Plathow C, Staab A, Schmaehl A, Aschoff P, Zuna I, Pfannenberg C, Peter SH, Eschmann S, Klopp M.

Department of Diagnostic Radiology, University of Tuebingen, Tuebingen, Germany. christian.plathow@uniklinik-freiburg.de

Abstract

Objective: To evaluate and compare the role of computed tomography (CT), positron emission tomography (PET), PET/CT, and magnetic resonance imaging (MRI) in the correct staging of patients with limited malignant pleural mesothelioma (MPM).

Materials and Methods: Fifty-four patients with an epithelial MPM (34 men and 20 women) were included in this study. Patients were referred to our department for staging in a predicted resectable state (stage II/III). Within 3 days, PET/CT and MRI was performed in all patients. Images were evaluated by 3 specialists in the field of PET/CT and MRI. The subexaminations of PET/CT, PET, and CT were independently evaluated with respect to tumor stage. Subexaminations were compared with each other, with MRI and PET/CT. N-stage was verified by mediastinoscopy. Afterward, consensus reading was performed.

In 52 patients, surgery served as gold standard. In 2 patients, follow-up control served as gold standard as an inoperable situation with distant metastases was found. Additionally, interobserver variability ([kappa] value) was calculated.

Results: In stage II, accuracy was 0.77 (CT), 0.86 (PET), 0.8 (MRI), 1.0 (PET/CT), and in stage III 0.75, 0.83, 0.9, 1.0. PET/CT was significantly more accurate (P < 0.05) in stages II and III compared with all other techniques. CT and MRI were not able to detect distant metastases in 2 patients, which changed therapy (operable vs. inoperable). Interobserver variability was 0.7, 0.9, 0.8, 1.0 in stage II and 0.9, 0.9, 0.9, 1.0 in stage III.

Conclusion: PET/CT makes it possible to stage patients with limited MPM with high accuracy and low interobserver variability.

Hinshaw JL, Pickhardt PJ.

Department of Radiology, University of Wisconsin Medical School, Madison, WI, 53792, USA.

Abstract

Peritoneal carcinomatosis and metastatic involvement of the retroperitoneum are relatively common manifestations of many organ-based malignancies and lymphoproliferative disorders. Primary malignancies of peritoneal and retroperitoneal origin occur much less frequently, and can be difficult to distinguish from metastatic disease. In many cases, a precise diagnosis based on imaging findings alone is not possible. However, the imaging features of these primary tumors, in combination with the clinical and demographic data, can be utilized to narrow the scope of the differential diagnosis. This chapter will present the clinical and imaging features of primary peritoneal and retroperitoneal tumors arising from the various tissue components that comprise the ligaments, mesenteries and connective tissues of these anatomic spaces.

Gill RR, Gerbaudo VH, Jacobson FL, Trotman-Dickenson B, Matsuoka S, Hunsaker A, Sugarbaker DJ, Hatabu H.

Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.

Abstract

MR imaging serves as a problem-solving tool in the diagnosis of inflammatory and infectious pleural diseases and primary and secondary pleural malignancies. Knowledge of MR imaging appearance of pleural diseases, including pleural effusions and empyema, benign and malignant pleural tumors, and especially mesothelioma, helps guide treatment decisions and surgical planning.

Plathow C, Klopp M, Thieke C, Herth F, Thomas A, Schmaehl A, Zuna I, Kauczor HU.

Department of Nuclearmedicine, University of Freiburg, Hugstetter 55, 79106, Freiburg, Germany, christian.plathow@uniklinik-freiburg.de.

