Gamma knife radiosurgery for central neurocytoma: primary and secondary treatment

BACKGROUND: Little is known about long-term results of gamma knife (GK) stereotactic radiosurgery (SRS) as a primary or a secondary postoperative therapy for central neurocytomas (CNs). The authors retrospectively reviewed long-term outcomes of 13 patients with CN treated with GK SRS. METHODS: Thirteen patients were treated with GK SRS as a primary (6 patients) or a secondary postoperative therapy (7 patients). Follow-up clinical status and brain magnetic resonance imaging (MRI) were thoroughly analyzed. The functional status of patients was assessed with the Karnofsky Performance Scale during follow-up. RESULTS: The median follow-up period for clinical status and imaging studies was 61 months (range, 6 months to 96 months). Tumors decreased in 5 patients who received GK SRS as a primary treatment. However, the tumor recurred in 2 patients treated with a secondary GK SRS after surgery from the residual tumor bed that was not covered by the GK SRS. Parenchymal changes and secondary malignancies were not found in follow-up MRIs of all 13 patients. The Karnofsky Performance Scale score of all patients, except for 1 patient who suffered from an unrelated anteriorly communicating arterial aneurysmal rupture, did not change after GK SRS. CONCLUSIONS: GK SRS may be useful as a primary or a secondary postoperative therapy for the treatment of CN. However, more attention should be paid to residual or recurrent CN during treatment, and regular long-term follow-up MRI should be mandatory to validate the procedure.     

Central Neurocytoma: A Review

Central neurocytomas are rare intraventricular neoplasms of the central nervous system, compromising 0.25-0.5% of brain tumors. The diagnosis and management of these tumors remains controversial since most clinical series are small. Typically, patients with central neurocytomas have a favorable prognosis, but in some cases the clinical course is more aggressive. Although histological features of anaplasia do not predict biologic behavior, proliferation markers including MIB-1 might be more useful in predicting relapse. The most important therapeutic modality is surgery, and a safe maximal resection confers the best long-term outcome. In cases of a subtotal resection,'standard external beam radiation can be added or radiation can be delayed until tumor progression occurs. Smaller residual tumor volumes or recurrences can be treated with more conformal radiation or focused radiosurgery. Re-operation for recurrence should be considered if the procedure can be safely performed. Chemotherapy may be useful for recurrent central neurocytomas that cannot be resected and have been radiated, although long-term responses have not been reported for chemotherapy. Overall, this paper reviews the findings of the larger studies and highlights some of the important case reports that contribute to the current management of central neurocytomas.     

Linear Accelerator Radiosurgery for Central Neurocytoma: A Case Report

This study presents a case of central neurocytoma successfully treated with linear accelerator (LINAC) stereotactic radiosurgery. Originally, the tumor in the left lateral ventricle was removed by craniotomy, but a small residual mass was detected in follow-up magnetic resonance imagery 6 months after the operation. A further 6 months later, additional radiographic studies revealed that the residual mass had grown. LINAC radiosurgery was then performed, in which 1750cGy doses were delivered at the 70% level with 3 isocenters (collimator size, 2cm). The mass was completely absent over the duration of follow-up, including the final MR imagery examination 51 months after radiosurgery. LINAC radiosurgery is suggested to be a good treatment modality for residual or recurrent central neurocytoma.     

