Clinical application of a GPU-accelerated monte carlo dose verification for cyberknife M6 with Iris collimator.

PURPOSE: To apply an independent GPU-accelerated Monte Carlo (MC) dose verification for CyberKnife M6 with Iris collimator and evaluate the dose calculation accuracy of RayTracing (TPS-RT) algorithm and Monte Carlo (TPS-MC) algorithm in the Precision treatment planning system (TPS). METHODS: GPU-accelerated MC algorithm (ArcherQA-CK) was integrated into a commercial dose verification system, ArcherQA, to implement the patient-specific quality assurance in the CyberKnife M6 system. 30 clinical cases (10 cases in head, and 10 cases in chest, and 10 cases in abdomen) were collected in this study. For each case, three different dose calculation methods (TPS-MC, TPS-RT and ArcherQA-CK) were implemented based on the same treatment plan and compared with each other. For evaluation, the 3D global gamma analysis and dose parameters of the target volume and organs at risk (OARs) were analyzed comparatively. RESULTS: For gamma pass rates at the criterion of 2%/2 mm, the results were over 98.0% for TPS-MC vs.TPS-RT, TPS-MC vs. ArcherQA-CK and TPS-RT vs. ArcherQA-CK in head cases, 84.9% for TPS-MC vs.TPS-RT, 98.0% for TPS-MC vs. ArcherQA-CK and 83.3% for TPS-RT vs. ArcherQA-CK in chest cases, 98.2% for TPS-MC vs.TPS-RT, 99.4% for TPS-MC vs. ArcherQA-CK and 94.5% for TPS-RT vs. ArcherQA-CK in abdomen cases. For dose parameters of planning target volume (PTV) in chest cases, the deviations of TPS-RT vs. TPS-MC and ArcherQA-CK vs. TPS-MC had significant difference (P < 0.01), and the deviations of TPS-RT vs. TPS-MC and TPS-RT vs. ArcherQA-CK were similar (P > 0.05). ArcherQA-CK had less calculation time compared with TPS-MC (1.66 min vs. 65.11 min). CONCLUSIONS: Our proposed MC dose engine (ArcherQA-CK) has a high degree of consistency with the Precision TPS-MC algorithm, which can quickly identify the calculation errors of TPS-RT algorithm for some chest cases. ArcherQA-CK can provide accurate patient-specific quality assurance in clinical practice.

A randomised controlled trial of Standard Of Care versus RadioAblaTion in Early Stage HepatoCellular Carcinoma (SOCRATES HCC).

BACKGROUND: Therapeutic options for early-stage hepatocellular carcinoma (HCC) in individual patients can be limited by tumor and location, liver dysfunction and comorbidities. Many patients with early-stage HCC do not receive curative-intent therapies. Stereotactic ablative body radiotherapy (SABR) has emerged as an effective, non-invasive HCC treatment option, however, randomized evidence for SABR in the first line setting is lacking. METHODS: Trans-Tasman Radiation Oncology Group (TROG) 21.07 SOCRATES-HCC is a phase II, prospective, randomised trial comparing SABR to other current standard of care therapies for patients with a solitary HCC ≤ 8 cm, ineligible for surgical resection or transplantation. The study is divided into 2 cohorts. Cohort 1 will compromise 118 patients with tumors ≤ 3 cm eligible for thermal ablation randomly assigned (1:1 ratio) to thermal ablation or SABR. Cohort 2 will comprise 100 patients with tumors > 3 cm up to 8 cm in size, or tumors ≤ 3 cm ineligible for thermal ablation, randomly assigned (1:1 ratio) to SABR or best other standard of care therapy including transarterial therapies. The primary objective is to determine whether SABR results in superior freedom from local progression (FFLP) at 2 years compared to thermal ablation in cohort 1 and compared to best standard of care therapy in cohort 2. Secondary endpoints include progression free survival, overall survival, adverse events, patient reported outcomes and health economic analyses. DISCUSSION: The SOCRATES-HCC study will provide the first randomized, multicentre evaluation of the efficacy, safety and cost effectiveness of SABR versus other standard of care therapies in the first line treatment of unresectable, early-stage HCC. It is a broad, multicentre collaboration between hepatology, interventional radiology and radiation oncology groups around Australia, coordinated by TROG Cancer Research. TRIAL REGISTRATION: anzctr.org.au, ACTRN12621001444875, registered 21 October 2021.

