Name:
5-ALA fluorescence in indeterminate grade gliomas
Description:
5-ALA fluorescence in indeterminate grade gliomas
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Duration:
T00H05M32S
Embed URL:
https://stream.cadmore.media/player/c5a55169-1c16-4692-b56b-ef37d0dba5f2
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/c5a55169-1c16-4692-b56b-ef37d0dba5f2/21-196.mp4?sv=2019-02-02&sr=c&sig=K6D9AfRkBoKYexGWxYdkWyxDmo9vUXNKEY%2FgVBc40YQ%3D&st=2024-05-05T17%3A25%3A26Z&se=2024-05-05T19%3A30%3A26Z&sp=r
Upload Date:
2021-12-07T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
SPEAKER: Here, we present the case of a 37-year-old otherwise healthy female who experienced progressive headaches for several months. A subsequent MRI demonstrates a left frontal lobe space-occupying lesion. The lesion is hyperintense on T2 with the T2-FLAIR signal mismatch. There is focal contrast enhancement of the center of the lesion has shown on the right image.
SPEAKER: For further evaluation, an FET-PET was obtained. An obvious hypermetabolic hotspot can be appreciated toward the cortical portion of the lesion. In addition, a second hypermetabolic spot can be seen around the area of MRI contrast enhancement. Given the T2-FLAIR mismatch, IDH mutation was probable. Still, according to the high metabolic activity, as provided by the FET-PET, the grading of the lesion was unclear.
SPEAKER: The patient consented for microsurgical fluorescence- guided resection. We anticipated a risk to speech- and language-associated subcortical structures. And therefore, the procedure was conducted in a standard awake setting. Starting with defining the posterior border of the tumor, intraoperative fluorescence was detected early. Factors associated with visible fluorescence and low- and intermediate-grade gliomas have not been fully determined.
SPEAKER: Generally, visible fluorescence is observed in 98% to 100% of glioblastoma patients treated with 5-ALA. In contrast, visible fluorescence is observed in approximately 75% to 85% of all grade III gliomas and 16% to 20% of grade II diffuse gliomas. In those cases, 5-ALA fluorescence is reported to correlate with signal intensity on FET-PET.
SPEAKER: Here, fluorescence was coregistered with the available preoperative imaging data using neuronavigation. Location of resting tissue exactly matched the minor spot of FET-PET positivity over the area of focal contrast enhancement. Separate biopsies were taken from both areas of FET-PET positivity including the fluorescent part of the tumor to best represent intratumoral heterogeneity.
SPEAKER: This helps not to underestimate the true grade of the lesion. Especially due to shift in tissue masses during resection of large lesions, finding an anaplastic focus can be challenging. Gross-total resection was achieved, and the further postoperative course was uneventful. After histopathological and molecular analyses, the diagnosis of IDH1- mutated diffuse astrocytoma was established.
SPEAKER: ATRX expression was lost. CDKN2A/B was retained. And the tumor was of increased cellular density within MIB-1 of 13%. The patient exhibited various favorable prognostic factors: age below 40 years, no neurological deficit, low tumor burden, and grade II pathology. Also, the patient was reluctant concerning adjuvant therapies. In line with current practice management guidelines, the decision was made to watch and wait.
SPEAKER: Early in the course of disease, 1 year after initial gross- total resection, follow-up MRI revealed tumor progression and the patient underwent resection. The diagnosis, again, was IDH- mutated diffuse astrocytoma. This was further confirmed by additional DNA methylation analysis. Now, the decision was made to start sequential radio- chemotherapy.
SPEAKER: The patient has been stable for 2 years now. This case highlights two important aspects that support the use of 5-ALA in indeterminate grade gliomas. Firstly, 5-ALA tissue sampling helps not to underestimate the true grade of the lesion. And secondly, 5-ALA fluorescence was found to be an unfavorable prognostic marker in low-grade glioma patients. This was first published by our group in 2019, and was recently corroborated by transatlantic initiative.
SPEAKER: This translates into a potential for 5-ALA fluorescence to unveil high-risk, low-grade patients. The molecular substrate underlying this phenomenon is currently under investigation. According to current clinical management guidelines, for certain cases of IDH- mutant diffuse astrocytoma, robust factors that support adjuvant treatment over watch- and-wait strategy are lacking. And coming back to the case presented with the data on prognostic impact on 5-ALA fluorescence now available, the notion of intraoperative fluorescence might have led to a stronger recommendation toward adjuvant treatment in the first place.
SPEAKER: And with this, early tumor progression might have been prevented. However, the influence of fluorescence on decision-making processes and the resulting outcome will be within the scope of future studies. Finally, with advancements in visualization techniques and administration schemes of 5-ALA, fluorescence-guided sections comparable to surgery in high-grade gliomas may be feasible soon.
SPEAKER: