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Objectives: Combined modality treatment (CMT) for malignant pleural mesothelioma (MPM) remains a matter of debate regarding the choice of surgical procedure: extrapleural pneumonectomy (EPP) or pleurectomy/decortication., Methods: We performed a prospective interventional cohort study between 2003 and 2014. All consecutive patients with any histological MPM subtype, ≤70 years old, World Health Organization performance status ≤1, medically fit for pneumonectomy and stage cT1-2cN0-2cM0 (TNM7) or lower were included. Eligibility for CMT was discussed by the multidisciplinary tumour board. Our local CMT protocol consisted of induction chemotherapy, followed by EPP and hemithoracic radiotherapy. Induction chemotherapy consisted of 3 cycles of cisplatin (75 mg/m2 day 1) and pemetrexed (500 mg/m2 day 1), each administered once every 3 weeks. If non-progressive, EPP was performed followed by hemithoracic radiotherapy (most frequently, intensity-modulated radiotherapy; dose 54 Gy/1.8 Gy ± boost). Feasibility and long-term survival analyses were performed. Overall survival and disease-free survival (DFS) were calculated from histological confirmation of a diagnosis of MPM., Results: Out of 197 patients, 97 started with CMT (79 epithelioid, 15 mixed and 3 sarcomatoid tumours, based on histological analysis). Clinical TNM was IA (n = 9)/IB (n = 8)/II (n = 57)/III (n = 23). A total of 76 patients underwent surgery (EPP: n = 56; exploratory thoracotomy: n = 20). The in-hospital mortality rate was 3.6%. Out of 56 patients who underwent surgery, 47 completed the entire CMT protocol. The intent-to-treat median and 5-year OS were 22.4 [95% confidence interval (CI) = 15.5-27.9] months and 11.2% (95% CI = 6.9-23.4). In patients who completed the CMT protocol (n = 47), these values were 33.2 (95% CI = 23.0-45.0) months and 24.2% (95% CI = 13.4-43.8). The intent-to-treat median and 5-year DFS were 15.6 (95% CI = 14.0-17.3) months and 9.9% (95% CI = 5.1-19.2), 19.8 (95% CI = 16.8-27.7) months and 17.2% (95% CI = 8.6-34.1) in those who had the full CMT. The Cox proportional hazards model showed a significantly lower DFS in positive lymph nodes (HR 2.79, 95% CI=1.35-5.78; P=0.006). In 30 (64%) patients with epithelioid type MPM without positive lymph nodes (pN0) after EPP, the 5-year DFS was 27.0% (95% CI=14.1-51.7)., Conclusions: CMT with EPP for MPM is feasible, with an acceptable surgical mortality rate, and results in a 5-year survival rate of 24%. Careful patient selection (staging and physical performance) is extremely important., (© The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: 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., Materials and Methods: 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])., Results: 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., Conclusion: 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.

Introduction: Nodal categories for malignant pleural mesothelioma are derived from the lung cancer staging system and have not been adequately validated. The International Association for the Study of Lung Cancer developed a multinational database to generate evidence-based recommendations to inform the eighth edition of the TNM classification of malignant pleural mesothelioma., Methods: Data from 29 centers were entered prospectively (n = 1566) or by transfer of retrospective data (n = 1953). Survival according to the seventh edition N categories was evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression analysis. Survival was measured from the date of diagnosis., Results: There were 2432 analyzable cases: 1603 had clinical (c) staging, 1614 had pathologic (p) staging, and 785 had both. For clinically staged tumors there was no separation in Kaplan-Meier curves between cN0, cN1 or cN2 (cN1 versus cN0 hazard ratio [HR] = 1.06, p = 0.77 and cN2 versus cN1 HR = 1.04, p = 0.85). For pathologically staged tumors, patients with pN1 or pN2 tumors had worse survival than those with pN0 tumors (HR = 1.51, p < 0.0001) but no survival difference was noted between those with pN1 and pN2 tumors (HR = 0.99, p = 0.99). Patients with both pN1 and pN2 nodal involvement had poorer survival than those with pN2 tumors only (HR = 1.60, p = 0.007) or pN0 tumors (HR = 1.62, p < 0.0001)., Conclusions: A recommendation to collapse both clinical and pN1 and pN2 categories into a single N category comprising ipsilateral, intrathoracic nodal metastases (N1) will be made for the eighth edition staging system. Nodes previously categorized as N3 will be reclassified as N2., (Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

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: GTV CT , GTV CT+PET/CT and GTV CT+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 GTV CT , GTV CT+PET/CT and GTV CT+MRI [±standard deviation (SD)] were 630.1 cm 3 (±302.81), 640.23 cm 3 (±302.83) and 660.8 cm 3 (±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.

