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PubMed2004

Seizure outcomes after stereotactic radiosurgery for cerebral arteriovenous malformations.

OBJECTIVES: To determine the effect of stereotactic radiosurgery on seizure outcomes for patients with intracerebral arteriovenous malformations (AVM). METHODS: Between May 1990 and December 1998, 65 patients with a history of single or recurrent seizures underwent AVM radiosurgery, had more than 1 year of follow-up, and sufficient data to record an Engel seizure frequency score. The authors reviewed their records and updated clinical information when necessary with direct patient contact. Follow-up ranged from 12 to 144 months (median, 48 months). Seizure frequency was compared before and after radiosurgery with the Engel Seizure Frequency Scoring System. RESULTS: Overall, 26 patients (51%) were seizure-free (aura-free) after radiosurgery at 3-year follow-up; 40 patients (78%) had an excellent outcome (non-disabling simple partial seizures only) at 3-year follow-up. Factors associated with seizure-free or excellent outcomes include a low seizure frequency score (<4) before radiosurgery and smaller size and diameter AVM. Twenty-three patients had intractable partial epilepsy prior to treatment. Twelve (52%) of 23 and 11 of 18 (61%) patients with medically intractable partial epilepsy had excellent outcomes at years 1 and 3. CONCLUSION: Overall, stereotactic radiosurgery improves seizure outcomes in the majority of patients and more than half of the patients with medically intractable partial epilepsy had an excellent seizure outcome after radiosurgery.

Adolescent↗
PubMed1993

Preservation of cranial nerve function after radiosurgery for nonacoustic schwannomas.

Microsurgical resection is the primary management approach for patients with intracranial schwannomas. Recent studies have demonstrated that stereotactic radiosurgery is an effective therapeutic modality for patients with acoustic schwannomas. To define the role of radiosurgery in the management of patients with nonacoustic schwannomas, we reviewed the results of gamma unit stereotactic radiosurgery in six patients with trigeminal and five patients with jugular foramen region schwannomas. No patient with a trigeminal schwannoma demonstrated tumor growth during a mean follow-up of 21 months (range, 7-35 mo), whereas one patient with a jugular foramen region schwannoma had an increase in tumor size 7 months after radiosurgery. No new cranial nerve or brain stem deficits were noted in either patient group after radiosurgery. In this early experience, radiosurgery proved an effective primary or adjuvant technique for selected patients with schwannomas of the trigeminal, glossopharyngeal, or vagus nerves. Using our described method, the safety of radiosurgery was demonstrated on the brain stem, regional cranial nerves, and especially those cranial nerves intimately associated with the tumor.

Cranial Nerve Neoplasms↗
PubMed1995

Outcome analysis of acoustic neuroma management: a comparison of microsurgery and stereotactic radiosurgery.

Currently, microsurgical resection of acoustic neuromas by an experienced, multidisciplinary team is thought to be the treatment of choice. During the past 20 years stereotactic radiosurgery has been used as an alternative to surgical removal. To compare the results of both microsurgery and stereotactic radiosurgery, we conducted a study of 87 patients with unilateral, previously unoperated acoustic neuromas with an average diameter less than 3 cm treated by the neurosurgical service during 1990 and 1991. Preoperative patient characteristics and average tumor size were similar between the treatment groups. State of the art microsurgical or radiosurgical techniques were used by experienced surgeons in both treatment groups. The treatment groups were compared based on cranial nerve preservation, tumor control, postoperative complications, patient symptomatology, length of hospital stay, total management charges, effect on employment status, and overall patient satisfaction. Stereotactic radiosurgery was more effective in preserving normal postoperative facial function (P < 0.05), and hearing preservation (P < 0.03) with less treatment associated morbidity (P < 0.01). Effect on preoperative symptoms were similar between the treatment groups. Postoperative functional outcomes and patients' satisfaction of their tumor management were greater after stereotactic radiosurgery when compared to the microsurgical group, although they did not reach statistical significance (P = 0.07 and P = 0.10, respectively). Patients returned to independent functioning sooner after stereotactic radiosurgery (P < 0.001). Hospital length of stay and total management charges were less in the radiosurgical group (P < 0.001). When compared to microsurgical removal, stereotactic radiosurgery proved to be an effective and less costly management strategy of unilateral acoustic neuromas less than 3 cm in diameter. For many acoustic neuroma patients, stereotactic radiosurgery should be offered as an alternative management strategy.

