Inherent diagnostic and treatment challenges in germinoma of the basal ganglia: a case report and review of the literature

Time to dismiss boost? Outcomes of children with localized and metastatic germinoma

PURPOSE

To determine long-term outcomes of a cohort of children with germinoma treated with chemotherapy and radiation therapy without primary tumor boost even in the absence of complete response to chemotherapy METHODS: This retrospective study analyzed the outcome of patients with germinoma consecutively diagnosed and treated at a tertiary care center from January 2000 to December 2021. MRIs were reviewed by two radiologists, blinded to patient data. Tumor location at diagnosis, tumor response to chemotherapy and at completion of radiation therapy and site of relapse were assessed. Tumor response was assessed radiologically by determining the tumor size and response on diffusion-weighted imaging, in addition to biochemical, cytological parameters and neurological status.

RESULTS

Of 46 pediatric germinoma patients, 29 children (14 male; median age 12.8 years) received no primary tumor boost. Median follow-up was 63 months (range 9-187 months). Twenty-five children had localized disease and tumor location was suprasellar (n = 11), pineal (n = 10), bifocal (n = 3) and basal ganglia (n = 1) while 4 children had metastatic disease at presentation. All patients completed multi-agent chemotherapy followed by either ventricular irradiation (VI) (23.4 Gy) (n = 23), whole brain (WBI) (23.4 Gy) (n = 5) or craniospinal radiation (CSI) (23.4 Gy) (n = 1). Two children, who had localized disease at presentation and received VI after chemotherapy, relapsed 9 months and 32 months after completion of treatment respectively. No patient had a local relapse. Location of relapse was distant, outside (n = 1) and out- and inside (n = 1) the irradiation field. Five-year progression free survival (PFS) was 91% and overall survival (OS) was 100%.

CONCLUSIONS

In this case series, excellent 5-year PFS and OS rates were achieved with chemotherapy followed by radiation therapy of 23.4 Gy delivered without primary tumor boost. No local relapse was observed despite omitting primary tumor boost in patients with localized and metastatic germinoma.

Germ cell tumors of the central nervous system: A brief review and site-specific considerations

Germ cell tumors of the central nervous system (GCT-CNS) arise predominantly in midline locations of the CNS and affect young patients in their first to third decades of life. Involvement of the CNS is thought to be a sequelae of residual primordial germ cells with incomplete embryologic migration. Clinically, GCT-CNS present with symptoms of ventricular obstruction or compression of affected brain structures. Histologically, these tumors are analogous to their gonadal and extra-gonadal counterparts. Diagnosis relies heavily on morphology and immunohistochemical findings, and can be complicated by limited tumor sampling. There is currently only a limited role for molecular studies. Treatment of these lesions is made difficult by their involvement of deep and vital brain structures and accurate pathologic diagnosis is essential for appropriate therapy. Diagnosis should involve review of the clinical history, imaging studies, and assessment of serum and cerebrospinal fluid tumor markers. Current therapeutic strategies involving radiation therapy with or without chemotherapy are quite effective, in spite of the locational difficulties that often prevent gross total resection.

Multi-institutional analysis of treatment modalities in basal ganglia and thalamic germinoma

BACKGROUND

Central nervous system (CNS) germinomas are treatment-sensitive tumors with excellent survival outcomes. Current treatment strategies combine chemotherapy with radiotherapy (RT) in order to reduce the field and dose of RT. Germinomas originating in the basal ganglia/thalamus (BGTGs) have proven challenging to treat given their rarity and poorly defined imaging characteristics. Craniospinal (CSI), whole brain (WBI), whole ventricle (WVI), and focal RT have all been utilized; however, the best treatment strategy remains unclear.

METHODS

Retrospective multi-institutional analysis has been conducted across 18 institutions in four countries.

