may make the appearance on an uncontrasted CT to have increased attenuation. Solid parts of the tumor often enhance with contrast MRI finding on T1 and T2 weighted images are variable. Precontrast T2 weighted images may show an isosignal or slightly hypersignal. Solid components of the tumor may enhance with contrast, but not always. MRI studies appear to be more able to pick up metastatic foci in other intracranial locations, as well as intraspinal locations. Preoperative and follow-up studies are needed to detect metastatic disease. Treatment Surgery Surgery plays a critical role in obtaining tissue to make an accurate diagnosis. Surgery alone is not curative. In addition, 30% of the AT/RTs are located supratentorially and a predilection exists for the cerebellopontine angle, which makes surgical resection difficult. One-third or more children will have disseminated disease at the time of diagnosis. Total or near-total resections are often not possible. Chemotherapy Around 50% of the AT/RTs will transiently respond, but chemotherapy by itself is rarely curative. No standard treatment for AT/RT is known. Various chemotherapeutic agents have been used against AT/RTs, which are also used against other CNS tumors including cisplatinum, carboplatinum, cyclophosphamide, vincristine, and etoposide. Some chemotherapy regimens are listed below: CCG clinical trial CCG-9921 was activated in 1993 and published its results in 2005. The proposed treatments did not have different outcomes and were not an improvement on prior treatments. Geyer published a review of chemotherapy on 299 infants with CNS tumors that evaluated response rate, event-free survival (EFS), and toxicity of two chemotherapeutic regimens for treatment of children younger than 36 months with malignant brain tumors. Patients were randomly assigned to one of two regimens of induction chemotherapy (vincristine, cisplatin, cyclophosphamide, and etoposide v vincristine, carboplatin, ifosfamide, and etoposide). Intensified induction chemotherapy resulted in a high response rate of malignant brain tumors in infants. Survival was comparable to that of previous studies, and most patients who survived did not receive radiation therapy. Sarcoma protocols. There has been at least one report in the literature of malignant rhabdoid tumors of the CNS being treated as a high-grade intracranial sarcoma. These three cases were treated with surgery, chemotherapy, radiotherapy and triple intrathecal chemotherapy similar to the Intergroup Rhabdomyosarcoma Study III guidelines. Intrathecal protocols. One of the difficulties with brain and spinal tumors is that the blood brain barrier needs to be crossed so that the drug can get to the tumor.