Pachymeningeal disease: a systematic review and metanalysis.

BACKGROUND: Pachymeningeal disease (PMD) is a newly recognized pattern of brain metastasis (BrM) failure that specifically occurs following surgery with adjuvant stereotactic radiosurgery (SRS) and has unique prognostic implications relative to leptomeningeal disease (LMD). Here, we report its prevalence, prognostic implications, and associated risk factors. METHODS: A literature search was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses on PUBMED and Cochrane from January 2000 to June 2023. RESULTS: We identified 12 studies that included a total of 3992 BrM patients, 659 (16.5%) of whom developed meningeal disease (MD) following surgery plus adjuvant SRS, including either PMD or LMD. The mean prevalence of MD across studies was 20.9% (7.9-38.0%), with PMD accounting for 54.6% of this prevalence and LMD comprising the remaining 45.4%. Mean of the median overall survivals following diagnosis of PMD and LMD was 10.6 months and 3.7 months p = 0.007, respectively, a significant difference. Only 2 risk factors for PMD were reported in ≥ 2 studies and also identified as statistically significant per our meta-analysis: infratentorial location and controlled systemic disease status. CONCLUSION: While PMD has a superior prognosis to LMD, it is nevertheless a critical oncologic event associated with significant mortality and remains poorly recognized. PMD is predominantly observed in patients with controlled systemic disease status and infratentorial location. Future treatment strategies should focus on reducing surgical seeding and sterilizing surgical cavities.

Solitary Extramedullary Plasmacytoma of the Head and Neck: A Report of Three Cases Treated With Curative Radiotherapy and a Review of the Dose-Control Relationship.

Solitary plasmacytoma is an uncommon hematologic malignancy characterized by the monoclonal proliferation of abnormal plasma cells in the bone or extramedullary tissues and the absence of other multiple myeloma-defining clinical characteristics. Mostly, solitary extramedullary plasmacytoma (SEP) occurs in the head and neck region, also called solitary extramedullary plasmacytoma of the head and neck (SEPHN). Although the standard of care for SEPHN is not well established, either a surgical approach or localized external beam radiotherapy (EBRT) can be used as a definitive treatment. Due to the high radiosensitivity of SEPHN, EBRT has been associated with adequate therapeutic effects in the management of SEP, with the advantage of being a noninvasive modality that yields high rates of local control with a reasonable toxicity profile. We present a case series of three patients with SEPHN treated with EBRT at our institution with clinical outcomes.