Protocol for a systematic review with prospective individual patient data meta-analysis in EGFR-mutant NSCLC with brain metastases to assess the effect of SRS+osimertinib compared to osimertinib alone: the STARLET Collaboration.

BACKGROUND: Patients with advanced non-small-cell lung cancer (NSCLC) with activating mutations in the epidermal growth factor receptor (EGFR) gene are a heterogeneous population who often develop brain metastases (BM). The optimal management of patients with asymptomatic brain metastases is unclear given the activity of newer-generation targeted therapies in the central nervous system. We present a protocol for an individual patient data (IPD) prospective meta-analysis to evaluate whether the addition of stereotactic radiosurgery (SRS) before osimertinib treatment will lead to better control of intracranial metastatic disease. This is a clinically relevant question that will inform practice. METHODS: Randomised controlled trials will be eligible if they include participants with BM arising from EGFR-mutant NSCLC and suitable to receive osimertinib both in the first-line and second-line settings (P); comparisons of SRS followed by osimertinib versus osimertinib alone (I, C) and intracranial disease control included as an endpoint (O). Systematic searches of Medline (Ovid), Embase (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL (EBSCO), PsychInfo, ClinicalTrials.gov and the WHO's International Clinical Trials Registry Platform's Search Portal will be undertaken. An IPD meta-analysis will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome is intracranial progression-free survival, as determined by response assessment in neuro-oncology-BM criteria. Secondary outcomes include overall survival, time to whole brain radiotherapy, quality of life, and adverse events of special interest. Effect differences will be explored among prespecified subgroups. ETHICS AND DISSEMINATION: Approved by each trial's ethics committee. Results will be relevant to clinicians, researchers, policymakers and patients, and will be disseminated via publications, presentations and media releases. PROSPERO REGISTRATION: CRD42022330532.

Letter to Editor: Cystic vestibular schwannoma - a subgroup analysis from a comparative study between radiosurgery and microsurgery.

This letter evaluates the recent study on the management of cystic vestibular schwannomas (VS) compared to solid VS, focusing on the clinical outcomes of surgery (SURGERY) and radiosurgery (SRS). The study offers significant insights into the differences between these tumor types, emphasizing the challenges posed by cystic VS, including rapid growth, enhanced peritumoral adhesion, and worse post-operative facial nerve outcomes. Notably, cystic VS are associated with higher recurrence rates and poorer preoperative status. The study also highlights lower gross total resection (GTR) rates and poorer long-term tumor control in cystic VS. While SRS shows high rates of functional preservation, it is less effective in ensuring recurrence-free survival in cystic VS compared to solid VS, suggesting surgery may be preferable for achieving the best long-term outcomes, particularly when safe maximal resection is possible. However, the study's retrospective design and limited sample size, along with the lack of standardized follow-up protocols, may impact the generalizability of the findings. Future research should focus on prospective, multicenter studies with standardized protocols to develop evidence-based guidelines for managing cystic VS. Innovative techniques, such as advanced imaging and minimally invasive surgical approaches, may further improve diagnostic accuracy and treatment efficacy. This study underscores the complexities of managing cystic VS and the need for tailored treatment strategies.

Serplulimab combined with gemcitabine, nab-paclitaxel and stereotactic body radiotherapy as the first-line treatment for patients with metastatic pancreatic adenocarcinoma in China: a multicentre, single-arm, phase II trial (ICSBR) protocol.