Purpose: To evaluate the diagnostic accuracy of the visual assessment of malignant pleural mesothelioma (MPM) on magnetic resonance (MR) images by using two known visual markers (mediastinal pleural thickness and shrinking of the lung) and a newly introduced one (pleural pointillism)., Materials and Methods: With the approval of the local ethics committee, 100 consecutive patients (mean age, 61.4 years; age range, 18-87 years; 75 men, 25 women) suspected of having MPM pleural abnormalities underwent positron emission tomography/computed tomography and MR imaging, including diffusion-weighted (DW) MR imaging, followed by explorative thoracoscopy or guided biopsy with histopathologic confirmation. Because visual assessment is still the preferred method of image interpretation, the diagnostic accuracy of mediastinal pleural thickening, shrinking lung (hemithorax volume decrease due to fibrosis), and pleural pointillism were examined. Pleural pointillism was denoted by the presence of multiple, hyperintense pleural spots on high-b-value DW images. Histopathologic findings in the surgical specimen served as the reference standard. McNemar tests with Bonferroni correction were used to assess differences in accuracy among the three examined markers., Results: Of 100 patients, 33 had benign pleural alterations, and 67 had malignant pleural diseases (MPDs); 57 of 67 had MPM. A total of 78 patients received a correct diagnosis (benign vs malignant) on the basis of mediastinal pleural thickening (sensitivity, 81%; specificity, 73%; accuracy, 78%); and 66 patients, on the basis of shrinking lung (sensitivity, 60%; specificity, 79%; accuracy, 66%). The correct diagnosis was indicated on the basis of pleural pointillism in 88 patients (sensitivity, 93%; specificity, 79%; accuracy, 88%)., Conclusion: Visual assessment of pleural pointillism on high-b-value DW images is useful to differentiate MPD from benign alterations, performing substantially better than mediastinal pleural thickness and shrinking lung, and might obviate unnecessary invasive procedures for MPM., (© RSNA, 2014.)

A 50-year-old patient with malignant pleural mesothelioma (epithelial subtype, clinically staged cT1bN0M0) underwent a combined modality treatment, including induction chemotherapy, followed by extrapleural pneumonectomy (EPP) and radical radiotherapy. After pathologic examination of the surgical specimen, a complete remission (pT0N0) was observed. The complete disappearance of solid tumour tissue after induction chemotherapy is a rarely observed and documented finding in the combined modality treatment of malignant pleural mesothelioma. The real prognostic value of the pathologic complete remission of a malignant pleural mesothelioma definitely needs to be further evaluated in a larger series of patients.

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Purpose To investigate if selective compared to elective pleural irradiation of malignant pleural mesothelioma (MPM) can allow dose escalation. Patients and methods Twelve consecutive stage I-IV MPM patients (6 consecutive left-sided and 6 consecutive right-sided) were retrospectively identified from a prospective institutional database and included. In all patients, the staging computed tomography and the staging magnetic resonance imaging (MRI) were used for gross tumor volume (GTV) definition. The patients had not received chemotherapy. An MRI-based pleural GTV was contoured and a planning target volume (PTV) was generated. Two sets of PTVs 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 for each patient: a “selective” pleural irradiation plan (SPI plan) and an “elective” pleural irradiation plan (EPI plan). Results In the SPI plans, the median dose to the S-PTV was 53.6 Gy (SD: 5.4, range: 41–63.6 Gy). In 4/12 patients it was possible to escalate the dose to the S-PTV to > 58 Gy. In the EPI plans, the median dose to the E-PTV was 48.6 Gy (SD: 5.8, range: 38.5–58.7), with a median dose to the S-PTV of 49 Gy (SD: 6, range: 38.6–59.5 Gy). No significant dose escalation was achievable. Conclusion The omission of elective irradiation of the whole ipsilateral pleural space allows dose escalation from 49 Gy to more than 58 Gy in 4/12 chemo-naive MPM patients. This strategy may form the basis for non-surgical radical combined modality treatment of MPM. [ABSTRACT FROM AUTHOR]