OP38 * ROBOT-ASSISTED CONVECTION-ENHANCED DELIVERY OF CARBOPLATIN FOR PROGRESSIVE DIPG - A SAFETY AND FEASIBILITY REPORT OF 5 CASES

Abstract

BACKGROUND: Convection-enhanced delivery (CED) describes a direct method of drug delivery to the brain through surgically implanted microcatheters. There has been significant research focus on applying CED to the treatment of DIPG, where the eloquent location of tumour usually precludes resective surgery. We report our initial experience of CED of carboplatin in 5 patients with DIPG. METHODS: 5 patients with clinical and/or radiological tumour progression after radiotherapy were selected. Up to 4 catheter trajectories per patient were planned using custom-made stereotactic planning software. Catheters were implanted using a robot-assisted guidetube directed implantation technique. Infusions of carboplatin (0.18 mg/mL) were performed on 2 consecutive days. Serial T2-weighted MR imaging was used as a proxy measure of drug distribution. RESULTS: Catheter implantations were well tolerated with satisfactory targeting accuracy. No patients suffered haemorrhagic complications. High volume (up to 9mL/day), high flow rate infusions (up to 10microL/min) were performed with real-time MRI guidance. During the infusions patients exhibited worsening of preexisting neurological dysfunction, which was transient in all except one patient who required a prolonged period of non- invasive respiratory support. One patient developed transient hydrocephalus which resolved without intervention. Analysis of T2-weighted imaging indicated drug distribution throughout the majority of the targeted tumour volume in 4 out of 5 patients. CONCLUSIONS: The robot-assisted catheter insertion technique was well-tolerated and achieved satisfactory targeting. No adverse events related to implantation of catheters were observed in this cohort. High volume, high flow rate infusions achieved drug distribution thoughout the majority of the targeted tumour volume in 4 out of 5. Infusions were associated with only transient worsening of neurological function in all but one patient, in whom CPAP was required in the post-infusion period. This initial experience represents a strong foundation for a clinical trial of CED of carboplatin for DIPG.