Hypofractionated Gamma Knife Radiosurgery: Institutional Experience on Benign and Malignant Intracranial Tumors

Abstract

Background/Aim: We investigated the treatment outcomes and complications associated with hypofractionated GKRS for the treatment of benign and malignant intracranial tumors. Patients and Methods: Patients with intracranial tumors not candidate or refusing surgery were evaluated to assess eligibility to undergo hypofractionated Gamma Knife radiosurgery (GKRS). Targeted volumes were calculated using the GammaPlan ® workstation, and GKRS protocols were delivered with 3 or 5 daily fractions and a maximal total dose of 25 Gy. The thermoplastic mask was used to immobilize the patient's head without pin-based fixation frames. Results: A total of 41 patients, affected with 6 different histologies, were treated and followed-up for a median of 12 months (range=4-24 months). Meningiomas were the most common tumors (33, 80.5%), followed by brain metastases (4, 9.7%). At last follow-up, 33 patients (80.5%) had stable disease, 8 tumor regression (19.5%), and 0 tumor progression. No acute radiation toxicity was observed. Death was reported in 3 patients (7.3%) due to malignant tumor progression. Conclusion: Our hypofractionated GKRS protocol proved to be effective and safe in the treatment of patients with benign and malignant intracranial tumors. Local tumor control was achieved in all patients, with 8 patients showing tumor regression and no cases of acute radiation toxicity.

Somatostatin Receptor Targeted PET-Imaging for Diagnosis, Radiotherapy Planning and Theranostics of Meningiomas: A Systematic Review of the Literature

“…Stereotactic radiosurgery (SRS) has been applied, with satisfying clinical results, for the management of high-risk and recurrent meningiomas [ 42 ]. The precise definition of target volume as well as the determination of the boundaries of organ at risk (OARs) is of utmost importance in planning SRS.…”

The Role of [68Ga]Ga-DOTA-SSTR PET Radiotracers in Brain Tumors: A Systematic Review of the Literature and Ongoing Clinical Trials

“…Accurate tumor volume contouring and target definition are of vital importance for optimizing the planning of surgical resection and radiotherapy protocols. This is especially true in recurrent tumors, such as malignant meningiomas or pituitary carcinomas, characterized by aggressive invasive growth patterns, which often require high doses of radiation, and by post-treatment changes, which may pose some challenges in the delineation of target volumes using morphological imaging studies [ 96 , 97 , 98 , 99 ]. In addition, skull base meningiomas are frequently difficult to contour at contrast-MRI and/or CT, as the degree of bone/dura infiltration may be underestimated.…”

Neoadjuvant Stereotactic Radiotherapy for Brain Metastases: Systematic Review and Meta-Analysis of the Literature and Ongoing Clinical Trials

“…Later, randomized clinical trials observed that surgery prior to WBRT correlated with significant OS improvement compared to WBRT alone [ 49 ], and with significantly lower rates of intracranial failure than surgery alone [ 6 ]. Owing to the adverse events related to surgery, namely brain tissue manipulation with injury to the functional cortex and white matter tracts, and WBRT, namely neurotoxicity with neurocognitive impairment, SRS gained increasing interest as stand-alone or adjunct therapy for 1–3 BMs [ 50 , 51 , 52 ]. As large BMs (>3 cm) causing intracranial hypertension with neurological deficits requiring surgery, adjuvant SRS to the postoperative cavity has been largely investigated, with 1-year LC rates ranging 70–90% and variable OS achieved across several retrospective cohorts [ 53 ].…”

“…Similarly to adjuvant SRS, hypofractionated and single-fraction NaSRS are both favorable for small-sized lesions (< 3–5 cm 3 ). Despite the limited available data on hypofractionated adjuvant SRS compared to standard single-session adjuvant SRS for BMs, previous studies have suggested that hypofractionated SRS may correlate with lower risks of radiation-related complications to the healthy brain tissue surrounding the targeted lesions [ 50 , 51 , 52 ]. However, a pitfall of performing hypofractionated NaSRS compared to single-session NaSRS comprises the requirement to have the patients undergo more than one radiotherapy session.…”