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PubMed2000

Radiosurgery in the management of pediatric brain tumors.

A total of 114 patients with benign and malignant intracranial tumors were treated by Valentino at the Flaminia Radiosurgical Center using a Philips 6-MeV linear accelerator between 1987 and 1995. The tumor locations break down as follows: 36 in the cerebral hemispheres, 14 in the region of the hypothalamus/optic chiasm, 21 in the III ventricle/pineal region, 3 in the basal ganglia, 27 in the posterior fossa, 13 in the brain stem. Seventy-nine patients had multivariate/combined treatment consisting of surgery or biopsy followed by chemotherapy, radiotherapy and/or radiosurgery. Thirty-five were not operated on or biopsied but were treated primarily by radiosurgery, which was associated with chemotherapy and conventional radiotherapy. The short- and long-term results were evaluated separately for each pathology in an attempt to derive guidelines for future treatment. For tumors of the pineal region, we are of the opinion that radiosurgery is the treatment of choice in children and that more than one-third of patients can be cured by this means. The remaining patients require surgery and/or chemotherapy in addition. For medulloblastomas radiosurgery may be useful to control local recurrence if coupled with chemotherapy. In the case of ependymomas, partly because of the extreme malignancy of the lesions in our series, radiosurgery did not succeed in controlling local recurrence. We fear that limiting treatment to radiosurgery, rather than prescribing conventional radiotherapy when indicated, could permit CNS seeding. For craniopharyngiomas radiosurgery proved useful for controlling solid remnants. In glial tumors radiosurgery helped either to "sterilize" the tumor bed after removal or to treat remnants of the lesions in critical areas; for diffuse brain stem gliomas it should be considered the treatment of choice.

Adolescent↗

PubMed2000

Stereotactic radiosurgery for brain metastases from breast cancer.

BACKGROUND: Stereotactic radiosurgery is an alternative to resection or to radiotherapy alone for patients with brain metastases. Outcomes after radiosurgery for patients with brain metastases specifically from breast cancer have not been defined. METHODS: We retrospectively studied survival and tumor control for all patients with brain metastases from breast cancer who underwent gamma knife stereotactic radiosurgery at the University of Pittsburgh. Univariate and multivariate analyses were used to determine which prognostic factors significantly affected survival. RESULTS: Thirty patients underwent radiosurgery between 1990 and 1997. A total of 58 metastases were treated. The median length of survival for all patients was 13 months from radiosurgery and 18 months from diagnosis of brain metastases. The tumor control rate on follow-up imaging was 93%. On multivariate analysis, the only factor that correlated with longer survival was the absence of multiple brain metastases. Age, presence of systemic disease, previous whole brain radiation, location, and total tumor volume did not significantly affect survival. Four patients had tumors with evidence of radiation-induced edema after radiosurgery but did not require resection. Two patients underwent delayed resection for tumor growth after radiosurgery. CONCLUSIONS: Stereotactic radiosurgery is an effective treatment for brain metastases from breast cancer and is associated with a low complication rate.

Adult↗

PubMed2005

Gamma Knife radiosurgery for intracranial metastatic melanoma: an analysis of survival and prognostic factors.

