Gamma Knife radiosurgery as a treatment modality for low-grade pediatric brainstem gliomas: report of two cases

Gamma knife radiosurgery as an efficacious treatment for paediatric central nervous system tumours: a retrospective study of 61 neoplasms

PURPOSE

Brain tumours have an incidence of 1.15 to 5.14 cases per 100,000 children and are associated with significant morbidity and mortality. Radiosurgery has become a promising approach to manage these paediatric CNS tumours. The aim of the present study was to analyse the efficacy of radiosurgery in the treatment of a variety of paediatric tumours of CNS.

METHODS

This retrospective study was conducted from 1997 to 2012 at a single Neurosurgery centre. All paediatric patients (≤ 18 years of age) with CNS tumours who were treated with gamma knife radiosurgery (GKRS) and had a minimum follow up of 6 months were included in the study. Patients with lesions other than tumours were excluded. Clinical, radiological and GKRS planning data was collected and analysed in all patients.

RESULTS

A total of 76 children with brain tumours had GKRS during the study period. Of these, 40 children (with 61 neoplasms) had follow-up available and were included in the study. The mean age was 16 years (6-18 years). Seventeen patients received primary GKRS, 20 patients received secondary, and 3 patients received both. The median tumour volume was 3.3 cm³ (0.14-38.9 cm3). The mean dose was 12.56 Gy at 50% isodose line. The majority of the tumours were meningioma (n = 20) followed by acoustic schwannoma (n = 17). The mean treatment time was 67.04 min. Thirty-three tumours responded favourably to GKRS, 24 showed a stable size, 3 had no response while 1 progressed, requiring surgery.

CONCLUSION

GKRS has the potential to become an indispensable tool in the management of paediatric brain neoplasms.

Cervicomedullary Gliomas in Pediatric Age: A Systematic Review of the Literature and Tertiary Care Center Experience

INTRODUCTION

Cervicomedullary gliomas (CMGs) are usually low-grade tumors often found in the pediatric age. Histological findings, treatments, and classification have been much the same for 40 years, although histological and molecular classifications have largely been developed for other pediatric CNS tumors. The management and treatment of pediatric CMG are still conducted by many authors according to their anatomical location and characteristics, independently from histology.

METHODS

We conducted a literature review in PubMed (Medline) to identify relevant contributions about pediatric CMG published until December 31, 2021. We also analyzed a series of 10 patients with CMG treated from 2006 to 2021 at IRCCS Istituto Nazionale dei Tumori. The aim of the present review was to see whether and how the diagnosis, treatment, and classification of CMGs in children have developed over time, especially in the context of molecular advancements, and to analyze our single-center experience in the last 15 years.

RESULTS

Thirty articles have been included in the review. Articles have been divided into two historical periods (1981-2000 and 2001-2021) and data from different series were analyzed to see how much the management and treatment of pediatric CMG have changed during years. Analysis of our series of 10 patients affected by CMG was also performed to compare it with the literature.

DISCUSSION

Management and classification of CMG in children have not dramatically changed during years. However, new insight from molecular diagnostics and target therapies and the development of radiological, neurophysiological, and radiotherapy techniques have updated treatment modalities in the last 20 years. Treatment modalities and their innovations have been reviewed and discussed. Further studies are needed to standardize and customize treatment protocols for these tumors.

Gamma Knife radiosurgery as primary treatment of low-grade brainstem gliomas: A systematic review and metanalysis of current evidence and predictive factors

The current standard of care for surgically inaccessible low-grade brainstem gliomas (BS-LLGs) is external-beam radiotherapy (RT). Developments toward more innovative conformal techniques have focused on decreasing morbidity, by limiting radiation to surrounding tissues. Among these Gamma Knife radiosurgery (SRS-GK) has recently gained an increasingly important role in the treatment of these tumors. Although SRS-GK has not yet been compared with conventional RT in patients harboring focal BS-LGGs, clinical practice has been deeply influenced by trials performed on other tumors. This is the first meta-analysis on the topic, systematically reviewing the most relevant available evidence, comparing RT and SRS-GK as primary treatments of BS-LGGs, focusing on survival, clinical outcome, oncological control, and complications. Predictive factors have been systematically evaluated and analyzed according to statistical significance and clinical relevance.

The Epidemiological Characteristics and Prognostic Factors of Low-Grade Brainstem Glioma: A Real-World Study of Pediatric and Adult Patients

Purpose: Our current understanding of low-grade brainstem glioma (LGBSG) is still limited. This study aimed to conduct a large-scale population-based real-world study to understand the epidemiological characteristics of LGBSG and determine the predictive factors of cancer-specific survival (CSS) and overall survival (OS) of LGBSG patients.

