History of metastatic colon ca with brain metastases. Status post whole brain radiation treatment. Please evaluate response. There are changes related previous left posterior fossa craniotomy. There is new/increased nodular, mass-like contrast-enhancing tissue at the resection bed. This measures in the axial plane 3.2 cm x 1.3 cm. Also, the dominantly infratentorial ring-enhancing brain lesions have progressed since the previous examination. For example, the oval shaped, 12 mm lesion just anterior to the surgical bed in the inferolateral aspect of the left cerebellar hemisphere now measures 16 mm. The more posterior medially located lesion along the inferior aspect of the left cerebellar hemisphere now measures 12 mm compared to 7 mm previously. An additional one involving the right cerebellar tonsil now measures 8 mm compared to 5 mm previously. Also, a ring-enhancing lesion involving the left thalamus now measures 10 mm compared to 4 mm previously. A new 4 mm contrast-enhancing cortically-based nodule has developed along the right middle frontal gyrus. The lesions are relatively small and are associated with relatively mild surrounding T2 hyperintensity/edema. This results in no midline shift or mass effect.T2/T2 FLAIR lesions without contrast enhancement involving the frontoparietal white matter have not changed significantly since April 7, 2015. These may represent chronic microvascular ischemia. The ventricles and the other CSF-containing spaces are enlarged reflecting volume loss.There is a 1 cm soft tissue nodule along the tail of the right parotid gland just superficial to the right masseter muscle. This is incompletely imaged but is most likely a soft-tissue metastasis as it was not present previously. The mastoid air cells are clear. There is minimal ethmoidal mucosal thickening without associated fluid. The other paranasal sinuses are clear. Orbits are normal. Besides the left retrosigmoid craniotomy defect, there not is a small contrast enhancing nodule involving the right parietal calvarium (best seen on image #9 of series #10) which was not present previously and suspected to represent osseous metastasis. Additionally, there is a contrast enhancing lesion along the superior medial right orbital wall. However, this was present on the previous examination of April 2015. This may represent an additional focus of osseous metastasis.
1.Compared to 4/14/2015, there is evidence of progression of intracranial metastatic disease. Multiple ring-enhancing lesions in the cerebellum and left thalamus have increased in size and number since April 2015. There are also new nodular enhancing lesions involving the left cerebellar resection bed. There is also a new right frontal lobe lesion. There is mild associated edema. No significant mass effect or herniation.2.Small right parietal calvarial enhancing lesion is suspected to represent an osseous metastasis and not well seen previously. An unchanged enhancing lesion is also seen along the right superior medial orbital wall which is nonspecific but may also represent an osseous metastasis.3.New nodule involving the right parotid tail also suspected to represent metastasis.