Objective of this study was to evaluate retrospectively the effectiveness of Gamma Knife radiosurgery for intracranial metastatic melanoma and to identify prognostic factors related to survival. Twenty-six patients with intracranial metastases (72 lesions) from melanoma underwent Gamma Knife radiosurgery. In 14 patients (54%) whole-brain radiotherapy (WBRT) was performed as part of the initial treatment, and in 12 patients (38%) immunotherapy and/or chemotherapy was given after Gamma Knife radiosurgery. The median tumor volume for Gamma Knife radiosurgery treated lesions was 1.72 cm3. The median prescribed radiation dose was 18 Gy (range 8-22 Gy) typically prescribed to the isodose at the tumor margin. Univariate and multivariate analyses were used to determine significant prognostic factors affecting survival. Overall median survival was 6 months after Gamma Knife radiosurgery, and 1-year survival was 25%. The median survival from the onset of brain metastases was 9 months and from the original diagnosis of melanoma was 50 months (range 4-160 months). There were no major acute or late GKS complications. In univariate testing, the Karnofsky score equal to or higher than 90% (P < 0.01, log-rank test), supratentorial localization (P < 0.001, log-rank test), intracranial tumor volume less than 1 cm3 (P < 0.02, log-rank test), and absence of neurological signs or symptoms before Gamma Knife radiosurgery (P < 0.003, log-rank test) were significant favorable factors for survival. In multivariate regression analyses, the most important predictors associated with increased survival were a KPS > or = 90 (P < 0.023), female sex (P < 0.004), supratentorial localization (P < 0.01), and absence of neurological symptoms (P < 0.008). Radiosurgery is a noninvasive, safe, and effective treatment option for patients with single or multiple intracranial metastases from melanoma. Female sex, Karnofsky score > or = 90, supratentorial localization and lack of symptoms before the Gamma Knife radiosurgery were good independent predictors of survival.

Adult↗

PubMed2006

LINAC radiosurgery as single treatment in cerebral metastases.

OBJECTIVE: Stereotactic radiosurgery is a radiation technique of high radiation dose focused on a stereotactic intracranial target in a single fraction with high precision. LINAC Radiosurgery has gained increasing relevance in the treatment of brain metastases since it was introduced by Sturm (1987). METHOD AND PATIENT SELECTION: From January 1996 to August 2003 110 patients were treated with LINAC Radiosurgery. A combination of the University of Florida system and the X Knife System developed by Radionics was used in all patients. Seventy patients had a single and 40 patients multiple metastatic lesions at the time of diagnosis and treatment. Overall 161 intracerebral metastases were treated. Median tumor volume was 3.1 ccm (0.3-15 ccm). Median radiation dose to the tumor margin was 1830 cGy (range 1100-2200 cGy) prescribed to the 80% isodose line. Whole brain radiation therapy with a total dose of 30 Gy in 10 fractions was performed in 35 patients because of multiple metastases and LINAC Radiosurgery was used as boost for recurrences. In 75 patients LINAC Radiosurgery was used as single treatment. RESULTS: The follow-up period was between 6 and 72 months. Local tumor control rate was 89.4%. Seventeen out of 161 metastases treated showed local recurrence. Eleven out of 75 patients treated with radiosurgery as single treatment developed distant recurrence and 3 out of 35 patients who were treated with whole brain radiation therapy (WBRT) and radiosurgery as boost. The 1-year survival rate is 54.9% with a median survival of 54 weeks. CONCLUSION: LINAC Radiosurgery is an effective and safe treatment modality in patients with cerebral metastases located in any area of the brain. WBRT should be preserved for patients with multiple metastases or be delayed until multiple recurrence occurs. Surgery is still the treatment of choice in metastases with mass effect and surgical accessible location.

Adult↗

PubMed1995

Stereotactic radiosurgery as an adjunct to surgery and external beam radiotherapy in the treatment of patients with malignant gliomas.