INTRODUCTION: Patients with pancreatic ductal adenocarcinoma (PDAC) remain a poor prognosis despite the development of chemotherapy. Although programmed cell death 1 (PD-1) blockade has shown great efficacy in various solid tumours, its application in treating PDAC is limited. Recent studies have indicated that chemotherapy or stereotactic body radiotherapy (SBRT) may improve the antitumour effect of PD-1 blockade in patients with PDAC. The objective of this study is to evaluate the efficacy and safety of combined therapy comprising PD-1 blockade, gemcitabine plus nab-paclitaxel chemotherapy and SBRT for patients with metastatic PDAC. METHODS AND ANALYSIS: This is a multicentre, single-arm, prospective phase II clinical trial. Forty-three patients diagnosed with metastatic PDAC will be enrolled. The eligible patients will be intravenously administered 1000 mg/m2 gemcitabine and 125 mg/m2 nab-paclitaxel on days 1 and 8 of the 21-day cycle. Serplulimab (200 mg) will be administered intravenously on day 1 of the 21-day cycle. Furthermore, during the second cycle, the patients will undergo SBRT with doses of 33 Gy in five fractions for primary lesions or doses of 24 Gy in three fractions for metastases. The primary endpoint is the 6-month progression-free survival (PFS) rate. The secondary endpoints overall survival, PFS, overall response rate, disease control rate, time to progression, duration of response, duration of disease control and safety. Moreover, this trial seeks to investigate biomarkers such as circulating tumour DNA and circulating hybrid cells in patients diagnosed with metastatic PDAC. ETHICS AND DISSEMINATION: The study was approved by the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University. The study results will be presented at international conferences and published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ChiCTR2300073237.

Quantitative assessment of intertarget position variations based on 4D-CT and 4D-CBCT simulations in single-isocenter multitarget lung stereotactic body radiation therapy.

BACKGROUND: In single-isocenter multitarget stereotactic body radiotherapy (SBRT), geometric miss risks arise from uncertainties in intertarget position. However, its assessment is inadequate, and may be interfered by the reconstructed tumor position errors (RPEs) during simulated CT and cone beam CT (CBCT) acquisition. This study aimed to quantify intertarget position variations and assess factors influencing it. METHODS: We analyzed data from 14 patients with 100 tumor pairs treated with single-isocenter SBRT. Intertarget position variation was measured using 4D-CT simulation to assess the intertarget position variations (ΔD) during routine treatment process. Additionally, a homologous 4D-CBCT simulation provided RPE-free comparison to determine the impact of RPEs, and isolating purely tumor motion induced ΔD to evaluate potential contributing factors. RESULTS: The median ΔD was 4.3 mm (4D-CT) and 3.4 mm (4D-CBCT). Variations exceeding 5 mm and 10 mm were observed in 31.1% and 5.5% (4D-CT) and 20.4% and 3.4% (4D-CBCT) of fractions, respectively. RPEs necessitated an additional 1-2 mm safety margin. Intertarget distance and breathing amplitude variability showed weak correlations with variation (Rs = 0.33 and 0.31). The ΔD differed significantly by locations (upper vs. lower lobe and right vs. Left lung). Notably, left lung tumor pairs exhibited the highest risk. CONCLUSIONS: This study provide a reliable way to assess intertarget position variation by using both 4D-CT and 4D-CBCT simulation. Consequently, single-isocenter SBRT for multiple lung tumors carries high risk of geometric miss. Tumor motion and RPE constitute a substantial portion of intertarget position variation, requiring correspondent strategies to minimize the intertarget uncertainties.

Local-Regional Therapy for Oligometastatic Colorectal Cancer.

ABSTRACT: Colorectal cancer is one of the most common malignancies in the United States as well as a leading cause of cancer-related death. Upward of 30% of patients ultimately develop metastatic disease, most commonly to the liver and lung. Untreated, patients have poor survival. Historically, patients with oligometastatic disease were treated with resection leading to long-term survival; however, there are many patients who are not surgical candidates. Innovations in thermal ablation, hepatic artery infusions, chemoembolization and radioembolization, and stereotactic ablative radiation have led to an expansion of patients eligible for local therapy. This review examines the evidence behind each modality for the most common locations of oligometastatic colorectal cancer.

Assessment of imaging risks for recurrence after stereotactic radiosurgery for brain metastases (IRRaS-BM).

