Diagnosis, management, and survival of patients with leptomeningeal cancer based on cerebrospinal fluid-flow status.

Background: The authors assessed cerebrospinal fluid (CSF) flow in patients with carcinomatous meningitis using technetium-99m-DTPA (Tc-99) ventriculography to determine the frequency of flow abnormalities, their reversibility with treatment, and the implications for successful therapy and survival.
Methods: Technetium-99m-DTPA flow studies were performed in 31 patients after placement of Ommaya reservoirs (Baxter, McGaw Park, IL). Two millicuries of Tc-99 were injected into the reservoir. Planar images of the head and entire spine were obtained after 10 and 30 minutes and after 1, 4, 6, and 24 hours. Follow-up studies were performed for 12 patients whose initial studies were abnormal or who developed complications of therapy.
Results: In 19 of the 31 patients (61%), ventricular-outlet, spinal, or convexity blocks were identified. In 11 of these 19 patients, focal radiotherapy to the site of the block restored normal flow. Survival among patients with initially normal, abnormal but correctable, and abnormal but uncorrectable CSF flow differed significantly (6.9, 13.0, and 0.7 months respectively; P < 0.001). Some patients who were treated intrathecally despite abnormal CSF flow experienced drug-related toxicity.
Conclusions: Cerebrospinal fluid-flow blocks are common in patients with carcinomatous meningitis and may occur at the skull base, in the spinal canal, and over the convexities. These flow abnormalities often can be corrected with appropriately directed radiotherapy. If untreated, CSF tumor progression (protected site effect), neurotoxicity (high concentration effect), and systemic toxicity (reservoir effect) can occur, resulting in shortened survival and treatment-related morbidity. Therefore, intrathecal chemotherapy should be preceded by a radionuclide flow study and should be delayed if abnormal flow is documented until appropriate radiotherapy reestablishes normal flow.