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Radiosurgery for vascular malformations of the brain stem.

The challenges associated with microsurgery of vascular malformations located in the midbrain, pons and medulla have promoted the development of alternative therapeutic techniques. To assess the efficacy and safety of radiosurgery in the management of brain stem vascular malformations we reviewed our 5-year experience in 50 patients evaluated between 4 and 51 months (mean, 25 months) after radiosurgery. Twenty-eight patients (56%) underwent gamma unit radiosurgery for symptomatic arteriovenous malformations (AVMs), and 22 patients (44%) for angiographically occult vascular malformations (AOVMs). Patients varied in age from 7 to 76 years (mean, 39 years). Forty-one patients (82%) had from 1 to 5 hemorrhages prior to gamma knife radiosurgery. Ten (20%) had one or two prior unsuccessful operations, and 37 (74%) presented with a neurological deficit. Of the patients with AVMs, 6 were considered Spetzler Grade III, and 22 (79%) Grade VI (inoperable: major component within the brain stem parenchyma). Forty-four malformations (88%) were adjacent to or within the midbrain and pons; the remainder involved the medulla. Average malformation diameters varied from 6 to 30.4 m (mean, 20.6; mean volume 4614 mm3). The minimal radiation dose to the margin of the malformations ranged from 12 to 25.6 Gy (mean, 18.9 Gy). Of the 28 patients with AVMs, 8 had follow-up angiograms at a minimum of 2-years after radiosurgery (or sooner if their MRIs suggested obliteration). Of these patients, 7 (88%) showed complete obliteration of their malformations. No patients with AOVMs rehemorrhaged if more than 15 months elapsed after radiosurgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Radiosurgery of the metastatic brain tumours with gamma-knife.

The results of treatment of metastatic brain tumours by radiosurgery are reported. Twenty cases including lung (11), colon (5), breast (1), ovary (1), liver cancer (1) and malignant melanoma (1) were involved. Seven cases had single and 13 had multiple brain metastases. In total 55 lesions were evaluated after radiosurgery with the gamma-knife. Following localization with MR1 and dose planning, radiosurgery with marginal doses between 12 to 25 Gy (mean 18.9 Gy) was delivered. In the follow-up studies with MRI after 3 months, 29 out of 55 (52.7%) lesions showed significant shrinkage. In contrast 25 showed either no change (17) or central necrosis (8), and one was enlarged. Thus the tumour control at 3 months was 98.2%, and subsequently 96.6% at 6 months. Clinical symptoms and signs were improved in most cases, but were aggravated in four cases either by tumour recurrence or by radiation-induced oedema. Although the tumours treated with radiosurgery were well controlled, tumour recurrence in another sites occurred in 4 case, of which 3 were treated by 2nd radiosurgery with 2 successful tumour control. Complications were generally mild and transient. In summary stereotactic radiosurgery is valuable new treatment not only for solitary metastases, but also for multiple or recurrent ones.

Adult↗

Tumour response and morphological changes of acoustic neurinomas after radiosurgery.

Twenty-seven of the 1560 patients treated by radiosurgery during the period 1984-1993 had acoustic neurinomas. Four cases were excluded from this study because they had a follow-up of less than 2 years. There were 24 neurinomas treated in 23 patients as one patient had a bilateral tumour. Seven patients underwent radiosurgery for a recurrent tumour (already operated on once or twice), while it was the first treatment for 16 patients. The tumour volume ranged from 1.99 cm3 to 18.30 cm3, and the patient follow-up was from 2 to 8 years. To determine the target on CT/NMR for linear accelerator stereotactic irradiation, the Greitz-Bergström non-invasive head fixation device was used. It was again adopted for subsequent serial imaging, and for repeat radiosurgery when necessary. The total peripheral tumour dose ranged from 12 to 45 Gy. In 9 patients there was a reduction in tumour volume varying from 39 to 100%, while 14 of the neurinomas appeared stable after an average follow-up of 3 years. In one patient there was an increase in size of the tumour. Variable morphological changes were present in 66% of the neurinomas treated. Radiosurgery is indicated as an alternative to microsurgery for inoperable patients and for those who refuse surgery, for recurrent tumours, and as a post-operative complementary treatment for partially removed tumours. A gradual approach to radiosurgery, depending on tumour response, allows a greater efficacy with minimal risk. In the present series no complications were observed. Hearing was preserved at almost the same level as that prior to radiosurgery in all patients.

