Michael G Jameson1, Shivani Kumar2, Shalini K Vinod2, Peter E Metcalfe3, Lois C Holloway4. 1. Liverpool and Macarthur Cancer Therapy Centres, Australia; Centre for Medical Radiation Physics, University of Wollongong, Australia; Ingham Institute of Applied Medical Research, Australia. Electronic address: michael.jameson@sswahs.nsw.gov.au. 2. Liverpool and Macarthur Cancer Therapy Centres, Australia; Ingham Institute of Applied Medical Research, Australia; South Western Sydney Clinical School, University of New South Wales, Australia. 3. Centre for Medical Radiation Physics, University of Wollongong, Australia. 4. Liverpool and Macarthur Cancer Therapy Centres, Australia; Centre for Medical Radiation Physics, University of Wollongong, Australia; Ingham Institute of Applied Medical Research, Australia; South Western Sydney Clinical School, University of New South Wales, Australia; Institute of Medical Physics, School of Physics, University of Sydney, Australia.
Abstract
BACKGROUND AND PURPOSE: Contouring variation is a well know uncertainty in modern radiotherapy. This study investigates the relationship between contouring variation, tumor control probability (TCP) and equivalent uniform dose (EUD) for conformal non-small cell lung cancer (NSCLC) radiotherapy. MATERIAL AND METHODS: Seven patients were retrospectively recruited to the study and multiple PTV contours were generated based on CT and PET imaging by three observers. Plans were created for each PTV volume. Volumes were analyzed geometrically using volume, location, dimension and conformity index (CI). Radiobiological plan analysis consisted of two TCP models and EUD. Spearman's correlation coefficient (ρ) was used to quantify the association between geometric variation and radiobiological metrics. RESULTS: The variation in CI and TCP for the study was 0.66-0.90% and 0.19-0.68%. Changes in lateral dimension and volume were significantly correlated with TCP and EUD with an average ρ of -0.49 and 0.43 (p<0.01) respectively. CONCLUSIONS: TCP and geometric contour variation show significant correlation. This correlation was most significant for changes in lateral dimensions of PTV volumes. This association may be used in the assessment of contouring protocol violations in multicenter clinical trials and aid in the design of future contouring studies. Crown
BACKGROUND AND PURPOSE: Contouring variation is a well know uncertainty in modern radiotherapy. This study investigates the relationship between contouring variation, tumor control probability (TCP) and equivalent uniform dose (EUD) for conformal non-small cell lung cancer (NSCLC) radiotherapy. MATERIAL AND METHODS: Seven patients were retrospectively recruited to the study and multiple PTV contours were generated based on CT and PET imaging by three observers. Plans were created for each PTV volume. Volumes were analyzed geometrically using volume, location, dimension and conformity index (CI). Radiobiological plan analysis consisted of two TCP models and EUD. Spearman's correlation coefficient (ρ) was used to quantify the association between geometric variation and radiobiological metrics. RESULTS: The variation in CI and TCP for the study was 0.66-0.90% and 0.19-0.68%. Changes in lateral dimension and volume were significantly correlated with TCP and EUD with an average ρ of -0.49 and 0.43 (p<0.01) respectively. CONCLUSIONS:TCP and geometric contour variation show significant correlation. This correlation was most significant for changes in lateral dimensions of PTV volumes. This association may be used in the assessment of contouring protocol violations in multicenter clinical trials and aid in the design of future contouring studies. Crown
Authors: T Konert; W V Vogel; D Paez; A Polo; E Fidarova; H Carvalho; P S Duarte; A C Zuliani; A O Santos; D Altuhhova; L Karusoo; R Kapoor; A Sood; J Khader; A Al-Ibraheem; Y Numair; S Abubaker; C Soydal; T Kütük; T A Le; N X Canh; B Q Bieu; L N Ha; J S A Belderbos; M P MacManus; D Thorwarth; G G Hanna Journal: Eur J Nucl Med Mol Imaging Date: 2019-07-31 Impact factor: 9.236
Authors: Gerard M Walls; Valentina Giacometti; Aditya Apte; Maria Thor; Conor McCann; Gerard G Hanna; John O'Connor; Joseph O Deasy; Alan R Hounsell; Karl T Butterworth; Aidan J Cole; Suneil Jain; Conor K McGarry Journal: Phys Imaging Radiat Oncol Date: 2022-07-26