LMD-01. Quantifying intrathecal drug delivery utilizing programmable ventriculoperitoneal shunts

Background Programmable ventriculoperitoneal shunts (pVP shunts) are increasingly utilized for intraventricular chemotherapy, radioimmunotherapy, and/or cellular therapy. Shunt adjustments allow optimization of thecal space drug concentrations with minimization in the peritoneum. Drug delivery quantification using several types of pVP shunts has not been reported. Methods We performed a retrospective analysis on patients with CNS tumors and pVP shunts at Memorial Sloan Kettering Cancer Center from 2003–2020, noting shunt model. CSF flow through the pVP shunt was evaluated using In-111-DTPA scintigraphy at approximately 4 and 24 hours after injection. pVP shunts were calibrated pre-injection to minimize peritoneal flow and re-calibrated to baseline setting 4–5 hours following injection. Scintigraphy studies quantified ventricular-thecal and peritoneal drug activity at these 2 time points. Results Twenty-one CSF flow studies were administered to 15 patients, ages 1–27 years. Diagnoses included medulloblastoma (N=10), metastatic neuroblastoma (N=3), pineoblastoma (N=1), and choroid plexus carcinoma (N=1). Models of pVP shunts included Aesculap Miethke proGAV (N=3), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 5), and Sophysa Polaris (N= 1). All 21 studies (100%) demonstrated ventriculo-thecal drug activity. 29% (6 of 21) of the studies had no peritoneal uptake visible by imaging. 73% (16 of 21) of the studies had minimal peritoneal uptake (<12%), and 24% (5 of 21) demonstrated moderate peritoneal uptake (12–37%). Models of pVP shunts measuring minimal to no peritoneal uptake included: Aesculap Miethke proGAV (N=2), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 3), and Sophysa Polaris (N= 1). Conclusions pVP shunts successfully deliver drugs to the ventriculo-thecal space with 80% of studies having minimal (<12%) peritoneal drug activity. Though efficacy varies by shunt model, low numbers preclude conclusions regarding model superiority. CSF flow scintigraphy studies reliably assess drug distribution.

IMMU-15. QUANTIFYING INTRATHECAL DRUG DELIVERY UTILIZING PROGRAMMABLE VENTRICULOPERITONEAL SHUNTS

Background Programmable ventriculoperitoneal (pVP) shunts are increasingly utilized for intraventricular chemotherapy, radioimmunotherapy, and/or cellular therapy. Shunt adjustments allow optimization of thecal space drug concentrations with minimization in the peritoneum. Drug delivery quantification using several types of pVP shunts has not been reported. Methods We performed a retrospective analysis on patients with CNS tumors and pVP shunts at Memorial Sloan Kettering Cancer Center from 2003–2020, noting shunt model. CSF flow through the pVP shunt was evaluated using In-111-DTPA scintigraphy at approximately 4 hours and 24 hours after injection. pVP shunts were calibrated pre-injection to minimize peritoneal flow and re-calibrated to baseline setting 4–5 hours following injection. Scintigraphy studies quantified ventricular-thecal and peritoneal drug activity at these 2 time points. Results Twenty-one CSF flow studies were administered to 15 patients, ages 1–27 years. Diagnoses included medulloblastoma (N=10), metastatic neuroblastoma (N=3), pineoblastoma (N=1), and choroid plexus carcinoma (N=1). pVP shunt models included Aesculap Miethke proGAV (N=3), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 5), and Sophysa Polaris (N= 1). All 21 studies (100%) demonstrated ventriculo-thecal drug activity. 29% (6 of 21) of the studies had no peritoneal uptake visible by imaging. 73% (16 of 21) of the studies had minimal peritoneal uptake (<12%), and 24% (5 of 21) demonstrated moderate peritoneal uptake (12–37%). pVP shunt models measuring minimal to no peritoneal uptake included: Aesculap Miethke proGAV (N=2), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 3), and Sophysa Polaris (N= 1). Conclusions Successful drug delivery to the ventriculo-thecal space can be accomplished using pVP shunts: 80% of studies have minimal (<12%) peritoneal drug activity. Though efficacy varies by shunt model, low numbers preclude conclusions regarding model superiority. CSF flow scintigraphy studies reliably assess drug distribution.