Adult↗

Different responses of benign and atypical meningiomas to gamma-knife radiosurgery: report of two cases with immunohistochemical analysis.

Recent reports have shown that gamma-knife radiosurgery provides a safe and effective strategy for the management of brain tumors. To evaluate the role of stereotactic radiosurgery in the management of meningiomas, we investigated the histopathology of two patients. The patients, a 37-year-old man and a 54-year-old woman, presented with visual field disturbance or headache. Imaging studies demonstrated intracranial meningiomas--tentorial and sphenoid ridge, respectively. Each patient undewent subtotal surgical resection (more than 90% in both patients), followed by gamma-knife radiosurgery of the remnant tumor marginal doses of 15 Gy. Pathological examination of the original tumors revealed a meningothelial meningioma and an atypical meningioma, respectively. Enlargement of the remnant tumors 4 months after radiosurgery resulted in total surgical resection in both patients. Thirteen months later, the patient with the atypical meningioma underwent a third operation for early recurrence of the tumor. Histopathology was investigated, and MIB-1, p53, and bcl-2 labeling indexes (LI) were analyzed immunohistochemically. Histopathologically, the specimens showed necrosis and intratumoral vessel obliteration after radiosurgery in both cases. However, more remnant tumor cells survived in the atypical meningioma. Immunohistochemically, increased wild-type p53, decreased bcl-2 expression, and decreased MIB-1 LI were observed in the benign meningioma. In the atypical meningioma, on the contrary, MIB-1 LI was decreased and mutant-type p53 and bcl-2 expression were unchanged. The specimen from the third operation revealed an anaplastic meningioma, and MIB-1 LI was markedly increased. These findings suggest that the efficacy of radiosurgery may differ between benign and atypical meningiomas.

Adult↗

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.

Adolescent↗

Gamma Knife radiosurgery of the glomus jugulare tumour - early multicentre experience.

Leksell Gamma Knife was used to treat 66 patients with glomus jugulare tumour at 6 European sites between 1992-1998. The age of the patients ranged between 18-80 years (median 54 years). Gamma Knife radiosurgery was a primary treatment in 30 patients (45. 5%). Open surgery preceded radiosurgery in 24 patients (36.4%), embolisation in 14 patients (21.2%) and fractionated radiotherapy in 5 patients (7.6%). The volume of the tumour ranged 0.5-27 cm(3) (median 5,7 cm(3)). The minimal dose to the tumour margin ranged between 10-30 Gy (median 16.5 Gy). After radiosurgery 52 patients were followed, the follow up period was 3-70 months (median 24 months). Neurological deficit improved in 15 patients (29%) and deteriorated in 3 patients (5,8%), one transient and two persistant. Neuroradiological follow up using MRI or CT was performed in 47 patients 4-70 months (median 24 months) after radiosurgery. Tumour size decreased in 19 patients (40%) while in the remaining 28 patients (60%) no change in the tumour volume was observed. None of the tumours increased in volume during the observation period. Control angiography was performed in 6 patients. Pathological vascularisation completely disappeared in one patient, reduced in two and there was no change in the remaining three. Radiosurgery proves to be a safe treatment for glomus jugulare tumour with no mortality and no acute morbidity. Because of its naturally slow growth rate, up to 10 years of follow up will be necessary to establish a cure rate after radiosurgery for these lesions.

Adolescent↗

Linac radiosurgery for high-grade gliomas: the University of Florida experience.

