DISEASE CHARACTERISTICS: Histologically confirmed primary or metastatic malignant melanoma OR Histologically confirmed supratentorial malignant brain tumor Newly diagnosed or recurrent primary or metastatic tumor Eligible primary histologies, including but not limited to: Glioblastoma multiforme Mixed anaplastic glioma Anaplastic astrocytoma Other astrocytoma Gliosarcoma Anaplastic oligodendroglioma The following excluded: Diffusely infiltrating tumors Multifocal tumors Infratentorial tumors Subependymal spread No measurable enhancing lesion extending more than 1 cm beyond margins of surgical cavity on contrast-enhanced CT or MRI performed within 72 hours after resection Intralesional catheter placed at resection Patency of catheter demonstrated by radiolabeled albumin flow Reactivity of neoplastic cells with intact Me1-14 IgG2a or Me1-14 F(ab')2 demonstrated by immunohistology with polyclonal rabbit antibody or monoclonal mouse antibody