Background: We describe the technical report and results of the first image-guided, linear accelerator, frameless radiosurgical third ventriculostomy. Methods: We report a 20 years old man, with diplopia, balance disturbances, and limitation for gaze supraversion. Magnetic resonance imaging resonance imaging of the brain and cranial computed tomography showed showed a left thalamic-midbrain lesion that caused partial compression of the Silvio aqueduct and mild ventricular dilatation. The biopsy revealed the diagnosis of pleomorphic xanthoastrocytoma. Before radical treatment of the tumor with fractionated stereotactic radiotherapy, the patient underwent to frameless radiosurgical third ventriculostomy, on the TrueBeam STX® platform with the ExacTrac localization system. The target used was the one defined on the floor of the third ventricle, at the midpoint between the mammillary bodies and the infundibular recess. The prescription dose was 120 Gy, given using a monoisocentric technique of multiple noncoplanar circular arches. The geometric arrangement of the plan consisted of 15 arches, with a 4 mm cone, distributed over a 110° table. Results: There was symptomatic and image improvement two days after radiosurgery. On CT, a reduction in ventricular dilation was observed with a reduction in the Evans index from 0.39 (initial CT) to 0.29 (CT at 15 days). In 3.0T magnetic resonance image at 3 months, we showed the third ventriculostomy. There have been no treatment failures or complications. Conclusion: It is possible to effectively perform the frameless radiosurgical third ventriculostomy without associated morbidity in the short term.

Sellar and parasellar tumors occupy a compact neurovascular region where millimetric differences in extension determine whether an effective dose is deliverable while preserving vision, endocrine function, and hypothalamic and cranial-nerve function. Evidence for choosing among single-fraction stereotactic radiosurgery (SRS), hypofractionated stereotactic radiotherapy in three to five fractions (hfSRT), and conventionally fractionated precision radiotherapy (cfRT) is fragmented, largely retrospective, and heterogeneous in visual and toxicity reporting. This structured narrative review integrates evidence for pituitary neuroendocrine tumors, craniopharyngiomas, and sellar or parasellar meningiomas, prioritizing guidelines, systematic reviews, multicenter cohorts, and studies with quantitative visual outcomes. Indication depends on histology and behavior; modality selection depends on target volume, optic contact, canal involvement, pathway deformation or encasement, temporal stability, previous treatment, and achievable coverage. Single-fraction SRS suits compact, stable targets coverable within organ-at-risk limits; hfSRT can improve deliverability for focal peri-optic interfaces; and broad contact, large or irregular targets, dynamic cystic anatomy, pediatric disease, and complex multi-organ geometry favor cfRT. Automated perimetry and optical coherence tomography (OCT) provide complementary functional and structural measures; isolated OCT change cannot alone diagnose radiation-induced optic neuropathy. We propose an anatomy-based framework weighing target coverage and functional risk together; it synthesizes observational evidence and is not prospectively validated.

Treatment of vestibular schwannomas and meningiomas in NF2-related schwannomatosis (NF2-SWN) requires decisions about individual lesions in patients who may need repeated interventions. This structured narrative review examines how tumor behavior, neurological function, anatomy, previous treatment, and late risk inform stereotactic radiation. We used recent systematic reviews to identify the evidence base, supplemented by targeted MEDLINE/PubMed searches through 24 August 2026, citation tracking, and bibliographic verification. Most radiation evidence comes from retrospective single-fraction stereotactic radiosurgery (SRS) cohorts. Selected vestibular schwannomas show durable control, but hearing preservation declines with follow-up. Meningioma control is generally high, while untreated lesions may progress and require further intervention. Hypofractionated stereotactic radiotherapy is an option when a therapeutic single-fraction plan cannot meet normal-tissue objectives; comparative superiority is unproven. Bevacizumab has prospective hearing-directed evidence for progressive vestibular schwannomas, and brigatinib has demonstrated multitumor activity. Their optimal sequence with local treatment remains undefined. Population-level evidence associates radiation exposure with later malignancy or malignant progression, although individual risk after contemporary SRS is uncertain. We translate these findings into a clinical-scenario matrix: establish the reason for intervention, identify any need for decompression or tissue, compare focal and systemic options, and document the functional objective and reassessment plan. This proposed framework is not a validated guideline. Its practical aim is to support treatment selection and follow-up without equating radiographic control with preserved hearing, vision, or independence.

In peri-optic sellar and parasellar tumors, visual preservation requires protection from both radiation injury and progression of inadequately controlled disease. This structured narrative review synthesizes guidelines, systematic reviews, and clinical cohorts identified through targeted PubMed/MEDLINE searches updated through 22 August 2026, covering pituitary neuroendocrine tumors, craniopharyngiomas, and meningiomas. Predominantly retrospective evidence and inconsistent functional reporting limit comparisons between radiation modalities. We propose an anatomy-based framework integrating therapeutic intent, tumor–optic geometry, achievable target coverage, anatomical stability, prior treatment, and baseline visual and endocrine function. Minimum tumor–optic distance alone is insufficient for modality selection. Single-fraction stereotactic radiosurgery is suited to compact, stable targets when disease-specific coverage is achievable within organ-at-risk limits. Hypofractionated stereotactic radiotherapy in three to five fractions may address focal peri-optic dose conflicts, whereas conventionally fractionated precision radiotherapy may accommodate broad contact, complex geometry, or dynamic cystic disease. Automated perimetry, optical coherence tomography, and axis-specific endocrine assessment support longitudinal surveillance; isolated retinal thinning does not establish radiation-induced optic neuropathy. New functional deficits require assessment of tumor status, treatment chronology, spatial dose, and competing causes. The proposed framework requires prospective validation and provides a practical basis for multidisciplinary decisions that jointly evaluate durable tumor control and long-term functional preservation.