BACKGROUND: The identification of viable tumors and radiation necrosis after stereotactic radiosurgery (SRS) is crucial for patient management. Tumor habitat analysis involving the grouping of similar voxels can identify subregions that share common biology and enable the depiction of areas of tumor recurrence and treatment-induced change. This study aims to validate an imaging biomarker for tumor recurrence after SRS for brain metastasis by conducting tumor habitat analysis using multi-parametric MRI. METHODS: In this prospective study (NCT05868928), patients with brain metastases will undergo multi-parametric MRI before SRS, and then follow-up MRIs will be conducted every 3 months until 24 months after SRS. The multi-parametric MRI protocol will include T2-weighted and contrast-enhanced T1-weighted imaging, diffusion-weighted imaging, and dynamic susceptibility contrast imaging. Using k-means voxel-wise clustering, this study will define three structural MRI habitats (enhancing, solid low-enhancing, and nonviable) on T1- and T2-weighted images and three physiologic MRI habitats (hypervascular cellular, hypovascular cellular, and nonviable) on apparent diffusion coefficient maps and cerebral blood volume maps. Using RANO-BM criteria as the reference standard, via Cox proportional hazards analysis, the study will prospectively evaluate associations between parameters of the tumor habitats and the time to recurrence. The DICE similarity coefficients between the recurrence site and tumor habitats will be calculated. DISCUSSION: The tumor habitat analysis will provide an objective and reliable measure for assessing tumor recurrence from brain metastasis following SRS. By identifying subregions for local recurrence, our study could guide the next therapeutic targets for patients after SRS. TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT05868928).

Radiotherapy for subependymal giant cell astrocytoma: time to challenge a historical ban? A case report and review of the literature.

BACKGROUND: Subependymal giant cell astrocytoma is a benign brain tumor that occurs in patients with tuberous sclerosis complex. Surgical removal is the traditional treatment, and expert opinion is strongly against the use of radiotherapy. Recently, success has been reported with the mTor inhibitor everolimus in reducing tumor volume, but regrowth has been observed after dose reduction or cessation. CASE REPORT: We present the case of a 40-year-old Asian female patient treated successfully for growing bilateral subependymal giant cell astrocytoma with fractionated stereotactic radiotherapy before everolimus became available. After a follow-up of 8 years, everolimus was administered for renal angiomyolipoma and the patient was followed up until 13 years after radiotherapy. Successive magnetic resonance imaging demonstrated an 80% volume reduction after radiotherapy that increased to 90% with everolimus. A review of the literature was done leveraging Medline via PubMed, and we assembled a database of 1298 article references and 780 full-text articles in search of evidence for contraindicating radiotherapy in subependymal giant cell astrocytoma. Varying results of single-fraction radiosurgery were described in a total of 13 cases. Only in two published cases was the radiation dose of fractionated radiotherapy mentioned. One single publication mentions an induced secondary brain tumor 8 years after whole-brain radiotherapy. CONCLUSION: There is no evidence of contraindication and exclusion of fractionated radiotherapy in treating subependymal giant cell astrocytoma. Our experience demonstrates that subependymal giant cell astrocytoma, as other benign intracranial tumors, responds slowly but progressively to radiotherapy and suggests that fractionated stereotactic radiotherapy holds promise to consolidate responses obtained with mTor inhibitors avoiding regrowth after cessation.

Subtotal resection of vestibular schwannoma with subsequent Gamma Knife irradiation - tumor growth control, facial and cochlear nerve outcome - preliminary results.

<b>Introduction:</b> The choice of treatment of vestibular schwannoma (VS) depends on several factors, including the tumor size, the patient's age and overall health, and the presence and severity of symptoms.<b>Aim:</b> The aim of the study was to assess the effectiveness of intentional subtotal resection (STR) of tumor followed by Gamma Knife surgery (GKS) in patients with larger VS (Koos 3 and 4).<b>Materials and methods:</b> The retrospective analysis was performed on 18 patients. Data of VS volumes measured in MRI, the facial nerve function assessed in the House-Brackmann scoring system (HB), and the results of audiological examination expressed on the Gardner-Robertson scale (GR) were collected preoperatively, postoperatively, and post-GKS.<b>Results:</b> Preoperatively, the main symptom was hearing loss observed in 13 out of 18 patients. The facial nerve function was assessed as HB 1 in 16, whereas HB 2 in 2 patients. The mean volume of the tumor in the initial MRI amounted to 16.81 cm³ . Postoperatively, the facial nerve was assessed as HB 1 or 2 in 16, whereas HB 3 in 2 patients. Serviceable hearing was presented by only 4 persons. The Mean diameter of the tumor after subtotal surgery amounted to 3.16 cm³ , 1.83 cm³ after GKS, and 1.58 cm³ at the last follow-up. The facial nerve function and hearing level remained the same as before GKS in all patients.<b>Conclusions:</b> STR followed by GKS can be a safe and effective method of treatment of large VS concerning the functional outcome of the facial nerve and the tumor volume growth control.

