Survival after Stereotactic Radiosurgery for Recurrent Glioblastoma Multiforme

This retrospective analysis details the experience of a tertiary care center with survival and results for patients with recurrent glioblastoma multiforme (GBM) treated with stereotactic radiosurgery (SRS). Between August 1990 and June 1999, 23 patients were treated for recurrent GBM with SRS using either modified 6-MV linear accelerator (linac) or -knife. Twenty-two patients (96%) had an initial histological diagnosis of GBM, while 1 patient had an initial diagnosis of anaplastic astrocytoma that was biopsied at recurrence and found to have upgraded to GBM. The median Karnofsky performance score at the time of SRS was 80; the median age was 53. The median-treated tumor volume was 9.9 cm³, with a dose of 15 Gy delivered to the 60% isodose line. Median progression-free survival was 4.7 months. Median survival time after SRS was 10.3 months. No prognostic factors were found to be significant. Patients with a KPS of 80 or higher had longer median survival times than those with lower KPS scores, but this was not found to be statistically significant. Our results suggest that for selected patients with recurrent GBM, SRS appears to be an appropriate salvage therapy.     

Salvage treatment for persistent and recurrent T1-2 nasopharyngeal carcinoma by stereotactic radiosurgery

OBJECTIVE: To study the efficacy of stereotactic radiosurgery in salvaging early-stage persistent and recurrent nasopharyngeal carcinoma (NPC) after primary radiotherapy. METHODS: A prospective single-arm study evaluating the response and outcome of patients with rT1-2 NPC treated by stereotactic radiosurgery. Eleven patients with rT1-2 were treated by radiosurgery between March 1998 and March 2000. Four patients were treated for persistent disease occurring within 4 months after primary radiotherapy, six were treated for first recurrence, and one for third recurrence. Six patients had rT1 disease and five had rT2 disease. Most patients had disease not amenable to brachytherapy, surgery, or external re-irradiation. The median target volume was 5.8 cc (range, 3.3-16.9). Radiosurgery was performed with multiple noncoplanar arcs of photon, with a median dose of 12.5 Gy delivered to the 80% isodose line (range, 12-14 Gy). Median follow-up time after radiosurgery was 18 months (range, 9-30). RESULTS: Nine patients had complete regression of tumor as assessed by imaging, nasopharyngoscopy, and biopsy; one patient had partial regression of tumor; whereas one patient had static disease. The overall response rate was 91% (10 of 11) and the complete response rate was 82% (9 of 11). Two patients with complete response subsequently had local relapse develop, with one recurrence outside the treated volume 8 months after radiosurgery, and the other within the treated volume 6 months after radiosurgery. One patient with a partial response had neck node recurrence develop. Temporal lobe necrosis occurred in one patient but probably represents sequelae of primary radiation after reviewing the dosimetry. Ten patients are still alive, whereas one patient with local relapse had distant metastases develop and died. The estimated 1-year local control rate after radiosurgery was 82%. CONCLUSIONS: Our preliminary results indicate that stereotactic radiosurgery is an effective treatment modality for persistent and recurrent T1-T2 NPC, and early control rate seems to be comparable to other salvage treatments. More clinical experiences and longer follow-up are still needed to validate our results and to address fully the role of radiosurgery in salvaging local failures of NPC.     

LINAC radiosurgery for brain metastasis of renal cell carcinoma

The purpose of the study was to evaluate the efficacy and toxicity of stereotactic radiotherapy in the treatment of the brain metastasis of renal cell carcinoma. From 1994 to 2001, 28 patients presenting with 65 metastases of renal cell cancer were treated by radiosurgery. Median age was 55 years (35-75), and median Karnofski performance status ranges between 50 and 100. Seven patients had received whole brain radiotherapy (WBRT) before radiosurgery. Twelve patients were treated by radiosurgery for 1 metastasis, 5 patients for two metastases and 6 for three, and 5 for more than three metastases. One procedure was performed in 22 patients and, 2 or 3 procedures for 6 patients. Median metastasis diameter was 19 mm (5-55 mm). Median metastasis volume was 1.28 cc (0.02-28 cc). Irradiation was delivered by linear accelerator. Median minimal dose (on the 70% isodose) was 14.7 Gy (10.8 Gy, 19.5 Gy), median maximal dose (at the isocenter) 20.5 Gy (14.3 Gy, 39.6 Gy). Median follow-up was 14 months (1-33). Two metastases progressed (3%), 2 and 12 months after radiosurgery. Overall, crude local control rate was 97% and 3-, 6- and 12-month local control rates were 98% +/- 2%, 98% +/- 2%, and 93% +/- 5%, respectively. In univariate analysis, no prognostic factor of local control was retrieved. Median brain disease-free survival was 25 months after RS. the 3-, 6- and 12-month distant brain control rates were 91% +/- 4%, 91% +/- 4%, and 70% +/- 12%, respectively. Median survival duration was 11 months. The 3-, 6-, 12- and 24-month overall survival rates were 82% +/- 7%, 67% +/- 9%, 48% +/- 10%, and 33% +/- 10%, respectively. According to univariate analysis, only site of metastasis was overall survival prognostic factor. Radiosurgery for brain metastasis of renal cell carcinoma is an effective and accurate treatment. The use of radiosurgery alone is an appropriate management strategy for many patients with brain metastasis of renal cell carcinoma. Radiosurgery is efficient even after development of new metastasis appearing after WBRT.     