Gamma knife radiosurgery for treatment resistant choroid plexus papillomas

Objective To report the results of gamma knife radiosurgery (GKR) for treatment resistant choroid plexus papillomas. Methods Six patients (median age 55 years; range 29-75) with residual (n = 2) or recurrent (n = 4) choroid plexus papillomas underwent GKR. All failed prior surgery and one failed prior proton beam radiation therapy. These six patients had a total of 11 locally or distant recurrent intracranial tumors. The median and mean tumor volumes were 2.7 and 3.9 cc (range, 0.23-21.1). A median margin dose of 12.0 Gy (range, 11.5-15) was prescribed to the tumor margin. Results The progression-free periods varied from 7 to 108 months (mean: 36.9). Four tumors were stable after GKR but seven showed progression. Four recurrent tumors in two patients were managed with repeat radiosurgery and three were observed. At the second GKR, the tumor volume varied from 1.3 to 12.4 cc, and the marginal radiation dose varied from 11 to 14 Gy. The overall survival after the first GKR varied from 15 to 120 months. Four patients were alive at the end of the study period. Conclusions Radiosurgery represents an additional management strategy for patients who progress despite surgical removal. It may especially be useful for patients with small deep seated residual choroid plexus papillomas, and for tumors that recur at a site distant from their origin.     

Melanotic neuroectodermal tumor of the brain recurring 12 years after complete remission: case report

We describe a rare case of melanotic neuroectodermal tumor (MNT) of the brain recurring 12 years after complete remission. An 11-year-old girl initially presented with exotropia and bilateral papilledema. Magnetic resonance (MR) imaging revealed an intracranial extraaxial large tumor at the midfrontal region. T₁-weighted MR imaging showed the tumor to be well delineated with homogeneous enhancement by gadolinium. The tumor was subtotally removed, and the histological diagnosis was MNT. The residual tumor became enlarged, so gamma knife radiosurgery was performed 5 months after initial surgery. The enhanced lesion disappeared, but another lesion emerged 3 years later. A second gamma knife radiosurgery was performed for this local recurrence. The enhanced lesion disappeared once again. Twelve years after the second gamma knife radiosurgery, another local recurrence was detected. This tumor was subtotally removed. Histological examination confi rmed the same diagnosis of MNT. This case suggests that MNTs not completely resected need long-term follow up, even if complete remission was achieved after adjuvant therapy.     

Phase II study of high central dose Gamma Knife radiosurgery and marimastat in patients with recurrent malignant glioma

: To assess the outcome of high central dose Gamma Knife radiosurgery plus marimastat in patients with recurrent malignant glioma.

: Twenty-six patients with recurrent malignant glioma were enrolled in a prospective Phase II study between November 1996 and January 1999. The radiosurgery dose was prescribed at the 25–30% isodose surface to increase the dose substantially within the tumor’s presumably hypoxic core. Marimastat was administered after radiosurgery to restrict regional tumor progression. Survival was compared with that of historical patients treated at our institution with standard radiosurgery.

: The median times to progression after radiosurgery for Grade 3 and 4 patients was 31 and 15 weeks, respectively. The corresponding median survival time after radiosurgery was 68 and 38 weeks. The median survival time after radiosurgery in the historical patients was 59 and 44 weeks.

: The dual strategies of using high central dose radiosurgery to overcome tumor hypoxia together with marimastat to inhibit local tumor invasion may offer a small survival advantage for recurrent Grade 3 tumors; they do not offer an advantage for recurrent Grade 4 tumors.     

伽玛刀治疗残留和复发颅底脊索瘤的疗效评估

目的：评估伽玛刀治疗残留和复发的颅底脊索瘤的疗效及安全性。方法：对27例残留和复发颅底脊索瘤进行伽玛刀治疗。肿瘤治疗平均周边剂量为11．8±2．1Gy（8—15Gy）,以40％～55％等剂量曲线覆盖病灶。伽玛刀治疗后定期进行随访观察,统计分析肿瘤控制情况及并发症发生情况。结果：共24例患者获得随访资料,平均随访27．8±7．9个月。15例（62．5％）患者临床症状获得不同程度改善,8例无明显变化（33．3％）,1例加重（4．2％）。24例患者共接受伽玛刀治疗31次。至随访结束,共有3人死亡。未观察到与伽玛刀治疗直接相关的近远期严重并发症。结论：对于手术和常规放射治疗后残留或复发的脊索瘤,伽玛刀治疗是一种安全、有效的放射治疗手段,可以显著改善患者预后和生活质量。     

Value of postoperative stereotactic radiosurgery and conventional radiotherapy for incompletely resected typical neurocytomas

