Relationship between tumor mutational burden (TMB) and SUVmax in 18F-FDG PET in cancer patients

Background: Radiogenomics is an evolving field that links radiologic and genomic data. ¹⁸F-FDG PET/CT is commonly used for cancer imaging, with maximum standardized uptake value (SUV_max) as the main quantitative parameter. Tumor mutational burden (TMB), the quantitative variable obtained using next-generation sequencing on a tissue biopsy sample, is a putative immunotherapy response predictor. We report the relationship between TMB and SUV_max, linking these two important parameters.

Methods: In this pilot study, we analyzed 1923 patients with diverse cancers and available TMB values. Overall, 273 patients met our eligibility criteria in that had no systemic treatment prior to imaging/biopsy, and also had ¹⁸F-FDG PET/CT within 6 months prior to the tissue biopsy, to ensure acceptable temporal correlation between imaging and genomic evaluation.

Results: We found a linear correlation between TMB and SUV_max (p<0.001). In the multivariate analysis, only TMB correlated with SUV_max whereas age, gender and tumor histology did not. TMB independently associated with SUV_max. Conclusion: This correlation links the SUV_max in readily available, routinely used, and non-invasive ¹⁸F-FDG PET/CT imaging to the TMB, which requires a tissue biopsy and time to process. Since higher TMB has been suggested to predict better outcomes after immunotherapy, further investigation will be needed to determine if SUV_max can stratify patient response to immunotherapy. <!--EndFragment-->

• Download figure
• Open in new tab
• Download powerpoint