Angela Botticella1, Gilles Defraene1, Kristiaan Nackaerts2, Christophe M Deroose3, Johan Coolen4, Philippe Nafteux5, Stephanie Peeters6, Umberto Ricardi7, Dirk De Ruysscher6,8. 1. a Department of Oncology, Experimental Radiation Oncology , KU Leuven-University of Leuven , Leuven , Belgium. 2. b Respiratory Diseases/Respiratory Oncology Unit , KU Leuven-University of Leuven, University Hospitals Leuven , Leuven , Belgium. 3. c Department Imaging and Pathology, Nuclear Medicine and Molecular Imaging , KU Leuven-University of Leuven, University Hospitals Leuven , Leuven , Belgium. 4. d Radiology Department , University Hospitals Leuven , Leuven , Belgium. 5. e Department of Thoracic Surgery , University Hospitals Leuven , Leuven , Belgium. 6. f Department of Radiation Oncology , KU Leuven-University of Leuven, University Hospitals Leuven , Leuven , Belgium. 7. g Department of Oncology, Radiation Oncology , University of Turin , Turin , Italy. 8. h GROW-School for Oncology and Developmental Biology, Department of Radiation Oncology (MAASTRO clinic) , Maastricht University Medical Center , Maastricht , The Netherlands.
Abstract
BACKGROUND: The gross tumor volume (GTV) definition for malignant pleural mesothelioma (MPM) is ill-defined. We therefore investigated which imaging modality is optimal: computed tomography (CT) with intravenous contrast (IVC), positron emission tomography-CT (PET/CT) or magnetic resonance imaging (MRI). MATERIAL AND METHODS: Sixteen consecutive patients with untreated stage I-IV MPM were included. Patients with prior pleurodesis were excluded. CT with IVC, 18FDG-PET/CT and MRI (T2 and contrast-enhanced T1) were obtained. CT was rigidly co-registered with PET/CT and with MRI. Three sets of pleural GTVs were defined: GTVCT, GTVCT+PET/CT and GTVCT+MRI. Quantitative and qualitative evaluations of the contoured GTVs were performed. RESULTS: Compared to CT-based GTV definition, PET/CT identified additional tumor sites (defined as either separate nodules or greater extent of a known tumor) in 12/16 patients. Compared to either CT or PET/CT, MRI identified additional tumor sites in 15/16 patients (p = .7). The mean GTVCT, GTVCT+PET/CT and GTVCT+MRI [±standard deviation (SD)] were 630.1 cm3 (±302.81), 640.23 cm3 (±302.83) and 660.8 cm3 (±290.8), respectively. Differences in mean volumes were not significant. The mean Jaccard Index was significantly lower in MRI-based contours versus all the others. CONCLUSION: As MRI identified additional pleural disease sites in the majority of patients, it may play a role in optimal target volume definition.
BACKGROUND: The gross tumor volume (GTV) definition for malignant pleural mesothelioma (MPM) is ill-defined. We therefore investigated which imaging modality is optimal: computed tomography (CT) with intravenous contrast (IVC), positron emission tomography-CT (PET/CT) or magnetic resonance imaging (MRI). MATERIAL AND METHODS: Sixteen consecutive patients with untreated stage I-IV MPM were included. Patients with prior pleurodesis were excluded. CT with IVC, 18FDG-PET/CT and MRI (T2 and contrast-enhanced T1) were obtained. CT was rigidly co-registered with PET/CT and with MRI. Three sets of pleural GTVs were defined: GTVCT, GTVCT+PET/CT and GTVCT+MRI. Quantitative and qualitative evaluations of the contoured GTVs were performed. RESULTS: Compared to CT-based GTV definition, PET/CT identified additional tumor sites (defined as either separate nodules or greater extent of a known tumor) in 12/16 patients. Compared to either CT or PET/CT, MRI identified additional tumor sites in 15/16 patients (p = .7). The mean GTVCT, GTVCT+PET/CT and GTVCT+MRI [±standard deviation (SD)] were 630.1 cm3 (±302.81), 640.23 cm3 (±302.83) and 660.8 cm3 (±290.8), respectively. Differences in mean volumes were not significant. The mean Jaccard Index was significantly lower in MRI-based contours versus all the others. CONCLUSION: As MRI identified additional pleural disease sites in the majority of patients, it may play a role in optimal target volume definition.
Authors: A Botticella; G Defraene; K Nackaerts; C Deroose; J Coolen; P Nafteux; B Vanstraelen; S Joosten; L A W Michiels; S Peeters; D De Ruysscher Journal: Strahlenther Onkol Date: 2017-02-14 Impact factor: 3.621