PURPOSE: To evaluate the efficacy and toxicity of a stereotactic radiosurgery boost as part of the primary management of a minimally selected population of patients with malignant gliomas. METHODS AND MATERIALS: Between June, 1991 and January, 1994 a stereotactic radiosurgery boost was given to 30 patients after completion of fractionated external beam radiotherapy. The study population consisted of 22 males and 8 females, with a range in age at treatment from 5 to 74 years (median: 54 years). Tumor volume ranged from 2.1 to 115.5 cubic centimeters (cc) (median: 24 cc). Histology included 17 with glioblastoma multiforme, 10 with anaplastic astrocytoma, 1 with a mixed anaplastic astrocytoma-oligodendroglioma, and 2 with a gliosarcoma. A complete resection was performed in 9 (30%) patients, while 18 (60%) underwent a subtotal resection, and 3 (10%) received a biopsy only. Fractionated radiation dose ranged from 44 to 62 Gy, with a median of 59.4 Gy. Prescribed stereotactic radiosurgery dose ranged from 0.5 to 18 Gy (median: 10 Gy), and the volume receiving the prescription dose ranged from 2.1 to 158.7 cc (median: 46 cc). The volume of tumor receiving the prescription dose ranged from 70-100% (median: 100%). One to four (median: 2) isocenters were used, and collimator size ranged from 12.5 to 50 mm (median size: 32.5 mm). The median minimum stereotactic radiosurgery dose was 70% of the prescription dose and the median maximum dose was 200% of the prescription dose. RESULTS: With a minimum follow-up of 1 year from radiosurgery, 7 (23%) of the patients are still living and 22 (73%) have died of progressive disease. One patient died of a myocardial infarction 5 months after stereotactic radiosurgery. Follow-up for living patients ranged from 12 to 45 months, with a median of 30 months. The 1- and 2-year disease-specific survival from the date of diagnosis is 57 [95% confidence interval (CI) 39 to 74%] and 25% (95% CI 9 to 41%), respectively (median survival: 13.9 months). No significant acute or late toxicity has been observed. CONCLUSION: Stereotactic radiosurgery provides a safe and feasible technique for dose escalation in the primary management of unselected malignant gliomas. Longer follow-up and a randomized prospective trial is required to more thoroughly evaluate the role of radiosurgery in the primary management of malignant gliomas.

Adolescent↗

PubMed2005

Repeat radiosurgery for idiopathic trigeminal neuralgia.

PURPOSE: Although frequently performed, the efficacy and safety of repeat trigeminal neuralgia radiosurgery is not well described. METHODS AND MATERIALS: Between August 1997 and December 2002, 19 patients (9 men, 10 women) underwent repeat trigeminal neuralgia radiosurgery. The median interval between procedures was 16 months. The median dose (based on an output factor of 0.87 for the 4-mm collimator) for repeat radiosurgery was 76.1 Gy; the median additive dose was 163.1 Gy. Outcomes were defined as excellent (no pain, no medications), good (no pain, reduced medications), fair (>50% pain reduction), and poor. Median follow-up was 24 months. RESULTS: Outcomes after repeat radiosurgery were excellent (n = 14, 74%), good (n = 1, 5%), fair (n = 3, 16%), and poor (n = 1, 5%). Two patients had recurrent pain at 7 and 22 months; 71% and 61% of patients had an excellent outcome at 1- and 2-years after radiosurgery, respectively. Eleven patients (58%) described facial parathesias (n = 3), numbness (n = 5) or dyesthesias (n = 3). Two patients (11%) developed corneal numbness. Nine of 11 patients (82%) with new trigeminal deficits had excellent outcomes at last follow-up compared with 3 of 8 patients (38%) with unchanged facial sensation (p = 0.07). CONCLUSIONS: Repeat trigeminal neuralgia radiosurgery at the dosage described has better facial pain outcomes than primary radiosurgery. However, because the procedure is nonselective and the rate of bothersome numbness was relatively high (16%), dose reduction is recommended to reduce the morbidity of repeat trigeminal neuralgia radiosurgery.

Adult↗

PubMed2005

The American Society for Therapeutic Radiology and Oncology (ASTRO) evidence-based review of the role of radiosurgery for malignant glioma.