Patients and Methods: We used Surveillance Epidemiology and End Results database to conduct this study of patients with histologically confirmed LGBSG. Patient demographics, tumor characteristics, and treatment options were compared between pediatric and adult patients. Univariate and multivariate analyses were employed to determine prognostic factors of CSS and OS. Kaplan–Meier curve and decision tree were used to confirm the prognostic factors. All variables were further identified by L1-penalized (Lasso) regression and then a nomogram was established to predict the 5- and 8-year CSS and OS rate. The precision of the nomogram was evaluated by calibration plots, Harrell's concordance index, and time-dependent receiver operating characteristic curve. The clinical use of nomogram was estimated by decision curve analysis.

Results: A cohort of 305 patients with LGBSG, including 165 pediatric and 140 adult patients, was analyzed. Adult and pediatric patients showed different patterns concerning tumor size, tumor extension, adjuvant therapy, and survival rate. Univariate analysis revealed that pediatric group, gross total resection (GTR), World Health Organization grade II, radiotherapy, extension to ventricular system, and diffuse astrocytic and oligodendroglial tumor (DAOT) were significantly associated with CSS. Multivariate analysis showed that pediatric group, metastasis, ventricular system involvement, and DAOT were independently associated with CSS. The prognostic factors were further confirmed by Kaplan–Meier curve and decision tree. Kaplan–Meier curve also showed that adjuvant therapy added no benefits in patients with GTR and non-GTR. In addition, the nomogram was developed and the C-index of internal validation for CSS was 0.87 (95% CI, 0.78–0.96).

Conclusion: This study shows that pediatric and adult patients have different tumor characteristics, treatment options, and survival rate. Pediatric group, DAOT, ventricular system involvement, and metastasis were identified as independent prognostic factors for CSS by multivariate analysis. Adjuvant therapy showed no benefits on CSS in patients with GTR and non-GTR. The nomogram was discriminative and clinically useful.

Rotating Gamma System Irradiation: A Promising Treatment for Low-grade Brainstem Gliomas

AIM

To evaluate the role of rotating gamma system (RGS) radiosurgery for low-grade brainstem gliomas.

PATIENTS AND METHODS

Thirty-seven patients undergoing RGS radiosurgery at the Bach Mai Hospital Hanoi for low-grade brainstem glioma were included in this prospective interventional study. The median RGS dose was 12 Gy (range=8-16 Gy). Endpoints included response to RGS radiosurgery given as change in glioma size (maximum diameter), survival and adverse events. Follow-up was performed for 36 months. Three dose-groups (<13, 13-14 and >14 Gy) were compared for survival.

RESULTS

Mean glioma size decreased from 1.87 cm before RGS irradiation to 1.15 cm at 36 months. Mean survival was 39.5 months. Mean survival after <13, 13-14 and >14 Gy were 22.7, 66.7 and 49 months, respectively (p<0.05). Adverse events, mainly reduced appetite, sleep disturbances, headache and edema, were not associated with RGS dose and were easily managed.

CONCLUSION

RGS radiosurgery led to promising results with acceptable toxicity in patients with low-grade brainstem gliomas.

Gamma Knife Radiosurgery for Low-Grade Gliomas: Clinical Results at Long-Term Follow-Up of Tumor Control and Patients' Quality of Life

OBJECTIVE

First-line therapy for low-grade gliomas (LGGs) is surgery, in some cases followed by radiotherapy and chemotherapy. Gamma Knife radiosurgery (GKRS) has gained more relevance in the management of these tumors. The aim of this study was to assess efficacy and safety of GKRS for treatment of LGGs.

METHODS

Between 2001 and 2014, 42 treatments were performed on 39 patients harboring LGGs; 48% of patients underwent previous surgery, and 20.5% underwent previous radiotherapy. Mean tumor volume was 2.7 cm³, and median margin dose was 15 Gy.

RESULTS

Mean follow-up was 60.5 months (range, 6-164 months). Actuarial progression-free survival was 74.9%, 52.8%, and 39.1% at 1 year, 5 years, and 10 years; actuarial overall survival was 97.4%, 94.6%, and 91.8% at 9 months, 1 year, and 5 years. Solid tumor control was achieved in 69.2% of patients, whereas cystic enlargement was recorded in 12.9% of cases. At last follow-up, volume reduction was recorded in 57.7% of cases, and median volume decreased by 33.3%. Clinical improvement was observed in 52.4% of patients. Karnofsky performance scale score was improved in 15 patients (45.5%), unchanged in 17 patients (51.5%), and worsened in 1 patient (3%). Mean posttreatment scores of 36-item short form health survey domains did not significantly differ from scores in a healthy Italian population.