Adult↗
PubMed2005

Radiosurgery for basal ganglia, internal capsule, and thalamus arteriovenous malformation: clinical outcome.

OBJECTIVE: Radiosurgery is accepted as the first option for treating deep arteriovenous malformations (AVMs), although the clinical outcome in this subgroup of brain AVMs is not well studied. The objective of this study is to review our experience with radiosurgical treatment for these AVMs. METHODS: Between October 1989 and December 2000, 45 patients with deep AVMs (including basal ganglia, internal capsule, and thalamus) underwent stereotactic radiosurgery. Three patients were lost to follow-up and therefore were excluded from this study. Patient characteristics and outcomes were collected and analyzed. The obliteration prediction index and the radiosurgery-based AVM score were calculated and tested. RESULTS: Forty-two patients were followed up for a median of 39 months (range, 25-90 mo; mean, 45.8 mo). The median maximum AVM diameter during the radiosurgery was 1.8 cm (range, 0.9-4.0 cm; mean, 2.07 cm), and the median AVM volume was 2.8 cm(3) (range, 0.2-18.3 cm(3); mean, 4.74 cm(3)). The mean marginal dose was 16.2 Gy (median, 15 Gy), and the median maximum dose was 22.4 Gy (range, 16.6-30 Gy). The AVM cure rate after the first radiosurgical treatment, using angiography- and magnetic resonance imaging-confirmed obliteration, was 61.9%. The predicted obliteration using the obliteration prediction index was 60%. Eight patients developed radiation-induced complications (19%). The deficit was transient in three patients (7.1%) and permanent in five patients (11.9%). The risk of postradiosurgical hemorrhage in this cohort was 9.5% for the first year, 4.7% for the second year, and 0% thereafter. Excellent outcome (obliteration plus no new deficit) was achieved in 70% of the patients in the group with radiosurgery-based AVM score less than 1.5 compared with 40.9% in the group with radiosurgery-based AVM score greater than 1.5% (P = 0.059). CONCLUSION: Radiosurgery for deep AVMs has a satisfactory obliteration rate and acceptable morbidity, considering the risk of hemorrhage without treatment and the risk of morbidity associated with other treatment modalities.

Adolescent↗
PubMed2006

Management of vestibular schwannomas that enlarge after stereotactic radiosurgery: treatment recommendations based on a 15 year experience.

OBJECTIVE: Stereotactic radiosurgery is an effective alternative to surgical resection for the majority of patients with vestibular schwannomas (VS). However, after radiosurgery, the imaging characteristics of VSs are variable, and correct interpretation is critical to prevent unnecessary surgery for these patients. METHODS: A retrospective study of 208 consecutive patients with unilateral VS having radiosurgery between March 1990 and December 2001. Thirty (14%) patients had tumors that enlarged at least 2 mm after radiosurgery. The median follow-up after radiosurgery was 56 months (range 24-132 mo). RESULTS: The median time to tumor enlargement was 9 months (5-60 mo). The median volume increase was 75%. A loss of central enhancement was noted in 28 (93%) patients. Six (20%) patients had new symptoms noted at the time of tumor enlargement including hemifacial spasm (n = 2), ataxia (n = 2), trigeminal neuralgia (n = 1), and facial numbness (n = 1). Additional treatment was performed at the time of initial enlargement in 3 patients (resection, n = 2; ventriculoperitoneal shunt, n = 1). In the 28 patients who did not undergo resection at the time of initial enlargement, three patterns were identified on later imaging. Sixteen (57%) patients showed eventual tumor regression (type 1), and eight (29%) patients had tumors that increased and remained larger but did not show progressive enlargement (type 2). Four (14%) patients showed progressive enlargement on serial imaging (type 3) and underwent additional treatment (resection, n = 3; stereotactic radiation therapy, n = 1). CONCLUSION: Tumor expansion after VS radiosurgery rarely denotes a failed procedure, and the majority of patients only require further imaging. Approximately one third of tumors that enlarge will remain increased in size compared with the time of radiosurgery but will not show sequential growth. Additional tumor treatment should be reserved only for patients who demonstrate progressive tumor enlargement on serial imaging (2% in this series).