Novel Insights into Diagnosis, Biology, and Treatment of Primary Diffuse Leptomeningeal Melanomatosis

Primary diffuse leptomeningeal melanomatosis (PDLMM) is an extremely rare and aggressive cancer type for which best treatment strategies remain to be elucidated. Herein, we present current and prospective diagnostic strategies and treatment management of PDLMM. Against the background of an extensive literature review of published PDLMM cases and currently employed therapeutic strategies, we present an illustrative case of a pediatric patient suffering from PDLMM. We report the first case of a pediatric patient with PDLMM who received combination treatment including trametinib and everolimus, followed by intravenous nivolumab and ipilimumab with concomitant intensive intraventricular chemotherapy, resulting in temporary significant clinical improvement and overall survival of 7 months. Following this clinical experience, we performed a comprehensive literature review, identifying 26 additional cases. By these means, we provide insight into current knowledge on clinical and molecular characteristics of PDLMM. Analysis of these cases revealed that the unspecific clinical presentation, such as unrecognized increased intracranial pressure (present in 67%), is a frequent reason for the delay in diagnosis. Mortality remains substantial despite diverse therapeutic approaches with a median overall survival of 4 months from diagnosis. On the molecular level, to date, the only oncogenic driver reported so far is mutation of NRAS (n = 3), underlining a close biological relation to malignant melanoma and neurocutaneous melanosis. We further show, for the first time, that this somatic mutation can be exploited for cerebrospinal fluid liquid biopsy detection, revealing a novel potential biomarker for diagnosis and monitoring of PDLMM. Last, we use a unique patient derived PDLMM cell model to provide first insights into in vitro drug sensitivities. In summary, we provide future diagnostic and therapeutic guidance for PDLMM and first insights into the use of liquid biopsy and in vitro models for this orphan cancer type.

Intraoperative Chemotherapy for Leptomeningeal Metastases After Ommaya Placement

IntroductionThere is a wide variety in the timing of the first intraventricular chemotherapy dose after Ommaya reservoir placement. Given the rapid nature of leptomeningeal metastasis, it is important to avoid any delays in treatment in order to have the optimal therapeutic benefit. We present the first series of immediate intraoperative intraventricular infusion of chemotherapy after Ommaya placement.MethodsA single-institution, retrospective review of twenty patients who underwent surgical placement of an Ommaya reservoir from 2012 to 2020 and had intraoperative infusion of chemotherapy was conducted. Inclusion criteria consisted of patients 18 years and older with a diagnosis of leptomeningeal metastases, central nervous system lymphoma or leukemia. Outcomes such as leukoencephalopathy, wound healing, intracranial hemorrhage, catheter malfunction, Ommaya days, mortality, and other complications were reviewed.ResultsThe mean patient age was 55.1 years and the most common diagnosis was breast cancer (40%). All catheters were placed into the ventricular system, and there were no wound healing complications, infections or symptomatic leukoencephalopathy. Intraventricular chemotherapy was administered for a total of 201 cycles and a mean of 10 times per patient. The number of Ommaya days ranged from 7 to 2177, with a mean of 326.5 days, and 30-day mortality was 10%.Conclusions Ommaya reservoirs are effective intraventricular delivery mechanism for chemotherapy in patients with leptomeningeal metastases. Endoscopy-assisted placement of Ommaya catheters provides a real-time, visual confirmation of adequate placement. Immediate intraoperative intraventricular infusion of chemotherapy after Ommaya placement is safe, effective, and may increase efficiency in time to treatment for patients.

DDEL-17. TRIPLE INTRAVENTRICULAR CHEMOTHERAPY FOR TREATMENT OF RELAPSED CHOROID PLEXUS CARCINOMA

Limited evidence for the optimal management of relapsed choroid plexus carcinoma (CPC) exists, with a few case reports involving surgery, radiotherapy and intravenous chemotherapy. However, the safety and tolerability of intraventricular chemotherapy in this setting has not been widely studied. We describe a case where triple intraventricular chemotherapy was administered to a child with relapsed metastatic CPC. A 7-year-old male with a history of CPC presented with relapsed metastatic disease. At initial diagnosis at 4 years of age, treatment involved gross total resection of an intraventricular mass in the left temporal region followed by chemotherapy and autologous stem cell transplantation (SCT) according to HEADSTART II-D. One year after SCT, craniospinal radiation was delivered following radiological relapse, achieving a partial response. Given previous treatment-limiting myelosuppression, intraventricular chemotherapy via Ommaya® reservoir with thiotepa 5mg, etoposide 0.5mg and topotecan 0.4mg twice a week (non-weight-based dosing) was commenced taking into consideration pharmaceutical formulation aspects for optimal intraventricular drug delivery. After six cycles of intraventricular chemotherapy, palliative radiotherapy was administered due to radiological progression. Following completion, weekly triple intraventricular chemotherapy continued for 9 months. The patient remained out of hospital with the main side effects being fatigue and occasional nausea amenable to ondansetron. This case study demonstrates the safety and tolerability of a triple intraventricular chemotherapy regimen used to delay disease progression and prolong quality of life in a child with relapsed CPC in the palliative setting. This could provide an alternative treatment regimen for patients with relapsed disease.