PURPOSE: Stereotactic radiosurgery has been reported as a promising boost technique for the treatment of selected patients with high-grade glioma. The first 11 patients given this treatment at the University of Florida are reported. METHODS AND MATERIALS: Six patients with glioblastoma multiforme and five with anaplastic astrocytoma were carefully selected for treatment with linac radiosurgery. All patients had a Karnofsky performance status > or = 90%. Median age of patients was 42.1 years. External-beam radiotherapy delivered a median dose of 60 Gy. Stereotactic radiosurgery was delivered to the enhancing tumor volume without margin. Median treatment volume was 14 cm3 (equivalent sphere diameter, 3 cm). The maximum volume of any tumor treated was 22.5 cm3 (equivalent sphere diameter, 3.5 cm). Median stereotactic radiosurgery boost dose was 12.5 Gy, and median prescription sphere was the 80% isodose shell. RESULTS: Despite rigorous selection and aggressive stereotactic boost irradiation, this patient cohort had a median actuarial survival of 17 months. All patients have had progression of intracranial disease within 1 year of radiosurgery, and only 3 of 11 remain alive with a median follow-up of 13 months. CONCLUSION: These results differ significantly from others reported. Comparative analysis suggests tumor volume may be an important prognostic factor in patients treated with stereotactic radiosurgery. Future studies need to define appropriate patient cohorts for the boost technique.

Adolescent↗

Radiosurgery in the initial management of malignant gliomas: survival comparison with the RTOG recursive partitioning analysis. Radiation Therapy Oncology Group.

PURPOSE: To evaluate the impact of stereotactic radiosurgery on the survival of patients treated with malignant gliomas. METHODS AND MATERIALS: A total of 115 patients from three institutions (75 from the Joint Center for Radiation Therapy, 30 from the University of Wisconsin, and 10 from the University of Florida) were treated with a combination of surgery, external beam radiation therapy, and linac-based radiosurgery as part of similar institutional protocols from March 1988 through July 1993. Patients were stratified into six prognostic classes (classes 1-6) based on the recursive partitioning analysis of multiple prognostic factors previously reported by the Radiation Therapy Oncology Group. RESULTS: The actuarial 2-year and median survival for all patients analyzed was 45% and 96 weeks, respectively. In comparison to the results from a previously published analysis of 1578 patients entered on three Radiation Therapy Oncology Group external beam radiotherapy protocols from 1974 to 1989, those patients treated with radiosurgery had a significantly improved 2-year and median survival (p = 0.01) corresponding with a standardized mortality risk ratio of 0.51 [95% confidence interval (CI): 0.31, 0.85]. This improvement in survival was seen predominantly for the worse prognostic classes (classes 3-6). The 2-year survival for the radiosurgical patients compared with the previously reported patients was 81% vs. 76% for classes 1/2, 75% vs. 35% for class 3, 34% vs. 15% for class 4, and 21% vs. 6% for classes 5/6, respectively. Although Karnofsky performance status and prognostic class were significant on univariate analysis, only the Karnofsky score was a significant predictor of outcome on multivariate analysis. Median and 2-year survival for patients with a Karnofsky score > or = 70 was 106 weeks and 51%, respectively, as compared to 38 weeks and 0% for patients with a Karnofsky score < 70% (p = 0.001). CONCLUSIONS: The addition of radiosurgery to conventional treatment (surgery and external beam radiotherapy) of malignant gliomas appears to improve survival when compared to historical reports. These results should be interpreted with caution because the recursive partitioning model does not completely predict the prognosis of the patients treated in the present study. Although this study suggests that radiosurgery may prolong survival in patients with malignant gliomas, the role of radiosurgery in the management of these patients remains to be defined by a prospective randomized trial.

Brain Neoplasms↗

Results of stereotactic radiosurgery for patients with imaging defined cavernous sinus meningiomas.