Abstract

To evaluate and compare early therapy response according to RECIST (response evaluation criteria in solid tumours) and modified RECIST criteria using MRI techniques in patients with malignant pleural mesothelioma (MPM) in comparison with CT. Fifty patients with MPM (32 male/18 female) were included in this study. Early therapy response was evaluated after 9 weeks [three of six chemotherapy (CHT)] cycles. Additionally patients were examined before chemotherapy, 4 weeks after early therapy response evaluation and after six cycles to evaluate diagnostic follow-up. RECIST and modified RECIST criteria were applied using CT and MRI (HASTE, VIBE, T2-TSE sequences). In MRI additionally a volumetric approach measuring tumour weight (overall segmented tumour volume) was applied. Additionally vital capacity (VC) was measured for correlation. Image interpretation was performed by three independent readers independently and in consensus. The ‘gold standard’ was follow-up examination. Twenty-eight patients showed partial response, 12 patients stable disease and 10 patients progressive disease at early therapy response evaluation. In the follow-up these results remained. For MRI, in 46 cases patients were identically classified using RECIST and modified RECIST criteria. Modified RECIST criteria were identically classified as gold standards in all cases, whereas using RECIST criteria in four cases there was a mismatch (partial response vs. stable disease). Modified RECIST kappa values showed better interobserver variability compared with RECIST criteria (κ=0.9–1.0 vs. 0.7–1.0). For CT, in 44 cases patients were identically classified using RECIST and modified RECIST criteria. Modified RECIST criteria were identically classified as in gold standards in 48 out of 50 patients, whereas using RECIST criteria in 6 cases there was a mismatch (partial response vs. stable disease). Modified RECIST kappa values showed better interobserver variability compared with RECIST criteria (κ=0.9–1.0 vs. 0.6–1.0). Modified RECIST criteria especially in combination with high-resolution MRI is a very accurate and reproducible technique to correctly evaluate early therapy response in MPM.

Keywords: Mesothelioma – RECIST – MRI – Tumour volumetry – Validation

Yamamuro M, Gerbaudo VH, Gill RR, Jacobson FL, Sugarbaker DJ, Hatabu H.

Department of Radiology and Surgery, Brigham and Women’s Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115, United States.

Abstract

Malignant pleural mesothelioma (MPM) is an aggressive tumor that arises from the pleura and frequently extends to adjacent structures. MPM cells produce and respond to many angiogenic factors, such as vascular endothelial growth factor (VEGF). VEGF expression in MPM is correlated with microvascular density, which is associated with poor survival.

CT has been widely used as the primary imaging modality for the clinical evaluation of MPM. Major findings include nodular pleural thickening, unilateral pleural effusion, and tumor invasion of adjacent structures. CT tends to underestimate early chest wall invasion and peritoneal involvement and has well-known limitations in the evaluation of lymph node metastases. Perfusion CT can evaluate the microvasculature of tumors, while its disadvantages, such as high radiation exposure or side effects from iodinated contrast, limit its use in both research and clinical settings.

MRI can provide additional information to CT. Because of its excellent contrast resolution, MRI is superior to CT, both in the differentiation of malignant from benign pleural disease, and in the assessment of chest wall and diaphragmatic involvement. Perfusion MRI is the most promising technique for the assessment of the tumor microvasculature. In MPM, therapeutic effects of chemotherapy can be monitored with perfusion MRI.

It has been shown that FDG–PET is useful for the differentiation of benign from malignant lesions, for staging and monitoring metabolic response to therapy against MPM, and that it has prognostic value. An initial report on PET/CT imaging of MPM has shown increased accuracy of overall staging, improving the assessment of tumor resectability. PET/CT seems to be superior to other imaging modalities in detecting more extensive disease involvement, and identifying unsuspected occult distant metastases.

Keywords: Malignant pleural mesothelioma, Angiogenesis, CT, MRI, PET, Perfusion, Staging

Qureshi NR, Gleeson FV.

Department of Radiology, Churchill Hospital, Headington, Oxford OX3 7LJ, UK. nagmiqureshi@doctors.org.uk

Abstract

Imaging plays an important role in the diagnosis and subsequent management of patients with pleural disease. The presence of a pleural abnormality is usually suggested following a routine chest x-ray, with a number of imaging modalities available for further characterization. This article describes the radiographic and cross-sectional appearances of pleural diseases, which are commonly encountered in every day practice. The conditions covered include benign and malignant pleural thickening, pleural effusions, empyema and pneumothoraces. The relative merits of CT, MRI and PET in the assessment of these conditions and the role of image-guided intervention are discussed.