RESULTS

For 43 cases of nonmetastatic BGTGs, the 5- and 10-year event-free survivals (EFS) were 85.8% and 81.0%, respectively, while the 5- and 10-year overall survivals (OS) were 100% and 95.5%, respectively (one patient fatality from unrelated cause). Median RT doses were as follows: CSI: 2250 cGy/cGy(RBE) (1980-2400); WBI: 2340 cGy/cGy(RBE) (1800-3000); WVI: 2340 cGy/cGy(RBE) (1800-2550); focal: 3600 cGy (3060-5400). Thirty-eight patients (90.5%) received chemotherapy. There was no statistically significant difference in the EFS based on initial field extent (p = .84). Nevertheless, no relapses were reported in patients who received CSI or WBI. Chemotherapy alone had significantly inferior EFS compared to combined therapy (p = .0092), but patients were salvageable with RT.

CONCLUSION

Patients with BGTGs have excellent outcomes and RT proved to be an integral component of the treatment plan. This group of patients should be included in future prospective clinical trials and the best RT field should be investigated further.

Precise detection of the germinomatous component of intracranial germ cell tumors of the basal ganglia and thalamus using placental alkaline phosphatase in cerebrospinal fluid

PURPOSE

The disadvantages of biopsy for lesions in the basal ganglia and thalamus include a risk of various complications, difficulty in selecting the target tissue in some cases due to indistinct neuroimaging findings and limited availability of sample tissue. Placental alkaline phosphatase (PLAP) plays a decisive role in the diagnosis and management of intracranial germ cell tumors (IGCTs) in the basal ganglia and thalamus. The present study aimed to demonstrate the ability, specificity, and optimal use of PLAP values obtained from cerebrospinal fluid (CSF).

METHODS

Twenty patients with lesions in the basal ganglia and thalamus were enrolled in this study: 11 had IGCTs and 9 had non-IGCTs. The values of PLAP and other established tumor markers in the CSF were measured in all patients before treatment.

RESULTS

The mean follow-up period was 76.0 months (range, 3-168) for all lesions. PLAP was elevated in all 11 patients with IGCTs in the basal ganglia or thalamus, whereas none of the patients with non-IGCT exhibited elevated PLAP. Thus, the sensitivity and specificity of PLAP were both 100%.

CONCLUSION

Our data demonstrated that the PLAP value can specifically identify the germinomatous component even in cases of IGCTs in the basal ganglia or thalamus with high sensitivity and specificity. PLAP is undoubtedly beneficial for the safe and timely detection of the germinomatous component of IGCTs in the basal ganglia and thalamus, because reliance on PLAP measurement enables us to avoid invasive surgical procedures and facilitates the prompt initiation of chemoradiation therapy.

Relapse pattern and quality of life in patients with localized basal ganglia germinoma receiving focal radiotherapy, whole-brain radiotherapy, or craniospinal irradiation

BACKGROUND AND PURPOSE

The optimal target volume in localized basal ganglia (BG) germinoma is still undetermined. Thus, based on the relapse pattern and health-related quality of life (HRQOL), we evaluated three target volumes.

MATERIAL AND METHODS

The clinical data of 161 patients with localized BG germinoma were included in this retrospective study. Relapse status and relapse sites after treatment were explored. HRQOL was evaluated using the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0) (≤15 years) and Short Form-36 (SF-36) (>15 years) questionnaires based on the patients' age at last follow-up.

RESULTS

After a median follow-up duration of 83 months (range, 20-214 months), 19 patients experienced relapse, including 15, 4, and 0 patients in the focal radiotherapy (FR) (n = 35), whole-brain radiotherapy (WBRT) plus boost (n = 109), and craniospinal irradiation (CSI) plus boost (n = 17) groups, respectively. The 5-year disease-free survival rates were 74.3%, 97.2%, and 100%, respectively (p < 0.001). Among the 15 patients who relapsed after FR, 14 had positive radiological findings, including seven (50.0%) with lesions in the periventricular area and seven (50.0%) with frontal lobe lesions. Relapse in both these areas were significantly reduced by WBRT or CSI. HRQOL data were available for 69 patients, who generally scored low. Among 38 patients evaluated by SF-36, those receiving CSI had significantly lower mental component scores than those receiving WBRT (p = 0.027) or FR (p = 0.011).

CONCLUSIONS

Considering both disease control and HRQOL, WBRT is the optimal target volume in our series. The relapse pattern identified in patients receiving FR is informative for further treatment volume optimization.