INTRODUCTION: The purpose of this study was to evaluate the efficacy and safety of stereotactic radiosurgery as primary management for patients with imaging defined cavernous sinus meningiomas. METHODS: Between 1992 and 2001, 49 patients had radiosurgery for dural-based masses of the cavernous sinus presumed to be meningiomas. The mean patient age was 55.5 years. The mean tumor volume was 10.2 mL; the mean tumor margin dose was 15.9 Gy. The mean follow-up was 58 months (range, 16-144 months). RESULTS: No tumor enlarged after radiosurgery. Twelve of 38 patients (26%) with preexisting diplopia or facial numbness/pain had improvement in cranial nerve function. Five patients (10%) had new (n = 3) or worsened (n = 2) trigeminal dysfunction; 2 of these patients (4%) underwent surgery at 20 and 25 months after radiosurgery despite no evidence of tumor progression. Neither patient improved after partial tumor resection. One patient (2%) developed an oculomotor nerve injury. One patient (2%) had an ischemic stroke related to occlusion of the cavernous segment of the internal carotid artery. Event-free survival was 98%, 85%, and 80% at 1, 3, and 7 years after radiosurgery, respectively. Univariate analysis of patient and dosimetric factors found no analyzed factor correlated with postradiosurgical morbidity. CONCLUSIONS: Radiosurgery was an effective primary management strategy for patients with an imaging defined cavernous sinus meningioma. Except in situations of symptomatic mass effect, unusual clinical presentation, or atypical imaging features, surgery to confirm the histologic diagnosis is unlikely to provide clinical benefit.

Adult↗

Linac stereotactic radiosurgery: an effective and safe treatment for elderly patients with brain metastases.

PURPOSE: To evaluate the outcomes of radiosurgery for brain metastases in patients 65 years or older. PATIENTS AND METHODS: Between January 1994 and January 2003, 117 patients (47 women, 70 men), median age 71 years (range, 65-86 years), received radiosurgery for 227 metastases. Sixty-one patients (55%) presented symptoms in relation to the brain metastases. Thirty-eight patients (32%) received whole-brain radiotherapy. Median metastasis diameter and volume were 21 mm (range, 0.5-75 mm) and 1.7 cc (range, 0.02-71 cc), respectively. RESULTS: Median follow-up was 7 months (range, 1-45 months), 9.5 months for alive patients (range, 1-45 months). Median minimum and maximum doses were 14.5 Gy (6.5 Gy, 19.5 Gy), and 20.4 Gy (13.2 Gy, 41.9 Gy), respectively. Median survival was 8 months from the date of radiosurgery. Overall survival rates at 6 and 24 months were 58% +/- 5% and 13% +/- 4%, respectively. According to multivariate analysis, a low Karnofsky performance status was an independent unfavorable prognostic factor for overall survival (p = 0.003; odds ratio [OR] = 0.28; 95% confidence interval [CI], 0.14-0.56). Median brain disease-free survival was 10 months. Brain disease-free survival rates at 6 and 24 months were 67% +/- 6% and 40% +/- 7%, respectively. According to multivariate analysis, a radiosensitive lesion was an independent favorable factor (p = 0.038; OR = 0.42; 95% CI, 0.18-0.95); more than two metastases and a low Karnofsky performance status were independent unfavorable factors for brain disease-free survival (p = 0.046; OR = 2.15; 95% CI, 1.01-4.58 and p = 0.003; OR = 30.4; 95% CI, 3.1-296, respectively). Local control rates were 98% +/- 2% and 91% +/- 8.5% at 6 and 24 months. Out of the 61 patients presenting symptoms before radiosurgery, complete symptomatic response was achieved in 12 patients (20%), partial improvement in 25 (41%), stabilization in 7 (11%), and worsening in 4 (6%) related to a progression of the irradiated metastasis. Seven cases of radionecrosis were described and were related to the margin dose (p = 0.03). CONCLUSION: Radiosurgery for elderly patients was effective and safe. Age alone should not be a criterion for denying radiosurgery to any patient with brain metastases.

Aged↗

Geometric parameter analysis to predetermine optimal radiosurgery technique for the treatment of arteriovenous malformation.

