Abstract
242301
Introduction: Reporting and Data Systems (RADS) are frameworks supported by the American College of Radiology that provide standardized terminology, report organization, assessment structure, and classification for diagnostic imaging. We have developed an Oncologic Response (OR) lexicon at our institution to address the general gap in how to report disease response or progression in all oncologic patients. By improving the quality of report interpretation, communication with referring physicians and patients, and large-scale data mining OR lexicon is striving to become the best way to report cancer response in routine clinical care CT/MRI imaging. The purpose of this abstract was to translate our current anatomical OR lexicon framework for use in functional PET/CT imaging.
Methods: OR lexicon is fundamentally similar to RADS in that it has five categories of response, from 1 to 5, which describe decreased (OR-1) to increased (OR-5) disease, with OR-3 used to describe unchanged disease. The category of OR-0 is included to capture patients who have no evidence of disease. In addition, two distinct categories are utilized, OR-E and OR-M, to describe equivocal progression and mixed response, respectively. Each category has a definition for CT/MRI imaging as seen in Table 1. This framework was used by two attending Nuclear Medicine physicians in consensus with our institutional Radiology Reporting committee to create analogous definitions for PET/CT imaging. Preliminary user data was obtained and analyzed.
Results: The developed criteria for PET/CT can be seen in detail in Table 1. In summary, here are the categories as follows. OR-0, patients who have no visible or FDG-avid disease after therapy. OR-1, this category should be applied to patients where there is an unequivocal reduction in extent and/or FDG uptake of disease. OR-2, this category should be applied to patients who have some evidence of response, but the magnitude of response is small, and potentially within measurement error or biological variability of FDG uptake. OR-3, this category is applied to patients where the existing disease is considered to be unchanged or that any change is probably within measurement error, biological variability, or attributable to differences between PET/CT scanners. OR-4, this category should be applied to patients who have some evidence of progression of disease, but the magnitude of progression is small, and possibly within measurement error or biological variability of FDG uptake. OR-5, this category should be applied to patients where there is an unequivocal increase in the extent of FDG-avid disease. OR-M, this category should be applied to patients where there is a clear decrease in some and an increase in other sites of disease, both in terms of size and FDG uptake. OR-E, this category should be applied when there is a discrepancy between changes in disease morphology/size and FDG uptake. Preliminary individual user data shows high variability in the distribution of different categories' frequency of use (Figure 1). However, the total distribution of use for each category for all users was in a similar distribution as the CT/MRI OR lexicon data. Readers predominantly and relatively equally use increased, decreased, unchanged, and no evidence of disease, with the remaining categories used infrequently (Figure 1).
Conclusions: We utilize a standardized oncologic response lexicon for CT/MRI imaging that improves the communication of diagnostic imaging reports to referring physicians and patients and facilitates real-world evidence through the assessment of longitudinal change in large populations of patients. We successfully developed and implemented criteria for OR lexicon use in PET/CT imaging.
In this issue
Jump to section
Related Articles
Cited By...
- No citing articles found.