Stereotactic Radiosurgery for Pineal Region Tumors

Evaluation of the Perioperative and Postoperative Course of Surgery for Pineal Germinoma in the SIOP CNS GCT 96 Trial

Background: CNS germinoma, being marker-negative, are mainly diagnosed by histological examination. These tumors predominantly appear in the suprasellar and/or pineal region. In contrast to the suprasellar region, where biopsy is the standard procedure in case of a suspected germ-cell tumor to avoid mutilation to the endocrine structures, pineal tumors are more accessible to primary resection. We evaluated the perioperative course of patients with pineal germinoma who were diagnosed by primary biopsy or resection in the SIOP CNS GCT 96 trial. Methods: Overall, 235 patients had germinoma, with pineal localization in 113. The relationship between initial symptoms, tumor size, and postoperative complications was analyzed. Results: Of 111 evaluable patients, initial symptoms were headache (n = 98), hydrocephalus (n = 93), double vision (n = 62), Parinaud syndrome (n = 57), and papilledema (n = 44). There was no significant relationship between tumor size and primary symptoms. A total of 57 patients underwent primary resection and 54 underwent biopsy. Postoperative complications were reported in 43.2% of patients after resection and in 11.4% after biopsy (p < 0.008). Biopsy was significantly more commonly performed on larger tumors (p= 0.002). Conclusions: These results support the practice of biopsy over resection for histological confirmation of pineal germinoma.

Pineal parenchymal tumors. Management with interstitial iodine-125 radiosurgery

PURPOSE

To evaluate the efficacy of interstitial radiosurgery (IRS) for pineal parenchymal tumors (PPTs).

PATIENTS AND METHODS

18 consecutively admitted patients (twelve male and six female, age range 6-68 years, median age 34 years) with PPTs (eight pineocytomas, ten malignant PPTs) were treated at the authors' institution with IRS using stereotactically guided iodine-125 seed implantation ((125)I-IRS) as either primary or salvage therapy. The cumulative tumor surface dose ranged from 40 to 64 Gy. Adjuvant radiotherapy of the whole brain or the craniospine was done in patients with grade III and grade IV PPT. The median follow-up period was 57.4 months (range 6-134 months).

RESULTS

Overall actuarial 5- and 8-year survival rates after IRS were 100% and 86% for pineocytomas, and the overall actuarial 5-year survival rate was 78% for high-grade PPTs. Follow-up magnetic resonance imaging showed complete remission in 72% (13/18) and partial remission in 28% (5/18) of the cases. One patient developed an out-of-field relapse 4 years after partial remission of a pineocytoma, which had already been treated with IRS. There was no treatment-related mortality. Treatment-related morbidity occurred in two patients only.

CONCLUSION

This study indicates that stereotactic (125)I-IRS for the management of PPTs is quite efficient and safe. Due to the low rate of side effects, IRS may develop into an attractive alternative to microsurgery in de novo diagnosed pineocytomas. In malignant PPTs, IRS may be routinely applied in a multimodality treatment schedule supplementary to conventional irradiation.

Endoscopic removal of a central neurocytoma from the posterior third ventricle

Central neurocytoma is a rare benign tumor that most commonly arises within the ventricular system of young adults. Its occurrence in the posterior third ventricle is one of the least reported presentations. These tumors are usually treated by a combination of either biopsy or open surgical resection, often followed by radiation (Gamma knife or Novalis) with or without chemotherapy. A 37-year-old woman with a posterior third ventricle neurocytoma presented with acute signs of aqueductal stenosis. The patient underwent endoscopic assisted gross total resection of the tumor with the aid of intraoperative laser followed by standard third ventriculostomy; no further treatment was required. The patient did not develop any subsequent neurological deficit. A 36-month follow-up was still consistent with a normal neurological examination. Serial post-operative MRIs show neither residual nor recurrent tumor. Thus, posterior third ventricle central neurocytomas are relatively benign tumors that can be successfully removed using a minimally invasive approach, thereby avoiding both the morbidity related to conventional open craniotomy and the potential toxicity of any adjuvant treatment.

Role of Gamma Knife surgery in the management of pineal region tumors

Object

Increasingly, radiosurgery is used to treat pineal region tumors, either as a primary treatment or as an adjunct to conventional radiation therapy. The authors report their experience with Gamma Knife surgery (GKS) for the treatment of pineal region tumors.