PURPOSE: To develop a method of predicting the values of dose distribution parameters of different radiosurgery techniques for treatment of arteriovenous malformation (AVM) based on internal geometric parameters. METHODS AND MATERIALS: For each of 18 previously treated AVM patients, four treatment plans were created: circular collimator arcs, dynamic conformal arcs, fixed conformal fields, and intensity-modulated radiosurgery. An algorithm was developed to characterize the target and critical structure shape complexity and the position of the critical structures with respect to the target. Multiple regression was employed to establish the correlation between the internal geometric parameters and the dose distribution for different treatment techniques. The results from the model were applied to predict the dosimetric outcomes of different radiosurgery techniques and select the optimal radiosurgery technique for a number of AVM patients. RESULTS: Several internal geometric parameters showing statistically significant correlation (p < 0.05) with the treatment planning results for each technique were identified. The target volume and the average minimum distance between the target and the critical structures were the most effective predictors for normal tissue dose distribution. The structure overlap volume with the target and the mean distance between the target and the critical structure were the most effective predictors for critical structure dose distribution. The predicted values of dose distribution parameters of different radiosurgery techniques were in close agreement with the original data. CONCLUSIONS: A statistical model has been described that successfully predicts the values of dose distribution parameters of different radiosurgery techniques and may be used to predetermine the optimal technique on a patient-to-patient basis.

Algorithms↗

Gamma knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part I: Differences in epidemiologic, morphologic, and clinical characteristics, permanent complications, and bleeding in the latency period.

PURPOSE: To compare the epidemiologic, morphologic, and clinical characteristics of 92 children/adolescents (Group A) and 362 adults (Group B) with cerebral arteriovenous malformations (cAVMs) considered suitable for radiosurgery; to correlate radiosurgery-related permanent complication and post-radiosurgery bleeding rates in the 75 children/adolescents and 297 adults available for follow-up. METHODS AND MATERIALS: Radiosurgery was performed with a model C 201-source Co60 Leksell Gamma Unit (Elekta Instruments, Stockholm, Sweden). Fisher exact two-tailed, Wilcoxon rank-sum, and two-sample binomial exact tests were used for statistical analysis. RESULTS: There were significant differences between the two populations in sex (p = 0.015), clinical presentation (p = 0.001), and location (p = 0.008). The permanent complication rate was lower in younger (1.3%) than in older patients (5.4%), although the difference was not significant (p = 0.213). The postradiosurgery bleeding rate was lower in Group A (1.3%) than in Group B (2.7%) (p = 0.694), with global actuarial bleeding rates of 0.56% per year and 1.15% per year, respectively. CONCLUSIONS: The different characteristics of child/adolescent and adult cAVMs suggest that they should be considered two distinct vascular disorders. The similar rates of radiosurgery-related complications and latency period bleeding in the two populations show that gamma knife radiosurgery does not expose young patients to a higher risk of sequelae than that for older patients.

Adolescent↗

Cyberknife radiosurgery for metastatic spine tumors.

Metastatic spine tumors affect a large number of patients each year, resulting in significant pain,destruction of the spinal column causing mechanical instability, and neurologic deficits. Standard therapeutic options include surgery and fractionated external beam radiotherapy. The first option can be associated with significant morbidity and limited local tumor control. Conversely, radiotherapy may provide less than optimal pain relief and tumor control, because the total dose is limited by the tolerance of adjacent tissues, such as the spinal cord. The emerging technique of spinal radiosurgery represents a logical extension of the current state-of-the-art radiation therapy. It has the potential to significantly improve local control of cancer of the spine, which could translate into more effective palliation and potentially longer survival. Spinal radiosurgery might offer improved pain control and a longer duration of pain control by giving larger radiobiologic doses.This technique also allows for the treatment of lesions previously irradiated using external beam radiation. Another advantage to the patient is that irradiation can be completed in a single day rather than several weeks, which is not inconsequential for patients with a limited life expectancy. In addition, cancer patients may have difficulty with access to a radiation treatment facility for prolonged daily fractionated therapy. This technique allows for the treatment of lesions previously irradiated using external beam radiation.Finally, the procedure is minimally invasive compared with open surgical techniques and can be performed in an outpatient setting. Similar to intracranial radiosurgery, stereo-tactic radiosurgery now has a feasible and safe delivery system available for the treatment of spinal metastatic lesions. The major potential benefit of radiosurgical ablation of spinal lesions is a relatively short treatment time in an outpatient setting combined with potentially better local control of the tumor with minimal risk of side effects. CyberKnife spinal radiosurgery offers a new and important alternative therapeutic modality for the treatment of spinal metastases in medically inoperable patients, previously irradiated sites, and for lesions not amenable to open surgical techniques or as an adjunct to surgery. Spinal radiosurgery is likely to become an essential part of any neurosurgical spine center that treats a large number of patients with spinal metastases.