Stereotactic radiosurgery for locally recurrent nasopharyngeal carcinoma

BACKGROUND: Stereotactic radiosurgery has been used to treat intracranial tumors. Recently, it has also been used for the treatment of head and neck tumors involving the base of skull, including recurrent NPC. METHODS: From October 1994 to April 1999, 36 patients with recurrent NPC, were retreated by stereotactic radiosurgery. These patients received radiosurgery as a boost treatment after reirradiation for recurrence. The external RT dose ranged from 20 to 60 Gy. The tumor volume ranged from 3.58 to 24.6 cc. The target surface dose ranged from 8 to 20 Gy. The median follow-up was 22.1 months. RESULTS: The 3-year local control rate was 56%. The 5-year overall survival was 49%. Persistence after radiosurgery had a worse survival than those who had secondary recurrence. Age and gender were marginally significant. No patient had new severe complications after retreatment. Four patients (11%) had nasopharyngeal necrosis after radiosurgery, none had nasal bleeding or headache, but a foul odor was present in one patient. CONCLUSIONS: Conformal radiotherapy and stereotactic radiotherapy provide good local control and survival without severe complications for patients with recurrent NPC.     

Recurrent Malignant Gliomas Treated with Radiosurgery

The inability to control malignant glioma results in a high incidence of local failure and poor survival. Focal therapy such as radiosurgery permits delivery of a high dose of radiation with moderate toxicity. This report summarizes the outcome of patients with recurrent malignant glioma treated with radiosurgery at University of Wisconsin Hospital, between January 1989 and December 1997, when 30 patients were treated radiosurgically. All patients had undergone and failed external beam radiotherapy (median dose of 59.4 Gy) prior to radiosurgery. All recurrences were detected by clinical deterioration and confirmed by radiographic progression. No patient was treated for radiographic progression only in the context of a screening protocol. Eight out of 30 patients underwent subtotal resection prior to radiosurgery and 3 received chemotherapy along with radiosurgery. Radiosurgery was delivered in a single fraction using a modified linear accelerator. The median tumor volume was 7.2 cm³ (range 0.42–35.1 cm³) and the median minimal tumor dose was 12 Gy at the 50–80% isodose line. Median follow-up is 70 months. The median overall survival is 8 months; the 1- and 2-year survival rates are 20% and 9%, respectively. For patients with an initial diagnosis of non-glioblastoma, the median survival is 11 months and for those with glioblastoma the median survival is 7 months. The median progression-free survival is 4 months for the entire cohort, 5 months for nonglioblastoma, and 3 months for glioblastoma. The 1-year actuarial reoperation rate after radio-surgery is 7.6%. Radiosurgery for recurrent malignant glioma may improve short-term survival for selected patients with a lower reoperation rate than brachytherapy.     

Stereotactic radiosurgery as a salvage treatment for locally persistent and recurrent nasopharyngeal carcinoma.