BACKGROUND: Two groups of central neurocytomas have been identified: typical and atypical neurocytomas. The more benign typical neurocytomas have a better prognosis. Complete resection of typical neurocytomas results in significantly better outcome than incomplete resection. The current study investigated whether the outcome after incomplete resection can be improved by postoperative stereotactic radiosurgery (SRS) or by conventional radiotherapy. METHODS: The data of all neurocytoma patients reported since 1997, when the first neurocytoma patient treated with SRS was described, were reviewed. Patients who underwent complete resection or those with atypical neurocytoma were excluded from the analysis. Three different therapies were compared for overall survival (OS) and local control (LC): incomplete resection alone (ITR), ITR followed by conventional radiotherapy (ITR+cRT), and ITR followed by stereotactic radiosurgery (ITR+SRS). RESULTS: Data were complete in 121 patients (59 ITR, 41 ITR+cRT, and 21 ITR+SRS). The 5-year-LC after ITR was 51%. LC was significantly better after ITR+cRT (87%, P = 0.001) and after ITR+SRS (100%, P = 0.004). The difference between ITR+cRT and ITR+SRS was not significant (P = 0.45). The 5-year-OS was 93% after ITR, 100% after ITR+cRT, and 100% after ITR+SRS. The differences between the various groups were not significant. The P-values were 0.13 for ITR versus ITR+cRT, 0.29 for ITR versus ITR+SRS, and 1.0 for ITR+cRT versus ITR+SRS. CONCLUSIONS: After ITR of typical neurocytomas, LC is significantly improved by both conventional radiotherapy and SRS. The results of both radiation treatments were similar. SRS is a reasonable alternative to conventional radiotherapy in selected patients.     

Gamma knife radiosurgery for the treatment of glomus jugulare tumors

The treatment of glomus jugulare tumors represents a challenge for the neurosurgeon, since they invade major vessels and compress critical cranial nerves, resulting in significant morbidity from tumor resection. Among alternative and complementary treatment options, gamma knife radiosurgery is a less invasive procedure and may provide better protection of vital structures. This study aimed to evaluate the efficacy and long-term outcomes of gamma knife surgery in the treatment of these tumors in a large series with the longest follow-up period compared with previous reports. A total of 18 patients with glomus jugulare tumors that underwent gamma knife radiosurgery (GKS) were included. Eleven patients had a history of previous microsurgical treatment. The mean marginal radiation dose was 15.6 Gy (median 15 Gy, range 13–20 Gy). Patients were followed for a mean period of 52.7 months (median 41.5 months); the effect of gamma knife radiosurgery was evaluated using magnetic resonance (MR) images. Based on the last MR images, tumor control could be achieved in 17 out of 18 patients (94.4%). No complications such as radiation-induced peritumoral edema or radiation necrosis occurred. Neurological follow-up examinations revealed improved clinical status in ten patients (55.6%), stable neurological status in seven (38.9%), and deterioration in one patient (5.5%). At the last visit, 17 out of 18 patients were alive. Our results indicate that stereotactic radiosurgery is an effective and safe treatment modality in the management of glomus jugulare tumors, particularly for residual or previously untreated small tumors.     

Stereotactic radiosurgery for pilocytic astrocytomas part 2: outcomes in pediatric patients

To assess outcomes after stereotactic radiosurgery (SRS) for newly diagnosed or recurrent pilocytic astrocytomas in pediatric patients. Fifty patients (28 male and 22 females) with juvenile pilocytic astrocytomas (JPA) underwent Gamma knife SRS between 1987 and 2006. The median patient age was 10.5 years (range, 4.2–17.9 years). Three patients had failed prior fractionated radiation therapy (RT) and two had failed RT and chemotherapy. The median radiosurgery target volume was 2.1 cc (range, 0.17–14.4 cc) and the median margin dose was 14.5 Gy (range, 11–22.5 Gy). At a median follow-up of 55.5 months (range 6.0–190 months), one patient died and 49 were alive. The progression free survival after SRS (including tumor growth and cyst enlargement) for the entire series was 91.7, 82.8 and 70.8% at 1, 3 and 5 years, respectively. Stereotactic radiosurgery for pediatric pilocytic astrocytomas should be considered when resection is not feasible, or if there is an early recurrence. The best response was observed in small volume residual solid tumors.     