PURPOSE: To systematically review the evidence for the use of stereotactic radiosurgery or stereotactic fractionated radiation therapy in adult patients with malignant glioma. METHODS: Key clinical questions to be addressed in this evidence-based review were identified. Outcomes considered were overall survival, quality of life or symptom control, brain tumor control or response and toxicity. MEDLINE (1990-2004 June Week 2), CANCERLIT (1990-2003), CINAHL (1990-2004 June Week 2), EMBASE (1990-2004 Week 25), and the Cochrane library (2004 issue 2) databases were searched using OVID. In addition, the Physician Data Query clinical trials database, the proceedings of the American Society of Clinical Oncology (1997-2004), ASTRO (1997-2004), and the European Society of Therapeutic Radiology and Oncology (ESTRO) (1997-2003) were searched. Data from the literature search were reviewed and tabulated. This process included an assessment of the level of evidence. RESULTS: For patients with newly diagnosed malignant glioma, radiosurgery as boost therapy with conventional external beam radiation was examined in one randomized trial, five prospective cohort studies, and seven retrospective series. There is Level I evidence that the use of radiosurgery boost followed by external beam radiotherapy and carmustine (BCNU) does not confer benefit with respect to overall survival, quality of life, or patterns of failure as compared with external beam radiotherapy and BCNU. There is Level I-III evidence of toxicity associated with radiosurgery boost as compared with external beam radiotherapy alone. The results of the prospective and retrospective studies may be influenced by selection bias. Radiosurgery used as salvage for recurrent or progressive malignant glioma after conventional external beam radiotherapy failure was reported in zero randomized trials, three prospective cohort studies, and five retrospective series. The available data are sparse and insufficient to make absolute recommendations. Stereotactic fractionated radiation therapy has been reported as boost therapy with external beam radiotherapy for patients with newly diagnosed malignant glioma in only three prospective studies. As primary therapy alone without conventional external beam radiotherapy for newly diagnosed malignant glioma patients, stereotactic fractionated radiation therapy has been reported in only one prospective study. There were only three prospective series and two retrospective studies reported for patients with recurrent or progressive malignant glioma. CONCLUSIONS: For patients with malignant glioma, there is Level I-III evidence that the use of radiosurgery boost followed by external beam radiotherapy and BCNU does not confer benefit in terms of overall survival, local brain control, or quality of life as compared with external beam radiotherapy and BCNU. The use of radiosurgery boost is associated with increased toxicity. For patients with malignant glioma, there is insufficient evidence regarding the benefits/harms of using radiosurgery at the time progression or recurrence. There is also insufficient evidence regarding the benefits/harms in the use of stereotactic fractionated radiation therapy for patients with newly diagnosed or progressive/recurrent malignant glioma.

Adult↗

PubMed2004

Adjuvant gamma knife radiosurgery after meningioma resection.

We evaluated the usefulness of adjuvant treatment with gamma knife radiosurgery following meningioma surgery. During the past 8 years, we operated on 78 patients with meningiomas. Among these, 28 patients (36%) received gamma knife radiosurgery postoperatively. The indications for radiosurgery were as follows: residual tumour after surgery in 13 patients (46.4%), regrowth of residual tumour during the follow-up period in 7 patients (25%), recurrence after total removal (Simpson grade 1 or 2) in 7 patients (25%), and another intracranial meningioma in one patient (3.6%). The tumour diameter at the time of radiosurgery ranged from 5.2 to 48.1 mm (median 21.6 mm). Larger tumours with a mean diameter above 40 mm in two patients were treated with two-staged radiosurgery. The tumor marginal dose ranged from 8 to 23 Gy (median 12 Gy). The follow-up period was 3-84 months (median 30 months) after radiosurgery. The tumour size decreased in 17 patients (60.7%), remained unchanged in 9 patients (32.1%), and increased in 2 patients (7.2%). No radiation injury was experienced. Adjuvant therapy using gamma knife radiosurgery for meningiomas can achieve control of tumour growth and may improve patient outcomes. Careful surgical planning and follow-up are required to understand the usefulness and limitations of radiosurgery in this setting.

Adult↗

PubMed2003

Surgery combined with radiosurgery of large acoustic neuromas.