BACKGROUND: The purpose of this work was to study the efficacy of stereotactic radiosurgery as a salvage treatment in patients with locally persistent and recurrent nasopharyngeal carcinoma (NPC). METHODS: Between March 1996 and August 1997, 10 patients with locally persistent or recurrent NPC were treated by linac-based stereotactic radiosurgery. Four patients had radiosurgery for persistent disease after a first course of radiotherapy, 3 had radiosurgery as a boost after reirradiation for local recurrence, and 3 had radiosurgery for disease that recurred after reirradiation. The tumor volume ranged from 1.3 to 23.7 cc (median: 5.2). Treatment was prescribed at 80% isodose line and ranged from 12 to 18 Gy (median: 13.4), with a mean tumor surface dose ranged from 10-21 Gy (median: 14). The median clinical follow-up was 10.5 months (range 8-27), and the median imaging follow-up was 9.5 months (range 6-26). RESULTS: One patient had complete regression of tumor after radiosurgery, five had reduction in tumor size, three had no change, and one had progression of tumor. The overall response rate to radiosurgery was 60% (6/10), with 10% (1/10) developing in-field progression. Excluding patients receiving radiosurgery as a boost treatment after reirradiation, the response rate was 57% (4/7) and none developed in-field progression. Only one patient developed a new cranial neuropathy in the absence of disease progression. CONCLUSION: In selected patients with locally persistent or recurrent NPC, stereotactic radiosurgery can be considered as a salvage treatment with good short-term local control. The complications appear to be minimal except for treating recurrence in the cavernous sinus. Early results are encouraging although more experience and longer follow-up are still needed to better define the role of radiosurgery in the management of persistent and recurrent NPC.     

Gamma knife radiosurgery for intraventricular meningiomas

Purpose  Intraventricular meningiomas are relatively rare tumors that may benefit from stereotactic radiosurgery as a minimally invasive treatment strategy. We report our experience using gamma knife radiosurgery (GKR) for intraventricular meningiomas. Methods  Over a 16-year period, we identified 9 patients with intraventricular meningiomas who were eligible for GKR out of a total management experience of 1,045 patients. The mean patient age was 51 years (range, 14 to 81). Three had radiosurgery for recurrent tumors after prior resection, and GKR was used as an adjunctive after subtotal resection in 1 patient. In the other 5 patients, GKR was used as primary management. Two had a diagnosis of meningioma confirmed by biopsy. The median tumor volume at GKR was 3.9 cc (range, 0.8–11.8). A median margin dose of 16.0 Gy (range, 14.0–22.5) was delivered to the tumor margin. Results  The average follow-up was 64 months. None of the patients developed hydrocephalus or treatment-related morbidity. The progression-free periods after radiosurgery varied from 7 to 160 months (mean, 60). Four tumors regressed and 2 remained unchanged. Three patients showed delayed tumor progression. Meningioma growth control was obtained in 7 out of 9 patients, but 1 patient required two radiosurgical procedures. Conclusions  Gamma knife radiosurgery may be an additional minimally invasive management option for small intraventricular meningiomas in patients who either fail or are unsuitable for resection.     

Radiosurgery for treatment of recurrent intracranial hemangiopericytomas

OBJECTIVE: Hemangiopericytomas are highly aggressive meningeal tumors with tendencies for recurrence and metastasis. The purpose of this retrospective, single-institution review was to evaluate the efficacy and role of stereotactic radiosurgery in the management of recurrent hemangiopericytomas. METHODS: We reviewed data for patients who underwent stereotactic radiosurgery at the University of Pittsburgh between 1987 and 2001. Fourteen patients underwent radiosurgery for 15 discrete tumors. Prior treatments included transsphenoidal resection (n = 1), craniotomy and resection (n = 27), embolization (n = 1), and conventional radiotherapy (n = 7). Clinical and radiological responses were evaluated. Follow-up periods varied from 5 to 76 months (mean, 31.3 mo; median, 21 mo). The mean radiation dose to the tumor margin was 15 Gy. RESULTS: Seventy-nine percent of patients (11 of 14 patients) with recurrent hemangiopericytomas demonstrated local tumor control after radiosurgery. Twelve of 15 tumors (i.e., 80%) dramatically decreased in size on follow-up imaging scans. Regional intracranial recurrences were retreated with radiosurgery for two patients (i.e., 15%); neither of those two patients experienced long-term tumor control. Local recurrences occurred 12 to 75 months (median, 21 mo) after radiosurgery. Local tumor control and survival rates at 5 years after radiosurgery were 76 and 100%, respectively (Kaplan-Meier method). We could not correlate prior irradiation or tumor size with tumor control. Twenty-nine percent of the patients (4 of 14 patients) developed remote metastases. Radiosurgery did not seem to offer protection against the development of intra- or extracranial metastases. CONCLUSION: Gamma knife radiosurgery provided local tumor control for 80% of recurrent hemangiopericytomas. When residual tumor is identified after resection or radiotherapy, early radiosurgery should be considered as a feasible treatment modality. Despite local tumor control, patients are still at risk for distant metastasis. Diligent clinical and radiological follow-up monitoring is necessary.     

