Since the previous exams, the 6 mm enhancing nodule in the left anterior corona radiata has developed into a multilobulated heterogeneous ring enhancing mass lesion. The right-sided midline shift of 6 mm remains stable. Mild distortion of the abutting lateral ventricle but without hydrocephalus.
At the left anterior margin of the posterior fossa surgical cavity is an ovoid nodule of enhancement measuring 11 x 9 x 10 mm that is cystic inferiorly, with moderate surrounding FLAIR hyperintensity and mild mass effect on the 4th ventricle. There appear to be some tethering of this to the inferior surface of the left tentorium. More ill-defined mild-to-moderate patchy FLAIR hyperintensity surrounds the cerebellar resection cavity.
Tiny focus of FLAIR hyperintensity in the right centrum semiovale, new, non-specific but most likely incidental.
8mm nodule of solid enhancement abutting the left anterior falx with a small dural tail, unchanged is more probably an incidental meningioma, although a small dural metastasis in this context remains a differential.
Conclusion: Findings are in keeping with progressive metastatic disease, with a markedly enlarged left frontal mass with moderate oedema. No post-operative MRI available for correlation, but a nodule of enhancement at the anterior cerebellar resection margin is in keeping with either residual and or recurrent metastasis. Unchanged since the earliest available MRI at the left anterior falx is more probably an incidental small left frontal meningioma than a dural metastasis.