Molinari F, Fink C, Risse F, Tuengerthal S, Bonomo L, Kauczor HU.

From the *Department of Radiological Sciences, Catholic University of Rome, Rome, Italy; daggerDepartment of Radiology and section signMedical Physics in Radiology, Deutsches Krebsforchungszentrum (DKFZ), Heidelberg, Germany; double daggerInstitute of Clinical Radiology Ludwig-Maximilians-University of Munich, University Clinics Grosshadern, Munich, Germany; and paragraph signDepartment of Radiology, Thoraxklinik, Heidelberg, Germany.

Abstract

Objectives: We sought to assess the agreement between lung perfusion ratios calculated from pulmonary perfusion magnetic resonance imaging (MRI) and those calculated from radionuclide (RN) perfusion scintigraphy.

Materials and Methods: A retrospective analysis of MR and RN perfusion scans was conducted in 23 patients (mean age, 60 +/- 14 years) with different lung diseases (lung cancer = 15, chronic obstructive pulmonary disease = 4, cystic fibrosis = 2, and mesothelioma = 2). Pulmonary perfusion was assessed by a time-resolved contrast-enhanced 3D gradient-echo pulse sequence using parallel imaging and view sharing (TR = 1.9 milliseconds; TE = 0.8 milliseconds; parallel imaging acceleration factor = 2; partition thickness = 4 mm; matrix = 256 x 96; in-plane spatial resolution = 1.87 x 3.75 mm; scan time for each 3D dataset = 1.5 seconds), using gadolinium-based contrast agents (injection flow rate = 5 mL/s, dose = 0.1 mmol/kg of body weight). The peak concentration (PC) of the contrast agent bolus, the pulmonary blood flow (PBF), and blood volume (PBV) were computed from the signal-time curves of the lung. Left-to-right ratios of pulmonary perfusion were calculated from the MR parameters and RN counts. The agreement between these ratios was assessed for side prevalence (sign test) and quantitatively (Deming-regression).

Results: MR and RN ratios agreed on side prevalence in 21 patients (91%) with PC, in 20 (87%) with PBF, and in 17 (74%) with PBV. The MR estimations of left-to-right perfusion ratios correlated significantly with those of RN perfusion scans (P < 0.01). The correlation was higher using PC (r = 0.67) and PBF (r = 0.66) than using PBV (r = 0.50). The MR ratios computed from PBF showed the highest accuracy, followed by those from PC and PBV. Independently from the MR parameter used, in some patients the quantitative difference between the MR and RN ratios was not negligible.

Conclusions: Pulmonary perfusion MRI can be used to assess the differential blood flow of the lung. Further studies in a larger group of patients are required to fully confirm the clinical suitability of this imaging method.

Frederik L. Giesel, MD; Helge Bischoff, MD; Hendrik von Tengg-Kobligk, MD; Marc-André Weber, MD; Christian M. Zechmann, MD; Hans-Ulrich Kauczor, MD and Michael V. Knopp, MD, PhD

^* From the German Cancer Research Center (Drs. Giesel, Tengg-Kobligk, Weber, Zechmann, and Kauczor), Department of Radiology, Heidelberg, Germany; Thoraxklinik (Dr. Bischoff), Heidelberg; and Department of Radiology (Dr. Knopp), The Ohio State University, Columbus, OH.