Adult↗
PubMed2006

Visual field preservation after multisession cyberknife radiosurgery for perioptic lesions.

OBJECTIVE: The restricted radiation tolerance of the anterior visual pathways represents a unique challenge for ablating adjacent lesions with single-session radiosurgery. Although preliminary studies have recently demonstrated that multisession radiosurgery for selected perioptic tumors is both safe and effective, the number of patients in these clinical series was modest and the length of follow-up limited. The current retrospective study is intended to help address these shortcomings. METHODS: Forty-nine consecutive patients with meningioma (n = 27), pituitary adenoma (n = 19), craniopharyngioma (n = 2), or mixed germ cell tumor (n = 1) situated within 2 mm of a "short segment" of the optic apparatus underwent multisession image-guided radiosurgery at Stanford University Medical Center. Thirty-nine of these patients had previous subtotal surgical resection, and six had previously been treated with conventional fractionated radiotherapy (6). CyberKnife radiosurgery was delivered in two to five sessions to an average tumor volume of 7.7 cm3 and a cumulative average marginal dose of 20.3 Gy. Formal visual testing and clinical examinations were performed before treatment and at follow-up intervals beginning at 6 months. RESULTS: After a mean visual field follow-up of 49 months (range, 6-96 mo), vision was unchanged postradiosurgery in 38 patients, improved in eight (16%), and worse in three (6%). In each instance, visual deterioration was accompanied by tumor progression that ultimately resulted in patient death. However, one of these patients, who had a multiply recurrent adrenocorticotropic hormone-secreting pituitary adenoma, initially experienced early visual loss without significant tumor progression after both a previous course of radiotherapy and three separate sessions of radiosurgery. After a mean magnetic resonance imaging follow-up period of 46 months, tumor volume was stable or smaller in all other cases. Two patients died of unrelated nonbrain causes. CONCLUSION: Multisession radiosurgery resulted in high rates of tumor control and preservation of visual function in this group of perioptic tumors. Ninety-four percent of patients retained or improved preradiosurgical vision. This intermediate-term experience reinforces the findings from earlier studies that suggested that multisession radiosurgery can be a safe and effective alternative to either surgery or fractionated radiotherapy for selected lesions immediately adjacent to short segments of the optic apparatus.

Adolescent↗
PubMed2006

Computer aided robotic radiosurgery.

Radiosurgery involves the precise delivery of sharply collimated high-energy beams of radiation to a distinct target volume along selected trajectories. Historically, accurate targeting required the application of a stereotactic frame, thus limiting the use of this procedure to single treatments of selected intracranial lesions. However, the scope of radiosurgery has undergone a remarkable broadening since the introduction of image-guided robotic radiosurgery. Recent developments in real-time image guidance provide an effective frameless alternative to conventional radiosurgery and allow both the treatment of lesions outside the skull and the possibility of performing hypofractionation. As a consequence, targets in the spine, chest and abdomen can now also be radiosurgically ablated with submillimetric precision. Meanwhile, the combination of image guidance, robotic beam delivery, and non-isocentric inverse planning can greatly enhance the conformality and homogeneity of radiosurgery. The aim of this article is to describe the technological basis of image-guided radiosurgery and provide a perspective on future developments. The current clinical usage of robotic radiosurgery will be reviewed with an emphasis on those applications that may represent a major shift in the therapeutic paradigm.

Brain Neoplasms↗
PubMed2001

Stereotactic radiosurgery and hypofractionated stereotactic radiotherapy for residual or recurrent cranial base and cervical chordomas.

