Focal and craniospinal irradiation for patients with intracranial germinoma and patterns of failure

Long-Term Outcomes and Sequelae Analysis of Intracranial Germinoma: Need to Reduce the Extended-Field Radiotherapy Volume and Dose to Minimize Late Sequelae

PURPOSE

We aimed to refine the radiotherapy (RT) volume and dose for intracranial germinoma considering recurrences and long-term toxicities.

MATERIALS AND METHODS

Total 189 patients with intracranial germinoma were treated with RT alone (n=50) and RT with upfront chemotherapy (CRT) (n=139). All cases were confirmed histologically. RT fields comprised the extended-field and involved-field only for primary site. The extended-field, including craniospinal, whole brain (WB), and whole ventricle (WV) for cranial field, is followed by involved-field boost. The median follow-up duration was 115 months.

RESULTS

The relapses developed in 13 patients (6.9%). For the extended-field, cranial RT dose down to 18 Gy exhibited no cranial recurrence in 34 patients. In CRT, 74 patients (56.5%) showed complete response to chemotherapy and no involved-field recurrence with low-dose RT of 30 Gy. WV RT with chemotherapy for the basal ganglia or thalamus germinoma showed no recurrence. Secondary malignancy developed in 10 patients (5.3%) with a latency of 20 years (range, 4 to 26 years) and caused mortalities in six. WB or craniospinal field rather than WV or involved-field significantly increased the rate of hormone deficiencies, and secondary malignancy. RT dose for extended-field correlated significantly with the rate of hormone deficiencies, secondary malignancy, and neurocognitive dysfunction.

CONCLUSION

De-intensifying extended-field rather than involved-field or total scheme of RT will be critical to decrease the late toxicities. Upfront chemotherapy could be beneficial for the patients with complete response to minimize the RT dose down to 30 Gy. Prospective trials focused on de-intensification of the extended-field RT are warranted.

Management trends and outcomes of pineal germinoma in a multi-institutional Australian cohort

Pineal germinoma is rare with high cure rates following craniospinal radiotherapy. Efforts to reduce the radiotherapy dose and field via combination with chemotherapy suggest comparable disease control and reduced neurocognitive impairments, while the efficacy of immunotherapy in pineal germinoma remains undetermined. This report aimed to review clinical outcomes in patients treated for pineal germinoma in Queensland, Australia, and assess for Programmed Death-Ligand1 (PD-L1) expression. Patients who commenced radiation and/or chemotherapy for pineal germinoma from 2005 to 2017 were retrospectively identified using Queensland Oncology Online database. Demographic, diagnostic, treatment, and outcome data was obtained from electronic medical records. PD-L1 immuno-histochemistry was performed on available specimens. Eighteen patients with long-term follow-up data were identified. Median age at diagnosis was 16.8 years (range 9-46 years). Diagnosis was made histologically in fifteen patients, and radiologically in three. All patients underwent radiotherapy (median 36 Gy (range 21-54 Gy)) with lower median dose delivered with whole ventricle irradiation (12/18patients) than craniospinal irradiation (5/18patients). Sixteen patients received chemotherapy preceding radiotherapy. All patients are alive at median 7.25 years from primary treatment completion (range 2.03-13.1 years). Relapse occurred in three patients (16.67%) following treatment response, all of whom achieved remission following high-dose chemotherapy with stem-cell support and craniospinal radiotherapy. Post-treatment functional outcomes were similarly excellent. PD-L1 expression was low (1-49% cells) or negative in 87% of tumours tested but results were confounded by specimen quality and availability. Reduced-dose radiotherapy with chemotherapy does not compromise outcome and is standard of care at this institution. Immunotherapy is unlikely to become standard treatment in the near future.

Upfront chemotherapy followed by response adaptive radiotherapy for intracranial germinoma: Prospective multicenter cohort study

PURPOSE

To assess the efficacy of upfront chemotherapy followed by response-adapted reduced-dose/reduced-volume radiotherapy (RT) for intracranial germinoma.

MATERIALS AND METHODS

Ninety-one patients from five institutions were registered in the KSPNO G051/G081 Protocol. Germinomas were classified as solitary or multiple/disseminated diseases, and upfront chemotherapy was administered. For all patients with multiple or disseminated disease, and patients with partial response after chemotherapy, 19.5-24 Gy of craniospinal irradiation plus 10.8-19.8 Gy of tumor bed boost were planned. For patients with complete response (CR), reduced-dose RT (30.6 Gy) was planned, along with a reduced field for solitary lesions.

