North American Multicenter Volumetric CT study For Clinical Staging Of Malignant Pleural Mesothelioma: Feasibility And Logistics Of setting up a Quantitative imaging Study

Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 2016 May 11 [Epub ahead of print] [Link]

Gill RR, Naidich DP, Mitchell A, Ginsberg M, Erasmus J, Armato SG, Strauss C, Katz S, Pastios D, Richards WG, Rusch VW; Malignant Mesothelioma Volumetric CT Study Group.


Clinical TNM staging is based on a qualitative assessment of features defining T descriptors and has been found suboptimal for predicting prognosis of patients with MPM. Previous work suggests that volumetric CT (VOLCT) is prognostic and, if found practical and reproducible, could improve clinical MPM classification.background METHODS: Six North American institutions electronically submitted clinical, pathologic and imaging data on patients with stages I-IV MPM to an established multicenter database and biostatistical center (BC). Two reference radiologists, blinded to clinical data, independently reviewed scans, calculated clinical TNM stage by standard criteria, performed semi-automated tumor volume calculations using commercially available software, and submitted the findings to BC. Study endpoints included feasibility of a multi-institutional VOLCT network, concordance of independent VOLCT assessments and association of VOLCT with pathologic T classification.
Of 164 submitted cases, 129 were evaluated by both reference radiologists. Discordant clinical staging of most cases confirmed the inadequacy of current criteria. The overall correlation between VOLCT estimates was good (Spearman Corr. = 0.822), but some were significantly discordant. Root-cause analysis of the most discordant estimates identified four common sources of variability. Despite these limitations, median tumor volume estimates were similar within subgroups of cases representing each pathological T descriptor, and increased monotonically for each reference pathologist with increasing pathological T status.results CONCLUSIONS: Good correlation between VOLCT estimates obtained for most cases reviewed by two independent radiologists, and qualitative association of VOLCT with pathological T status combine to encourage further study. Identified sources of user error will inform design of a follow-on prospective trial to more formally assess inter-observer variability of VOLCT and its potential contribution to clinical MPM staging.