Meningioma surgery in the era of 5-aminolevulinic acid fluorescence-guided surgery

摘要

The authors' aim was to assess the role of 5-ami- nolevulinic acid (5-ALA) fluorescence in guiding the resection of bone-invading meningiomas. Because the Simpson grading system does not evaluate bone invasion, they radiologically assessed the amount of tumor resection, bone invasion, and hyperostosis by comparing pre-and postoperative MR images and CT scans. When reading the article, we were confirmed in our opinion that in the era of 5-ALA fluorescence-guided surgery, another item has to be added to the Simpson grading scale.2 In fact, 5-ALA holds the potential to visualize tumor tissue infiltrating bone, dura mater, and brain, which would remain unrecognized under white light. When resecting meningiomas with 5-ALA there are 2 possible surgical scenarios at the end of surgery: 1) fluorescing tissue may be completely resected (for example, in cases of infiltration of bone and dura); or 2) further resection is impossible because it would compromise neurological function (for example, if there is infiltration of venous sinus, eloquent brain area, or cranial nerve), resulting in residual fluorescing tissue. Hence 5-ALA fluorescence-guided surgery has the potential to increase the extent of resection in a way not encompassed by the Simpson grading system. We therefore suggest adding an item to the Simpson grading scale reflecting whether or not fluorescing tissue was present at the end of surgery.