RARE-12. EARLY FOCAL RADIOTHERAPY AND TEMOZOLOMIDE FOLLOWING COMPLETE RESECTION APPEAR SUPERIOR TO INTENSIVE CHEMOTHERAPY IN CHILDREN WITH EMBRYONAL TUMORS WITH MULTILAYERED ROSETTES (ETMR)

BACKGROUND Embryonal tumor with multilayered rosettes (ETMR) is an extremely rare entity characterized by LIN28A expression and alterations in the C19MC locus. ETMRs predominantly occur in young children and have a dismal prognosis. We report on our single institution experience in seven consecutive patients. METHODS Between 2006 and 2016, seven patients were diagnosed with ETMR. Diagnosis was established prospectively by characteristic histopathologic features, LIN28A immunostaining and amplification of the C19MC region in five patients and retrospectively confirmed in two additional patients originally diagnosed as central nervous system primitive neuroectodermal tumor. Tumor location was supratentorial in all patients. Median age at diagnosis was 25 months (range 5–38). Male to female ratio was 1:6. RESULTS All patients received gross total tumor resection and four patients were treated with intensive chemotherapy regimens including high-dose chemotherapy in three patients. Four patients recurred after a median of 6 months (range 2–11 months) and all except one patient who died after high-dose chemotherapy, succumbed to their disease after a median of 13 months (range 7–28 months). Consequently, the two most recent patients were treated with gross total tumor resection, primary focal radiotherapy and concomitant temozolomide followed by temozolomide for one year. Due to the high risk of leptomeningeal dissemination intraventricular chemotherapy was administered to all except one patient. Both patients who were treated with primary focal radiotherapy are in continuous complete remission 41 and 36 months after diagnosis. CONCLUSION Gross total resection followed by early focal radiotherapy, temozolomide, and intrathecal chemotherapy seem to be superior to intensive chemotherapy including high-dose chemotherapy.

CMET-02. ESTABLISHING THE SAFETY AND EFFICACY OF A NEW MULTI-AGENT INTRATHECAL TREATMENT PROTOCOL FOR PATIENTS WITH NEOPLASTIC MENINGITIS

BACKGROUND The prognosis for neoplastic meningitis (NM) remains dismal and single-agent (rather than multi-agent) chemotherapy remains the standard of care. Objective: To analyze survival of patients with NM receiving multi-agent vs. single-agent intrathecal chemotherapy and evaluate the safety of antitumor intrathecal biological agents. METHODS We compared a standardized multi-agent intrathecal treatment cohort to the corresponding patient level data acquired from 6 of the 7 randomized controlled trials (RCTs) conducted in patients with NM, all of which used single-agent intraventricular therapies. The toxicity of intrathecal biological agents was studied by analyzing the outcome data form patients with NM treated with at least 1 intrathecal biological drug. RESULTS 283 patients receiving multi-agent therapy were compared to 290 patients from the RCTs. Patients and tumor characteristics did not differ between groups. All patients from the multi-agent patient group were included in an intent-to-treat model. For all solid tumors, median survival (multi-agent vs. single-agent treatment) was 211 vs. 97 days, hazard ratio (HR) 3.39, p< 0.001. For lymphoma, survival was 304 vs. 81 days, HR 2.10, p< 0.001. Stratified by tumor histology, median survival for breast cancer NM was 315 days [95% CI 248–449], for lung cancer 193 days [127- 200]; for melanoma 307 days [65–1492], and for primary brain tumors 253 days [187- 348]. No additional toxicity was seen in the multi-agent compared to the single-agent treatment groups. In 110 patients, grade III toxicity occurred in 5.3%, 3.1%, 0% and 0% of patients receiving rituximab, trastuzumab, panitumumab, and alpha interferon. No difference in survival was seen when comparing patients with and without treatment related toxicity in any histological groups. CONCLUSION Multi-agent intraventricular chemotherapy was associated with dramatically increased survival in patients with solid tumor and lymphomatous NM. Incorporating biologic agents as part of a multi-agent intrathecal treatment regimen is very safe.