UNLABELLED: The treatment of acoustic neuromas has been improved by advancements in microsurgical techniques and in radiosurgery. To further elucidate the degree of clinical improvement, we evaluated the treatment results of a combination of surgery and radiosurgery for large acoustic neuromas. METHODS: From January 1994 through December 2000, we treated 14 patients with large acoustic neuromas using a combination of surgery and radiosurgery. Of these, 8 were male and 6 were female patients, with an average age of 47 years (range, 18-64). The average maximum diameter of the tumor was 42 mm (range, 30-58 mm). All patients underwent operations using the retrosigmoid approach, and one patient was retreated using the transpetrosal transtentorial approach. The tumors were removed subtotally in thirteen patients and partially in one who had a very large hypervascular acoustic neuroma. There were no mortality and no surgical complications, such as hemorrhage or CSF leakage. Postoperative facial palsy was avoided in 10 patients (71%). Radiosurgery was performed 1 to 6 months (mean, 2.9 months) after surgery. At the time of radiosurgery, the treatment size (mean diameter) became 19.2 mm (range, 9.8-36.1 mm). The average tumor marginal dose was 12.1Gy (range, from 10-14 Gy). The mean follow-up period was 32 months after radiosurgery. RESULTS: The tumor size decreased in 6 patients, unchanged in 5 patients, and increased in 3 patients. Only 1 patient (7%) with extra large tumor needed surgical resection 1 year after radiosurgery. Excellent facial nerve function (House & Brackmann Grade I or II) was preserved in 12 patients (85.7%) in the final follow-up. CONCLUSIONS: In the case of large acoustic neuromas, subtotal removal and subsequent radiosurgery is one option for maintaining cranial nerve function and long-term tumor growth control.

Adolescent↗

PubMed1997

Volume changes following gamma knife radiosurgery of intracranial tumors.

BACKGROUND: The primary goal of radiosurgery for brain tumors is the prevention of further growth. The purpose of this article is to evaluate temporal changes of tumor volume after Gamma Knife radiosurgery on intracranial tumors. METHOD: Some 137 patients with 148 intracranial tumors who were treated with Gamma Knife radiosurgery and underwent radiological follow-up were reviewed. The tumors with high radiosensitivities to conventional external radiation were excluded. RESULT: The median radiological follow-up period was 12 months (range 1.5-38 months). Volume decreased after radiosurgery in 15 of 45 meningiomas; 10 of 37 schwannomas; 6 of 21 pituitary adenomas; 4 of 15 benign gliomas, including both of 2 subependymal giant cell astrocytomas; and 2 of 8 malignant gliomas. Some 87% of meningiomas and 60% of schwannomas whose volume had decreased began to shrink within 12 months and after 12 months, respectively. Transitory increase in volume preceded shrinkage in 16.2% of schwannomas, 13.3% of benign gliomas, 4.8% of pituitary adenomas, and 2.2% of meningiomas. Marked shrinkage occurred in 17 of 19 metastatic tumors and in all 3 neurocytomas shortly after radiosurgery. Of eight malignant gliomas, five began to grow 2-14 months (median = 5 months) after radiosurgery. CONCLUSION: Several points should be considered carefully while following up on patients after radiosurgery: the possibility of transient volume increase, tumor-specific volume change patterns, and the tumor-specific goals of radiosurgery.

Adolescent↗

PubMed2002

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

PURPOSE: To assess the outcome of high central dose Gamma Knife radiosurgery plus marimastat in patients with recurrent malignant glioma. METHODS AND MATERIALS: 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. RESULTS: 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. CONCLUSION: 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.

Adult↗

PubMed2003

Stereotactic radiosurgery provides equivalent tumor control to Simpson Grade 1 resection for patients with small- to medium-size meningiomas.

PURPOSE: To compare tumor control rates after surgical resection or stereotactic radiosurgery for patients with small- to medium-size intracranial meningiomas. MATERIALS AND METHODS: Between 1990 and 1997, 198 adult meningioma patients treated at our center underwent either surgical resection (n = 136) or radiosurgery (n = 62) as primary management for benign meningiomas <35 mm in average diameter. Tumor recurrence or progression rates were calculated by the Kaplan-Meier method according to an independent radiographic review. The mean follow-up was 64 months. RESULTS: The tumor resections were Simpson Grade 1 in 57 (42%), Grade 2 in 57 (42%), and Grade 3-4 in 22 (16%). The mean margin and maximal radiation dose at radiosurgery was 17.7 Gy and 34.9 Gy, respectively. Tumor recurrence/progression was more frequent in the surgical resection group (12%) than in the radiosurgical group (2%; p = 0.04). No statistically significant difference was detected in the 3- and 7-year actuarial progression-free survival (PFS) rate between patients with Simpson Grade 1 resections (100% and 96%, respectively) and patients who underwent radiosurgery (100% and 95%, respectively; p = 0.94). Radiosurgery provided a higher PFS rate compared with patients with Simpson Grade 2 (3- and 7-year PFS rate, 91% and 82%, respectively; p <0.05) and Grade 3-4 (3- and 7-year PFS rate, 68% and 34%, respectively; p <0.001) resections. Subsequent tumor treatments were more common after surgical resection (15% vs. 3%, p = 0.02). Complications occurred in 10% of patients after radiosurgery compared with 22% of patients after surgical resection (p = 0.06). CONCLUSIONS: The PFS rate after radiosurgery was equivalent to that after resection of a Simpson Grade 1 tumor and was superior to Grade 2 and 3-4 resections in our study. If long-term follow-up confirms the high tumor control rate and low morbidity of radiosurgery, this technique will likely become the preferred treatment for most patients with small- to moderate-size meningiomas without symptomatic mass effect.

