The "STARS" study: advanced preoperative rehearsal and intraoperative navigation in neurosurgical oncology

BACKGROUND

Neurosurgical 3D visualizers and simulators are innovative devices capable of defining a surgical strategy in advance and possibly making neurosurgery safer by rehearsing the phases of the operation beforehand. The aim of this study is to evaluate Surgical Theater™ (Surgical Theater LLC, Mayfield, OH, USA), a new 3D neurosurgical planning, simulation, and navigation system, and qualitatively assess its use in the operating room.

METHODS

Clinical data were collected from 30 patients harboring various types of brain tumors; Surgical Theater™ was used for the preoperative planning and intraoperative 3D navigation. Preoperative and postoperative questionnaires were completed by first and second operators to get qualitative feedback on the system's functionality. Furthermore, we measured and compared the impact of this technology on surgery duration.

RESULTS

Neurosurgeons were overall satisfied when using this rehearsal and navigation tool and found it efficient and easy to use; interestingly, residents considered this device more useful as compared to their more senior colleagues (with significantly higher scores, P<0.05), possibly because of their limited anatomical experience and spatial/surgical rehearsal ability. The length of the surgical procedure was not affected by this technology (P>0.05).

CONCLUSIONS

Surgical Theater™ system was found to be clinically useful in improving anatomical understanding, surgical planning, and intraoperative navigation, especially for younger and less experienced neurosurgeons.

A phase I-IIa study of genetically modified Tie-2 expressing monocytes in patients with glioblastoma multiforme (TEM-GBM Study)

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Background: Genetically modified cell-based therapies are relevant in immuno-oncology due to their potential for tumor specificity & potential durability. We developed a cell-based treatment, Temferon, relying on ex-vivo transduction of autologous HSPCs to express therapeutic payloads within the tumor microenvironment. Temferon targets IFNa to Tie-2 expressing macrophages (TEMs). Methods: TEM-GBM is an open-label, Phase I/IIa dose-escalation study evaluating safety & efficacy of Temferon in up to 21 newly diagnosed patients with glioblastoma & unmethylated MGMT promoter. Autologous HSPCs are transduced ex-vivo with a lentiviral vector encoding for IFNa. The transgene expression is confined to TEMs due to the Tie2 promoter & the post-transcriptional regulation by miRNA-126. Results: As of January 17 2021, 15 patients have been enrolled; 9 received Temferon (D+0) with follow-up of 61 – 559 days. There was rapid engraftment & hematological recovery after the conditioning regimen. Median neutrophil & platelet engraftment occurred at D+13 & D+12, respectively. Temferon-derived differentiated cells, as determined by the presence of vector genomes in the DNA of peripheral blood & bone marrow cells, were found within 14 days post treatment & persisted subsequently, albeit at lower levels (up to 18 months). We also detected very low concentrations of IFNa in the plasma (median 5pg/ml at D+30; baseline < LLOQ) & in the cerebrospinal fluid, suggesting tight regulation of transgene expression. Three deaths occurred: two at D+343 & +402 after Temferon administration due to disease progression, & one at D+60 due to complications following the conditioning regimen. Seven patients had progressive disease (PD; range D+27-239) as expected for this tumor type. SAEs include infections, venous thromboembolism, brain abscess, hemiparesis, GGT elevation & poor performance status compatible with autologous stem cell transplantation, concomitant medications & PD. Four patients underwent second surgery. These recurrent tumors had gene-marked cells present & increased expression of IFN-responsive gene signatures compared to diagnosis, indicative of local IFNa release by TEMs. In one patient a stable lesion (as defined by MRI) had a higher proportion of T cells & TEMs within the myeloid infiltrate & an increased IFN-response signature than in a progressing lesion. The T-cell immune repertoire changed with evidence for expansion of tumor-associated clones. Tumor microenvironment characterization by scRNA & TCR sequencing is ongoing. Conclusions: Our interim results show that Temferon is well tolerated by patients, with no dose limiting toxicities identified to date. The results provide initial evidence of Temferon potential to modulate the TME of GBM patients, as predicted by preclinical studies. Clinical trial information: NCT03866109.

Incidence and risk factors of neurosurgical site infections: results of a prospective multicenter cohort study on 6359 surgeries

BACKGROUND

Neurosurgical surgical site infections (SSI) are life-threatening complications, requiring medical treatment and additional surgeries and remain a substantial cause of morbidity. In order to identify the incidence and the main risk factors for SSI, we developed the Prophylaxis with Antibiotic Protocol for Neurosurgical Site Infections Study (PASSIS), a prospective observational multicenter cohort study for examining a large number of neurosurgical procedures.

METHODS

The study PASSIS involved four Italian departments of neurosurgery applying the same antibiotic prophylaxis (ABP) protocol on 6359 consecutive neurosurgical procedures. In high-risk conditions (intra-operative contamination and/or postoperative cerebro-spinal fluid [CSF], and/or subcutaneous drainage and/or postoperative hyperpyrexia) and in presence of wound complication (CSF leak and/or CSF collection and/or wound diastasis), a prolongation protocol was prescribed.

RESULTS

The crude rate of SSI in the whole series was and 1.7% for patient and 1.5% for procedure. Patient related SSI risk factors: Younger patients (≤14 years) had a significantly higher SSI risk compared with older patients (RR: 2.17; 95% CI: 1.13-4.14). Patients underwent two surgeries were at increased SSI risk (RR: 3.80; 95% CI: 2.33-6.18), and the risk increased with the number of surgeries. Surgeries lasting longer than 3 hours (RR: 2.27; 95% CI: 1.15-4.50), undergoing two or more surgeries and the presence of prosthetic implants (RR: 2.40; 95% CI: 1.53-3.77) were procedure related SSI risk factors positively associated with SSI. In high-risk conditions and in wound complication as defined previously, ABP prolongation showed limited efficacy (RR:1.97; 95% CI: 1.21-3.22 and 9.31; 95% CI: 5.90-14.68 respectively).

CONCLUSIONS

The subjects submitted to complicated, repeated, long lasting craniotomies, especially if experiencing postoperative deterioration, display the higher risk of SSIs, as a final life-threatening complication. In order to reduce the SSI rate, further studies should address to design tailored prophylaxis protocols for each high risk situation as hereby defined; the wound complications deserve an increased microbiological surveillance, focusing the attention on the timing and source of infections.