Management of neurocytomas: case report and review of the literature

The purpose of this report is to review the available literature on the presentation, pathology, and treatment of central nervous system (CNS) neurocytomas. A case report of an extraventricular neurocytoma is presented along with a comprehensive literature search of patients with a diagnosis of CNS neurocytoma. CNS neurocytomas are rare neoplasms, with fewer than 240 cases reported in the literature. The majority of neurocytomas are found in the ventricular system of the brain. Immunohistochemistry is frequently used to help distinguish this tumor from other CNS neoplasms. MIB-1 proliferation index is commonly used in an attempt to predict biologic behavior. Little is known about the management of patients with this tumor, because most reports are from the pathologic literature and contain sparse information regarding clinical management. Neurocytomas are rare CNS tumors with varied biologic behavior. MIB-1 index may help direct adjuvant therapy. An excellent prognosis can be expected if a gross total resection is achieved. Postoperative radiation therapy (RT) may be considered after subtotal resection. Otherwise, RT is an option for medically inoperable or recurrent disease.     

Mid-term prognosis of non-functioning pituitary adenomas with high proliferative potential: really an aggressive variant?

Pituitary adenomas with high proliferation rate and rapid growth are well known, but the clinical characteristics, prognosis, and treatment algorithm remain unclear. The clinical characteristics and mid-term prognosis of patients with non-functioning pituitary adenomas with high proliferative potential were retrospectively investigated. This study identified 53 patients with Ki-67 labeling index of > 3% among 845 patients with non-functioning pituitary adenoma (6.3%) initially treated by surgery. Prophylactic treatment was not applied for patients with residual tumor, but salvage treatment was performed if tumor progression was identified within the follow-up period. Twenty-two patients remained progression-free, whereas 31 patients suffered tumor progression. Comparison of gross total removal (n?=?22) and non-total removal (n?=?31) groups showed significantly longer progression-free period in the former group (P?<?0.001). As salvage treatment gamma knife radiosurgery was applied for 11 patients resulting in 10 patients remaining progression-free and regrowth in 1 patient. Fractionated irradiation was applied for 10 patients, resulting in 2 patients remaining progression-free, deaths in 5 patients including 3 of transformation to pituitary carcinoma, dementia in 1 patient caused by frontal lobe dysfunction, and progression in 2 patients requiring additional surgery and gamma knife radiosurgery. Temozolomide was administered in 2 patients, resulting in deaths in both patients including 1 transformation to pituitary carcinoma. Total removal and gamma knife radiosurgery can result in good outcome. However, the prognosis is extremely poor for patients inadequate for gamma knife radiosurgery. Development of new salvage treatments is essential.     

低级别胶质瘤伽玛刀术后的磁共振研究

ObjectiveTo evaluate the therapeutic efficacy of low-grade glioma (WHO grades Ⅰ-Ⅱ) patients treated with gamma knife radiosurgery and study on the efficacy evaluation method and radiobiological effect.Methods140 MRI data of 52 patients after gamma knife radiosurgery were analyzed in tumor size,necrosis or cyst formation,radiation-induced edema and MRI contrast enhancement and circumsciption change for therapeutic efficacy was evaluated.ResultsThe efficiency rate was 84.3%.The salient efficiency rates were 54.3% for total and 30%,36.4%,50%,68%,69.2%,and 73.1% for segmenting,respectively.Aggrandizement of tumor related to MRI contrast enhancement and necrosis or cyst formation.Radiation-induced oedema occurred for 32.7%.The MRI contrast enhancement occurred for 57.7% and showed special lace-like ring while some piece-like.ConclusionEvaluation by MRI has showed gamma knife radiosurgery is efficient for low-grade glioma.The segmenting salient efficiency rate that increase with time is better for evaluation than the efficiency rate especially for long-term MRI follow-up.Radiobiological effect affect the efficacy evaluation.MRI contrast enhancement appears after therapy and shows special as lace-like ring and partly minificates or vanishes subsequently.     