Clinical and neuropsychological outcome of pediatric non-midline central nervous system germinoma treated with chemotherapy and reduced dose/volume irradiation: The Children's Hospital Los Angeles experience

BACKGROUND

Germ cell tumors (GCT) arising from non-midline structures (basal ganglia, thalamus, and posterior fossa) are rare. Although patients with midline (pineal and suprasellar) germinoma have excellent survival with chemotherapy and whole ventricular irradiation (WVI), germinoma in non-midline locations have traditionally been treated with craniospinal irradiation (CSI) or whole brain irradiation (WBI) to achieve similar outcomes. However, CSI and WBI are associated with significant long-term neuropsychological sequelae.

METHODS

We describe the clinical and neuropsychological outcomes of patients with non-midline germinoma treated at the Children's Hospital Los Angeles between 1990 and 2015.

RESULTS

Nine patients had basal ganglia/thalamic germinoma and one patient had a cerebellar primary. Eight patients received chemotherapy followed by reduced dose/volume irradiation, whereas two patients received chemotherapy alone as upfront therapy. One patient in the chemotherapy alone group relapsed after 4.3 years and was salvaged with CSI plus boost. The overall survival for the entire cohort was 100% at a median follow-up of 8.5 years. Neuropsychological data were available for six patients at a median of five months (baseline) and 4.2 years (follow-up) post-diagnosis. At four-year follow-up, data available revealed intact overall cognitive ability, verbal memory, and executive functioning, but persistent deficits in fine motor function. Comparison of baseline to follow-up suggests a downward trend in working memory, planning/problem-solving, verbal memory, and visuospatial integration.

CONCLUSION

Chemotherapy followed by reduced dose/volume of irradiation is an effective strategy resulting in long-term survival in patients with non-midline germinoma. Neuropsychological data suggest relatively minimal morbidity over time.

Clinico-radiological approach to cerebral hemiatrophy

INTRODUCTION

Cerebral hemiatrophy is an uncommon neuroimaging finding of diverse etiologies, conventionally classified into two broad categories: congenital and acquired. The authors propose an alternative pragmatic clinical approach to cerebral hemiatrophy, classifying its diverse etiologies into a single event insult such as an in utero stroke, or a progressive disorder from an inflammatory or neoplastic process, the latter of which needs urgent intervention and will be the focus of our review paper. Illustrative cases will also be presented to facilitate the understanding of the discussed disorders.

CONCLUSION

A systematic approach, linking both clinical and neuroimaging features, is important to facilitate the diagnostic workup of cerebral hemiatrophy. This may potentially help avoid large-scale investigations. Determining the underlying aetiology of cerebral hemiatrophy may impact treatment and prognostication as some conditions such as Rasmussen encephalitis and Parry-Romberg syndrome may benefit from timely implementation of immunomodulatory therapy.

Progressive hemiparesis in a young man: Hemicerebral atrophy as the initial manifestation of basal ganglia germinoma

Basal ganglia germinomas are rare and patients are classically young Oriental males presenting with gradually progressive hemiparesis. Although early treatment with chemo-radiotherapy can be curative and significantly improve the quality of life, medical attention is often delayed. A young Chinese male experienced a 6-month history of right hemiparesis with magnetic resonance imaging findings of hemicerebral atrophy and lentiform nucleus microhemorrhage, highly suggestive and early signs of basal ganglia germinomas. No further imaging was performed until 2 years later when he was admitted for acute neurological deterioration and a repeat scan revealed a large infiltrative tumor pathologically confirmed to be a pure germinoma.

Germinoma Mimicking Tumefactive Demyelinating Disease in Pediatric Patients

Cases of intracranial germinoma with granulomatous reaction are rare, so a pathological diagnosis of this disease is difficult. In this report, we describe the case of a 13-year-old boy with a bilateral thalamic germinoma which initially mimicked tumefactive demyelinating disease with inflammation, based on the clinical symptoms, imaging results and histology of a biopsy specimen obtained endoscopically. Upon examination of the cerebrospinal fluid, oligoclonal bands were detected. Although his symptoms and radiological findings improved following steroid pulse treatment, they worsened dramatically almost 1 year after the first surgery and even after an additional steroid pulse treatment. Prompted by the clinical course, a second biopsy was performed, and a pathological examination of the specimen showed a two-cell pattern. The diagnosis was changed to intracranial germinoma. After chemotherapeutic treatment with etoposide and cisplatin, the patient's symptoms and radiological findings dramatically improved. We conclude that it is very challenging to distinguish germinomas with a granulomatous reaction due to other inflammatory diseases, especially when only small specimens can be obtained. Stereotactic or endoscopic biopsies should be performed using samples from several different points even if the lesions are associated with eloquent brain regions.

