Surveillance imaging in pediatric ependymoma

Recurrence Patterns and Surveillance Imaging in Pediatric Brain Tumor Survivors

Surveillance magnetic resonance imaging (MRI) is routinely used to detect recurrence in pediatric central nervous system (CNS) tumors. The frequency of neuroimaging surveillance varies without a standardized approach. A single-institutional retrospective cohort study evaluated the frequency of recurrences. This study included 476 patients with the majority diagnosed with low-grade glioma (LGG) (n=138, 29%), high-grade glioma (HGG) (n=77, 16%), ependymoma (n=70, 15%), or medulloblastoma (n=61, 13%). LGG, HGG, and ependymoma patients more commonly had multiply recurrent disease ( P =0.08), with ependymoma patients demonstrating ≥2 relapses in 47% of cases. Recurrent disease was identified by imaging more often than clinical symptoms (65% vs. 32%; P =<0.01). Patients diagnosed with meningioma demonstrated the longest mean time to first relapse (74.7 mo) whereas those with atypical teratoid rhabdoid tumor and choroid plexus carcinoma tended to have the shortest time to relapse (8.9 and 9 mo, respectively). Overall, 22 patients sustained first relapse >10 years from initial diagnosis. With a higher tendency toward detection of tumor recurrence/progression on MRI surveillance in comparison to clinical progression, surveillance imaging is necessary in routine follow up of pediatric CNS tumor survivors. With some relapses >10 years from initial diagnosis, imaging beyond this time point may be useful in particular tumor types. While the study is limited in outcome analysis, earlier detection of recurrence would lead to earlier initiation of treatment and implementation of salvage treatment regimens which can impact survival and quality of life.

Ependymoma: Evaluation and Management Updates

PURPOSE OF REVIEW

To review state of art and relevant advances in the molecular genetics and management of ependymomas of children and adults.

RECENT FINDINGS

Ependymomas may occur either in the brain or in the spinal cord. Compared with intracranial ependymomas, spinal ependymomas are less frequent and exhibit a better prognosis. The new WHO classification of CNS tumors of 2021 has subdivided ependymomas into different histomolecular subgroups with different outcome. The majority of studies have shown a major impact of extent of resection; thus, a complete resection must be performed, whenever possible, at first surgery or at reoperation. Conformal radiotherapy is recommended for grade 3 or incompletely resected grade II tumors. Proton therapy is increasingly employed especially in children to reduce the risk of neurocognitive and endocrine sequelae. Craniospinal irradiation is reserved for metastatic disease. Chemotherapy is not useful as primary treatment and is commonly employed as salvage treatment for patients failing surgery and radiotherapy. Standard treatments are still the mainstay of treatment: the discovery of new druggable pathways will hopefully increase the therapeutic armamentarium in the near future.

Proton Therapy for Pediatric Ependymoma: Mature Results From a Bicentric Study

PURPOSE

To report the long-term efficacy and toxicity of proton therapy for pediatric ependymoma.

METHODS AND MATERIALS

Between 2000 and 2019, 386 children with nonmetastatic grade 2/3 intracranial ependymoma received proton therapy at 1 of 2 academic institutions. Median age at treatment was 3.8 years (range, 0.7-21.3); 56% were male. Most (72%) tumors were in the posterior fossa and classified as World Health Organization grade 3 (65%). Eighty-five percent had a gross total or near total tumor resection before radiation therapy; 30% received chemotherapy. Median radiation dose was 55.8 Gy relative biologic effectiveness (RBE) (range, 50.4-59.4).

RESULTS

Median follow-up was 5.0 years (range, 0.4-16.7). The 7-year local control, progression-free survival, and overall survival rates were 77.0% (95% confidence interval [CI], 71.9%-81.5%), 63.8% (95% CI, 58.0%-68.8%), and 82.2% (95% CI, 77.2%-86.3%), respectively. Subtotal resection was associated with inferior local control (59% vs 80%; P < .005), progression-free survival (48% vs 66%; P < .001), and overall survival (70% vs 84%; P < .05). Male sex was associated with inferior progression-free (60% vs 69%; P < .05) and overall survival (76% vs 89%; P < .05). Posterior fossa tumor site was also associated with inferior progression-free (59% vs 74%; P < .05) and overall survival (79% vs 89%; P < .01). Twenty-one patients (5.4%) required hearing aids; of these, 13 received cisplatin, including the 3 with bilateral hearing loss. Forty-five patients (11.7%) required hormone replacement, typically growth hormone (38/45). The cumulative incidence of grade 2+ brain stem toxicity was 4% and occurred more often in patients who received >54 GyRBE. Two patients (0.5%) died of brain stem necrosis. The second-malignancy rate was 0.8%.

CONCLUSION

Proton therapy offers disease control commensurate with modern photon therapy without unexpected toxicity. The high rate of long-term survival justifies efforts to reduce radiation exposure in this young population. Independent of radiation modality, this large series confirms extent of resection as the most important modifiable factor for survival.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.