Correspondence to: Michael V. Knopp, MD, PhD, Professor of Radiology and Biomedical Informatics, Novartis Chair and Director of Imaging Research, Department of Radiology, The Ohio State University, University Hospitals, 657 Means Hall, 1654 Upham Dr, Columbus, OH 43210-1228; e-mail: Knopp.16@osu.edu

Abstract

Study objective: Dynamic contrast-enhanced MRI (DCE-MRI) followed by pharmacokinetic analysis has been successfully used in a variety of solid tumors. The aims of this study were to evaluate the feasibility of DCE-MRI in malignant pleural mesothelioma (MPM), to differentiate benign from pathologic tissue and compare pharmacokinetic with clinical parameters and survival in order to map out its microcirculation; and to compare pharmacokinetic with clinical parameter and survival in order to improve our understanding of the in vivo biology of this malignancy.

Methods: Nineteen patients with a diagnosis of MPM who were scheduled to receive chemotherapy with gemcitabine were enrolled in the study. DCE-MRI was performed before treatment (n = 19) and after the third cycle (n = 12) and sixth cycle (n = 7) of chemotherapy. An established pharmacokinetic two-compartment model was used to analyze DCE-MRI. Tumor regions were characterized by the pharmacokinetic parameters amplitude (Amp), redistribution rate constant (kep), and elimination rate constant (kel). Kinetic parameters of tumor tissue and normal tissue were compared using the Student t test. Patients were classified as clinical responders or nonresponders according to clinical outcome, and these groups were compared with the pharmacokinetic parameters derived from DCE-MRI.

Results: Normal and tumor tissue could be distinguished by the pharmacokinetic parameters Amp and kel (p </= 0.001). Clinical responders had a median kep value within the tumor of 2.6 min, while nonresponders showed a higher value (3.6 min), which coincided with longer survival (780 days vs 460 days).

Conclusions: DCE-MRI can be used in patients with MPM to assess tumor microvascular properties and to demonstrate tumor heterogeneity for therapy monitoring. High pretherapeutic values of kep within the tumor correlated with a poor overall response to therapy.

Keywords: angiogenesis, dynamic contrast enhanced MRI, malignant pleural mesothelioma, therapy monitoring

Laurent F, Corneloup O, Montaudon M, Latrabe V, Laffon E.

Unite d’Imagerie Thoracique et Cardiovasculaire, Hopital du Haut-Leveque, CHU de Bordeaux, 33604 Pessac. francois.laurent@chu-bordeaux.fr

Abstract

Imaging plays an essential role in management of patients of with pleural mesothelioma. In this article, we discuss the respective roles for ultrasonography, computed tomography, magnetic resonance imaging, and positon emission tomography for the diagnosis, staging, and postherapeutic evaluation of pleural mesothelioma.

R. Eibel1, 3 Contact Information, P. Herzog1, O. Dietrich1, C. Rieger2, H. Ostermann2, M. Reiser1 und S. O. Schoenberg1

1. Institut für Klinische Radiologie, Ludwig-Maximilians-Universität München,
2. Abteilung für Hämatologie/Onkologie, Klinikum Großhadern, Ludwig-Maximilians-Universität München,
3. Institut für Klinische Radiologie, Klinikum Innenstadt, Ludwig-Maximilians-Universität München, Ziemssenstraße 1, 80336 München

Abstract

Magnetic resonance imaging (MRI) of the lung is challenging because of substantial drawbacks. However, lung pathologies that are associated with increased attenuation values in CT enhance visualization in MRI: proton density is increased and tissue-air interfaces, resulting in susceptibility artifacts, are reduced in pneumonia, pneumonitis, edema, and carcinoma. On the other hand, many lung diseases result in shortness of breath, so that patients cannot hold their breath for long periods. Therefore, fast imaging techniques are required which should also allow for high spatial resolution so that small lesions can be detected. Calcifications and air pockets within lesions are not readily recognized with MRI. Thin section CT is standard for the diagnosis of pneumonia. With parallel imaging techniques, MRI examination of the lungs can be performed with short periods of breath holding, which allow for sub-centimeter resolution in the z-axis. Especially for follow-up examinations in immunocompromised patients and, in some instances, for the staging of malignant diseases (malignant pleural mesothelioma, lung cancer, respectively), MRI is very promising and may contribute to a decrease in the radiation exposure of the patients.