Stereotactic interstitial radiosurgery with a miniature X-ray device in the minimally invasive treatment of selected tumors in the thalamus and the basal Ganglia

The aim of this study was to evaluate the role of interstitial radiosurgery (IR) using the photon radiosurgery system (PRS) in the treatment of selected tumors within the thalamus and the basal ganglia. The PRS is a miniature X-ray generator that was developed for interstitial irradiation. This series included 14 patients (5 with glioblastomas, 4 with low-grade astrocytomas and 5 with metastases) harboring spheroidal lesions with dimensions ranging from 13 to 42 mm (mean 30 mm). After stereotactic biopsy, a radiation dose ranging from 6 to 15.4 Gy (mean 11.3 Gy) was delivered at the target volume margins. Follow-up varied from 3 to 26 months (mean 10.2 months). In the group of glioblastomas, 3 patients died (3-12 months after the procedure) because of tumor progression, while the remaining had tumor control. Two patients with metastases died from systemic disease (4-9 months after the treatment), and 3 were alive and well at the end of the study. Local control was achieved in all metastases. Patients with low-grade astrocytomas were well and imaging studies showed tumor control PRS IR is a minimally invasive procedure for the treatment of selected glial or secondary brain tumors. Compared to conventional radiosurgery (brachytherapy and external radiosurgery), PRS IR presents dose delivery characteristics useful for the treatment of tumors in the thalamus and basal ganglia, without inconveniences such as handling radioisotopes, the need of expensive facilities and radiation protection measures. Although the clinical value needs further investigations, PRS IR seems to be effective in metastases while it provides less benefit in malignant gliomas. PRS IR could have a major role in the treatment of low-grade astrocytomas.     

Gamma knife radiosurgery for trigeminal schwannomas

BACKGROUND: Trigeminal schwannomas are uncommon tumors that may be microsurgically removed in selected cases, albeit with significant risk for new neurological morbidity. We evaluated the role of stereotactic radiosurgery as an alternative for patients with newly diagnosed or residual trigeminal schwannomas. METHODS: The records of 23 patients who underwent radiosurgery for trigeminal schwannoma were reviewed. The most frequent presenting symptoms were facial numbness (11 patients), diplopia (6 patients), and facial pain (3 patients). One patient presented with partial complex seizures as the first symptom. Twelve patients had undergone one or more prior resections. Eleven underwent radiosurgery on the basis of imaging diagnosis only. The mean tumor volume was 4.5 mL (range 0.46-11.2 cc). Radiosurgery was performed using a median marginal dose of 15 Gy (range, 13-20 Gy). RESULTS: At a median imaging follow-up of 40 months (range, 12-146), 20 of 22 evaluable patients (91%) had tumor growth control (regression in 15 and no further tumor growth in 5). One 80-year-old patient died of unrelated cause 4 months after radiosurgery. Two patients with enlarged tumors were treated effectively with repeat radiosurgery. Twelve of 23 patients (52%) reported improvement and 9 (39%) had no change in their symptoms. Two patients noted new neurological complaints (transient facial weakness in 1 patient and worsening of the preradiosurgery facial numbness in another patient). CONCLUSIONS: Radiosurgery is an effective minimally invasive management option for patients with residual or newly diagnosed trigeminal schwannomas.     

Adjuvant stereotactic radiosurgery for anaplastic ependymoma

OBJECT: The purpose of this retrospective study is to evaluate the role of stereotactic radiosurgery using the Gamma Knife as an adjuvant to other modalities used in the treatment of malignant ependymomas of both children and adults and to assess its efficacy in terms of tumor control and overall survival. METHOD: Between 1987 and 1998, 22 patients in the age range of 1.5-65 years (mean age 22. 3) with progressive anaplastic ependymoma were treated by stereotactic radiosurgery using the 201 source Co-60 Leksell Gamma Knife at the University of Pittsburgh. The irradiated tumor volume varied from 0.84 to 36.8 cm(3) (mean 13.7). The median dose delivered to the tumor margin was 16.1 Gy (range 10-20), and the mean maximal dose was 32.2 Gy (range 20-40). The disease-free survival, the tumor control rate and the overall survival were recorded to evaluate the efficacy of radiosurgery. The median follow-up from radiosurgery was 21 months (range 4-84). RESULTS: Median survival after radiosurgery was 2.2 years (46.6 +/- 12.1% 5-year actuarial). Median survival from the initial diagnosis was 10. 1 years (50.3 +/- 12.5% at 5 years, 37.7 +/- 14.4% at 10 years). Reduction or stabilization of the treated tumor was seen in 16 out of 22 (68%) patients. Forty-one percent of the patients eventually developed delayed distant cerebral recurrence outside the treated volume. The 5-year actuarial rates for local control and cranial control at any location were 62.3 +/- 13.6% and 32.4 +/- 10.8%, respectively. No complication occurred as a side effect of radiosurgery. CONCLUSION: For patients with locally recurrent or progressive anaplastic ependymomas, Gamma Knife stereotactic radiosurgery proved to be safe and effective as a salvage adjuvant therapy to achieve local tumor control and improve survival.     

