Evaluation of semiautomated measurements of mesothelioma tumor thickness on CT scans.
ABSTRACT To evaluate the clinical acceptability of semiautomated methods for the measurement of mesothelioma tumor thickness in computed tomography (CT) scans.
A computer interface was developed to allow the acquisition of semiautomated mesothelioma tumor thickness measurements, which require the manual selection of a point along the outer margin of the tumor in a CT section. After application of an automated lung segmentation method, the computer automatically identifies a corresponding point along the inner margin of the tumor (as represented by the lung boundary), constructs a line segment between the manually selected outer tumor margin point and the computer-determined inner tumor margin point, and computes tumor thickness as the length of this line segment. Three radiologists and oncologists independently reviewed line segments representing the semiautomated measurements generated by three different algorithms at 134 measurement sites in the CT scans of 22 mesothelioma patients. The observers either accepted a measurement line segment or modified it through the interface. Differences between the initial semiautomated measurements and the measurements as modified by the observers were analyzed.
The frequency with which observers accepted the semiautomated measurements without modification was as high as 86%. Of all measurements across all observers and methods (1,206 measurements), 89% were changed by 2 mm or less.
We have developed semiautomated methods to measure mesothelioma tumor thickness. The potential of these methods has been demonstrated through an observer study. We expect these methods to become important tools for the efficient quantification of tumor extent.
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ABSTRACT: Measurement of tumor response to chemotherapy in malignant pleural mesothelioma (MPM) is problematic because of non-spherical tumor growth patterns and difficulty in choosing target lesion. In this study, we aimed to determine the effectiveness of tumor volume measurement for evaluating chemotherapy response. Fifty-seven MPM patients were included. Chemotherapy responses were evaluated by computed tomography (CT) using volumetric method, World Health Organization (WHO), and modified Response Evaluation Criteria in Solid Tumor (RECIST). The tumor volume was measured using the Cavalieri principle of stereological approaches. According to the volumetric method, median survival was 10.0 months for progressive disease (PD), 14.0 months for stable disease (SD) and 16.0 months for objective response (OR). According to the WHO method, median survival was 11.3, 14.0, and 13.0 months, respectively. For modified RECIST, median survival was 10.0, 14.0, and 14.0 months, respectively. The correspondence between the WHO and modified RECIST methods was substantial (K=0.66), as was that between the volumetric and WHO methods (K=0.64); however the correspondence between the volumetric and modified RECIST methods was only moderate (K=0.52). The most suitable chemotherapy response measurement technique is the volumetric method because of non-spherical tumor growth patterns in MPM. However, larger studies should be performed to better establish the suitability of this method. We recommend our method for determining the chemotherapy response in mesothelioma cases. However, modified RECIST criteria can also be applied due to favourable prediction of survival, ease of application, and moderate correspondence with the volumetric method.European journal of radiology 04/2009; 74(1):130-5. · 2.65 Impact Factor
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ABSTRACT: To evaluate the importance of assessing volume-based parameter of (18)F-FDG PET/CT in patients with malignant pleural mesothelioma (MPM) for the prediction of response and patient outcome early in the course of treatment. Patients (n = 13; M:F = 9:4, mean age, 54 years) with histopathologically proven MPM, all of whom were scheduled to undergo curative extrapleural pneumonectomy (EPP) or palliative chemotherapy, were included in this study. They were evaluated using integrated (18)F-FDG PET/CT at baseline. Maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured using PET/CT data. Relationships between tumor progression and PET parameters were statistically analyzed. Of the 13 patients, 8 (62%) developed disease recurrence after surgery or tumor progression after chemotherapy (median follow-up, 329 days; range, 28-536 days). Between subgroups with and without tumor progression, significant differences were noted in MTV (P = 0.045). On ROC curve analysis, MTV (AUC = 0.850, 95% confidence interval [95% CI] 0.550-0.977) and TLG (AUC = 0.800, 95% CI 0.494-0.960) showed good predictive performance for tumor progression. Multivariate analysis adjusted for treatment modality showed that MTV (HR 1.003, P = 0.025) and TLG (HR 1.001, P = 0.031) were independent factors associated with tumor progression. Time to tumor progression was shorter in patients with a high volume-based parameter of PET than in those with a low value. Volume-based parameters of (18)F-FDG PET/CT have the potential to provide prognostic information in MPM patients who are receiving surgery or palliative chemotherapy.Annals of Surgical Oncology 05/2010; 17(10):2787-94. · 4.12 Impact Factor
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ABSTRACT: : The purpose of this study was to investigate the continuous changes in three distinct response assessment methods during treatment as a marker of response for patients with mesothelioma. Linear tumor thickness measurements, disease volume measurements, and lung volume measurements (a physiological correlate of disease volumes) were investigated in this study. : Serial computed tomography scans were obtained during the course of clinically standard chemotherapy for 61 patients. For each of the 216 computed tomography scans, the aerated lung volumes were segmented using a fully automated method, and the pleural disease volume was segmented using a semiautomated method. Modified Response Evaluation Criteria in Solid Tumors linear-thickness measurements were acquired clinically. Diseased (ipsilateral) lung volumes were normalized by the respective contralateral lung volumes to account for the differences in inspiration between scans for each patient. Relative changes in each metric from baseline were tracked over the course of follow-up imaging. Survival modeling was performed using Cox proportional hazards models with time-varying covariates. : Median survival from pretreatment baseline imaging was 12.7 months. A negative correlation was observed between measurements of lung volume and disease volume, and a positive correlation was observed between linear-thickness measurements and disease volume. As continuous numerical parameters, all three response assessment methods were significant imaging biomarkers of patient prognosis in independent survival models. : Analysis of trajectories of linear-thickness measurements, disease volume measurements, and lung volume measurements during chemotherapy for patients with mesothelioma indicates that increasing linear thickness, increasing disease volume, and decreasing lung volume are all significantly and independently associated with poor patient prognosis.Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 04/2013; 8(4):478-86. · 4.55 Impact Factor