OBJECT: In patients with chordomas the lesions often recur. Furthermore, the location of some chordomas within the base of the skull and the cervical spine can prevent complete resection from being achieved. Previous series have shown that stereotactic radiosurgery can be used as a treatment for residual chordomas with good overall results. The authors review their experience in using linear accelerator (LINAC) stereotactic radiosurgery to treat patients with recurrent and/or residual cranial base and cervical chordomas. METHODS: Ten patients with chordomas (eight with cranial base and two with cervical lesions [below C-2]) underwent LINAC stereotactic radiosurgery. The mean patient age was 49 years (range 30-73 years). There were seven men and three women. Three patients had undergone one prior surgery, five had undergone two previous surgeries, and two had undergone three prior operations. The mean radiation dose was 19.4 Gy (range 18-24 Gy), and the maximum intratumoral dose averaged 27 Gy (range 24.1-33.1 Gy). The mean secondary collimator size was 14.4 mm (range 7.5-20 mm). The volume of the tumor treated ranged from 1.1 to 21.5 ml. In five patients a standard frame-based LINAC radiosurgery system was used, whereas in the other five the CyberKnife, a frameless image-guided LINAC radiosurgical system, was used. All patients were available for follow-up review, which averaged 4 years (range 1-9 years). Over the course of follow up, one chordoma (10%) was smaller in size, seven were stable, and two chordomas progressed (one in a patient who underwent reoperation and a second course of stereotactic radiosurgery, and the second in a patient who underwent reoperation alone). There were no new neurological deficits noted following radiosurgery in the eight of 10 patients in whom there was no tumor progression, and no patient developed radiation-induced necrosis. CONCLUSIONS: Stereotactic radiosurgery can be used to treat patients with recurrent or residual chordomas with excellent tumor control rates. Longer follow-up review in larger series is warranted to confirm these findings.

Adult↗
PubMed2003

The role of radiosurgery for hemangiopericytomas.

OBJECT: Hemangiopericytomas represent a small subset of meningeal tumors. Despite their relatively uncommon nature, they are aggressive tumors known for recurrence. Resection is the standard treatment in most, although regrowth and metastases are common even after resection. The authors evaluate the role of stereotactic radiosurgery in the treatment of recurrent hemangiopericytomas. METHODS: In a review of the Stanford radiosurgery patient database between 1989 and 2002, the authors found eight patients with recurrent hemangiopericytoma who underwent stereotactic radiosurgery. The mean age of this population was 45.1 years (range 24-67 years). All patients had been previously treated with resection, and five patients (63%) had undergone conventional radiotherapy. The mean radiosurgery dose to the tumor margin was 20.5 Gy (range 16-24 Gy). The mean clinical and radiographic follow-up period was 44 months (range 8-77 months). Of the eight tumors treated with radiosurgery, six decreased in size and two ultimately progressed. There were no radiosurgery-related complications. CONCLUSIONS: Stereotactic radiosurgery of hemangiopericytomas can result in increased tumor control and should be considered as a treatment option for patients in whom the diagnosis has been established and in whom residual tumor is demonstrated postoperatively. Close clinical and radiographic follow-up evaluation is necessary in this patient population because of the high rate of local recurrence and distant metastases.

Adult↗
PubMed2004

Comparison of radiosurgery and conventional surgery for the treatment of glomus jugulare tumors.