CONCLUSIONS

This study confirms safety and effectiveness of GKRS for LGGs in controlling tumor growth, relevantly improving patients' overall and progression-free survival. GKRS improved patients' functional performance and quality of life, optimizing social functioning and minimizing disease-related psychological impact.

Management and outcome of focal low-grade brainstem tumors in pediatric patients: the St. Jude experience

OBJECT

Whereas diffuse intrinsic pontine gliomas generally have a short symptom duration and more cranial nerve involvement, focal brainstem gliomas are commonly low grade, with fewer cranial neuropathies. Although these phenotypic distinctions are not absolute predictors of outcome, they do demonstrate correlation in most cases. Because there is a limited literature on focal brainstem gliomas in pediatric patients, the objective of this paper was to report the management and outcome of these tumors.

METHODS

The authors reviewed the records of all children diagnosed with radiographically confirmed low-grade focal brainstem gliomas from 1986 to 2010. Each patient underwent biopsy or resection for tissue diagnosis. Event-free survival (EFS) and overall survival were evaluated. Univariate analysis was conducted to identify demographic and treatment variables that may affect EFS.

RESULTS

Fifty-two patients (20 girls, 32 boys) with follow-up data were identified. Median follow-up was 10.0 years, and the median age at diagnosis was 6.5 years (range 1-17 years). The tumor locations were midbrain (n = 22, 42%), pons (n = 15, 29%), and medulla (n = 15, 29%). Surgical extirpation was the primary treatment in 25 patients (48%). The 5- and 10-year EFS and overall survival were 59%/98% and 52%/90%, respectively. An event or treatment failure occurred in 24 patients (46%), including 5 deaths. Median time to treatment failure was 3.4 years. Disease progression in the other 19 patients transpired within 25.1 months of diagnosis. Thirteen of these patients received radiation, including 11 within 2 months of primary treatment failure. Although children with intrinsic tumors had slightly better EFS at 5 years compared with those with exophytic tumors (p = 0.054), this difference was not significant at 10 years (p = 0.147). No other variables were predictive of EFS.

CONCLUSIONS

Surgery suffices in many children with low-grade focal brainstem gliomas. Radiation treatment is often reserved for disease progression but offers comparable disease control following biopsy. In the authors' experience, combining an assessment of clinical course, imaging, and tumor biopsy yields a reasonable model for managing children with focal brainstem tumors.

Stereotactic iodine-125 brachytherapy for treatment of inoperable focal brainstem gliomas of WHO grades I and II: feasibility and long-term outcome

Microsurgical resection is the most frequently suggested treatment option for accessible focal brainstem gliomas (F-BSG) of World Health Organization (WHO) grades I and II. Because of their location in the highly eloquent brain, however, resection is associated with permanent postoperative morbidity, ranging from 12 to 33 %. Only a few reports have suggested stereotactic brachytherapy (SBT) with implantation of iodine-125 seeds as a local treatment alternative. Between 1993 and 2010, 47 patients were treated with SBT (iodine-125 seeds; cumulative surface dose 50-65 Gy) for inoperable F-BSG, WHO grades I and II, in one of the largest reported patient series. We evaluated procedure-related complications, clinical outcome, and progression-free and overall survival (PFS, OS). Median follow-up was 81.6 months. Procedure-related mortality was zero. Within 30 days of seed implantation six patients (12.8 %) had transient neurological deficits. Two patients (4.3 %) deteriorated permanently. Space-occupying cysts occurred in six patients (12.8 %) after a median of 28.5 months, and required surgical intervention. Nine patients (19.1 %) presented with tumor relapse after a median of 56.6 months (range 7.9-118.0 months). For the remaining 38 patients complete response was observed for 23.4 %, partial response for 29.8 %, and stable disease for 27.7 %. Actuarial PFS was 97.7 ± 2.2, 92.8 ± 4.0, 81.2 ± 6.5, and 62.0 ± 10.4 % after 1, 2, 5, and 10 years, respectively. Corresponding OS was 100 ± 0.0 % (1 and 2 years), 97.4 ± 2.6 % (5 years), and 87.6 ± 7.0 % (10 years). SBT is a comparatively safe, minimally invasive, and highly effective local treatment option for patients with inoperable F-BSG WHO grades I and II; it merits further evaluation in prospective randomized trials.