RESULTS

The median patient age was 14 (range, 3-30) years. Sixty-five patients (71.4%) had a solitary lesion. The median follow-up duration was 67.9 (range, 6.6-119.3) months. Recurrence was not observed in 32 patients in the protocol compliant group. Four patients (4.4%) in the protocol non-compliant group experienced relapse after CR and one patient died of the disease. The 5-year and 7-year overall survival rates were 98.8% and 98.8%, while the corresponding event-free survival rates were 96.6% and 93.8%, respectively. All three patients with basal ganglia germinomas who were treated with local RT experienced recurrence outside the RT field. Among the 23 patients with pineal or suprasellar lesions who received whole-ventricle RT, there was no recurrence.

CONCLUSIONS

Currently used upfront chemotherapy followed by reduced-dose, reduced-volume RT appears acceptable, when whole-ventricle RT for pineal or suprasellar tumors and, at minimum, whole-brain RT for basal ganglia/thalamus lesions are applied.

Recent advances in molecular biology and treatment strategies for intracranial germ cell tumors

BACKGROUND

Intracranial germ cell tumors (IGCTs) are a group of rare pediatric brain tumors which include various subtypes. The current understanding of the etiology of the tumors and their optimal management strategies remain controversial.

DATA SOURCES

The data on IGCTs were collected from articles published in the past 20 years, and the origin and etiology of IGCTs at molecular level as well as the relative roles of varied treatment strategies in different prognosis groups according to Matsutani's classification were reviewed.

RESULTS

Recent cellular and molecular evidence suggests that IGCTs may arise from the transformation of endogenous brain cells; and findings in the molecular characterization of IGCTs suggest roles of CCND2, RB1, and PRDM14 in the pathogenesis of IGCTs and identify the KIT/RAS and AKT1/mTOR pathways as potential therapeutic targets in future. According to Matsutani's classification of IGCTs, the good prognosis group includes both germinomas and mature teratomas. For germinomas, both radiation alone and reduced-dose radiotherapy in combination with adjuvant chemotherapy are effective, while complete surgical excision is recommended for mature teratomas. In the intermediate prognosis group, immature teratoma has been successfully treated with gamma knife surgery. However, for intermediate prognosis IGCTs other than immature teratomas, gross total resection with adjuvant chemotherapy and radiotherapy or gamma knife surgery may be necessary to achieve cure. In the poor prognosis group, survival outcomes are unsatisfactory, and complete surgical resection combined with more intensive chemotherapy and radiotherapy remains the best available treatment option at this time.

CONCLUSIONS

IGCTs should be strictly classified according to their pathological categories before administering pathology-specific treatments. Although open microsurgical excision is the traditional surgical strategy for IGCTs, recent publications also support the role of endoscopic surgical options for pineal region IGCTs.

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.

Germinoma recurrence in the conus medullaris 12 years after remission of primary intracranial lesion in the pituitary

Intracranial germinomas are rare primary central nervous system tumours that are highly sensitive to radiotherapy and chemotherapy. Recurrences are infrequent, with the majority occurring within 5 years. Although multidisciplinary treatments have resulted in good event-free survival, long-term outcomes, over decades, are relatively poorly reported. We present a rare case of a recurrence in the conus medullaris 12 years after complete remission of the primary pituitary germinoma. To the best of our knowledge, this represents the first case of a significantly delayed spinal recurrence, occurring at a very distant and uncommon site, from the primary tumour. This case highlights the importance of long-term follow-up, even after complete remission, in order to identify and limit disability from late spinal recurrences in a relatively young patient population. We consider the literature regarding identifying high risk patients, and the role of craniospinal irradiation in limiting late spinal recurrences.

Gamma knife radiosurgery (GKRS) for pineal region tumors: a study of 147 cases

Background

The purpose of this study is to evaluate the effectiveness of gamma knife radiosurgery (GKRS) in the treatment of pineal region tumors (PRTs).

Methods

We retrospectively reviewed 147 cases of PRTs primarily treated with GKRS at our hospital between 1999 and 2009. Mean follow-up time was 67 months (range 60.5–100.1). The local tumor control rates (LTCRs) and overall survival rates were calculated to evaluate the results of the GKRS treatment.