Humans↗

Radiosurgery of cavernous hemangiomas in the cavernous sinus.

BACKGROUND: Cavernous hemangiomas in the cavernous sinus are rare and demonstrate unique clinical courses. Although they rarely cause spontaneous bleeding, serious bleeding is not uncommon during operations. Total eradication of such tumors is very difficult because of the location and intraoperative bleeding. Consequently, alternatives to operative resection have been examined. METHODS: Three cases of cavernous hemangiomas in the cavernous sinus, presenting chiefly with ocular signs and facial pain, were treated by radiosurgery using a gamma knife. Two of the patients had been operated on before radiosurgery, while the third patient was diagnosed on the basis of neurological signs as well as radiological findings. RESULTS: MRI scans at the time of radiosurgery showed tumors in the cavernous sinus with low or iso-intensity on T1-weighted images and high signal intensity on T2-weighted images. All of the tumors intensely enhanced with gadolinium-DTPA. The tumors had diameters of 14 to 28 mm and were treated with a marginal dose of 14 to 17 Gy (mean 15.7 Gy). In the mean follow-up period of 27 months after radiosurgery, all of the tumors decreased in size (PR). Neurologically, none of the patients showed any deterioration, and one demonstrated an obvious improvement in ocular movement. CONCLUSIONS: Radiosurgery for cavernous hemangioma in the cavernous sinus is apparently safe and effective with consistent tumor shrinkage. Therefore, radiosurgery is an excellent alternative to operative intervention and may even replace operative procedures if the tumors are small in diameter or when they recur.

Adult↗

Stereotactic radiosurgery for brain metastases from gastrointestinal tract cancer.

BACKGROUND: Outcomes in patients with brain metastases from gastrointestinal tract cancers are not well defined. In this study we used precise, single-session, focal tumor irradiation (radiosurgery) in patients with brain metastases and evaluated the results. METHODS: Thirty-nine patients had brain metastases from gastrointestinal tract cancer and were treated with radiosurgery. Thirty-two also had whole brain radiotherapy. Primary lesions included colorectal cancer (n = 25), esophageal cancer (n = 11), cholangiocarcinoma (n = 1), duodenal cancer (n = 1), and jejunal cancer (n = 1). Seventy-two tumors were treated. RESULTS: The overall median survival was 9 months after diagnosis of metastatic brain disease and 5 months after radiosurgery. The 1-year survival rate after radiosurgery was 19%. The last imaging study of 49 tumors showed complete remission (CR) in 3 tumors (6.1%), partial remission (PR) in 27 tumors (55.1%), no change (NC) in 11 tumors (22.4%), and progression in 8 tumors (16.3%). The local tumor control rate (CR, PR, NC) was 84%. Two patients (5.1%) had a new or worsening neurologic deficit after radiosurgery. CONCLUSIONS: Stereotactic radiosurgery provides reasonable local control of brain metastases from gastrointestinal tract cancer with few side effects. However, it should be used judiciously in patients with active extracranial cancers since the expected survival may be limited.

Adult↗

Radiosurgery for re-irradiation of brain metastasis: results in 54 patients.