OBJECT: The optimal management of glomus jugulare tumors remains controversial. Available treatments were once associated with poor outcomes and significant complication rates. Advances in skull base surgery and the delivery of radiation therapy by stereotactic radiosurgery have improved the results obtained using these treatment options. The authors summarize and compare the contemporary outcomes and complications for these therapies. METHODS: Papers published between 1994 and 2004 that detailed the use of radiosurgery or surgery to treat glomus jugulare tumors were reviewed. Eight radiosurgery series including 142 patients and seven surgical studies including 374 patients were evaluated for neurological outcome, change in tumor size (radiosurgery) or percent of total resection (surgery), recurrences, tumor control, need for further treatment, and complications. The mean age at treatment for patients who underwent surgery and radiosurgery was 47.3 and 56.7 years, respectively. The mean follow-up duration was 49.2 and 39.4 months, respectively. The surgical control rate was 92.1%, with 88.2% of tumors totally resected in the initial surgery. A cerebrospinal fluid leak occurred in 8.3% of patients who underwent surgery and recurrences were found in 3.1%; the mortality rate was 1.3%. Among patients who underwent radiosurgery, tumors diminished in 36.5%, whereas 61.3% had no change in tumor size, and subjective or objective improvements occurred in 39%. Despite the presence of residual tumor in 100% of radiosurgically treated patients, recurrences were found in only 2.1%, the morbidity rate was 8.5%, and there were no deaths. CONCLUSIONS: Death and recurrences after these treatments are infrequent, and therefore both treatments are considered to be safe and efficacious. Although surgery is associated with higher morbidity rates, it immediately and totally eliminates the tumor. The radiosurgery results are very promising, although the incidence of late recurrence (after 10-20 years) is unknown.

Adult↗
PubMed1993

Stereotactic radiosurgery for cerebral metastatic melanoma.

To determine local tumor control rates and survival of patients with melanoma metastases to the brain, the authors reviewed the results of 23 consecutive patients with a total of 32 tumors (19 patients had a solitary tumor and four had multiple tumors) who underwent adjuvant stereotactic radiosurgery. Tumor locations included the cerebral hemisphere (24 cases), brain stem (four cases), basal ganglia (two cases), and cerebellum (two cases). Fifteen patients had associated cranial symptomatology and eight had incidental metastases. All patients had tumors of 3 cm or less in diameter (mean tumor volume 2.5 cu cm), and all received fractionated whole-brain radiation therapy (30 Gy) in addition to radiosurgery (mean tumor margin dose 16 Gy). Nineteen patients were managed with both modalities at the time of diagnosis; four underwent radiosurgery 3 to 12 months after fractionated whole-brain radiotherapy. The mean patient follow-up period was 12 months (range 3 to 38 months). After radiosurgery, eight patients improved, 13 remained stable, and two deteriorated. One patient subsequently required craniotomy because of intratumoral hemorrhage; this patient and three others are living 13 to 38 months after radiosurgery. Nineteen patients died, 18 from progression of their systemic disease and one from another hemorrhage into a new brain metastasis. The local tumor control rate was 97%. Only two patients subsequently developed new intracranial metastases. The median survival period after diagnosis was 9 months (range 3 to 38 months). The authors believe that stereotactic radiosurgery coupled with fractionated whole-brain irradiation is an effective management strategy for cerebral metastases from a melanoma. Multi-institutional trials are warranted to confirm that stereotactic radiosurgery results equal or surpass the outcome achieved with craniotomy and tumor resection.

Adult↗
PubMed1999

Stereotactic radiosurgery in the management of acoustic neuromas associated with neurofibromatosis Type 2.

OBJECT: Stereotactically guided radiosurgery is one of the primary treatment modalities for patients with acoustic neuromas (vestibular schwannomas). The goal of radiosurgery is to arrest tumor growth while preserving neurological function. Patients with acoustic neuromas associated with neurofibromatosis Type 2 (NF2) represent a special challenge because of the risk of complete deafness. To define better the tumor control rate and long-term functional outcome, the authors reviewed their 10-year experience in treating these lesions. METHODS: Forty patients underwent stereotactic radiosurgery at the University of Pittsburgh, 35 of them for solitary tumors. The other five underwent staged procedures for bilateral lesions (10 tumors, 45 total). Thirteen patients (with 29% of tumors) had undergone a median of two prior resections. The mean tumor volume at radiosurgery was 4.8 ml, and the mean tumor margin dose was 15 Gy (range 12-20 Gy). The overall tumor control rate was 98%. During the median follow-up period of 36 months, 16 tumors (36%) regressed, 28 (62%) remained unchanged, and one (2%) grew. In the 10 patients for whom more than 5 years of clinical and neuroimaging follow-up results were available (median 92 months), five tumors were smaller and five remained unchanged. Surgical resection was performed in three patients (7%) after radiosurgery; only one showed radiographic evidence of progression. Useful hearing (Gardner-Robertson Class I or II) was preserved in six (43%) of 14 patients, and this rate improved to 67% after modifications made in 1992. Normal facial nerve function (House-Brackmann Grade 1) was preserved in 25 (81%) of 31 patients. Normal trigeminal nerve function was preserved in 34 (94%) of 36 patients. CONCLUSIONS: Stereotactically guided radiosurgery is a safe and effective treatment for patients with acoustic tumors in the setting of NF2. The rate of hearing preservation may be better with radiosurgery than with other available techniques.