Results

At 2 months after GKRS, tumor volume was significantly reduced in 91 cases (61.9 %). At 6 months, average tumor volume was 4.2 cm³ as compared to 8.47 cm³ before GKRS. By 1 year after GKRS, the tumor completely disappeared in 57 patients. Fourteen patients underwent second treatment, and one patient had third treatment. The overall survival rates were 72.1 % at 3 years and 66.7 % at 5 years for all patients and 62.4 % at 3 years and 54.5 % at 5 years for germ cell tumors (GCTs). The LTCRs were 94.30 % at 3 years and 90.80 % at 5 years for all patients and 88.00 % at 3 years and 77.27 % at 5 years for GCTs.

Conclusions

GKRS is an effective and safe modality that can be widely used to PRTs as the primary therapy.

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.

Long-term follow-up and quality of life in patients with intracranial germinoma

Intracranial germinomas are fairly rare tumors occurring mostly in children or young adults with a comparatively good prognosis. Radiation is the preferred treatment of choice for this diagnosis. It has been thoroughly studied to what extent radiation doses and fields can be limited in order to avoid side effects in these young patients. The role of chemotherapy remains unclear, whereas surgery is limited to biopsy for proof of histology. Regarding the good overall survival rate, quality of life is a significant aspect to consider in these patients. We present a single institution analysis of patients with intracranial germinoma and analyze the long-term outcome with special regard to quality of life. Thirty-three patients with intracranial germinomas were analyzed by chart review, telephone interview, and neurological assessment. Additionally, a survey on quality of life was performed. The 10-year overall survival rate was 82.1 % at a mean follow-up of 141 (22-306) months. Three quarters (76 %) of the patients reached a favorable neurological outcome on the Modified Rankin Scale (mRS 0-2). However, the self-reported quality of life was significantly worse in germinoma patients compared with a healthy control group (p < 0.001). Surgical resection of the tumor led to no improvement regarding overall survival, neurological outcome, and quality of life. In terms of cognitive functioning, patients with tumor resection were significantly more impaired than biopsied patients (p = 0.04). Although germinomas are efficiently treatable tumors, the restrictions in quality of life in these often young patients are considerable, including financial difficulties. There seems no justification for tumor resection in newly diagnosed cases suspicious for germinoma as the cognitive outcome is worse than in biopsied patients, and there is no effect on overall survival.

Current concepts and future strategies in the management of intracranial germinoma

Radiation therapy is the backbone in the management of intracranial germinoma. In localized disease chemotherapy followed by whole brain irradiation is the present standard providing cure rates in excess of 90%. Craniospinal irradiation alone in metastatic disease provides equally excellent outcome. Chemotherapy is able to convert macroscopic to microscopic disease permitting a dose reduction to the tumor site and possibly the ventricular system and is investigated in prospective trials. Chemotherapy alone cannot replace radiotherapy as sole treatment. Whole-ventricular radiotherapy followed by a boost to tumor site without chemotherapy might be feasible. New treatment technologies such as intensity-modulated radiotherapy or proton therapy permit a dose reduction to non-target brain. Data on functional outcome are conflicting and based on small heterogeneous series only mandating prospective investigations.

Late recurrence of a pineal germinoma 14 years after radiation and chemotherapy: a case report and review of the literature

BACKGROUND

Intracranial germinomas (IG) are rare and highly curable tumors. The incidence and optimal treatment of recurrences are not well defined.

CASE REPORT

A 34-year-old male was diagnosed with a late recurrence of an IG 14 years after the initial diagnosis and treatment. The diagnosis was complicated by the absence of tumor markers and delayed histological sampling of the lesion. Upon histological confirmation, the patient received 2 cycles of conventional chemotherapy, followed by 2 cycles of highdose chemotherapy and peripheral blood stem cell transplantation. The patient achieved a complete remission on magnetic resonance imaging scan. Consolidating radiation of the involved field was performed after termination of the chemotherapy.

CONCLUSION

Limited information on the optimal management of late relapses of IG call for individualized therapeutic approaches. Platinum-based chemotherapy, followed by high-dose chemotherapy and consolidative radiation, appears to be feasible and effective in this situation.