Methods

The authors retrospectively reviewed the charts of all patients undergoing GKS at their institution between 1997 and 2005. Seventeen patients underwent GKS for nonmetastatic tumors of the pineal region. All patients were treated using Leksell Gamma Plan treatment planning software (versions 4.12::5.34). The mean treatment volume was 7.42 cm3 (range 1.2–32.5 cm3). Prescribed doses ranged from 12 to 18 Gy. All doses were prescribed to the 50% isodose line. Independent neuroradiologists reviewed all follow-up imaging studies for evidence of progression of disease.

Results

One patient (Case 10) died 6 days after GKS. Mean clinical and imaging follow-up in the remaining 16 cases was 31 months. Local control was established during a mean neuroimaging follow-up period of 31 months (range 1–95) in 16 patients (100%). In 2 of these 16 patients (one with an anaplastic astrocytoma, the other with a primitive neuroectodermal tumor), leptomeningeal and spinal spread of tumor developed despite control of the pineal lesions. There were no new neurological deficits attributable to GKS. Three patients died (including the one who died 6 days after GKS) during the follow-up period.

Conclusions

Excellent control of pineal region brain tumors can be obtained with GKS when it is used in conjunction with surgery, conventional radiation therapy, or both. Patient survival and quality of life can be optimized through the use of multimodal treatment, including surgery, conventional radiation therapy and/or radiosurgery, and chemotherapy, when applicable.

Less Common Indications for Stereotactic Radiosurgery or Fractionated Radiotherapy for Patients with Benign Brain Tumors

Microsurgical resection remains the mainstay of treatment for truly benign brain tumors that can be safely resected because of the potential for permanent cure with most histologic findings, including most of the histologic findings discussed in this article. Physicians must keep in mind the indolent nature of many of the benign brain tumors and realize that many patients are likely to live out normal life spans if tumor control is achieved. Therefore, it is not sufficient simply to consider local tumor control rates and short-term toxicity risks when choosing between surgery, stereotactic radiosurgery, and fractionated radiotherapy. Patients need to be apprised of all therapeutic options and to make their decisions with all information required to evaluate the risks and benefits. For benign brain tumors, these decisions may have consequences that last for decades.

The role of Gamma Knife radiosurgery in the treatment of pineal parenchymal tumours

OBJECT

The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep and well limited tumors, in the management of pineal parenchymal tumors (PPT).

POPULATION AND METHODS

We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy).

RESULTS

With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing. Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures. At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery.

CONCLUSION

This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas. It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy for the management of malignant pineal tumors.

The role of radiosurgery for the treatment of pineal parenchymal tumors

OBJECTIVE

Radiosurgery is an appealing alternative management strategy for selected patients with biopsy-proved pineal parenchymal tumors. The purpose of this report was to clarify its role in conjunction with other surgical, radiation, and medical approaches.

METHODS

We retrospectively evaluated 16 patients who had undergone radiosurgery as the primary or adjuvant treatment for pineal parenchymal tumors. Ten patients (62.5%) had pineocytomas, two (12.5%) had mixed pineocytoma and pineoblastoma, and four (25%) had pineoblastomas. The mean marginal dose was 15 Gy, and the mean tumor volume was 5.0 cm(3). The mean follow-up periods from the time of diagnosis or the time of radiosurgery were 61 and 52 months, respectively.

RESULTS

The overall actuarial 2- and 5-year survival rates after diagnosis were 75.0 and 66.7%, respectively. In 14 patients who were evaluated with imaging, 4 (29%) demonstrated complete remission, 8 (57%) had partial remission, 2 (14%) had no change, and no patient had local progression. The local tumor control rate (complete remission, partial remission, or no change) was 100%. Five patients died during follow-up. One patient with a pineocytoma and three patients with pineoblastomas died secondary to leptomeningeal or extracranial spread tumor. No cause of death was established for one patient. Two patients developed adverse radiation effects after radiosurgery.

CONCLUSION

Our initial experience suggests that stereotactic radiosurgery is a valuable primary management modality for patients with pineocytomas. As adjuvant therapy, radiosurgery may be used to boost local tumor dose during multimodality management of malignant pineal parenchymal tumors.

Pineal region tumors and the role of stereotactic biopsy: review of the mortality, morbidity, and diagnostic rates in 370 cases

OBJECTIVE

It is classically considered that the morbidity and mortality rates are greater for stereotactic biopsies of pineal region tumors, compared with tumors in other regions. However, to date, the number of cases studied in the literature has been insufficient to evaluate these parameters and compare them with the morbidity and mortality rates for stereotactic biopsies of tumors located elsewhere.

