Induction Chemotherapy Reduces Radiation Therapy Dose and Volume in the Treatment of Intracranial Germinoma: Results of the SMC-G13 Trial

Tandem High-Dose Chemotherapy Increases the Risk of Secondary Malignant Neoplasm in Pediatric Solid Tumors

PURPOSE

This study aimed to investigate the incidence and risk factors for secondary malignant neoplasms (SMN) in pediatric solid tumors, focusing on the effects of tandem high-dose chemotherapy (HDCT).

MATERIALS AND METHODS

Patients (aged < 19 years) diagnosed with or treated for pediatric solid tumors between 1994 and 2014 were retrospectively analyzed. The cumulative incidence of SMN was estimated using competing risk methods by considering death as a competing risk.

RESULTS

A total of 1,435 patients (413 with brain tumors and 1,022 with extracranial solid tumors) were enrolled. Seventy-one patients developed 74 SMNs, with a 10-year and 20-year cumulative incidence of 2.680±0.002% and 10.193±0.024%, respectively. The types of SMN included carcinoma in 28 (37.8%), sarcoma in 24 (32.4%), and hematologic malignancy in 15 (20.3%) cases. Osteosarcoma and thyroid carcinoma were the most frequently diagnosed tumors. Multivariate analysis showed that radiotherapy (RT) > 2, 340 cGy, and tandem HDCT were significant risk factors for SMN development. The SMN types varied according to the primary tumor type; carcinoma was the most frequent SMN in brain tumors and neuroblastoma, whereas hematologic malignancy and sarcomas developed more frequently in patients with sarcoma and retinoblastoma, respectively.

CONCLUSION

The cumulative incidence of SMN in pediatric patients with solid tumors was considerably high, especially in patients who underwent tandem HDCT or in those who received RT > 2,340 cGy. Therefore, the treatment intensity should be optimized based on individual risk assessment and the long-term follow-up of pediatric cancer survivors.

Histopathological, Demographic, and Clinical Signatures of Medulla Oblongata Germ Cell Tumors: A Case Report With the Review of Literature

The medulla oblongata is one of the rarest sites of occurrence for germ cell tumors (GCTs) of the central nervous system. As there is scant data regarding epidemiology, clinical presentations, optimal intervention, and long-term prognosis, we aimed to delineate the features of this rare entity by presenting our representative case and performing a quantitative review of the literature. A 24-year-old woman presented to our department with vertigo and swallowing difficulties. Magnetic resonance imaging revealed a homogenously enhanced exophytic lesion arising from the medulla oblongata and extending to the fourth ventricle. Surgical resection was performed and a histological diagnosis of pure germinoma was made. The patient underwent chemotherapy and whole-ventricular irradiation. No recurrence has been experienced for 4 months after the surgery. According to the literature, the prognosis of GCTs at the medulla oblongata seems no worse than those at typical sites. Striking features including occurrence at an older age, female preponderance, and a predominance of germinoma were noteworthy. The pattern of local recurrence suggests extensive radiation coverage is not a prerequisite. Special attention is needed for cardiac and respiratory functions as the main factors eliciting mortality.

Intracranial Germ Cell Tumors

Intracranial germ cell tumors are rare tumors occurring in adolescents and young adults, which include germinomas and non-germinomatous type germ cell tumors (NGGCT). In the past few decades, cooperative trial groups in Europe and North America have developed successful strategies to improve survival outcomes and decrease treatment-related toxicities. New approaches to establishing diagnosis have deferred the need for radical surgery. The 5-year event-free survival (EFS) is above 90% and even patients who present with metastatic germinoma can still be cured with chemotherapy and craniospinal irradiation. The combination of surgery, chemotherapy, and radiation therapy is tailored to patients based on grouping and staging. For NGGCT, neoadjuvant chemotherapy followed by delayed surgery for residual disease and radiotherapy can yield a 5-year EFS of 70%. Further strategies should focus on reducing long-term complications while preserving high cure rates.

The role of neoadjuvant chemotherapy in the management of metastatic central nervous system germinoma: A meta-analysis

BACKGROUND

The role of neoadjuvant chemotherapy in treating patients with metastatic central nervous system (CNS) germinoma is controversial.

METHODS

We compared the relapse-free survival (RFS) of different treatment modalities by performing a meta-analysis using published data. We summarized all data using standard descriptive statistics. We used the Kaplan-Meier method to estimate RFS and their corresponding 95% confidence intervals (CIs). We used the log-rank test for the comparison of survival functions.

RESULTS

We identified 97 patients with a median age at presentation of 15 years (range: 7-38). Sites of metastasis were cerebrospinal fluid (CSF) disease only (n = 12), brain parenchyma (n = 18), spinal cord (n = 9), ventricular and CSF (n = 10), ventricular only (n = 31), and other (n = 17). The 3-year RFS among patients who received any form of radiotherapy was 89% (95% CI: 83-96) compared with 0% for patients who received a chemotherapy-only regimen (p = .001). Five-year RFS among patients who received craniospinal irradiation (CSI) was 92% (95% CI: 84-100) compared with 76.4% (95% CI: 63-90) in the non-CSI group (with or without neoadjuvant chemotherapy) (p = .014). Five-year RFS of patients who received CSI less than 24 Gy with neoadjuvant chemotherapy was 100% compared with 92% (95% CI: 83-100) CSI dose greater than or equal to 24 Gy alone (p = .3).

CONCLUSIONS

Our analysis does not support avoiding spinal irradiation among patients with radiographic metastatic CNS germinoma. Future studies are needed to confirm whether neoadjuvant chemotherapy will allow a reduction of irradiation dose without compromising survival.