PURPOSE: To evaluate in terms of probabilities of local-regional control and survival, as well as of treatment-related toxicity, results of radiosurgery for brain metastasis arising in previously irradiated territory. PATIENTS AND METHODS: Between January 1994 and March 2000, 54 consecutive patients presenting with 97 metastases relapsing after whole brain radiotherapy (WBRT) were treated with stereotactic radiotherapy. Median interval between the end of WBRT and radiosurgery was 9 months (range 2-70). Median age was 53 years (24-80), and median Karnofski performance status (KPS) 70 (60-100). Forty-seven patients had one radiosurgery, five had two and two had three. Median metastasis diameter and volume were 21 mm (6-59) and 1.2 cc (0.1-95.2), respectively. A Leksell stereotactic head frame (Leksell Model G, Elektra, Instrument, Tucker, GA) was applied under local anesthesia. Irradiation was delivered by a gantry mounted linear accelerator (linacs) (Saturne, General Electric). Median minimal dose delivered to the gross disease was 16.2 Gy (11.8-23), and median maximal dose 21.2 Gy (14- 42). RESULTS: Median follow-up was 9 months (1-57). Five metastases recurred. One- and 2-year metastasis local control rates were 91.3 and 84% and 1- and 2-year brain control rates were 65 and 57%, respectively. Six patients died of brain metastasis evolution, and three of leptomeningeal carcinomatosis. One- and 2-year overall survival rates were 31 and 28%, respectively. According to univariate analysis, KPS, RPA class, SIR score and interval between WBRT and radiosurgery were prognostic factors of overall survival and brain free-disease survival. According to multivariate analysis, RPA was an independent factor of overall survival and brain free-disease survival, and the interval between WBRT and radiosurgery longer than 14 months was associated with longer brain free-disease survival. Side effects were minimal, with only two cases of headaches and two of grade 2 alopecia. CONCLUSION: Salvage radiosurgery of metastasis recurring after whole brain irradiation is an effective and accurate treatment which could be proposed to patients with a KPS>70 and a primary tumour controlled or indolent. We recommend that a dose not exceeding 14 Gy should be delivered to an isodose representing 70% of the maximal dose since local control observed rate was similar to that previously published in literature with upper dose and side effects were minimal.

Adult↗

A comparison of arc-based and static mini-multileaf collimator-based radiosurgery treatment plans.

BACKGROUND: The purpose of this study is to compare arc-based and mini-multileaf collimator (mMLC)-based radiosurgery treatment plans using isodose distributions and dose-volume histograms. METHODS: Of 11 patients who underwent conventional arc-based radiosurgery for intracranial malignancies, four were treated with one isocenter, four were treated with two isocenters and three were treated with three isocenters. The same cases were re-planned using a test version of mMLC-based radiosurgery software for multiple static non-coplanar fields. RESULTS AND CONCLUSION: For non-spherical targets, treatment planning is relatively intuitive with mMLC-based radiosurgery, reducing the amount of time required for planning. Moreover, a lower dose of radiation is delivered to normal tissue with mMLC-based radiosurgery than with arc-based radiosurgery, which theoretically should lead to a reduced risk of complications.

Brain Neoplasms↗

Treatment of brain metastases in patients with non-small cell lung cancer (NSCLC) by stereotactic linac-based radiosurgery: prognostic factors.

A restrospective study of patients with brain metastases from non-small cell lung cancer (NSCLC) is performed to identify patients who benefit from radiosurgery and to determine prognostic factors for survival. Eighty-six consecutive patients with a total of 110 brain metastases from NSCLC were treated with linac-based radiosurgery. Six patients with eight brain metastases who received radiosurgery as a focal boost to whole brain radiotherapy where excluded. Median age at treatment was 60 years. Median dose was 20 Gy/80%-isodose. A chi(2)-test was used to identify potential prognostic factors for local control of brain metastases and survival of the patients. Median follow-up was 6 months (range 1 1/2-77 months) with 17/80 patients still alive. Median actuarial survival was significantly longer (P<0.004) in patients with metachronous onset of brain metastases in comparison to synchronous onset (8.3 vs. 3.3 months). Survival was significantly increased after radiosurgery in the absence of extracranial tumor progression (P<0.03). Eleven patients (14%) developed new brain metastases after radiosurgery after a latency of median 5 months. Actuarial local control rate was 96% after 3 months. Local control was significantly increased with a prescribed dose > or=18 Gy/80%-isodose (P<0.01). We conclude that especially patients with poor prognostic factors and a limited number of brain metastases may be palliatively treated with radiosurgery alone. This approach allows to effectively control CNS manifestation of the disease and can be integrated into chemotherapeutic protocols.

Adult↗