METHODS

With the aim of evaluating these parameters, we reviewed 370 stereotactic biopsies of pineal region tumors, from 15 French neurosurgical centers. We statistically verified the absence of heterogeneity of the different French centers with regard to diagnostic, mortality, and morbidity rates. In contrast, statistical heterogeneity was clearly seen for the large stereotactic biopsy series (for all tumor locations) in the literature.

RESULTS

The mortality rate was 1.3% (5 patients of 370), and 3 patients suffered severe neurological complications. This study is the first to clearly demonstrate that the mortality, morbidity, and diagnostic rates for stereotactic biopsies are not different in the pineal region.

CONCLUSION

Our conclusion is that stereotactic biopsy must remain a main diagnostic modality for tumors of the pineal region.

Intracranial germ-cell tumours--treatment results and residuals

There is only sparse information about the development of children after successful treatment for intracranial germ-cell tumours. Between January 1981 and June 1992, 26 children with intracranial germ-cell tumours were treated in the University Hospital Hamburg-Eppendorf. We report on treatment results, long standing residuals and the "quality of life" of these patients. The long-term event-free survival was 88% for the germinomas and 43% for the malignant teratomas. Of the patients 58% had no relevant functional neurological deficits and 37% had mild impairment. Only 1 patient with metastatic disease was severely handicapped. Six patients showed neuro-endocrine dysfunction. All of them had suprasellar/hypothalamic lesions and all received successful substitution therapy. As to neuropsychological functions, 53% of the patients had no or only mild disturbances. The most affected function was speed of information processing. Of the children 69% were able to proceed with their education at the same level as before therapy. The overall self-assessment revealed good results in 75% of the patients.

CONCLUSION

After surgical removal and radiation therapy long-term survival of intracranial germinomas amounts to 88%. Despite craniospinal axis radiation severe residuals are rare and a good quality of life is common. In malignant teratomas treatment regimens including chemotherapy are much less successful.

The lazaroid U74389G protects normal brain from stereotactic radiosurgery-induced radiation injury

PURPOSE

To test an established model of stereotactic radiosurgery-induced radiation injury with pretreatments of either methylprednisolone or the lazaroid U74389G.

METHODS AND MATERIALS

Nine cats received stereotactic radiosurgery with a linear accelerator using and animal radiosurgery device. Each received a dose of 125.0 Gy prescribed to the 84% isodose shell to the anterior limb of the right internal capsule. One animal received no pretreatment, two received citrate vehicle, three received 30 mg/kg of methylprednisolone, and three received 5 mg/kg of U74389G. After irradiation, the animals had frequent neurologic examinations, and neurologic deficits developed in all of them. Six months after the radiation treatment, the animals were anesthetized, and had gadolinium-enhanced magnetic resonance (MR) scans, followed by Evans blue dye perfusion, euthanasia, and brain fixation.

RESULTS

Magnetic resonance scans revealed a decrease in the size of the lesions from a mean volume of 0.45 +/- 0.06 cm(3) in the control, vehicle-treated, and methylpredniosolone-treated animals to 0.22 +/- 0.14 cm(3) in the U74389G-treated group. The scans also suggested the absence of necrosis and ventricular dilatation in the lazaroid-treated group. Gross pathology revealed that lesions produced in the untreated, vehicle-treated, and methylprednisolone-treated cats were similar and were characterized by a peripheral zone of Evans blue dye staining with a central zone of a mature coagulative necrosis and focal hemorrhage. However, in the U74389G-treated animals, the lesions were found to have an area of Evans blue dye staining, but lacked discrete areas of necrosis and hemorrhage.

CONCLUSION

These results suggest that the lazaroid U74389G protects the normal brain from radiation injury produced by stereotactic radiosurgery.

Prediction of complications in gamma knife radiosurgery of arteriovenous malformation

The incidence of complications following radiosurgical treatment of arteriovenous malformations (AVM) is presented. A simple relationship exists between average dose and risk of complications, and on this basis a model is presented that gives a qualitatively correct description of this relationship. The parameters of the model have been determined using a clinical material of 862 AVM treatments to give a quantitatively correct description of the risk of complications. The dose-response curve is described by a double-exponential function. An accurate description of the dose-response curve at high dose levels is shown to be very important in radiosurgery.