Primary intracranial germ-cell tumors in adults: a practical review

Primary intracranial germ-cell tumors are rare tumors primarily of adolescence, and literature on this disease in adults is scarce. The available evidence on intracranial germ-cell tumors is reviewed with a focus on adult patients whenever possible, and used to make suggestions for diagnosis and treatment. Diagnostic and treatment algorithms were developed to provide an evidence-based backbone to base treatment on in adult patients with a (suspected) primary intracranial germ-cell tumor.

Treatment strategy for intracranial primary pure germinoma

OBJECT

This prospective randomized clinical study will address the efficacy of radiation (RT)-alone and combined with pre-RT chemotherapy (CTX) treatments and propose the novel standard treatment strategy for intracranial primary pure germinoma.

MATERIALS AND METHODS

Between 2005 and 2008, there were 54 patients diagnosed with intracranial primary pure germinomas in a single institute. Twenty-eight patients were enrolled. The mean age of the patients was 16.2 years (range 6-31 years). There were 19 men and 9 women (men/women ratio = 2.1:1). There were 21 patients with solitary tumors and 7 with multiple tumors. These patients were randomized as RT-only treatment group (11 solitary and 3 multiple tumors) and combined (10 solitary and 4 multiple tumors, neo-adjuvant CTX followed by response-adapted RT) treatment group. The follow-up period for RT only group has a median of 58 months (mean 58.2 months, range 41-82 months), and for combine therapy group, the median was 68.5 months (mean 67.8 months, range 41-88 months). All 14 patients in the RT-only group showed complete response (CR) and no recurrence. Eleven patients in the combined group had CR and three patients had partial response after neo-adjuvant CTX. All patients responded to RT as CR without recurrence. At the time of analysis, all 28 patients were alive without evidence of disease.

CONCLUSION

Neo-adjuvant CTX for localized germinomas seems to be unnecessary as a method to reduce radiation dose in our RT protocol. However, the effective control of multifocal or disseminated germinoma can be achieved by neo-adjuvant CTX followed by response-adapted reduced dose RT.

Patterns of failure in patients with primary intracranial germinoma treated with neoadjuvant chemotherapy and radiotherapy

External beam radiotherapy has proven effective in managing intracranial germinoma. However, concerns regarding long-term neurocognitive and endocrine sequelae led to the addition of chemotherapy, to reduce radiation target volumes. There is a paucity of data on patterns of failure in patients treated with differing radiation field sizes. We review our experience at a tertiary children's hospital treating children with intracranial germinoma, using induction chemotherapy followed by radiation therapy to various treatment volumes (craniospinal irradiation, whole ventricular irradiation, whole brain radiation therapy, and focal radiotherapy). Ten patients with primary intracranial germinoma, treated from November 1995-March 2011, were included. The primary treatment involved platinum-based chemotherapy, followed by definitive radiotherapy. The median follow-up period was 4.3 years (range, 0.75-13.25 years). The 5-year overall survival for the entire group was estimated at 85.7%, and the 5-year disease-free survival was estimated at 75.0%. Two treatment failures occurred at 5 and 28 months, both in patients with single lesions in the pineal region treated with focal radiotherapy only. Based on the patterns of failure, our outcomes support the continued use of the whole ventricular field vs a focal field, even in patients with limited disease who demonstrate a complete response to neoadjuvant chemotherapy.

Change in treatment strategy for intracranial germinoma: long-term follow-up experience at a single institute

BACKGROUND

Previous intracranial germinoma (IG) studies have investigated the effect of different radiotherapy (RT) volumes and the necessity for adjunctive chemotherapy, but there is currently no consensus on the best treatment for this tumor.

METHODS

From January 1989 to December 2009, 80 IG patients (≤20 years old) were treated with various RT regimens. Of them, 14 patients had craniospinal irradiation (CSI) + primary boost (PB); 8 patients had whole-brain irradiation (WBI) + PB; 31 patients had whole ventricular irradiation (WVI) + PB; and 27 patients had focal RT only. Twenty-nine patients (36.2%) also received systemic chemotherapy (CHT). Survival was estimated by the Kaplan-Meier method and variables affecting survival were analyzed by the Cox proportional hazard model.

RESULTS

Eleven patients (13.8%) developed local recurrence or dissemination after treatment, and 10 of these patients were in the focal RT group. The 5-year relapse-free survival (RFS) for the CSI, WBI, WVI, and focal RT patients were 100%, 85.7%, 100%, and 84.6%, respectively (P = .001). The 5-year overall survival (OS) for CSI, WBI, WVI, and focal RT patients was 100%, 83.3%, 100%, and 87.9%, respectively (P = .125). Focal irradiation (P = .02) and initial use of CHT (P = .021) were negatively associated with RFS.