Adolescent↗
PubMed2001

Combination of stereotactic radiosurgery and cytokine gene-transduced tumor cell vaccination: a new strategy against metastatic brain tumors.

OBJECT: To determine if the combination of radiosurgery and tumor cell vaccine would enhance the therapy of metastatic lesions of the central nervous system (CNS), the authors examined the antitumoral effects of radiosurgery and cytokine-transduced tumor cell vaccine. METHODS: Fifty-five rats underwent intracranial implantation of 5 x 10(3) MADB 106 cells. On Day 3 after tumor implantation, 34 rats were inoculated in the flank with nonirradiated MADB 106 cells that had been retrovirally transduced to express granulocyte-macrophage colony-stimulating factor or interleukin-4. Twenty-seven rats (17 animals that had received the vaccine and 10 that had not) underwent radiosurgery performed using a gamma knife at maximum doses of 32 Gy on Day 5. No animals in the untreated group or in the vaccine-alone groups survived longer than 21 days. Animals treated by ra diosurgery alone displayed prolonged survival in comparison with untreated animals (p < 0.0001), but only one of 10 animals survived longer than 55 days. In contrast, 14 of 17 animals that received the combination therapy of radiosurgery and vaccination survived longer than 55 days (p = 0.0003 compared with animals that underwent radiosurgery alone). On Day 55, the long-term survivors were challenged by parental MADB 106 cells, which were implanted in the contralateral hemisphere. All animals from the combination therapy groups survived longer than 50 days after this challenge, but the single survivor from the radiosurgery-alone group died of tumor growth in 27 days. CONCLUSIONS: The combination of radiosurgery and cytokine gene-transduced tumor cell vaccine markedly prolonged animal survival and protected animals from a subsequent challenge by parental tumor cells placed in the CNS. The data provided by this study indicate that this combination therapy represents a strategy that may have clinical applicability for single and/or multiple metastatic brain tumors.

Adenocarcinoma↗
PubMed2002

A proposed radiosurgery-based grading system for arteriovenous malformations.

