5-Aminolevulinic Acid-Guided Surgery for Recurrent Supratentorial Pediatric Neoplasms

Role of sodium fluorescein in pediatric low-grade glioma surgery: an update

PURPOSE

Complete surgical resection is still the mainstay in the treatment of central nervous system low-grade tumors, eventually resulting curative. The complete surgical removal of these lesions, however, may be difficult in some cases because of their infiltrative nature. Intraoperative adjuncts may be a game changer. Sodium fluorescein (SF) is among the ideal candidates as intraoperative tools to favor the actual recognition of the tumor extension, since it accumulates in areas of altered blood-brain barrier, a typical characteristic of pediatric gliomas, and has a low rate of adverse events. This work proposes an update of previous works about the evaluation of the feasibility and usefulness of a systematic use of SF in a low-grade lesion group of pediatric patients.

METHODS

Pediatric patients operated on for a resection or a biopsy of a low-grade glial or glioneuronal lesion (WHO grade I and II) at our Institution between September 2021 and December 2023, with the intraoperative use of sodium fluorescein (SF), were enrolled in the study. We collected pre-operative and postoperative clinical and radiological data, intraoperative findings, and post-operative pathological diagnoses.

RESULTS

No adverse events were registered related to the intraoperative use of SF. SF appeared useful for the localization of boundaries of tumors, especially when characterized by a high degree of infiltration or by a deep-seated location, and for the checking of possible tumor remnants at the end of surgery. A good tumor-to-healthy tissue contrast was registered when tumor visualization was in a range between 1 to 2 h and 30 min after SF injection. Possible "false positives" due to intraoperative vascular wall injury and clearance of SF from both tumor and healthy tissue were observed in some cases and still remain open issues.

CONCLUSIONS

SF is a feasible and safe intraoperative adjunct tool in the surgical removal of pediatric low-grade tumors. SF may show its usefulness especially in selected cases, such as deep-seated lesions and infiltrating tumors. Its safety profile, user-friendly management, and potential utility in both tumor resections and neuronavigated biopsies favor its wider use in the surgical treatment of pediatric low-grade tumors.

The Landscape of Neurosurgical Oncology Adjunct Usage in Africa: A Scoping Review

BACKGROUND

Intraoperative neurosurgical adjuncts improve extent of resection whilst mitigating patient morbidity. The delivery of neurosurgical care via these adjuncts is the norm in high-income countries, but there is yet to be a study highlighting the usage of neurosurgical oncology adjuncts in Africa. This paper aims to provide awareness of the use of these adjuncts in Africa, reasons for limited procurement, and possible solutions to the problem.

METHODS

This scoping review was conducted in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis Extension for Scoping Reviews guidelines. Semantic derivatives of neurosurgical oncology, adjuncts, and Africa were applied to medical databases. Studies in Africa with outcomes relating to adjunct usage, morbidity, mortality, and quality of life were selected. Book chapters and reviews were excluded.

RESULTS

Thirteen studies with 287 patients (0.5 to 74 years) were included in the final analysis. Most studies were cohort observational (46.2%) and originated from South Africa (46.2%). Meningioma was the most prevalent tumor histology (39.4%), and neuronavigation was the most readily used adjunct for surgical resection (30.8%). Using adjuncts, gross total resection was achieved in close to half the patient cohort (49.8%). Limited technology, lack of experience, cost of equipment, and inconsistency in power supply were noted as factors contributing to lack of adjunct usage.

CONCLUSIONS

Neurosurgical adjuncts provide significant benefits in neurosurgical oncology. There is limited utilization of intraoperative adjuncts in most of Africa owing to limited resources and experienced professionals. Bilateral partnerships with a focus on donation and education will foster safe and sustainable adjunct incorporation in Africa.

5-ALA fluorescence in randomly selected pediatric brain tumors assessed by spectroscopy and surgical microscope

PURPOSE

Fluorescence-guided surgery applying 5-aminolevulinic acid (5-ALA) in high-grade gliomas is an established method in adults. In children, results have so far been ambiguous. The aim of this study was to investigate 5-ALA-induced fluorescence in pediatric brain tumors by using the surgical microscope and a spectroscopic hand-held probe.

