Dario Di Perri1,2, John A Lee1, Anne Bol1, François-Xavier Hanin1,3, Guillaume Janssens4, Daniel Labar1, Annie Robert5, Edmond Sterpin1, Xavier Geets1,2. 1. a Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain , Brussels , Belgium. 2. b Department of Radiation Oncology , Cliniques universitaires Saint-Luc , Brussels , Belgium. 3. c Department of Nuclear Medicine , Cliniques universitaires Saint-Luc , Brussels , Belgium. 4. d Ion Beam Applications , Louvain-la-Neuve , Belgium. 5. e Department of Epidemiology and Biostatistics (EPID) , Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain , Brussels , Belgium.
Abstract
BACKGROUND: Dose painting (DP) aims to improve radiation therapy (RT) outcome by targeting radioresistant tumour regions identified through functional imaging, e.g., positron emission tomography (PET). Importantly, the expected benefit of DP relies on the ability of PET imaging to identify tumour areas which could be consistently targeted throughout the treatment. In this study, we analysed the spatial stability of two potential DP targets in lung cancer patients undergoing RT: the tumour burden surrogate [18F]fluorodeoxyglucose (FDG) and the hypoxia surrogate [18F]fluoroazomycin arabinoside (FAZA). MATERIALS AND METHODS: Thirteen patients with unresectable lung tumours underwent FDG and FAZA 4D-PET/CT before (pre), and during the second (w2) and third (w3) weeks of RT. All PET/CT were reconstructed in their time-averaged midposition (MidP) for further analysis. The metabolic tumour volume (MTV: FDG standardised uptake value (SUV) > 50% SUVmax) and the hypoxic volume (HV: FAZA SUV >1.4) were delineated within the gross tumour volume (GTVCT). The stability of FDG and FAZA PET uptake distributions during RT was subsequently assessed through volume-overlap analysis and voxel-based correlation analysis. RESULTS: The volume-overlap analysis yielded median overlapping fraction (OF) of 0.86 between MTVpre and MTVw2 and 0.82 between MTVpre and MTVw3. In patients with a detectable HV, median OF was 0.82 between HVpre and HVw2 and 0.90 between HVpre and HVw3. The voxel-based correlation analysis yielded median Spearman's correlation coefficient (rS) of 0.87 between FDGpre and FDGw2 and 0.83 between FDGpre and FDGw3. Median rS was 0.78 between FAZApre and FAZAw2 and 0.79 between FAZApre and FAZAw3. CONCLUSIONS: FDG and FAZA PET uptake distributions were spatially stable during the 3 first weeks of RT in patients with unresectable lung cancer, both based on volume- and voxel-based indicators. This might allow for a consistent targeting of high FDG or FAZA PET uptake regions as part of a DP strategy.
BACKGROUND: Dose painting (DP) aims to improve radiation therapy (RT) outcome by targeting radioresistant tumour regions identified through functional imaging, e.g., positron emission tomography (PET). Importantly, the expected benefit of DP relies on the ability of PET imaging to identify tumour areas which could be consistently targeted throughout the treatment. In this study, we analysed the spatial stability of two potential DP targets in lung cancerpatients undergoing RT: the tumour burden surrogate [18F]fluorodeoxyglucose (FDG) and the hypoxia surrogate [18F]fluoroazomycin arabinoside (FAZA). MATERIALS AND METHODS: Thirteen patients with unresectable lung tumours underwent FDG and FAZA 4D-PET/CT before (pre), and during the second (w2) and third (w3) weeks of RT. All PET/CT were reconstructed in their time-averaged midposition (MidP) for further analysis. The metabolic tumour volume (MTV: FDG standardised uptake value (SUV) > 50% SUVmax) and the hypoxic volume (HV: FAZA SUV >1.4) were delineated within the gross tumour volume (GTVCT). The stability of FDG and FAZA PET uptake distributions during RT was subsequently assessed through volume-overlap analysis and voxel-based correlation analysis. RESULTS: The volume-overlap analysis yielded median overlapping fraction (OF) of 0.86 between MTVpre and MTVw2 and 0.82 between MTVpre and MTVw3. In patients with a detectable HV, median OF was 0.82 between HVpre and HVw2 and 0.90 between HVpre and HVw3. The voxel-based correlation analysis yielded median Spearman's correlation coefficient (rS) of 0.87 between FDGpre and FDGw2 and 0.83 between FDGpre and FDGw3. Median rS was 0.78 between FAZApre and FAZAw2 and 0.79 between FAZApre and FAZAw3. CONCLUSIONS: FDG and FAZA PET uptake distributions were spatially stable during the 3 first weeks of RT in patients with unresectable lung cancer, both based on volume- and voxel-based indicators. This might allow for a consistent targeting of high FDG or FAZA PET uptake regions as part of a DP strategy.
Authors: Xu Cao; Srinivasa Rao Allu; Shudong Jiang; Jason R Gunn Bs; Cuiping Yao PhD; Jing Xin PhD; Petr Bruza PhD; David J Gladstone ScD; Lesley A Jarvis Md PhD; Jie Tian PhD; Harold M Swartz Md Msph PhD; Sergei A Vinogradov PhD; Brian W Pogue PhD Journal: Int J Radiat Oncol Biol Phys Date: 2020-09-28 Impact factor: 7.038
Authors: Seth T Gammon; Federica Pisaneschi; Madhavi L Bandi; Melinda G Smith; Yuting Sun; Yi Rao; Florian Muller; Franklin Wong; John De Groot; Jeffrey Ackroyd; Osama Mawlawi; Michael A Davies; Y N Vashisht Gopal; M Emilia Di Francesco; Joseph R Marszalek; Mark Dewhirst; David Piwnica-Worms Journal: Cells Date: 2019-11-21 Impact factor: 6.600