Current concepts and future strategies in the management of intracranial germinoma

A deep learning model for differentiating paediatric intracranial germ cell tumour subtypes and predicting survival with MRI: a multicentre prospective study

BACKGROUND

The pretherapeutic differentiation of subtypes of primary intracranial germ cell tumours (iGCTs), including germinomas (GEs) and nongerminomatous germ cell tumours (NGGCTs), is essential for clinical practice because of distinct treatment strategies and prognostic profiles of these diseases. This study aimed to develop a deep learning model, iGNet, to assist in the differentiation and prognostication of iGCT subtypes by employing pretherapeutic MR T2-weighted imaging.

METHODS

The iGNet model, which is based on the nnUNet architecture, was developed using a retrospective dataset of 280 pathologically confirmed iGCT patients. The training dataset included 83 GEs and 117 NGGCTs, while the retrospective internal test dataset included 31 GEs and 49 NGGCTs. The model's diagnostic performance was then assessed with the area under the receiver operating characteristic curve (AUC) in a prospective internal dataset (n = 22) and two external datasets (n = 22 and 20). Next, we compared the diagnostic performance of six neuroradiologists with or without the assistance of iGNet. Finally, the predictive ability of the output of iGNet for progression-free and overall survival was assessed and compared to that of the pathological diagnosis.

RESULTS

iGNet achieved high diagnostic performance, with AUCs between 0.869 and 0.950 across the four test datasets. With the assistance of iGNet, the six neuroradiologists' diagnostic AUCs (averages of the four test datasets) increased by 9.22% to 17.90%. There was no significant difference between the output of iGNet and the results of pathological diagnosis in predicting progression-free and overall survival (P = .889).

CONCLUSIONS

By leveraging pretherapeutic MR imaging data, iGNet accurately differentiates iGCT subtypes, facilitating prognostic evaluation and increasing the potential for tailored treatment.

Radiotherapy management of paediatric cancers with synchronous metastasis

Cancer in childhood represent 1% of all the new diagnosed cancers. About 30% of children with cancer receive radiation therapy, representing about 600 to 700 patients per year in France. As a consequence, paediatric cancers with synchronous metastasis is a very rare situation in oncology, with usually poor standard of care. However, considerable efforts are made by paediatric oncology scientific societies to offer trials or treatment consensus despite these rare situations. The article proposes to synthesize the radiotherapy management of both primary tumour and synchronous metastasis in the most "common" childhood or adolescent cancers.

Intracranial germ cell tumors in Adolescents and Young Adults: European and North American consensus review, current management and future development

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

Emergency irradiation with 3.4 Gy/2f in sellar/suprasellar germinoma patients with rapid visual acuity decline

Background:

Rapid visual acuity (VA) decline was a common complaint in patients with sellar/suprasellar germinoma. In our hospital, 3.4 Gy/2f of emergency irradiation was applied to save patient VA and enable subsequent chemoradiotherapy. This study aimed to investigate the efficacy of emergency irradiation with 3.4 Gy/2f in patients with sellar/suprasellar germinoma who had rapid VA decline.

Methods:

From January 2014 to December 2017, 33 patients with sellar/suprasellar germinoma who complained of VA decline within 3 months received 3.4 Gy/2f of emergency irradiation in Beijing Tiantan Hospital. The best-corrected VA (BCVA) and mean deviation (MD) were measured. Correlations between visual function change and clinical factors, including age at diagnosis, duration of VA decline, extent of tumor regression, serum level of tumor markers, were analyzed.

Results:

Among 33 patients with sellar/suprasellar germinoma, the median diameter and volume of sellar/suprasellar lesions were 32 mm (range: 5–55 mm) and 12.9 cm³ (range 0.6–58.5 cm³), respectively. Data on pre- and post-emergency-irradiation BCVA were obtained in 32 patients. For the right eyes, BCVA was improved in 23 patients (71.9%), unchanged in 7 (21.9%), and worsened in 2 (6.2%); and for the left eyes, these numbers were 27 (84.4%), 4 (12.5%), and 1 (3.1%), respectively. In terms of the logarithm of the minimum angle of resolution (logarithm of the minimum angle of resolution = Log (1/BCVA) score, the improvement was significant in both eyes (P < 0.001). In terms of MD, six patients had paired data and the improvement was marginal in the right eyes (P = 0.068) and significant in the left eyes (P = 0.043). However, no clinical factor was found to have correlation with visual function improvement.