METHODS

Fourteen randomly selected children (age 4-17) with newly MRI-verified brain tumors were included. No selection was based on the suspected diagnosis prior to surgery. All patients received 5-ALA (20 mg /kg) either orally or via a gastric tube prior to surgery. Intratumoral fluorescence was detected with the microscope and the probe. Moreover, fluorescence in the skin of the forearm was measured. Histopathology samples revealed seven low-grade gliomas, four medulloblastomas, one diffuse intrinsic pontine glioma, one glioblastoma and one atypical meningioma. Blood samples were analyzed, and potential clinical side effects were monitored.

RESULTS

Microscopically, vague fluorescence was visible in two patients. Intratumoral fluorescence could be detected in five patients with the probe, including the two patients with vague microscopic fluorescence. Three of the oldest children had PpIX fluorescence in the skin. Nine children did not show any fluorescence in the tumor or in the skin. No clinical side effects or laboratory adverse events were observed.

CONCLUSION

Fluorescence could not be used to guide surgery in this study, neither with the surgical microscope nor with the hand-held probe. In nine children, no fluorescence was discerned and children with noticeable fluorescence were all older than nine years. 5-ALA was considered safe to apply in children.

5-Aminolevulinic Acid False-Positive Rates in Newly Diagnosed and Recurrent Glioblastoma: Do Pseudoprogression and Radionecrosis Play a Role? A Meta-Analysis

Background

Several studies have confirmed the impact of 5-aminolevulinic acid (5-ALA) on the extent of resection in newly diagnosed glioblastoma (GBM). However, there are controversies on the 5-ALA fluorescence status in recurrent GBM surgery, with specific reference to pseudoprogression or radionecrosis; therefore, the safety and accuracy of surgical planning in 5-ALA-assisted procedures in the recurrent context are still unclear.

Materials and Methods

This is a systematic review and meta-analysis of comparative studies on the use of 5-ALA in newly diagnosed and recurrent GBM, consistently conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Data on fluorescence status and correlation between fluorescence and histological findings were collected. We performed a meta-analysis of proportions to estimate the pooled rates of each outcome.

Results

Three online medical databases (PubMed, Scopus, Cochrane Library) were screened, 448 articles were evaluated, and 3 papers were finally included for data analysis. Fluorescence rate was not different between newly diagnosed and recurrent GBM [p = 0.45; odds ratio (OR): 1.23; 95% CI: 0.72–2.09; I² = 0%], while the rate of 5-ALA fluorescence-positive areas not associated with histological findings of GBM cells was higher in recurrent GBM (p = 0.04; OR: 0.24; 95% CI: 0.06–0.91; I² = 19%). Furthermore, there were no cases of radionecrosis in false-positive samples, while inflammation and signs of pseudoprogression were found in 81.4% of the cases.

Discussion and Conclusions

Therefore, a robust awareness of 5-ALA potentialities and pitfalls in recurrent GBM surgery should be considered for a cognizant surgical strategy. Further clinical trials could confirm the results of the present meta-analysis.

Surgical outcomes of pediatric brain tumors in Sub-Saharan Africa: A systematic review

Background

Pediatric Brain Tumors (PBT) are a common cause of cancer-related mortality globally. Contrary to high-income countries (HIC), survival rates in low-and-middle income countries (LMIC) remains low despite advances in neurosurgical care and diagnostics over the past decades. The aim of this systematic review was to investigate the surgical outcomes for PBT in Sub-Saharan Africa, and the distribution of PBT types.

Methods

A systematic review was conducted on PubMed, for all available literature on the surgical outcomes of PBT in Sub-Saharan Africa, published before May 3, 2022. Two reviewers performed abstract, full text screening and data collection independently, resolving any conflicts by consensus.

Results

The search yielded 256 studies, of which 22 met the inclusion criteria, amounting to a total of 243 patients. Nigeria was the country with most data. Only subgroups of patients could be extracted from 12 studies, and variables of interest in 6 studies had inconsistent sample sizes. The age centered around 9 years, and there were approximately equal number of girls and boys. The most common tumor was medulloblastoma, followed by craniopharyngioma and astrocytoma. There was large heterogeneity in the reporting of outcomes, and a trend was difficult to discern, considering the large number of different tumor types and different extents of resection.

Discussion and conclusion

Data is insufficient and inconsistent, precluding statistical conclusions. There is a need for more studies in the field.

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Data on outcomes of pediatric brain tumor surgery in Sub-Saharan Africa is insufficient, preventing statistical conclusions.

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Nigeria is over-represented among studies on pediatric brain tumor and associated surgical outcomes in Sub-Saharan Africa.

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Medulloblastoma was the most commonly reported pediatric brain tumor in surgical outcome studies in Sub-Saharan Africa.