OBJECT: Radiosurgery is an effective treatment strategy for properly selected patients harboring arteriovenous malformations (AVMs). Grading scales that are currently used to predict patient outcomes after AVM resection are unreliable tools for the prediction of the results of AVM radiosurgery. METHODS: A grading system was developed to predict outcomes following AVM radiosurgery, based on the multivariate analysis of data obtained in 220 patients treated between 1987 and 1991 (Group 1). The dependent variable in all analyses was excellent patient outcome (complete AVM obliteration without any new neurological deficit). The grading scale was tested on a separate set of 136 patients with AVMs treated between 1990 and 1996 at a different center (Group 2). One hundred twenty-one (55%) of 220 Group 1 patients had excellent outcomes. Multivariate analysis identified five variables related to excellent patient outcomes: AVM volume (p = 0.001), patient age (p < 0.001), AVM location (p < 0.001), previous embolization (p = 0.02), and number of draining veins (p < 0.001). Regression analysis modeling permitted removal of two significant variables (previous embolization and number of draining veins) and resulted in the following equation to predict patient outcomes after AVM radiosurgery: AVM score = (0.1)(AVM volume in cm3) + (0.02)(patient age in years) + (0.3)(location of lesion: frontal or temporal) = 0; parietal, occipital, intraventricular, corpus callosum, cerebellar = 1; or basal ganglia, thalamic, or brainstem = 2). Seventy-nine (58%) of 136 Group 2 patients had excellent outcomes. All variables in the model remained significant for the Group 2 patients: AVM volume (p = 0.01), patient age (p = 0.01), and AVM location (p < 0.001). Testing of the entire model on the Group 2 patients demonstrated that the AVM score could be used to predict patient outcomes after radiosurgery (p < 0.0001). All patients with an AVM score of 1 or lower had an excellent outcome compared with only 39% of patients with an AVM score higher than 2. The Spetzler-Martin grade (p = 0.13), the K index (p = 0.26), and the obliteration prediction index (p = 0.21) did not correlate with excellent patient outcomes. CONCLUSIONS: Despite significant differences in preoperative patient characteristics and dose prescription guidelines at the two centers, the proposed AVM grading system strongly correlated with patient outcomes after single-session radiosurgery for both patient groups. Although further testing of this model by independent centers using prospective methodology is still required, this system allows a more accurate prediction of outcomes from radiosurgery to guide choices between surgical and radiosurgical management for individual patients with AVMs.

Adolescent↗
PubMed2004

Radiosurgery for arteriovenous malformations of the basal ganglia, thalamus, and brainstem.

OBJECT: Although stereotactic radiosurgery is frequently performed for arteriovenous malformations (AVMs) in deep locations, outcomes after radiosurgery for these patients have not been well studied. The goal of this paper was to study these outcomes. METHODS: Between 1990 and 2000, 56 patients underwent radiosurgery for AVMs located in the basal ganglia (10 patients), thalamus (30 patients), or brainstem (16 patients). The median age of these patients was 34.2 years. Thirty-five patients (62%) had experienced previous bleeding. The AVMs were classified Grade IIIB in 62% of patients and Grade IV in 38% according to the modified Spetzler-Martin Scale; the median radiosurgery-based AVM score was 1.83. The median volume of the lesion was 3.8 cm3 and the median radiation dose delivered to its margin was 18 Gy. The median duration of follow-up review after radiosurgery was 45 months (range 3-121 months). In seven patients (12%) hemorrhage occurred at a median of 12 months after radiosurgery; five patients (9%) died and two recovered without any deficit. Permanent radiation-related complications occurred in six (12%) of 51 patients (excluding the five patients who died of hemorrhage) after one procedure and in three (18%) of 17 patients after repeated radiosurgery. Obliteration of the AVM was noted in 24 patients (43%; obliteration was confirmed by angiography in 18 patients and by magnetic resonance [MR] imaging in six patients) after a single procedure and in 32 patients (57%; confirmed by angiography in 25 patients and by MR imaging in seven patients) after one or more procedures. Excellent outcomes (obliteration of the lesion without any new deficit) were obtained in 39% of patients after one radiosurgical procedure and in 48% after one or more procedures. Twelve (67%) of 18 patients with AVM scores lower than 1.5 had excellent outcomes compared with 15 (39%) of 38 patients with AVM scores greater than 1.5 (p = 0.053). CONCLUSIONS: Less than half of the patients with deeply located AVMs were cured of the future risk of hemorrhage without new neurological deficits. This experience emphasizes the difficulty in treating patients with deeply located AVMs; the majority of whom are also poor candidates for resection or embolization.

Adult↗
PubMed1999

[Linac-based stereotactic radiosurgery for arteriovenous malformations (AVMs) in brain: estimation for efficacy of therapeutic response using angiography].