Conclusion:

In sellar/suprasellar germinoma patients with VA decline, 3.4 Gy/2f of emergency irradiation was effective in improving visual function.

Basal Ganglionic Germinoma With Syncytiotrophoblastic Giant Cells Mimicking a Growing Hematoma

Basal ganglionic germinoma (BGG) with syncytiotrophoblastic giant cells (STGC) is a rare type of ectopic germ cell tumors with mild elevation of human chorionic gonadotropin level. Intratumoral hemorrhage is not uncommon for BGG, but presenting with repeated hemorrhage is very rare. Herein, we described an extremely rare case of BGG with STGC mimicking a growing hematoma. Furthermore, the characteristics, treatment, and prognosis of BGG with STGC were investigated and reviewed.

Emergency irradiation of 3.4Gy/2f in pineal gland germinoma patients with symptomatic hydrocephalus

Background

Surgical interventions including ventriculostomy and ventriculo-peritoneal shunt were usually administrated in pineal germ cell tumor patients with symptomatic hydrocephalus. Considering higher sensitivity of germinoma to anti-tumor therapy, we explored emergency irradiation as non-invasive measure in this situation.

Methods

Data of 35 germinoma patients with symptomatic hydrocephalus who received emergency irradiation of 3.4 Gy/2f were studied retrospectively. The maximum width of frontal horn and the minimum width of trunk of corpus callosum (TCC) were measured to evaluate hydrocephalus changing. Besides, mean deviation (MD) of Humphrey perimetry was employed to evaluate visual field defect. Correlations between hydrocephalus changing and clinical factors, including age, percentage of tumor regression, radiographic re-evaluation interval, and serum beta-human chorionic gonadotropin (β-HCG) level, were analyzed.

Results

The median maximum diameter and volume of pineal lesions was 27 mm (range 10-55 mm) and 6.5cm³ (range 0.4-74.1 cm³), respectively. At median 8 days after irradiation, the median percentage of tumor remission was 55% (range 10-100%). The median maximum width of FN and the median minimum width of TCC were 11.6 mm and 39.0 mm, and 8.0 mm and 31.4 mm, before and after irradiation, respectively. The improvement of both parameters reached significant level (p < 0.001). However, none clinical factor was found to have correlation with their improvement. In 14 patients with paired data of pre- and post-irradiation MD, its change did not reach the significant level for both eyes. All patients successfully received subsequent chemoradiotherapy without surgical intervention.

Conclusions

Emergency irradiation of 3.4 Gy/2f was an effective non-invasive measure to relief hydrocephalus in pineal germinoma patients.

β-human chorionic gonadotropin-secreting intracranial germ-cell tumor associated with high testosterone in an adult man: A case report

A 38-year-old male patient presented with general weakness, polydipsia and a body weight loss of 10 kg in two years. Hypopituitarism with central hypothyroidism and central adrenal insufficiency were noted at Taipei City Hospital (Taipei, Taiwan). However, hypogonadotropic hypergonadism was also observed. The patient was diagnosed with an intracranial β-human chorionic gonadotropin (β-hCG) secreting germ-cell tumor, and brain magnetic resonance imaging revealed that the tumor involved the pineal gland, stalk, posterior pituitary gland, right basal ganglion, hypothalamus, corpus callosum and posterior hippocampus. The cerebrospinal fluid (CSF) β-hCG level was 1936 IU/l, while the α-fetoprotein (AFP) level was <0.24 ng/ml. The serum AFP level of the patient was 3.28 ng/ml, and the β-hCG level was 178 IU/l with a CSF:serum β-hCG ratio >2:1. The patient was successfully treated with chemotherapy and radiotherapy, as demonstrated by a marked decrease in size of the tumor and in the serum β-hCG levels. Intracranial β-hCG secreting germ-cell tumors are rare in adults and manifest differently compared with patients of early pubertal age. In contrast with the precocious puberty frequently observed in young patients, the diagnosis of adult patients is often delayed and the symptoms are associated with tumor size and location. The present case report described an adult male with an intracranial β-hCG secreting GCT, demonstrating hypopituitarism and asymptomatic hyperandrogenemia, and reviews and discusses the literature relevant to the case.

