Providing pre-operative accurate localization with intra-operative rendering, has been the main stay of brain tumor surgery for over two decades. Asfaw et al. [3] report on over 19,000 patients who underwent cranial tumor surgery using neuronavigation and chart the progression its from idea to adoption and evolution in the US and abroad.

The need for intraoperative image update, recognized by a robust body of literature, is further explored by Mirzayeva et al. [4] They report on the effect of intraoperative magnetic resonance imaging (ioMRI) on overall and progression-free survival (OS and PFS) in 153 patients. The authors conclude that ioMRI results in increased the PFS, and providing the surgeon with a maximal resection in the first operation.

For over two decades, 5-aminolevulinic acid (5-ALA) fluorescence-guided resection (FGR) has been an essential tool in resection of malignant gliomas, albeit gaps in its use still exist. da Silva Jr et al. [5] report a retrospective series of 707 CNS tumors patients who underwent FGR with a pharmacological equivalent 5-ALA and discuss the financial implications.

Advances in systemic treatment of cancer, including targeted and immunotherapies, result in increased overall survival (OS) and consequently in an increased number of patients with both brain and spine metastatic disease. Intra-operative radiotherapy (IORT) is an alternative treatment to post-operative radiosurgery. Kahl et al. [6] report on the outcome of 105 patients concluding that it is a safe procedure with excellent local control.

The efficacy and safety of laser interstitial thermal therapy followed by consolidation radiosurgery (LITT-cSRS) was studied in brain metastasis that recurs locally after initial radiosurgery (BMRS) as reported by xx et al.l [7]. Dharnipragada et al. [8] report on 10 patients with newly diagnosed brain metastasis treated with upfront LITT-cSRS concluding that it is a safe new paradigm.

Finally, Rodriguez et al. [9] provide a narrative review of other used intra-operative techniques used such us intraoperative brachytherapy, photodynamic therapy (PDT), sonodynamic therapy (SDT), and focused ultrasound (FUS).