Understanding the Treatment Strategies of Intracranial Germ Cell Tumors: Focusing on Radiotherapy

Intracranial germ cell tumors (ICGCT) occur in 2-11% of children with brain tumors between 0-19 years of age. For treatment of germinoma, relatively low radiation doses with or without chemotherapy show excellent 10 year survival rate of 80-100%. Past studies showed that neoadjuvant chemotherapy combined with focal radiotherapy resulted in unacceptably high rates of periventricular tumor recurrence. The use of generous radiation volume which covers the whole ventricular space with later boost treatment to primary site is considered as standard treatment of intracranial germinomas. For non-germinomatous germ cell tumors (NGGCT), 10-year overall survival rate is still much inferior than that of intracranial germinoma despite intensive chemotherapy and high-dose radiotherapy. Craniospinal radiotherapy combined with cisplatin-based chemotherapy provides the best treatment outcome for NGGCT; 60-70% of overall survival rate. There is a debate on the surgical role whether surgery can contribute to improved treatment outcome of NGGCT when added to combined chemoradiotherapy. Because higher dose of radiotherapy is required for treatment of NGGCT than for germinoma, it is tested whether whole ventricular irradiation can replace craniospinal irradiation in intermediate risk group of NGGCT to minimize radiation-related late toxicity in the recent studies. To minimize the treatment-related neural deficit and late sequelae while maintaining long-term survival rate of ICGCT patients, optimized administration of chemotherapy and radiotherapy should be selected. Use of technically upgraded radiotherapy modalities such as intensity-modulated radiotherapy or proton beam therapy is expected to bring an improved neurocognitive outcome with longitudinal assessment of the patients.

Basal ganglia germinoma: MRI classification correlates well with neurological and cognitive outcome

Basal ganglia germinomas (BGG) are often associated with delayed diagnosis because of their nonspecific clinical presentation and subtle abnormalities on initial neuroimaging. Despite excellent survival, the prognostic indicators still remained unclear. From our case series, we demonstrated that the MRI classification scheme devised by Phi and colleagues is useful in predicting neurological and cognitive outcomes for patients with unilateral BGG. Subtle lesions with faint or no contrast enhancement are associated with early cerebral atrophy with progressive neurological deficits and poor cognitive outcomes. BGG along with bilateral involvement, regardless of the types of lesion, are also associated with poor neurological and cognitive outcomes.

Germinoma of the Corpus Callosum

A case is described of a young man presenting with diabetes insipidus and a junctional scotoma. A diffuse infiltrating mass centred in the corpus callosum and suprasellar area is found, which on pathological examination proved to be a primary intracranial germinoma. The case illustrates that rarely the corpus callosum can be involved by this tumour and that diagnosis may be delayed in atypical presentations.

Re-evaluation of the significance of cerebrospinal fluid human chorionic gonadotropin in detecting intracranial ectopic germinomas

This study was conducted to establish a reference value for cerebrospinal fluid (CSF) human chorionic gonadotropin (hCG) levels. We also evaluated the sensitivity of CSF hCG as a biomarker to detect intracranial ectopic germinomas that arise in rare sites other than the pineal and suprasellar regions. CSF hCG was measured in 201 male patients who had various types of neurological disease (not tumours of germ cell origin or other malignant tumours). A reference value of 1.009 U/L was established, and the CSF hCG level among different age groups was not significantly different. CSF and serum hCG were measured before and after radiotherapy in 14 consecutive patients with intracranial ectopic germinomas. The CSF hCG levels were all above 1.009 U/L before radiotherapy. In male patients, a CSF hCG value above 1.009 U/L suggests abnormal intrathecal hCG secretion. These results demonstrate that the CSF hCG assay is a sensitive method for diagnosing intracranial ectopic germinoma.

