Updated NCCN language continues to support CSF analysis in the diagnosis and management of leptomeningeal metastases, including CSF cytology follow-up every 4 to 8 weeks for patients receiving intrathecal therapy, to enable longitudinal patient monitoring
HOUSTON, July 14, 2026 (GLOBE NEWSWIRE) -- Plus Therapeutics, Inc. (Nasdaq: PSTV) ("Plus" or the "Company"), today highlighted the recent update to the National Comprehensive Cancer Network® (NCCN®) Clinical Practice Guidelines in Oncology for Central Nervous System Cancers, including guidance relevant to leptomeningeal metastases (LM), a serious and often underdiagnosed complication of advanced cancer.
The updated NCCN CNS Cancers Guidelines reinforce that cerebrospinal fluid (CSF) analysis remains a standard component of LM diagnosis and disease assessment and that, in patients receiving intrathecal therapy, CSF cytology is typically re-evaluated every four to eight weeks alongside MRI and clinical evaluation.
CNSide is a CSF assay platform designed to support the diagnosis, treatment monitoring, and management of patients with LM and other metastatic central nervous system cancers. The Company believes the updated NCCN framework underscores the value of more sensitive and quantitative CSF-based tools that can operate within existing clinical workflows and complement standard CSF cytology over the course of a patient's treatment.
"A quantitative assay such as CNSide Tumor Cell Enumeration can complement standard cytology by detecting disease more sensitively and by enabling longitudinal monitoring of tumor burden over time," said Michael Youssef, M.D., neuro-oncologist at Houston Methodist. "For neuro-oncologists managing patients with leptomeningeal disease, that combination of higher sensitivity and serial quantitative assessment can be clinically very meaningful."
Recent publicly presented CNSide data suggest the platform may provide materially greater sensitivity than conventional cytology in matched CSF samples while also providing quantitative tumor-cell information that may influence patient management. In data presented from the FORESEE study, investigators reported that compared with cytology in matched samples, CNSide more than doubled the sensitivity of tumor detection in patients with LM. The Company has also previously described CNSide as a quantitative CSF assay platform intended to support rapid diagnosis, treatment monitoring, and treatment guidance in metastatic CNS cancers.
The NCCN update also reflects the growing role of CSF-based molecular testing across CNS cancers, including expanded recommendations in certain biopsy-infeasible high-grade gliomas and glioblastoma settings. The Company believes this broader recognition of CSF-based diagnostics supports long-term strategic interest in integrated CSF testing approaches that combine tumor-cell analysis with molecular characterization from a single patient specimen.