This is an interesting idea. Gleolan (5-ALA) is a dye given to a patient (orally) before a surgery. During the surgery, the surgeon shines a special light on the brain and ny tumor lights up with the dye. This report then adds in the next step - photodynamic therapy. Once the maximal amount of tumor is removed, they then hit the tumor bed with a laser which hurts the tumor cells which picked up the dye to mop up the remaining bad cells. This could be simply added to most surgeries and used in addition to whatever else was going to be done.
Posted on: 01/26/2020
J Neurosurg. 2020 Jan 24:1-11. doi: 10.3171/2019.11.JNS192443. [Epub ahead of print]
Combination of ALA-induced fluorescence-guided resection and intraoperative open photodynamic therapy for recurrent glioblastoma: case series on a promising dual strategy for local tumor control.
Schipmann S1, Müther M1, Stögbauer L1, Zimmer S2, Brokinkel B1, Holling M1, Grauer O3, Suero Molina E1, Warneke N1, Stummer W1.
1. 1Department of Neurosurgery.
2. 2Institute of Radiology, and.
3. 3Department of Neurology, University Hospital Münster, Germany.
High-grade glioma (HGG) prognosis remains dismal, with inevitable, mostly local recurrence. Regimens for improving local tumor control are therefore needed. Photodynamic therapy (PDT) using porfimer sodium has been investigated but was abandoned due to side effects and lack of survival benefits. Intracellular porphyrins induced by 5-aminolevulinic acid (5-ALA) are approved for fluorescence-guided resections (FGRs), but are also photosensitizers. Activated by light, they generate reactive oxygen species with resultant cytotoxicity. The authors present a combined approach of 5-ALA FGR and PDT.
After 5-ALA FGR in recurrent HGG, laser diffusors were strategically positioned inside the resection cavity. PDT was applied for 60 minutes (635 nm, 200 mW/cm diffusor, for 1 hour) under continuous irrigation for maintaining optical clarity and ventilation with 100% oxygen. MRI was performed at 24 hours, 14 days, and every 3 months after surgery, including diffusion tensor imaging and apparent diffusion coefficient maps.
Twenty patients were treated. One surgical site infection after treatment was noted at 6 months as the only adverse event. MRI revealed cytotoxic edema along resection margins in 16 (80%) of 20 cases, mostly annular around the cavity, corresponding to prior laser diffusor locations (mean volume 3.3 cm3). Edema appeared selective for infiltrated tissue or nonresected enhancing tumor. At the 14-day follow-up, enhancement developed in former regions of edema, in some cases vanishing after 4-5 months. Median progression-free survival (PFS) was 6 months (95% CI 4.8-7.2 months).
Combined 5-ALA FGR and PDT provides an innovative and safe method of local tumor control resulting in promising PFS. Further prospective studies are warranted to evaluate long-term therapeutic effects.
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