Adult↗

PubMed1996

A comparison of intensity modulated conformal therapy with a conventional external beam stereotactic radiosurgery system for the treatment of single and multiple intracranial lesions.

PURPOSE: To compare the stereotactic radiosurgery treatment plans generated by a conventional radiosurgery treatment system with the plan generated by a system using intensity modulated beams. METHODS AND MATERIALS: Optimized conformal radiation treatment plans were generated for both single and multiple intracranial lesions using a conventional radiosurgery treatment-planning system computer and the Peacock treatment-planning computer. The Peacock system is a conformal therapy system that uses intensity modulated beams, back projection, and the simulated annealing optimization technique. The dose delivered to critical structures and the target volume were compared by means of dose volume histograms between plans generated by the two different systems. The Radiation Therapy Oncology Group (RTOG) stereotactic radiosurgery criteria were also used to evaluate each plan. RESULTS: (a) For a single small target, radiosurgery plans generated by the conventional radiosurgery system and the Peacock system were comparable. (b) For two separate small targets, where nonoverlapping arcs could be used, plans generated by the two systems were also comparable. (c) For a single large (>4 cm) irregular-shaped target, the Peacock system appeared to be able to generate a treatment plan superior to that of the conventional radiosurgery system. CONCLUSIONS: A treatment plan generated using intensity modulated beams appears to be superior to a multiple isocenter plan using a conventional radiosurgery system, for the treatment of a large irregular shaped intracranial target.

Radiosurgery↗

PubMed1997

Radiosurgery for skull base malignancies and nasopharyngeal carcinoma.

PURPOSE: Patients with skull base lesions present a challenging management problem because of intractable symptoms and limited therapeutic options. In 1989 we began treating selected patients with skull base lesions using linac stereotactic radiosurgery. In this study the efficacy and toxicity of this therapeutic modality is investigated. METHODS AND MATERIALS: Forty-seven patients with 59 malignant skull base lesions were treated with linac radiosurgery between 1989 and 1995. Eleven patients were treated for primary nasopharyngeal carcinoma using radiosurgery as a boost (7 Gy-16 Gy, median: 12 Gy) to the nasopharynx after a course of fractionated radiotherapy (64.8-70 Gy) without chemotherapy. Another 37 patients were treated for 48 skull base metastases or local recurrences from primary head and neck cancers. Eight of these patients had 12 locally recurrent nasopharyngeal carcinoma lesions occuring 6-96 months after standard radiotherapy, including one patient with nasopharyngeal carcinoma who developed a regional relapse after radiotherapy with a stereotactic boost. Lesion volumes by CT or MRI ranged from 0 to 51 cc (median: 8 cc). Radiation doses of 7.0 Gy-35.0 Gy (median: 20.0 Gy) were delivered to recurrent lesions, usually as a single fraction. RESULTS: All 11 patients who received radiosurgery as a nasopharyngeal boost after standard fractionated radiotherapy remain locally controlled (follow-up: 2-34 months, median: 18). However, one patient required a second radiosurgical treatment for regional relapse outside the initial radiosurgery volume. Thirty-three of 48 (69%) recurrent/metastatic lesions have been locally controlled, including 7 of 12 locally recurrent nasopharyngeal lesions. Follow-up for all patients with recurrent lesions ranged from 1 to 60 months (median: 9 months). Local control did not correlate with lesion size (p = 0.80), histology (p = 0.78), or radiosurgical dose (p = 0.44). Major complications developed after 5 of 59 treatments (8.4%), including three cranial nerve palsies, one CSF leak, and one trismus. Complications were not correlated with radiosurgical volume (p = 0.20), prior skull base irradiation (p = 0.90), or radiosurgery dose > 20 Gy (p = 0.49). CONCLUSION: Stereotactic radiosurgery is a reasonable treatment modality for patients with skull base malignancies, including patients with primary and recurrent nasopharyngeal carcinoma. The dose distribution obtained with stereotactic radiosurgery provides better homogeneity than an intracavitary implant when used as a boost for nasopharyngeal lesions, especially lesions which involve areas distant to the nasopharyngeal mucosa.

