{"id":"5cc36738-81eb-4aec-b128-4e818b3f6336","slug":"intraoperative-fluorescein-for-improved-tumor-visualization-in-pediatric-medulloblastoma-surgery","title":"Intraoperative fluorescein for improved tumor visualization in pediatric medulloblastoma surgery","authors":["Vitor de Deus da Rocha Ribeiro Gonçalves","André Guimarães Soares","Franklin Bernardes Faraj de Lima","Bruno Silva Costa","Marcos Dellaretti"],"abstract":"Background: The application of intraoperative fluorescein has emerged as a valuable technique to enhance tumor visualization during neuro-oncological procedures. Fluorescein sodium (FS) is a dye that accumulates in areas where the blood–brain barrier (BBB) is disrupted, with a major excitation wavelength peak ranging from 460 to 500 nm and a primary green emission peak between 540 and 690 nm. The intact BBB prevents FS uptake; however, the presence of a tumor can impair the BBB, allowing FS to accumulate within the tumor tissue. This provides enhanced visualization of the tumor. When administered intravenously, fluorescein selectively accumulates in tumor tissues, allowing surgeons to differentiate these areas from healthy brain tissue under a specialized fluorescence filter. This technique has the potential to improve resection accuracy and reduce the likelihood of residual tumor tissue. Case Description: This study presents the case of a 6-year-old patient diagnosed with medulloblastoma who underwent surgical resection with fluorescein guidance. The use of fluorescein enabled improved delineation of the tumor, facilitating a more precise resection. Postoperative magnetic resonance imaging confirmed complete removal of the lesion. This case supports the utility of fluorescein in pediatric brain tumor surgeries, particularly for achieving maximal safe resection, and underscores the potential benefits of incorporating fluorescein as an adjunct in pediatric neuro-oncological procedures. Conclusion: This case illustrates an effective and safe alternative using a fluorescent technique with FS in the pediatric population. Fluorescein is a valuable tool in the surgical management of medulloblastoma, aiding in the visualization and resection of the tumor. 00:10 – Case presentation 00:24 – Neuro-imaging finding 00:50 – Differential diagnosis 01:16 – Surgical Plan 01:52 – Fluorescein-guided microsurgery 02:14 – Intraoperative demonstration of the use of sodium fluorescein. 03:45 – Postoperative magnetic resonance imaging (MRI) 04:28 – Adjuvant treatment 04:47 – Prognostic features 05:15 – Sodium fluorescein in pediatric medulloblastoma 00:01–00:10 – This video article [ Video 1 ] aims to be a case presentation followed by a discussion about the relevance of fluorescein enhancing intraoperative scenarios. 00:11–00:21 – A 6-year-old child presented with persistent headaches and gait difficulty as gait ataxia. The headache was persistent for weeks, getting worse, just like ataxia, and MRI was done for investigation. 00:25–00:33 – On T2-weighted MRI, a lesion in the posterior fossa can be observed, appearing hyperintense and causing obstructive hydrocephalus. 00:37–00:46 – On T1-weighted MRI with contrast, the lesion demonstrates only minimal contrast enhancement and appears isointense relative to gray matter. 00:50 – 01:06 – The main differential diagnosis was between medulloblastoma and ependymoma. However, on diffusion-weighted imaging, the lesion shows evidence of restricted diffusion, suggesting a highly cellular tumor. Given these findings, the most likely diagnosis is medulloblastoma. 01:06–01:15 – Both tumors are frequent in childhood and both of them have surgical treatment with maximal safe resection as the main strategy for surgical planning.[ 4 ] 01:18–01:31 – The patient was positioned in the park bench position. A midline craniocervical incision was made extending from the superior nuchal line to the arch of C1. The schematic illustrations help showing the right side up of park bench position. 01:33–01:47 – A suboccipital craniotomy was performed in combination with the C1 laminectomy. The schematic illustrations help showing the anatomic aspects of the craniotomy and C1 laminectomy planning, providing access for a telovelar approach. 01:52–02:12 – The microsurgical phase was conducted using a fluorescent filter for enhanced visualization. Fluorescein was infused through a peripheral vein at a 10% concentration with an adjusted dose of 3 milligrams per kilogram in the pediatric population. This was administered during anesthesia induction approximately 1 h before the microsurgical phase.[ 2 ] 02:16–02:47 – After craniotomy and dural opening, we are allowed to proceed with the telovelar approach and very soon, we identify the tumor by delicate dissection. We delimit its limits from cerebellar normal tissue anatomically, and the fluorescent filter shows a great fluorescence enhancement. Ultrasonic aspirator helps the resection, and when it is mostly aspirated, the residual lesions are seen as fluorescent-enhanced at the microscope for optimizing the extent of resection. 03:30–03:45 – As you can see by the end of the microscope phase in normal light, we achieved a gross total resection. What can be checked by the use of the filter showing no fluorescence enhancement area and no signals of residual lesion. 03:46–04:03 – In postoperative MRI, we can see a reduction of the ventricular dimensions, after decompression from a gross total resection of the tumor, with no evidence of residual lesion or suspect contrast enhancement of the pathology. 04:04–04:15 – Results diagnosed the medulloblastoma with immunohistochemistry tests, typing it: medulloblastoma, Wingless/Integrated signaling pathway (WNT)-activated, World Health Organization grade 4.[ 6 ] 04:15–04:28 – There was no central nervous system dissemination, as confirmed by oncologic cytology investigation, from A cerebrospinal fluid examination, or even from total brain and spine MRI, done 3 weeks after the surgery. 04:29–04:47 – The complementary treatment was based on radiotherapy and chemotherapy as described. The patient kept follow-up care associated with adjuvant treatment and rehabilitation and no neurological deficits or gait disturbance remained. 04:48–05:05 – The most recent MRI at 24-month postoperative showed no evidence of residual tumor. As established, the main prognostic factors are the age of presentation under 3 years old, presence of metastatic tumor, extent of resection, molecular subtype, and timing of therapy. 05:05–05:15 – The extent of resection has a critical importance and is the only factor that can be modified with the aim of achieving gross total resection.[ 5 ] 05:15–05:57 – Falco et al reported fluorescent-guided resection under a yellow 560 filter, which was fundamental in distinguishing tumors from viable tissue in the majority of cases.[ 3 ] Chen et al found that fluorescein sodium was effective in visualizing medulloblastoma intraoperatively with no significant side effects reported. In summary, fluorescein is a valuable tool in the surgical management of medulloblastoma, aiding the visualization and resection of the tumor and helping decision-making to optimize the extent of resection in children. [ 1 ] Institutional Review Board approval is not required. The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Patient’s consent not required as there are no patients in this study renumbered. There are no conflicts of interest. The authors confirm that there was use of artificial intelligence (AI)-assisted technology to improve the quality of an original drawing related to the park bench position and suboccipital craniotomy. https://dx.doi.org/10.25259/SNI_28_2026 The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.","thumbnailUrl":"https://sni-digital-videos.s3.amazonaws.com/placeholders/specialty/pediatric-neurosurgery.png","publishDate":"2026-05-15T00:00:00.000Z","doi":"10.25259/SNI_28_2026","categories":["Pediatric Neurosurgery","Video Abstract"],"fullTextUrl":"https://surgicalneurologyint.com/wp-content/uploads/2026/05/14547/SNI-17-285.pdf"}