Purpose: Detection of metastasis in the whole body is important for sufficient the staging of malignant melanoma. Sufficient imaging of the brain is particularly important. Although there is evidence that clinical examination is not sufficient for prediction of cerebral metastasis, MRI scan is not always regarded as reasonable in neurological asymptomatic patients. Therefore, we explored the incidence of cerebral metastasis in our patient population in relation to the stage of disease to estimate the reasonability of this examination.
Materials and methods: 120 consecutive patients with malignant melanoma were retrospectively evaluated. All patients were neurologically without pathological findings and received routine staging by cranial MRI. The incidence of brain metastasis was evaluated. The examination protocol consisted of an axial orientated flair and a T 1 sequence. Ten minutes after administration of contrast agent, a T 1 sequence in axial and coronal orientation was performed using the magnetization transfer technique. The type of melanoma, the thickness of the tumor, the Clark level, the location of the primary tumor, and the clinical stage were recorded from the clinical records.
Results: 15 (12.5 %) of the 120 patients (clinical stage I: 27 patients, stage II: 29 patients, stage III: 25 patients, stage IV: 39 patients) had cerebral metastasis in MRI. 14 patients were in stage III or IV at this time. Consequently 21.8 % of the patients in stage III and IV had cerebral metastasis. Only one patient in stage IIc had cerebral metastasis.
Conclusion: Cranial MRI of neurologically asymptomatic patients seems to be an important factor in the staging of melanoma especially in the advanced stage of this disease and in patients with a thick primary tumor.