The purpose of this study was to determine whether it is possible to predict the efficacy of therapeutic response to linac-based stereotactic radiosurgery for AVMs on the basis of the stagnation rate in the nidus, which was defined as follows: [(pooling time of contrast material in the nidus of AVM)/ (intracranial circulation time)] x 100. Cerebral angiograms of twenty-five AVMs were retrospectively evaluated, and the stagnation rates in the nidus were calculated before and one year after stereotactic radiosurgery. Reduction rate was also calculated by using angiography, and we statistically evaluated the relationship between the stagnation rates in the nidus and the reduction rates. The stagnation rates in the nidus prior to linac-based stereotactic radiosurgery were positively correlated with the reduction ratios of AVMs after stereotactic radiosurgery (r = 0.406, p = 0.0432). Our study suggested that a higher stagnation rate in the nidus of the AVM might be obliterated faster after linac-based stereotactic radiosurgery. Thus, calculation of the stagnation rate in the nidus before stereotactic radiosurgery is useful in predicting the efficacy of therapeutic response to linac-based stereotactic radiosurgery for AVMs.

Adolescent↗
PubMedDate not supplied

Radiosurgery for the treatment of brain metastases in renal cell carcinoma.

BACKGROUND: In the treatment of brain metastases using a stereotactically modified linear accelerator it could be shown that a single dose between 15 and 25 Gy leads to partial or complete remission of so-called radioresistant metastases from melanoma and hypernephroma. Radiosurgery of brain metastases then started in centers all over the world, however, experiences with brain metastases of renal cell carcinoma are yet limited. The aim of this analysis is therefore to present the treatment results of radiosurgery of brain metastases. Furthermore, in this paper prognostic subgroups shall be defined, in order to establish guidelines for an optimal therapy strategy. MATERIALS AND METHODS: Radiosurgery means stereotactically guided high-precision irradiation methods by extremely focussing ionizing radiation within the target volume as a single dose application. The characteristic steep dose decrease allows the selective destruction of small intracranial lesions, while the surrounding brain tissue is optimally protected. Two methods, Gamma Knife and stereotactic modified linear accelerator are clinically available. RESULTS: In larger studies from different groups all over the world, local tumor control rates from 85% to 95%, recurrence rates from 6% to 15% and side effects between 3% and 15% have been attained, independent of the system used. Prognostic factors, like volume of metastases < 10 ml, applied dose > 18 Gy, one or two metastases, absence of extracranial metastases, good patient performance with a Karnofsky score > 70%, primary treatment and more than one year between primary diagnosis and brain metastases showed a trend toward improved survival. Depending on the prognostic factors the median survival after radiosurgery ranged from 6 to 12 months. Retrospective comparison of radiosurgery and surgical series suggest that both modalities attain similar results. The dose can be applied with an accuracy of 0.3 mm. DISCUSSION: Based on these experiences, brain metastases can be treated by radiosurgery, primarily in patients with one or two metastases or in combination with whole brain irradiation as a boost in patients with more than two metastases. Furthermore with radiosurgery a new treatment modality exists to re-irradiate patients who have been failed after surgery or whole brain irradiation.

Bone Neoplasms↗
PubMed1999

[Radiosurgery for brain metastases].

This article presents the state of art in radiosurgery as a new therapeutic strategy of brain metastases. Radiosurgery of brain metastases is ten years old and we propose to make an update of the literature. X-rays and gamma-rays are commonly used for radiosurgery and does not make a difference for dosimetry and precision. Selected patients for this treatment have usually good Karnofsky status and the mean size of their metastases is about 20 mm. Mean number of metastases treated in the same procedure is 2. Most frequent primary sites are lung and breast, but also kidney and skin (malignant melanoma) which are supposed to be radioresistant and so often untreatable by other techniques. Usual dose administrated ranges between 15 and 25 Grays in center of target with a 80% isodose in peripheral. Results are quite good for local control (80% to 100%) but survival does not seem to be improved (11 months). Radiation complication rate is 4% and sometimes hemorrhagic complications occur (1 to 2%). For local control, quality of life and cost/benefit ratio, there are strong arguments in favor of radiosurgery, especially for radioresistant metastases in spite of the lack of improvement of survival duration. Moreover published studies do not allow any comparison with efficacy of surgery and radiosurgery, whole brain radiosurgery and radiosurgery of the present metastases. Evaluations are still going on in several centers. Their results will allow more precise indications of this technique.

Aged↗