Metastatic base of tongue squamous cell carcinoma, treated with pembrolizumab, palliative RT to left orbit, and started palliative carbo/paclitaxel/cetuximab. The left cerebellar tonsil lesion is now intrinsically hyperintense with associated susceptibility effect and measures up to 5 mm in diameter. There is no evidence of other infratentorial or supratentorial lesions. There is no evidence of acute infarct. The ventricles and basal cisterns are unchanged in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. There is interval decrease in size of the enhancing left posterior globe lesion, measuring up to 3 mm in thickness, previously 7 mm. The left lateral retinal detachment has resolved. There is mild diffuse conjunctival and lacrimal gland enhancement, likely related to radiation therapy effects. The skull and scalp soft tissues are grossly unremarkable. There is a small left maxillary sinus retention cyst. There are left mastoid air cell effusions.
1. Interval evolution of the appearance of the subcentimeter left cerebellar tonsil metastasis, likely due to treatment effects. 2. Interval decrease in size of the left ocular metastasis with improvement of the associated retinal detachment.