Re-irradiation of Recurrent Pineal Germ Cell Tumors with Radiosurgery: Report of Two Cases and Review of Literature

Primary intracranial germ cell tumors are rare, representing less than 5% of all central nervous system tumors. Overall, the majority of germ cell tumors are germinomas and approximately one-third are non-germinomatous germ cell tumors (NGGCT), which include teratoma, embryonal carcinoma, yolk sac tumor (endodermal sinus tumor), choriocarcinoma, or mixed malignant germ cell tumor. Germ cell tumors may secrete detectable levels of proteins into the blood and/or cerebrospinal fluid, and these proteins can be used for diagnostic purposes or to monitor tumor recurrence. Germinomas have long been known to be highly curable with radiation therapy alone. However, many late effects of whole brain or craniospinal irradiation have been well documented. Strategies have been developed to reduce the dose and volume of radiation therapy, often in combination with chemotherapy. In contrast, patients with NGGCT have a poorer prognosis, with about 60% cured with multimodality chemoradiation. There are no standard approaches for relapsed germ cell tumors. Options may be limited by prior treatment. Radiation therapy has been utilized alone or in combination with chemotherapy or high-dose chemotherapy and transplant. We discuss two cases and review options for frameless radiosurgery or fractionated radiotherapy.

Successful Treatment of Intracranial Germ Cell Tumor: Report of Two Unusual Cases and Literature Review

Primary intracranial germ cell tumor (GCT) is a rare tumor that generally occurs due to developmental anomaly. Although intracranial GCT is sensitive to treatment, a high recurrence rate, treatment-related long-term complications and the heterogeneity of this tumor group make treatment complicated. Moreover, because of its location, hydrocephalus and visual field defect, functional disturbance of the pituitary gland can occur and require attention. Treatment primarily relies on chemotherapy and radiation therapy but the management of intracranial GCT remains unsettled, especially in the case of unusual circumstances such as multifocal tumor or nongerminomatous GCT. Here, we present two unusual cases of intracranial GCT: one case with a bifocal intracranial germinoma, and the other with an intracranial choriocarcinoma. Both cases were treated with neoadjuvant chemotherapy followed by reduced-field radiation therapy without significant treatment-related complication. Further, we performed a PubMed search to investigate the appropriate treatment strategy for this unusual subtype of intracranial GCT.

Management of dual intracranial germinoma by radiotherapy alone

Synchronous intracranial germ cell tumor in the pineal and suprasellar region is rare. They represent only 5–10% of all intracranial germinomas. They are also known by the entity “double midline atypical teratoma” and are common in the second decade of life. We report a case of an 11-year-old girl having dual midline intracranial lesions with obstructive hydrocephalus treated by ventriculo-peritoneal shunt. Diagnosis of germinoma was made on the basis of imaging and elevated beta-human chorionic gonadotropin in cerebrospinal fluid. Radiotherapy was instituted, which resulted in the total disappearance of both the lesions. Clinical expression, diagnosis and management strategies are discussed.

Imaging of brain tumors

Neuroimaging plays a crucial role in diagnosis of brain tumors and in the decision-making process for therapy. Functional imaging techniques can reflect cellular density (diffusion imaging), capillary density (perfusion techniques), and tissue biochemistry (magnetic resonance [MR] spectroscopy). In addition, cortical activation imaging (functional MR imaging) can identify various loci of eloquent cerebral cortical function. Combining these new tools can increase diagnostic specificity and confidence. Familiarity with conventional and advanced imaging findings facilitates accurate diagnosis, differentiation from other processes, and optimal patient treatment. This article is a practical synopsis of pathologic, clinical, and imaging spectra of most common brain tumors.