Pattern of relapse and outcome of non-metastatic germinoma patients treated with chemotherapy and limited field radiation: the SFOP experience

Over the last two decades, chemotherapy has been introduced in protocols for patients with intracranial germinoma with the objective of reducing the volume and the dose of irradiation without compromising survival rates. The aim of this work is to critically analyze the pattern of relapse in a cohort of patients with nonmetastatic germinoma prospectively treated with chemotherapy followed by focal field radiation. Data of all germinoma patients registered in the French protocol for intracranial germ cell tumors between 1990 and 1999 were reviewed. The pattern of relapse, management, and outcome were analyzed in 10 of 60 patients who developed a recurrence after initial treatment. In 9 patients, the site of recurrence was local or loco-regional, notably in the periventricular area for 8. One patient only had isolated distant leptomeningeal relapse. The review of the sites of relapse suggests that most recurrences could have been avoided with a larger ventricular field of radiation. Treatment at first relapse included chemotherapy (10 patients), high-dose chemotherapy and stem cell transplant (8 patients), and/or radiation therapy (4 patients). Five patients experienced a second relapse. At a median follow-up of 72 months since the first relapse, 8 patients are alive in second or third remission. This review identified an excess of periventricular relapses when the focal field of radiation is used in the combined management of germinoma. These relapses are predominantly marginal or outside radiation fields. Ventricular field radiation appears a logical alternative to decrease the incidence of such relapses. Future trials should aim at better identifying patients who may benefit from local and ventricular radiation, respectively.

Use of 11C-methionine positron emission tomography in basal germinoma: assessment of treatment response and residual tumor

INTRODUCTION

Prognosis of germinoma arising in the basal ganglia or thalamus is worse compared to that in the pineal or suprasellar region. One of the reasons for poor prognosis is the difficulty in evaluating the efficacy of treatment by conventional neuroimaging tools. PET STUDIES: The usefulness of (11)C-methionine (MET) positron emission tomography (PET) in monitoring the biological nature of brain tumors has been proved in glioma patients.

CASE REPORTS

Herein, we describe MET-PET findings in three cases of germinomas in the basal ganglia or thalamus and discuss the use of MET-PET in the assessment of treatment response and residual tumor for the next treatment strategy. The patients showed transient increase of MET uptake in the lesions after the initial treatment. Although we did not perform histological verification, MET- PET findings suggested that active tumor cells were still alive in the lesions after the initial treatment. MET uptake gradually decreased during the course of intensive therapy in these patients. MET-PET also revealed germinoma invasion in the brain before discernible signal abnormality or mass lesion in conventional magnetic resonance images in two patients.

DISCUSSION

Further studies including histological verification and long-term follow-up might validate the use of MET-PET in monitoring the treatment efficacy and evaluation of active residual tumor after the treatment.

CONCLUSION

Until we understand what MET uptake truly represents, treatment strategy based on MET uptake must be carefully designed to prevent overtreatment and resultant complications.

Atypical basal ganglia germinoma presenting as cerebral hemiatrophy: diagnosis and follow-up with 11C-methionine positron emission tomography

OBJECTS

Some basal ganglia germinomas are difficult to diagnose in early stage of disease due to vague initial presentation without discernable mass lesion on brain imaging. We performed this study to determine the usefulness of 11C-methionine positron emission tomography (MET PET) for the diagnosis and monitoring of disease activity.

MATERIALS AND METHODS

MET PET was performed in three consecutive patients; they presented with cerebral hemiatrophy without definite mass lesions on brain image. The maximum standard tracer uptake values (max SUVs) were calculated and used for the quantitative evaluation of the abnormal MET uptake. A pathological diagnosis was made after stereotactic biopsy using MET PET/computed tomography. The max SUVs significantly decreased after treatment.

CONCLUSION

Basal ganglia germinoma should be considered in the differential diagnosis of patients with progressive hemiparesis and hemiatrophy on magnetic resonance imaging. The MET PET was useful for diagnosis, and it can be valuable in evaluation of treatment effects and monitoring for tumor recurrence.