CONCLUSIONS

Focal RT plus CHT were associated with inferior control of IG and a higher incidence of CHT-related toxicities. Adjustment of the radiation volume to the whole ventricular system without CHT is sufficient for treatment of nondisseminated IGs, even with lower primary RT doses (<36 Gy).

Clinical outcomes of adult patients with primary intracranial germinomas treated with low-dose craniospinal radiotherapy and local boost

The authors document the long term follow up of adult patients with histologically proven primary intracranial germinoma treated with radiotherapy alone using a craniospinal with local boost technique. A retrospective review was conducted on adults diagnosed with intracranial germinoma who received radiotherapy at the Princess Margaret Hospital, Toronto from 1990 to 2007. The study group consisted of 10 males with a median age of 24.1 years. All patients received radiotherapy alone using craniospinal radiotherapy and local boost. There were 10 patients (all male) with a median follow up of 10.9 years (range 2.2-18.9 years). At date of last follow up all patients were still alive, none with relapsed disease. Seven of ten patients (70%) had panhypopituitarianism prior to commencing radiotherapy and hormonal function was not affected in those with an intact pituitary axis. There was no reported cognitive decline in the treated cohort. For adult intracranial germinomas, with long term follow up, low-dose craniospinal radiotherapy with in field boost is highly effective with minimal morbidity.

Primary chemotherapy for intracranial germ cell tumors: results of the third international CNS germ cell tumor study

BACKGROUND

The treatment of central nervous system (CNS) germ cell tumors (GCT) remains controversial. The purpose of this study was to demonstrate efficacy of a chemotherapy only strategy, with less morbidity, when compared to regimens with irradiation.

METHODS

Between January 2001 and December 2004 newly diagnosed patients with CNS GCT were treated with one of two risk-tailored chemotherapy regimens. Twenty-five patients aged 4 months to 24.5 years were stratified: Regimen A consisted of 4-6 cycles of carboplatin/etoposide alternating with cyclophosphamide/etoposide for low risk (LR) localized germinoma with normal cerebrospinal fluid (CSF) and serum tumor markers. Regimen B consisted of 4-6 cycles of carboplatin/cyclophosphamide/etoposide for intermediate-risk (IR) germinoma with positive human chorionic gonadotrophin-beta (HCGbeta) and/or CSF HCGbeta <50 mIU/ml and high-risk (HR) biopsy-proven non-germinomatous malignant elements (MMGCT) or elevated serum/CSF alpha-fetoprotein and/or HCGbeta serum/CSF >50 mIU/ml.

RESULTS

Eleven patients were classified as LR, 2 IR, and 12 HR. Seventeen (68%) patients achieved complete radiographic and marker responses after two courses and 19 (76%) after four courses of chemotherapy. Eleven patients relapsed at a mean of 30.8 months; eight of them subsequently received irradiation. The 6-year event free and overall survival for the 25 patients was 45.6% and 75.3%, respectively.

CONCLUSION

These intensive chemotherapy regimens proved less effective than irradiation containing regimens. Our results indicate that, at the present time, standard treatment for CNS GCT continues to include irradiation either alone or combined with chemotherapy for pure germinomas and with chemotherapy for those with MMGCT.

Long-term follow-up of dose-adapted and reduced-field radiotherapy with or without chemotherapy for central nervous system germinoma

PURPOSE

To update our institutional experience with neoadjuvant chemotherapy and minimized radiotherapy vs. radiation monotherapy for intracranial germinoma.

METHODS AND MATERIALS

We retrospectively reviewed records of 59 patients with diagnosis of primary intracranial germinoma between 1977 and 2007. Treatment was irradiation alone or neoadjuvant platinum-based chemotherapy and local irradiation (initial tumor plus margin) for patients with localized complete response and reduced-dose craniospinal irradiation for others.

