Journal of Clinical and Cellular Immunology
Open Access
ISSN: 2155-9899
ISSN: 2155-9899
S Agarwal, P Chokron, A Thabet, R S Arellano, X Ma, H Le, I Kazam, M Harisinghani and R Walovitch
Accepted Abstracts: J Clin Cell Immunol
The objective of this study was to validate an image assessment method that combines RECIST 1.1 and irRC criteria. Regulatory agencies often request that immunotherapeutic tumor burden be assessed using validated methods (i.e., RECIST) and newer irRC paradigm. Two sets of image datasets (10 RECIST and 10 irRC/RECIST), consisting of pre/post- treatment CT images from melanoma subjects enrolled in a PD-1 immunotherapeutic trial, were read twice by five independent radiologists (IR). Inter- and intra- reader variability of the combined irRC/RECIST and RECIST methods were measured. In a separate analysis, overall read time for the combined method was compared to irRC and RECIST alone. The combined irRC review had the best inter-reader agreement (90-98%; kappa 0.74-0.94) and intra-reader agreement (80 -100%; kappa 0.38-1.0) with excellent intra-reader homogeneity for number of lesions assessed. No significant differences were observed between RECIST IR variability using the combined vs. independent method. Inter-reader agreement ranged from 85 to 95% with kappa 0.55-0.84. Combining the RECIST and irRC assessments resulted in an approximate 20% decrease in assessment time compared to individual RECIST and irRC assessments. In conclusion, in immunotherapeutic trials RECIST may lead to errors in tumor burden as lesions initially grow despite favorable treatment response. This study indicates that the Combined irRC/ RECIST review method is robust, as it is reproducible and simplifies the process of simultaneously assessing the cytotoxic and immunotherapeutic responses of drugs, and may be an efficient time saving analytical tool
S Agarwal is a practicing radiologist in the division of Abdominal Imaging and Intervention at Massachusetts General Hospital (MGH). She is Associate Director of Radiology Clinical Trials at MGH and an instructor in radiology at Harvard Medical School. She is board certified in diagnostic radiology.