Benign and Malignant Tumors of the Pineal Region

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.

Primary central nervous system germ cell tumors in children and young adults: A review of controversies in diagnostic and treatment approach

Primary central nervous system (CNS) germ cell tumors (GCT) are a rare heterogenous group of cancers, arising most commonly in the second decade of life. Through several clinical trials conducted around the world by various groups, the treatment approach for CNS GCT has advanced substantially with generally improved overall outcomes. In recent years, the goal of clinical trials has been focused on reduction of the radiotherapy burden and minimization of long-term toxicity. This review summarizes the current diagnostic and treatment regimens for CNS GCT, examines the controversies associated with these approaches, gaps in contemporary knowledge, and underscores the challenges we face. We also explore future directions in the management of CNS GCT with the ultimate overall aim of preserving curative outcomes, identifying novel biomarkers, and mitigating neurocognitive, endocrine, and psychological toxicity through prospective clinical studies.

Outcomes of intracranial germinoma-A retrospective multinational Asian study on effect of clinical presentation and differential treatment strategies

BACKGROUND

This multinational study was conducted to report clinical presentations and treatment strategies in patients with intracranial germinomas across selected Asian centers, including failure patterns, risk factors, and outcomes.

METHODS

A retrospective data collection and analysis of these patients, treated between 1995 and 2015 from eight healthcare institutions across four countries was undertaken.

RESULTS

From the results, 418 patients were analyzed, with a median follow-up of 8.9 years; 79.9% of the patients were M0, and 87.6% had β-human chorionic gonadotropin values <50 mIU/mL. The 5/10-year overall survival (OS) and recurrence-free survival (RFS) rates were 97.2%/96.2% and 89.9%/86.9%, respectively. RFS was predicted by the radiotherapy (RT) field, with focal RT having the worst outcome, whereas chemotherapy usage had no impact on survival. Among patients who received chemotherapy, response to chemotherapy did not predict survival outcomes. In M0 patients, primary basal ganglia tumors predicted a worse RFS. In patients with bifocal tumors, an extended field RT was associated with better outcomes. In multivariable analysis, only RT fields were associated with RFS. In relapsed patients, salvage rates were high at 85.7%. Additionally, patients who received salvage RT had a better outcome (91.6% vs. 66.7%).

CONCLUSIONS

Survival outcomes of patients with germinoma were excellent. Thus, the focus of treatment for intracranial germinoma should be on survivorship. Further studies are warranted to find the optimal intensity and volume of radiation, including the role of chemotherapy in the survival of patients with intracranial germinomas, considering age, primary tumor location, and extent of disease.

Outcome of endoscopic transcortical intraventricular biopsy of isolated thickened pituitary stalk lesions in children

OBJECTIVE

The purpose of this study was to investigate the efficacy and safety of endoscopic transcortical intraventricular biopsy in pediatric patients with isolated thickened pituitary stalk lesions.

METHODS

From 1994 to 2018, 16 pediatric patients (8 males and 8 females) underwent endoscopic transcortical intraventricular biopsy at a single institution to establish an accurate pathological diagnosis for appropriate treatment strategies.

RESULTS

Preoperatively, the median diameter of the pituitary stalks was 5.31 ± 1.67 mm (range 3.86-9.17 mm). Overall, the diagnostic yield at endoscopic intraventricular biopsy was 93.8%. Histopathological diagnosis included germinoma (n = 10, 62.5%), Langerhans cell histiocytosis (n = 4, 25%), pilocytic astrocytoma (n = 1, 6.3%), and pituicytoma (n = 1, 6.3%). Two patients developed new diabetes insipidus after the procedure, and 3 patients had new postoperative hypothyroidism. There were no postoperative neurological deficits in this series.

CONCLUSIONS

Neuroendoscopic biopsy via the transcortical intraventricular corridor was shown to be safe and to aid in a reliable histopathological diagnosis in the management of isolated pituitary stalk lesions in pediatric patients. It can be considered a minimally invasive alternative to open biopsy via transcranial or endonasal corridors.

Chronological Analysis of Acute Hematological Outcomes after Proton and Photon Beam Craniospinal Irradiation in Pediatric Brain Tumors

Purpose

This study aimed to compare the early hematological dynamics and acute toxicities between proton beam craniospinal irradiation (PrCSI) and photon beam craniospinal irradiation (PhCSI) for pediatric brain tumors.

Materials and Methods

We retrospectively reviewed patients with pediatric brain tumors who received craniospinal irradiation (CSI). The average change in hemoglobin levels (ΔHb_avg), absolute lymphocyte counts (ΔALC_avg), and platelet counts (ΔPLT_avg) from baseline values was evaluated and compared between the PrCSI and PhCSI groups at 1 and 2 weeks after the initiation of CSI, 1 week before and at the end of radiotherapy, and 3–4 weeks after the completion of radiotherapy using t-test and mixed-model analysis.

Results

The PrCSI and PhCSI groups consisted of 36 and 30 patients, respectively. There were no significant differences in ΔHb_avg between the two groups at any timepoint. However, ΔALC_avg and ΔPLT_avg were significantly lower in the PhCSI group than in PrCSI group at every timepoint, demonstrating that PrCSI resulted in a significantly lower rate of decline and better recovery of absolute lymphocyte and platelet counts. The rate of grade 3 acute anemia was significantly lower in the PrCSI group than in in the PhCSI group.

Conclusion

PrCSI showed a lower rate of decline and better recovery of absolute lymphocyte and platelet counts than PhCSI in the CSI for pediatric brain tumors. Grade 3 acute anemia was significantly less frequent in the PrCSI group than in the PhCSI group. Further large-scale studies are warranted to confirm these results.