Two cases of lung cancer patients with postoperative brain metastases obtaining long-term survival after gamma knife radiosurgery

We report two cases of lung cancer patients with postoperative solitary brain metastases obtaining long-term survival after gamma knife stereotactic radiosurgery. Both were seventies men and had good performance status without active extracranial disease. In one case, an asymptomatic metastatic brain tumor 1.8 cm in maximum diameter appeared one year and two months after the operation and was irradiated with gamma knife resulting in complete local control for seven years. He is alive with solitary lung metastasis in good performance status. In the other case, gamma knife was employed for a metastatic brain tumor 2.7 cm in maximum diameter that appeared nine months after the operation accompanying incomplete left hemiplegia. Six months later, the tumor was enlarged and gamma knife was repeated, but the tumor growth could not be suppressed. Following deterioration of hemiplegia and appearance of convulsion, he died of neurological disorder three years and two months after the onset of brain metastasis. Gamma knife stereotactic radiosurgery for metastatic brain tumors is less invasive and a repeatable technique, and is expected to provide a good local control and a survival benefit for appropriately selected patients.     

Stereotactic gamma radiosurgery for pineal and related tumors

The role of gamma knife radiosurgery as an additional therapy after conventional treatments for pineal and related tumors was studied in 30 of 33 tumors with a mean follow-up of 23.3 months. Overall results showed that a complete response was obtained in 8 cases (26.7%) and the response rate was 73.3%. However, tumor progression was found in 8 cases (26.7%), of whom 7 (23.3%) died as a consequence. Germinoma and pineocytoma showed higher response and control rates (100%), and neither progression nor death occurred after gamma knife treatment. Germinoma with syncytiotrophoblastic giant cells (STGC) has been thought to have an intermediate prognosis. Two of our cases showed a partial response and another progression. Malignant germ cell tumor and pineoblastoma showed unfavorable responses and prognosis, with the response and progression rates both being 50%.Gamma knife radiosurgery was the initial treatment in three pineal tumor cases without a histological diagnosis, and one complete and two partial responses were obtained.Gamma knife radiosurgery is expected to be an effective and novel approach to pineal and related tumors, not only as an adjuvant but also as an initial treatment.     

Gamma knife radiosurgery for patients with nonfunctioning pituitary adenomas: results from a 15-year experience

PURPOSE: To evaluate the efficacy and complications of stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas (NFA). METHODS AND MATERIALS: This was a retrospective review of 62 patients with NFA undergoing radiosurgery between 1992 and 2004, of whom 59 (95%) underwent prior tumor resection. The median treatment volume was 4.0 cm(3) (range, 0.8-12.9). The median treatment dose to the tumor margin was 16 Gy (range, 11-20). The median maximum point dose to the optic apparatus was 9.5 Gy (range, 5.0-12.6). The median follow-up period after radiosurgery was 64 months (range, 23-161). RESULTS: Tumor size decreased for 37 patients (60%) and remained unchanged for 23 patients (37%). Two patients (3%) had tumor growth outside the prescribed treatment volume and required additional treatment (fractionated radiation therapy, n = 1; repeat radiosurgery, n = 1). Tumor growth control was 95% at 3 and 7 years after radiosurgery. Eleven (27%) of 41 patients with normal (n = 30) or partial (n = 11) anterior pituitary function before radiosurgery developed new deficits at a median of 24 months after radiosurgery. The risk of developing new anterior pituitary deficits at 5 years was 32%. The 5-year risk of developing new anterior pituitary deficits was 18% for patients with a tumor volume of < or = 4.0 cm(3) compared with 58% for patients with a tumor volume >4.0 cm(3) (risk ratio = 4.5; 95% confidence interval = 1.3-14.9, p = 0.02). No patient had a decline in visual function. CONCLUSIONS: Stereotactic radiosurgery is effective in the management of patients with residual or recurrent NFA, although longer follow-up is needed to evaluate long-term outcomes. The primary complication is hypopituitarism, and the risk of developing new anterior pituitary deficits correlates with the size of the irradiated tumor.     