RESULTS

For the chemoradiotherapy group (n = 28), median follow-up was 7 years. No patient died. The freedom from progression (FFP) rate was 88% at 5 years and 80% at 10 years. In 4 patients, disease recurred 1.1 to 6.8 years after diagnosis. All were young male patients who received 30.6 Gy to local fields after complete response to chemotherapy. The FFP rate was 88% for local irradiation vs. 100% for more extensive fields (p = .06). For the radiotherapy-alone group (n = 31), median follow-up was 15 years. Overall and disease-free survival rates were 93% and 93% at 5 years and 90% and 87% at 15 years. In 5 patients, disease recurred 1.1 to 4.9 years after diagnosis. Most patients in this group were young men 18 to 23 years of age with suprasellar primary disease treated with about 50 Gy to local fields. The FFP rate was 44% for local irradiation vs. 100% for more extensive fields (p < .01).

CONCLUSIONS

The addition of neoadjuvant chemotherapy to local-field radiotherapy reduced central nervous system cancer recurrence when high-risk patients were excluded by thorough pretreatment staging. There was trend toward improved central nervous system tumor control when larger fields (whole brain, whole ventricle, or craniospinal axis) were used.

Optimal treatment strategy for intracranial germ cell tumors: a single institution analysis

OBJECT

This study retrospectively analyzed the long-term outcomes of 108 consecutive patients to establish the classification and optimal treatment strategy for each subgroup of newly diagnosed germ cell tumors (GCTs).

METHODS

A retrospective review of medical records from the authors' department between April 1989 and March 2007 identified 108 patients with newly diagnosed intracranial GCT. The diagnoses were germinoma in 83 patients, and nongerminomatous GCT (NGGCT) in 25 patients.

RESULTS

In patients with germinoma, the 10-year overall and progression-free survival (PFS) rates at a median follow-up period of 99 months were 86 and 74%, respectively. Recurrences developed during a range of 6 to 153 months (median 26 months) after starting the initial therapy. Patients treated only with chemotherapy demonstrated a shorter PFS rate, and patients treated with chemotherapy followed by reduced-dose radiation therapy to the whole ventricle, whole brain, or craniospinal axis showed significantly better PFS than patients treated with only radiation or reduced-dose radiation therapy to the focal field. Nongerminomatous GCTs were divided into good, intermediate, and poor prognosis groups as proposed by the Japanese Pediatric Brain Tumor Study Group. In the good and intermediate prognosis groups, the 10-year overall and PFS rates were 100 and 93%, respectively. In the poor prognosis group, the 3-year overall and PFS rates were 56 and 29%, respectively. All patients with NGGCTs, in whom the lesions on MR imaging disappeared after combination therapies consisting of resection, radiation therapy, and chemotherapy, remained alive.

CONCLUSIONS

Chemotherapy followed by reduced-dose radiation therapy covering the whole ventricle improves the prognosis for patients with germinoma. Combined therapy of radiation therapy, chemotherapy, and radical resection as an initial or salvage treatment achieved excellent tumor control in the intermediate prognosis NGGCT group. The outcomes were still dismal in the poor prognosis NGGCT group, so initial therapy should target complete disappearance of all lesions on MR imaging.

Central nervous system germ cell tumors: classification, clinical features, and treatment with a historical overview

Central nervous system germ cell tumors are neoplasms that affect children and young adults. They are subclassified into germinoma and nongerminomatous germ cell tumors. The latter include teratoma (mature teratoma, immature teratoma, teratoma with malignant transformation), choriocarcinoma, embryonal carcinoma, yolk sac tumors, and mixtures of these entities. Germinoma with syncytiotrophoblastic giant cells is a variant of germinoma. Germinomas respond well to radiation therapy, but late sequelae due to irradiation have been reported. The results of radiation treatment alone for nongerminomatous germ cell tumor are not satisfactory. Combination radiochemotherapy has been applied, and this yields a good outcome with less toxicity for germinomas and better survival of nongerminomatous germ cell tumors. This article also discusses other issues, including the controversy regarding spinal irradiation and the treatment of recurrent disease.

CNS germinomas: what is the best treatment strategy?

CNS germ cell tumors are rare primary brain malignancies. Germinomas comprise approximately two-thirds of CNS germ cell tumors. Owing to their radiosensitivity, radiotherapy has been used to treat patients with CNS germinomas, with favorable treatment outcomes. Historically, craniospinal irradiation has been used. Given the concerns over long-term toxicities associated with craniospinal irradiation, reduced volume radiotherapy with or without chemotherapy has been employed. Data on the use of different strategies in the treatment of CNS germinomas are emerging but a standard strategy has not been established. This article reviews the different strategies used in the management of CNS germinomas.