Audit of Presentation, Primary Site, and Pattern of Treatment in 778 Indian Patients with Brain Metastasis in 15 Years (2007-2022).

BACKGROUND AND AIM: Audit of brain metastasis (BM) patients treated with radiation therapy (RT) in a tertiary cancer center from South India was carried out to assess the incidence of BM by site with a specific focus on their primary origin, with an aim to evaluate the relationship between the primary site and the site of metastases, pattern of care, and RT over the years. MATERIALS AND METHODS: All consecutive BM patients who received RT with whole-brain radiation therapy (WBRT), hippocampal avoidance WBRT (HA-WBRT), and radiosurgery SRS between 2007 and 2022 after radiologic confirmation of a known case of malignancy or histology-proven BM were audited. RESULTS: From January 2007 to December 2022, hospital information system (HIS)-identified 778 patients with BM treated with RT were audited. Incidence of BM was 0.64% in 2008 and over the years, it had increased to 0.89% in 2020, 0.93% in 2021, and 1.24% in 2022. Usage of SRS was almost nil in 2007, whereas in 2022, it was 40%. Also, 593 (76%) patients were treated with WBRT, 157 (20%) with SRS, and only 23 (3%) received HA-WBRT. Lung and breast cancers (40%) were the most common primary, and among rare primary tumors were those of larynx (two), tonsil (one), tongue (three), pancreas (one), and blood disorders (two). Lung primary presented with frontal lesion in 51%, parietal lesion in 43%, cerebellar lesion in 38%, and temporal lesion in 33% of cases. CONCLUSIONS: Audit of BM in the Indian population suggests a shift in treatment paradigm from WBRT to SRS as a primary modality in oligo-brain metastasis with a good performance status. This audit provides us information regarding geographic variation in presentation and primary site.

Stereotactic body radiation therapy for multiple lung cancers in a patient with six primary cancers: a case report.

BACKGROUND: Surgery is the standard care for patients with early-stage lung cancer, and stereotactic body radiation therapy is an option for those who are medically inoperable or refuse surgery. Medical developments in diagnostic and therapeutic strategies would prolong prognosis of patients with cancer. The number of patients with multiple cancers has also increased. Duplex primary malignant neoplasms are the most common, and triple or more primary malignant neoplasms were extremely rare. This is the first case of sextuple primary malignant neoplasms with lung cancer. CASE PRESENTATION: We report a case of two courses of stereotactic body radiation therapy for an 88-year-old Japanese male patient with six primary cancers in five organs. Cancers were detected in the thyroid, prostate, esophagus, bladder, and lungs. He also had a history of angina pectoris and had undergone percutaneous coronary intervention. Although he was capable of undergoing surgery for lung cancers, he refused it because he had experienced many invasive treatments, such as surgeries and percutaneous coronary intervention. In January 2020, the first stereotactic body radiation therapy was performed for the adenocarcinoma in the right lung. In March 2022, the second stereotactic body radiation therapy was performed for the nodule of the left lung. Although he complained of mild dyspnea after the first stereotactic body radiation therapy, we did not use steroids because his peripheral oxygen saturation was within the normal range. He had pleural effusion, cardiac dilatation, and pericardial effusion 2 months after the second stereotactic body radiation therapy, which improved with the use of compression stockings. CONCLUSION: A total of 43 and 17 months have passed since the first and second stereotactic body radiation therapy, respectively, there is no local recurrence and the patient can walk independently. We safely performed stereotactic body radiation therapy twice for our older patient with metachronous early-stage lung cancers. If another new tumor is detected, stereotactic body radiation therapy would be a good treatment option for the functional preservation of organs.