Adult↗

PubMedDate not supplied

Stereotactic radiosurgery for pituitary adenomas: a review of the literature.

OBJECTIVE: Pituitary adenomas are very common neoplasms and represent between 10 and 20% of all primary brain tumors. Historically, the treatment armamentarium for pituitary adenomas included medical management, microsurgery, and fractionated radiotherapy. More recently, radiosurgery has emerged as a viable treatment option. The goal of this research is to define accurately the efficacy, safety, and role of radiosurgery for treatment of pituitary adenomas. METHODS: Medical literature databases from 1965 to 2003 were searched for articles pertaining to pituitary adenomas and stereotactic radiosurgery. Each study was evaluated for the number of patients, radiosurgical parameters (e.g. tumor margin dose), length of follow-up, tumor growth control rate, complications, and rate of hormonal normalization in the case of functioning adenomas. RESULTS: A total of 34 published studies including 1567 patients were reviewed. Radiosurgery offers a tumor growth control rate of approximately 90%. The reported rates of hormonal normalization for functioning adenomas vary substantially. This range is in part due to widespread differences in endocrinological criteria utilized for post-radiosurgical assessment. Thus far, the risks of radiation induced neoplasia and cerebral vasculopathy associated with radiosurgery appear to be lower than for fractionated radiation therapy. The incidence of other serious complications following radiosurgery is quite low. CONCLUSIONS: Although surgical resection typically is the primary treatment modality, stereotactic radiosurgery offers safe and effective treatment for recurrent or residual pituitary adenomas. In rare instances, radiosurgery may be the best initial treatment for patients with pituitary adenomas. Refinements in the radiosurgical technique will likely lead to improved outcomes.

Adenoma↗

PubMed2001

Low-dose stereotactic radiosurgery is inadequate for medically intractable mesial temporal lobe epilepsy: a case report.

The successful surgical treatment of medically refractory epilepsy is based on one of three different principles: (1) elimination of the epileptic focus, (2) interruption of the pathways of neural propagation, and (3) increasing the seizure threshold through cerebral lesions or electrical stimulation. Temporal lobe epilepsy, being the most common focal epilepsy, may ultimately require temporal lobectomy. This is a case report of a 36-year-old male with drug-resistant right mesial temporal lobe epilepsy who failed to obtain seizure control after stereotactic radiosurgery to the seizure focus. Complex-partial seizures occurred 6-7 times monthly, and consisted of a loss of awareness followed by involuntary movements of the right arm. EEG/CC TV monitoring indicated a right mesial temporal lobe focus, which was corroborated by decreased uptake in the right temporal lobe by FDG-PET and by MRI findings of right hippocampal sclerosis. Stereotactic radiosurgery was performed with a 4MV linac, utilizing three isocenters with collimator sizes of 10, 10, and 7 mm respectively. A dose of 1500 cGy (max dose 2535 cGy) was delivered in a single fraction to the patient's right amygdala and hippocampus. There were no acute complications. Following radiosurgery the patient's seizures were improved in both frequency and intensity for approximately 3 months. Antiepileptic medications were continued. Thereafter, seizures increased in both frequency and intensity, occurring 10-20 times monthly. At 1 year post radiosurgery, standard right temporal lobectomy including amygdalohippocampectomy was performed with subsequent resolution of complex-partial seizures. Histopathology of the resected temporal lobe revealed hippocampal cell loss and fibrillary astrocytosis, consistent with hippocampal sclerosis. No radiation-induced histopathologic changes were seen. We conclude that low-dose radiosurgery doses temporarily changed the intensity and character of seizure activity, but actually increased seizure activity long-term. If radiosurgery is to be an effective alternative to temporal lobectomy for medically intractable temporal lobe epilepsy, higher radiosurgery doses will be required. The toxicity and efficacy of higher-dose radiosurgery is currently under investigation.