Low-dose craniospinal irradiation as a definitive treatment for intracranial germinoma

PURPOSE

To determine the optimal radiotherapy (RT) dose and volume for treatment of intracranial germinoma.

MATERIALS AND METHODS

Eighty-one intracranial germinoma patients (33 pathologically-verified; 48 presumed by radiosensitivity testing) treated with RT alone between 1971 and 2002 were analyzed. The RT volume varied from focal (13) to whole brain (8), or to the entire neuraxis (60). All the cases after 1982 received craniospinal irradiation (CSI). Radiation dose was reduced gradually during the study period from 59 to 39.3 Gy for primary tumors, and from 34.2 to 19.5 Gy for the neuraxis. The median follow-up time was 120 months (48-260 months).

RESULTS

Five- and ten-year relapse-free survival rates were 98.8% and 94.1%, respectively. All the recurrences occurred in the patients who received local (4/13) or whole brain RT (1/8). None of the patients who received CSI suffered from a recurrence. Forty-six patients received 45 Gy or less to the primary site and 22 patients received less than 20 Gy to the spinal axis.

CONCLUSION

Low-dose CSI-based RT should remain the standard treatment for intracranial germinoma. The RT dose can be reduced to 39.3 Gy for primary tumor sites and to 19.5 Gy for the spinal axis.

Late recurrence and salvage therapy of CNS germinomas

Central nervous system (CNS) germinoma is a curable tumor and its recurrence rate after initial therapy may be approximately 10% or higher. This study elucidates the time-course of recurrence and results of salvage therapy. Twenty-five patients with recurrent germinoma treated at Hokkaido University Hospital were retrospectively reviewed. The median age at initial treatment was 12 years (range: 8-37). All patients had been tumor-free for at least 6 months after the initial treatment. The median follow-up period was 134 months (range: 44-338). The median age at first recurrence was 18 years and the median time to the first recurrence was 50 months. Among the patients, 9 (36%) had the first recurrence at 60 months or later. The latest recurrence in a patient occurred 230 months after the initial treatment. The results of salvage therapy were estimated in all 25 patients. Seventeen patients (68%) were salvaged and were tumor-free at the final observation. The remaining 8 patients died of disease. At first recurrence, 11 patients were treated using radiation therapy with or without surgery and 7 out of the 11 patients died due to the recurrent tumor. On the other hand, 13 patients who received salvage chemotherapy and radiotherapy were tumor-free at the last follow-up. In conclusion, late recurrence is not a rare event in patients with CNS germinoma. To identify a true cure rate of this disease, a 10-year or longer observation period may be required. As a salvage therapy, platinum-based chemotherapy followed by wide-field low-dose radiation therapy appears to be effective.

Spinal recurrence from intracranial germinoma: risk factors and treatment outcome for spinal recurrence

PURPOSE

To analyze retrospectively the risk factors of spinal recurrence in patients with intracranial germinoma and clinical outcomes of patients who developed spinal recurrence.

METHODS AND MATERIALS

Between 1980 and 2007, 165 patients with no evidence of spinal metastases at diagnosis were treated with cranial radiotherapy without spinal irradiation. The median follow-up in all 165 patients was 61.2 months (range, 1.2-260.1 months).

RESULTS

After the initial treatment, 15 patients (9.1%) developed spinal recurrences. Multivariate analysis revealed that large intracranial disease (>/=4 cm) and multifocal intracranial disease were independent risk factors for spinal recurrence. Radiation field, total radiation dose, and the use of chemotherapy did not affect the occurrence of spinal recurrences. Of the 15 patients who experienced spinal recurrence, the 3-year actuarial overall survival and disease-free survival (DFS) rates from the beginning of salvage treatments were 65% and 57%, respectively. In the analysis, presence of intracranial recurrence and salvage treatment modality (radiotherapy with chemotherapy vs. radiotherapy alone) had a statistically significant impact on DFS. The 3-year DFS rate in patients with no intracranial recurrence and treated with both spinal radiotherapy and chemotherapy was 100%, whereas only 17% in patients with intracranial recurrence or treated with radiotherapy alone (p = 0.001).

CONCLUSION

Large intracranial disease and multifocal intracranial disease were risk factors for spinal recurrence in patients with intracranial germinoma with no evidence of spinal metastases at diagnosis. For patients who developed spinal recurrence alone, salvage treatment combined with spinal radiotherapy and chemotherapy was effective in controlling the recurrent disease.