Proteomics shows that brain metastases of lung adenocarcinoma overexpress ribosomal proteins in response to gamma knife radiosurgery.

Gamma knife radiosurgery (GKRS) is recommended as the first-line treatment for brain metastases of lung adenocarcinoma (LUAD) in many guidelines, but its specific mechanism is unclear. We aimed to study the changes in the proteome of brain metastases of LUAD in response to the hyperacute phase of GKRS and further explore the mechanism of differentially expressed proteins (DEPs). Cancer tissues were collected from a clinical trial for neoadjuvant stereotactic radiosurgery before surgical resection of large brain metastases (ChiCTR2000038995). Five brain metastasis tissues of LUAD were collected within 24 h after GKRS. Five brain metastasis tissues without radiotherapy were collected as control samples. Proteomics analysis showed that 163 proteins were upregulated and 25 proteins were downregulated. GO and KEGG enrichment analyses showed that the DEPs were closely related to ribosomes. Fifty-three of 70 ribosomal proteins were significantly overexpressed, while none of them were underexpressed. The risk score constructed from 7 upregulated ribosomal proteins (RPL4, RPS19, RPS16, RPLP0, RPS2, RPS26 and RPS25) was an independent risk factor for the survival time of LUAD patients. Overexpression of ribosomal proteins may represent a desperate response to lethal radiotherapy. We propose that targeted inhibition of these ribosomal proteins may enhance the efficacy of GKRS.

Comparative analysis of upfront stereotactic radiosurgery and watchful waiting in the management of newly diagnosed vestibular schwannomas: a systematic review and meta-analysis.

Vestibular schwannomas (VS) are benign intracranial tumors posing significant management challenges. This study aims to compare the outcomes of stereotactic radiosurgery (SRS) and watchful waiting (WW) in the management of newly diagnosed VS, integrating findings from both retrospective and the pioneering V-REX prospective trial. Adhering to PRISMA guidelines, a systematic review was conducted using MEDLINE, Embase, and Cochrane databases. Studies directly comparing SRS with WW for newly diagnosed VS were included. Primary outcomes focused on hearing preservation assessed through the AAO-HNS or Gardner-Robertson hearing classification scales and tumor progression, with secondary outcomes focusing on neurological symptoms, and the need for further treatment. Thirteen studies encompassing 1,635 patients (WW: 891; SRS: 744) were included.While no significant difference was found in serviceable hearing loss at last follow-up (RR = 1.51, [95%CI: 0.98, 2.32], p = 0.06), significant differences favoring WW were observed in pure tone audiometry (PTA) (MD = -13.51 [95%CI: -22.66, -4.37], p = 0.004) and word recognition score (WRS) (MD = 20.48 [95%CI: 9.72, 31.25], p = 0.0002). Analysis of tumor progression indicated no overall significant difference in risk between SRS and WW (RR = 0.40, [95%CI 0.07, 2.40], p = 0.32), but subgroup analysis suggested a lower risk with SRS in certain contexts. The need for further treatments favored SRS (RR = 0.24, [95%CI: 0.07, 0.74], p = 0.007). No significant differences were found in tinnitus and imbalance between the two groups. This comprehensive analysis suggests no marked difference in functional hearing preservation between SRS and WW in managing VS. However, untreated tumors commonly necessitate additional interventions. These findings highlight the need for individualized treatment decisions and underscore the importance of continued monitoring. The study advocates for further prospective trials to refine management strategies for VS.

Stereotactic radiosurgery for intraventricular meningioma: a systematic review and meta-analysis.

