1. Cone-beam computed tomography for lung cancer - validation with CT and monitoring tumour response during chemo-radiation therapy.
- Author
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Michienzi, Alissa, Kron, Tomas, Callahan, Jason, Plumridge, Nikki, Ball, David, and Everitt, Sarah
- Subjects
LUNG cancer diagnosis ,COMPUTED tomography ,RADIOTHERAPY ,SMALL cell lung cancer ,BRONCHIAL carcinoma ,LUNG cancer treatment ,TREATMENT of lung tumors ,ANTHROPOMETRY ,COMPUTER software ,LONGITUDINAL method ,LUNG cancer ,LUNG tumors ,RADIATION doses ,TUMOR classification ,TREATMENT effectiveness ,DISEASE progression - Abstract
Introduction: Cone-beam computed tomography (CBCT) is a valuable image-guidance tool in radiation therapy (RT). This study was initiated to assess the accuracy of CBCT for quantifying non-small cell lung cancer (NSCLC) tumour volumes compared to the anatomical 'gold standard', CT. Tumour regression or progression on CBCT was also analysed.Methods: Patients with Stage I-III NSCLC, prescribed 60 Gy in 30 fractions RT with concurrent platinum-based chemotherapy, routine CBCT and enrolled in a prospective study of serial PET/CT (baseline, weeks two and four) were eligible. Time-matched CBCT and CT gross tumour volumes (GTVs) were manually delineated by a single observer on MIM software, and were analysed descriptively and using Pearson's correlation coefficient (r) and linear regression (R2 ).Results: Of 94 CT/CBCT pairs, 30 patients were eligible for inclusion. The mean (± SD) CT GTV vs CBCT GTV on the four time-matched pairs were 95 (±182) vs 98.8 (±160.3), 73.6 (±132.4) vs 70.7 (±96.6), 54.7 (±92.9) vs 61.0 (±98.8) and 61.3 (±53.3) vs 62.1 (±47.9) respectively. Pearson's correlation coefficient (r) was 0.98 (95% CI 0.97-0.99, ρ < 0.001). The mean (±SD) CT/CBCT Dice's similarity coefficient was 0.66 (±0.16). Of 289 CBCT scans, tumours in 27 (90%) patients regressed by a mean (±SD) rate of 1.5% (±0.75) per fraction. The mean (±SD) GTV regression was 43.1% (±23.1) from the first to final CBCT.Conclusion: Primary lung tumour volumes observed on CBCT and time-matched CT are highly correlated (although not identical), thereby validating observations of GTV regression on CBCT in NSCLC. [ABSTRACT FROM AUTHOR]- Published
- 2017
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