Computed tomography and Modified RECIST criteria for assessment of response in malignant pleural mesothelioma Poster No.: C-0729 Congress: ECR 2013 Type: Scientific Exhibit Authors: A. Marin, I. Pozek, R. Cesar; Golnik/SI Keywords: Cancer, Staging, Efficacy studies, CT, Thorax, Oncology DOI: 10.1594/ecr2013/C-0729 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 11
Purpose Malignant pleural mesothelioma (MPM) is a rare tumor with increasing frequency throughout the world. Most patients are treated with chemotherapy, which may lead to a short-term remission. In spite of all efforts, over 90% of patients will die from the disease (1). Due to its aggressive local growth and only modest sensitivity to modern anti-cancer treatment, malignant mesothelioma is among the most difficult challenges of thoracic oncology. RECIST (response evaluation criteria in solid tumours) criteria are easily applicable and repeatable for unidimensionally measurable lesions. MPM most commonly grows as a rind around the pleural surface and does not produce spherical lesions with bidimensionally measurable diameters (Figure 1). Due to its unique pattern of growth conventional RECIST criteria had to be modified to be applicable to MPM (2). We applied modified RECIST criteria to assess therapy response in a gemcitabine and cisplatin Phase II trial for patients with MPM (3). Images for this section: Fig. 1: CT scans of a man with MPM: Tumorous rind around the pleural surface of the right hemitorax Page 2 of 11
Methods and Materials All included patients had biopsy-proven MPM in the years from 2003 to 2008. Before the initiation of chemotherapy with gemcitabin and cisplatin ll patients had computed tomography of the thorax. Response was first assessed at least 6 weeks after the intitation and after 6th cycle of chemotherapy using CT examination with modified RECIST criteria (Figure 2). Tumour thickness was measured perpendicular to the chest wall in two sites at 3 levels. For each individual patient, the sum of the initial measurements was taken as 100% and compared to the corresponding measurements during and after the treatment. Confirmation of response after at least 6 weeks was required for classification of response as partial or complete remission. However, best response at any time was used for construction of waterfall plot (Figure 3). We tested correlation between tumour change size and overall survival with linear regression (Figure 4). Images for this section: Fig. 2: CT examination with modified RECIST criteria: tumour thickness was measured perpendicular to the chest wall in two sites at 3 levels. Page 3 of 11
Fig. 3: Waterfall plot with the best response of patients with different histologic types of MPM. The bars indicate the percent change in tumor burden from baseline, as measured according to modified RECIST criteria for mesothelioma. Page 4 of 11
Fig. 4: Correlation between Percent Change from Baseline (%) and Overall survival of patients with MPM. Page 5 of 11
Results Seventy-eight patients (58 male, 20 female; age 33 to 82 years, median 58) were recruited into the trial. Histologic type: epitheloid 56 (71.8%); sarcomatoid 4 (5.1%); mixed 15 (19.2%); mesothelioma, not otherwise specified 3 (3.8%). Four (5.1%) patients had complete response and 35 (44.9%) had partial response, for a 39 (50%) response rate. Minimal response or stable disease was seen in 35 (44.9%), while only 4 (5.1%) patients progressed during treatment. Images for this section: Fig. 3: Waterfall plot with the best response of patients with different histologic types of MPM. The bars indicate the percent change in tumor burden from baseline, as measured according to modified RECIST criteria for mesothelioma. Page 6 of 11
Fig. 4: Correlation between Percent Change from Baseline (%) and Overall survival of patients with MPM. Page 7 of 11
Conclusion During most of the study period, MRI was not routinely used and PET-CT scanning was not available. MRI and PET-CT are more sensitive diagnostic methods for MPM, especially for early stages of the disease. Implementation of modified RECIST criteria in therapy response assessment for MPM showed significant correlation between percent change in tumour burden and overall survival. MRI has additionally a superior soft tissue contrast, and plays an important role in MPM detection. References 1. Milano MT, Zhang H. Malignant pleural mesothelioma. A population-based study of survival. J Thorac Oncol 2010; 5:1841-48. 2. Byrne MJ, Nowak AK. Modified RECIST criteria for assessment of response in malignant pleural mesothelioma. Ann Oncol 2004; 15:257-60. 3. Kovac V, Zwitter M, Rajer M, et all. A phase II trial of low-dose gemcitabine in a prolonged infusion and cisplatin for malignant pleural mesothelioma. Anti-cancer drugs 2012; 23: 230-8. Personal Information Aleksander Marin, M.D. University Clinic of Respiratory and Allergic Diseases, Radiology Departement, Golnik 36, 4204 Golnik, Slovenia. email: aleksander.marin@klinika-golnik.si Page 8 of 11
www.klinika-golnik.si Images for this section: Page 9 of 11
Fig. 5: Hospital Golnik University Clinic of Pulmonary and Allergic Diseases Golnik, Golnik 36, 4204 Golnik, Phone: +386 4 25 69 100 Fax: +386 4 25 69 117 E-mail: kopa.tajnistvo@klinika-golnik.si Page 10 of 11
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