BACKGROUND: Intraventricular meningioma (IVM) is a rare subtype of intracranial meningioma, accounting for 9.8 to 14% of all intraventricular tumors. Currently, there is no clear consensus on which patients with IVM should receive conservative treatment, surgery, or stereotactic radiosurgery (SRS). This research aims to analyze the outcomes, including survival and recurrence rates of patients who undergo SRS for IVM as a primary or adjuvant treatment. METHODS: A systematic search was conducted in Scopus, Web of Science, PubMed, and Embase till June 5th 2023. Screening and data extraction were performed by two independent authors. Random-effect meta-analysis was performed to determine the tumor control proportion of IVM cases treated with SRS. Individual patient data (IPD) meta-analysis was performed for the progression-free survival (PFS) of the patients in the follow-up time. All analyses were performed using the R programming language. RESULTS: Out of the overall 132 records, 14 were included in our study, of which only 7 had enough data for the meta-analysis. The tumor control proportion was 0.92 (95% CI, 0.69-0.98) in patients who underwent SRS for primary IVM. The overall tumor control in both primary and adjuvant cases was 0.87 (95% CI, 0.34-0.99). the heterogeneity was not significant in both meta-analyses (P = 0.73 and P = 0.92, respectively). Post-SRS perifocal edema occurred in 16 out of 71 cases (0.16; 95% CI, 0.03-0.56), with no significant heterogeneity (P = 0.32). IPD meta-analysis showed a PFS of 94.70% in a 2-year follow-up. Log-rank test showed better PFS in primary SRS compared to adjuvant SRS (P < 0.01). CONCLUSIONS: According to this study, patients with IVM can achieve high rates of tumor control with a low risk of complications when treated with SRS, regardless of whether they have received prior treatment. Although SRS could be a promising first-line treatment option for asymptomatic IVM, its efficacy in symptomatic patients and its comparison with resection require further investigation.

Stereotactic radiosurgery versus combined stereotactic radiosurgery and bevacizumab for recurrent glioblastoma; a systematic review and meta-analysis of survival.

Recurrent glioblastoma (rGBM) is a brain tumor that is resistant to standard treatments. Although stereotactic radiosurgery (SRS) is a non-invasive radiation technique, it cannot fully prevent tumor recurrence and progression. Bevacizumab blocks tumor blood supply and has been approved for rGBM. However, the best way to combine SRS and bevacizumab is still unclear. We did a systematic review and meta-analysis of studies comparing SRS alone and SRS plus bevacizumab for rGBM. We searched three databases for articles published until June 2023. All statistical analysis was performed by STATA v.17. Our meta-analysis included 20 studies with 926 patients. We found that the combination therapy had a significantly lower rate of overall survival (OS) than SRS alone at 6-month 0.77[95%CI:0.74-0.85] for SRS alone and (100%) for SRS plus bevacizumab. At 1-year OS, 0.39 [95%CI: 0.32-0.47] for SRS alone and 0.61 [95%CI:0.44-0.77] for SRS plus bevacizumab (P-value:0.02). However, this advantage was not seen in the long term (18 months and two years). Additionally, the combination therapy had lower chances of progression-free survival (PFS) than SRS alone at the 6-month and 1-year time points, but the differences were insignificant. Our study indicates that incorporating bevacizumab with SRS may lead to a short-term increase in OS for rGBM patients but not long-term. Additionally, the PFS rate did not show significant improvement in the group receiving combination therapy. Further clinical trials are necessary to validate the enhanced overall survival with combination therapy for rGBM.

[Malignant Transformation of Benign Meningiomas with or without Radiotherapy].

Most meningiomas are benign, slow growing tumors, which rarely progress to a higher grade. The incidence rate of malignant progression is estimated to be 2.98/1000 patient-year. However, non-skull base location is a significant risk factor for progression. The median time to malignant progression is 4.3 years; however, the cumulative rate of progression approaches a plateau after 10 years. Although radiosurgery does not appear to increase the incidence rate(0.5/1000 patient-year), exact comparisons have been difficult because of differences in study populations. The median time to progression is 7.0 years from initial diagnosis and 5.0 years from radiosurgery. The cumulative rate appears to increase even after 10 years. The risk of malignant transformation after radiotherapy may increase in patients with tumor-prone syndromes, with some controversies regarding patients with neurofibromatosis type 2. Although short term follow-up in patients with meningioma suggests that radiosurgery is safe, there is uncertainty regarding its use in pediatric patients, and those with tumor-prone syndromes.