Patients with Leptomeningeal Carcinomatosis and Hydrocephalus-Feasibility of Combined Ventriculoperitoneal Shunt and Reservoir Insertion for Intrathecal Chemotherapy

Therapeutic management of patients with leptomeningeal carcinomatosis (LC) may require treatment of concomitant hydrocephalus (HC) in addition to intrathecal chemotherapy (ITC). Ventriculoperitoneal shunts (VPS) equipped with a valve for manual deactivation of shunt function and a concomitant reservoir for application of ITC pose an elegant solution to both problems. The present study evaluates indication, feasibility, and safety of such a modified shunt/reservoir design (mS/R). All patients with LC aged ≥ 18 years who had undergone mS/R implantation between 2013 and 2020 at the authors' institution were further analyzed. ITC was indicated following the recommendation of the neuro-oncological tumor board and performed according to a standardized protocol. Sixteen patients with LC underwent mS/R implantation for subsequent ITC and concomitant treatment of HC. Regarding HC-related clinical symptoms, 69% of patients preoperatively exhibited lethargy, 38% cognitive impairment, and 38% (additional) visual disturbances. Postoperatively, 86% of patients achieved subjective improvement of HC-related symptoms. Overall, postoperative complications occurred in three patients (19%). No patient encountered cancer treatment-related complications. The present study describes a combination procedure consisting of a standard VPS-system and a standard reservoir for patients suffering from LC and HC. No cancer treatment-related complications occurred, indicating straightforward handling and thus safety.

Two signs indicative of successful access in nuclear medicine cerebrospinal fluid diversionary shunt studies

BACKGROUND

Successful shunt access is the first step in a properly performed nuclear medicine cerebrospinal fluid (CSF) shunt study.

OBJECTIVE

To determine the significance of the radiotracer configuration at the injection site during initial nuclear medicine CSF shunt imaging and the lack of early systemic radiotracer activity as predictors of successful shunt access.

MATERIALS AND METHODS

With Institutional Review Board approval, three nuclear medicine physicians performed a retrospective review of all consecutive CSF shunt studies performed in children at our institution in 2015. Antecedent nuclear medicine CSF shunt studies in these patients were also assessed and included in the review. The appearance of the reservoir site immediately after radiotracer injection was classified as either figure-of-eight or round/ovoid configuration. The presence or absence of early systemic distribution of the tracer on the 5-min static images was noted and separately evaluated.

RESULTS

A total of 98 nuclear medicine ventriculoperitoneal CSF shunt studies were evaluated. Figure-of-eight configuration was identified in 87% of studies and, when present, had 93% sensitivity, 78% specificity, 92% accuracy, 98% positive predictive value (PPV) and 54% negative predictive value (NPV) as a predictor of successful shunt access. Early systemic activity was absent in 89 of 98 studies. Lack of early systemic distribution of the radiotracer had 98% sensitivity, 78% specificity, 96% accuracy, 98% PPV and 78% NPV as a predictor of successful shunt access. Figure-of-eight configuration in conjunction with the absence of early systemic tracer activity had 99% PPV for successful shunt access.

CONCLUSION

Figure-of-eight configuration at the injection site or lack of early systemic radiotracer activity had moderate specificity for successful shunt access. Specificity and PPV significantly improved when both signs were combined in assessment.

Best practices for the use of intracerebroventricular drug delivery devices

For decades, intracerebroventricular (ICV), or intraventricular, devices have been used in the treatment of a broad range of pediatric and adult central nervous system (CNS) disorders. Due to the limited permeability of the blood brain barrier, diseases with CNS involvement may require direct administration of drugs into the brain to achieve full therapeutic effect. A recent comprehensive literature review on the clinical use and complications of ICV drug delivery revealed that device-associated complication rates are variable, and may be as high as 33% for non-infectious complications and 27% for infectious complications. The variability in reported safety outcomes may be driven by a lack of consensus on best practices of device use. Numerous studies have demonstrated that employing strict aseptic techniques and following stringent protocols can dramatically reduce complications. Key practices to be considered in facilitating the safe, long-term use of these devices are presented.

Intracerebroventricular Delivery as a Safe, Long-Term Route of Drug Administration

Intrathecal delivery methods have been used for many decades to treat a broad range of central nervous system disorders. A literature review demonstrated that intracerebroventricular route is an established and well-tolerated method for prolonged central nervous system drug delivery in pediatric and adult populations. Intracerebroventricular devices were present in patients from one to 7156 days. The number of punctures per device ranged from 2 to 280. Noninfectious complication rates per patient (range, 1.0% to 33.0%) were similar to infectious complication rates (0.0% to 27.0%). Clinician experience and training and the use of strict aseptic techniques have been shown to reduce the frequency of complications.