Purpose: Contrary to cutaneous melanoma, uveal melanoma is little responsive to immune checkpoint inhibitors. This is thought to result from a different immunogenicity of these two melanoma variants. We sought to investigate whether imaging properties in magnetic resonance imaging (MRI) were able to predict the response of liver metastases of uveal melanoma to immune checkpoint blockade. Study Design: Pre- and post-therapeutic liver MRIs, including a native T1-weighted fat-saturated FLASH sequence, were analyzed in a population of patients with uveal melanoma, segmenting the metastasis into areas of active tumor, necrosis and edema. Different lesions from all of the patients were investigated and their patterns correlated with response to immunotherapy. Results: Contrary to previous results of other research groups, MRI signal intensity scores in our population could not predict response to immunotherapy. Therefore, we could not validate the MRI assessment as a clinical biomarker. Other parameters need to be integrated in the radiomic signature. Conclusions: Current MRI imaging methods are limited in their ability to predict response of liver metastases of uveal melanoma to immune checkpoint blockade. Advanced MRI imaging methods, more sensitized to different biophysical processes including blood perfusion and tumor metabolism, which can provide more specific information on tissue physiology, should be investigated in the light of emerging immunotherapies for uveal melanoma, such as tumor-infiltrating lymphocytes and recent developments in dendritic cell cancer vaccines.

Citation Format: Alvaro Moreira, Marc Saake, Gerold Schuler, Lucie Heinzerling. Predicting the response of uveal melanoma to immunotherapy with MRI assessments [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B030.