Role of CT and modified Response Evaluation Criteria in Solid Tumors (RECIST criteria) in response evaluation of malignant pleural mesothelioma

Background Malignant pleural mesothelioma is a rare and aggressive tumor that the growth pattern of it poses unique difficulties in measurement and response assessment . however, robust and reproducible assessment of response is critically important in the conduct, interpretation, and reporting of clinical trials. Objectives The aim of this study is to assess the value of CT and modified RECIST criteria in follow up patients of malignant pleural mesothelioma patient during treatment with chemotherapy . Patients and methods We evaluated 20 malignant pleural mesothelioma patients undergoing to chemotherapy . Tumor thickness is measures perpendicular to the chest wall or mediastinum in two positions at three separate levels on thoracic CT scans. The sum of the six measurements defined a pleural unidimensional measure. A reduction of at least 30% on two occasions 6 weeks apart defined a partial response; an increase of 20% over the nadir measurement known as progressive disease. Patients who fulfilled the criteria for neither PR nor PD called CD .The validity of the modified criteria was gauged by clinical evaluation . Results In our study, CT and modified RECIST criteria were used as the method of choice in response evaluation of malignant pleural mesothelioma .Our study showed as follow up results of each group and comparison between clinical evaluation and modified RECIST criteria show over all accuracy 73.3% with P value = 0.03 and this results confirm accuracy of CT with modified RECIST criteria as good predictor of disease outcome . Conclusion These Modified RECIST criteria for tumor response correlate with clinical evaluation and can be used to measure outcome in pleural mesothelioma.