional) and between pre-treatment and post-treatment CBCT (intra-fractional; only for fractions without rotational treatment couch correction) were calculated in left–right (LR), cranio-caudal (CC) and anterior-posterior (AP) direction after bony-anatomy and soft-tissue matching. Systematic/random setup errors were estimated; treatment margins were calculated. Results: No serious adverse events occurred. Twenty-three (67.6%) markers were visible during radiotherapy (n = 3 middle oesophagus, n = 16 distal oesophagus, n = 4 proximal stomach). Margins for inter-fractional displacement after bony-anatomy match depended on the localisation of the primary tumour and were 11.2 mm (LR), 16.4 mm (CC) and 8.2 mm (AP) for distal markers. Soft-tissue matching reduced the CC margin for these markers (16.4 mm to 10.5 mm). The mean intra-fractional shift of 12 distal markers was 0.4 mm (LR), 2.3 mm (CC) and 0.7 mm (AP). Inclusion of this shift resulted in treatment margins for distal markers of 12.8 mm (LR), 17.3 mm (CC) and 10.4 mm (AP) after bony-anatomy matching and 12.4 mm (LR), 11.4 mm (CC) and 9.7 mm (AP) after soft-tissue matching. Conclusion: This study demonstrated that the implantation of gold markers was safe, albeit less stable compared to other marker types. Inter-fractional motion was largest cranio-caudally for markers in the distal oesophagus, which was reduced after soft-tissue compared to bony-anatomy matching. The impact of intra-fractional baseline shifts on margin calculation was rather small.