Adult↗

PubMed2002

Long term results of radiosurgery for vestibular schwannomas.

UNLABELLED: Radiosurgery is either a primary or an adjunct management approach used to treat patients with vestibular schwannomas. The goals are long-term tumour growth control, maintenance of cranial nerve function and prevention of new neurologic deficiencies. We sought to determine long-term outcomes measuring the potential benefits against the neurological risks of radiosurgery. METHODS: 278 patients with vestibular schwannomas underwent Gamma Knife radiosurgery as a treatment modality for from April 1992 to November 2001. The long-term results of 60 patients were evaluated who received radiosurgery as primary treatment. 12 cases presented with previously performed subtotal microsurgical resection or recurrence of disease (12-96 months, median 39). The median treatment volume was 3.8 ccm and the median dose to the tumour margin was 12 Gy. The median patient follow-up time was 88 months (range 72-114 months). RESULTS: Four tumours progressed after primary radiosurgery. Tumour control rate was 93%. Useful hearing (Gardner-Robertson I/II) was preserved in 16 patients (55%). Clinical neurological improvement occurred in 36 patients (60%). Adverse effects comprised neurological symptoms (incomplete facial palsy) (House-Brackman II/III) in five cases (three recovered completely), mild trigeminal neuropathy in three cases, and morphological changes displaying rapid enlargement of preexisting macrocysts in two patients and tumour growth in two other ones. Microsurgical resection was performed in three cases (5%) and one patient underwent a shunting procedure because of hydrocephalus formation. In patients who had undergone previous microsurgery, neither new cranial nerve deficit nor any tumour growth was observed. CONCLUSIONS: Radiosurgery performed with current techniques proved to be an effective method for growth control of vestibular schwannomas with both a low mortality rate and a good quality of life. An increasing percentage of patients will undergo radiosurgery as accessibility to this alternative increases, and more data regarding long-term follow-up are available. It is a post-operative complementary treatment for partially removed tumours. Accordingly, radiosurgery is a useful method for the management of properly selected patients.

Adolescent↗

PubMed2004

LINAC radiosurgery in skull base meningiomas.

LINAC radiosurgery has provided increasing access and changed treatment strategies in patients with benign skull base meningiomas in recent years. From January 1996 to January 2003, 37 patients with skull base meningiomas were treated with LINAC radiosurgery. A combination of the University of Florida system and the X Knife System, developed by Radionics, was used in all patients. Eight patients were treated by microsurgical resection before radiosurgery, in two patients tumor recurrence was treated and in 29 patients LINAC radiosurgery was the initial treatment procedure. The median treatment volume was 5.9 mL (0.7 to 22 mL) and the median given dose was 14.6 Gy (12.8 to 18 Gy) prescribed to the 80 percent isodose line. The follow-up period is between 12 and 96 months, median 66 months. 12 patients (32.4 %) showed a significant reduction in tumor size, in 11 patients (29.7 %) there was significantly less contrast enhancement and in 13 patients (35.1 %) the skull base meningioma was without any change. In one patient (2.8 %) there was tumor growth 48 months after radiosurgery, so the tumor control rate was 97.2 %. Two patients (5.6 %) showed neurological worsening after radiosurgery, whereas the symptoms were transient in one patient. LINAC radiosurgery offers us an effective treatment modality and changes treatment strategies in skull base meningiomas towards a less aggressive surgical approach. By combining microsurgery and radiosurgery we can achieve high tumor control rates with an acceptable low morbidity and a high level of quality of life.

Adult↗