[en] Complete text of publication follows: Aim/Introduction: To assess the feasibility of a fully integrated dynamic PET-MRI approach applied to the characterization of lung lesions specifically. Materials and Methods: A total of 9 patients underwent a one-hour dynamic PET-MRI imaging protocol for suspected lung cancer. FDG PET and DCE MRI full kinetic analyses (Sokoloff and extended Toft models respectively), together with DWI-ADC and T1/T2-mapping were performed. All the PET-MRI data were warped into the same isotropic reference space before analyses. For each lung lesion, voxel-wise 3D maps of 14 biological features / 4 main categories were computed using an in-house fully integrative multimodal post-processing pipeline developed for this purpose specifically : perfusion/vascularization (K_trans, K_ep, V_e and V_p); metabolism (SUV, k1, k2, k3, Ki, V_b, and MRGlu); diffusion (ADC); and tissular characterization (T1 and T2 mapping). For each lesion, voxel-wise monotonic relationships between all the PET-MRI features were explored (Spearman correlations). Finally, all the lesions were partitioned by using multidimensional unsupervised gaussian mixture approach, and features profiles/relationships were explored at the supervoxel regional level. Results: Relationships between the perfusion/vascularization, metabolism, diffusion and tissular feature categories differed among the lesions. At the feature level, strong correlations (absolute r value superior to 0.5) were observed for the perfusion/vascularization features pairs and the metabolic feature pairs. At the category level, absolute r values were inferior to 0.5 for the vast majority of the feature pairs. Combining the 14 features together, unsupervised clustering provided 2 to 4 supervoxels depending on the lesion. At the supervoxel regional levels, feature profiles differed, as well as their monotonic relationships. Conclusion: Our one-stop-shop fully integrative dynamic PETMRI protocol provided 14 biological features (4 main categories) in the same examination. For all lesions, the heterogeneity of features profiles/relationships at the regional supervoxel level highlights the unique capability of PET-MRI to get better insight of the biological characterization of lung masses

[en] After lung-sparing radiotherapy for malignant pleural mesothelioma (MPM), local failure at sites of previous gross disease represents the dominant form of failure. Our aim is to investigate if selective irradiation of the gross pleural disease only can allow dose escalation. In all, 12 consecutive stage I-IV MPM patients (6 left-sided and 6 right-sided) were retrospectively identified and included. A magnetic resonance imaging-based pleural gross tumor volume (GTV) was contoured. Two sets of planning target volumes (PTV) were generated for each patient: (1) a ''selective'' PTV (S-PTV), originating from a 5-mm isotropic expansion from the GTV and (2) an ''elective'' PTV (E-PTV), originating from a 5-mm isotropic expansion from the whole ipsilateral pleural space. Two sets of volumetric modulated arc therapy (VMAT) treatment plans were generated: a ''selective'' pleural irradiation plan (SPI plan) and an ''elective'' pleural irradiation plan (EPI plan, planned with a simultaneous integrated boost technique [SIB]). In the SPI plans, the average median dose to the S-PTV was 53.6 Gy (range 41-63.6 Gy). In 4 of 12 patients, it was possible to escalate the dose to the S-PTV to >58 Gy. In the EPI plans, the average median doses to the E-PTV and to the S-PTV were 48.6 Gy (range 38.5-58.7) and 49 Gy (range 38.6-59.5 Gy), respectively. No significant dose escalation was achievable. The omission of the elective irradiation of the whole ipsilateral pleural space allowed dose escalation from 49 Gy to more than 58 Gy in 4 of 12 chemonaive MPM patients. This strategy may form the basis for nonsurgical radical combined modality treatment of MPM. (orig.)