Radiosurgery of Meningeal Melanocytoma

The authors present a case of meningeal melanocytoma arising from Meckel's cave. A coal-black, vascular tumor was partially removed by surgery. Histopathologically, the tumor lacked anaplastic features. Immunohistochemical studies confirmed that the tumor was of neuroectodermal origin and had low proliferating activity. The patient underwent gamma knife radiosurgery for the residual tumor, in which 25Gy of radiation was delivered to the tumor margin. Three years after irradiation, the tumor showed marked shrinkage without complication.     

Stereotactic radiosurgery of residual or recurrent craniopharyngioma, after surgery, with or without radiation therapy

This study evaluated the role of stereotactic radiosurgery in the multimodality management of craniopharyngioma patients whose prior therapies failed. Ten consecutive patients (3 males and 7 females) had radiosurgery for craniopharyngioma during a 10-year interval. Their ages ranged from 9 to 64 years (median, 14.5 years). The median interval between diagnosis and radiosurgery was 46.5 months. In total, 12 stereotactic radiosurgical procedures were performed to control the solid component of the tumor (2 intrasellar and 10 suprasellar tumors). The median tumor volume was 1.35 cm3. One to 9 isocenters with different beam diameters were used; the median marginal dose was 16.4 Gy; and the dose to the optic apparatus was limited to less than 8 Gy. Clinical and imaging follow-up data were obtained at a median of 63 months (range, 13-150 months) from radiosurgery. Overall, 7 of 12 tumors became smaller or vanished within a median of 8.5 months. Prior visual defects objectively improved in 6 patients. One patient with prior visual defect deteriorated further and lost vision 9 months after radiosurgery. Multimodality therapy is often necessary for patients with refractory solid and cystic craniopharyngiomas. Stereotactic radiosurgery is a reasonable option in select patients with small recurrent or residual craniopharyngioma.     

Radiological response and histological changes in malignant astrocytic tumors after stereotactic radiosurgery

Stereotactic radiosurgery is an encouraging approach to deliver higher doses of radiation boost for malignant gliomas safely and precisely. The purpose of this study was to investigate the radiation response and histological changes of malignant astrocytic tumors after stereotactic linac radiosurgery (SLRS). We studied an autopsy case of recurrent glioblastoma multiforme (GBM) and two surgical cases with gross total removal of recurrent GBM and anaplastic astrocytoma transformed from fibrillary astrocytoma treated with SLRS. Destructive changes, such as the disappearance of viable cells, coagulation necrosis, and fibrinoid degeneration of vascular walls, were observed in the center of the target of SLRS, which showed histologically similar radiobiological reactions to well-known delayed central nervous system radiation necrosis caused by conventional radiotherapy. The region showing such radiation necrosis was within the area irradiated with approximately 15–20Gy or more by SLRS; however, dense viable tumor cells remained in the periphery that was irradiated with less than 15 Gy. In a comparative immunohistochemical study of the tumors before and after SLRS, neither MIB-1 and p53 labeling indices nor immunoreactivity for GFAP represented any persistent tendencies. There were very few TUNEL-positive cells in either tumor before and after SLRS. These results showed that radiosurgery for malignant gliomas leads to earlier radiation necrosis than conventional radiation and that it is useful in eradicating tumor cells in the center of the target. However, some viable tumor cells may remain in the periphery irradiated with an insufficient dose for cell death and may be partly transformed in character by DNA damage due to radiation. Proton magnetic resonance spectroscopy (MRS) was suggested to characterize the radiation response in radiosurgery tumor targets for correlation with histological findings.