Stereotactic radiosurgery as a salvage treatment for recurrent epipharyngeal carcinoma

Fourteen patients with recurrent epipharyngeal carcinoma (EPC) were treated by gamma knife stereotactic radiosurgery. The tumor volume ranged from 0.3 to 80 ml (median 18.9 ml). Treatment was done with a tumor margin dose of 10-27 Gy (median 15 Gy). The median follow-up period was 15 months (range 2-47 months). Ten patients were alive and 4 were dead at the end of the follow-up period. In 6 patients (43%), the tumor disappeared or decreased in size until the end of the follow-up period. In 2 (14%), the tumor remained unchanged in size. In 6 (43%), the tumor showed regression initially but was enlarged later. A second radiosurgery was performed in 4 of those 6 cases and the tumor decreased in size again in 3 of them. Thus, the overall control rate of local tumor was 79% (11/14). In selected patients with recurrent EPC, stereotactic radiosurgery can be considered as a salvage treatment producing local control.     

Use of trans sodium crocetinate for sensitizing glioblastoma multiforme to radiation: laboratory investigation

OBJECT: Adjuvant treatment with radiation (radiation therapy or radiosurgery) is a mainstay of treatment for patients harboring glioblastomas multiforme (GBM). Hypoxic regions within the tumor make cells less sensitive to radiation therapy. Trans sodium crocetinate (TSC) has been shown to increase oxygen diffusion in the brain and elevate the partial brain oxygen level. The goal of this study was to evaluate the radiosensitizing effects of TSC on GBM tumors. METHODS: A rat C6 glioma model was used, in which C6 glioma cells were stereotactically injected into the rat brain to create a tumor. Following creation of a right frontal tumor, animals were randomized into 1 of 4 groups: 1) TSC alone (animal treated with moderate-dose TSC only); 2) radiation (animals receiving 8 Gy of cranial radiation); 3) radiation and low-dose TSC (animals receiving 8 Gy of radiation and 50 microg/kg of TSC); or 4) radiation and moderate-dose TSC (animals receiving 8 Gy of radiation and 100 microg/kg of TSC). Animals were observed clinically for 60 days or until death. Magnetic resonance (MR) imaging was performed at 2-week intervals on each animal and quantitatively evaluated for tumor response. Immunohistochemical analysis was performed on all brain tumors. Survival differences were also evaluated using the Kaplan-Meier method. RESULTS: On MR imaging, a statistically significant reduction in tumor size was seen in the group receiving moderate-dose TSC and radiation treatment compared with the group receiving radiation treatment alone. The rate of tumor growth was significantly less for the combination of TSC and radiation treatment compared with either modality alone. Median survival times for the TSC-only and the radiation therapy-only groups were 15 and 30 days, respectively. The 60-day median survival times for the groups receiving a combination of either low- or moderate-dose TSC with radiation therapy were statistically improved compared with those for the other treatment groups. CONCLUSIONS: Use of TSC improves the extent of GBM tumor regression following radiation therapy and enhances survival. Radiosensitization of hypoxic tumors through increased oxygen diffusion may have clinical utility in patients with GBM tumors but must be explored in a clinical trial.     

Stereotactic radiosurgery for motor cortex region arteriovenous malformations

OBJECTIVE: The optimal management of arteriovenous malformations (AVMs) in critical brain locations remains controversial. To reduce the risk of an AVM hemorrhage and to enhance the possibility of preserving neurological function, stereotactic radiosurgery was performed in 33 patients with newly diagnosed or residual AVMs located within the motor cortex. The role of embolization also was examined. METHODS: During a 9-year study period, 33 patients with AVMs located primarily in the motor cortex region were treated with stereotactic radiosurgery. These patients were followed up radiographically for a minimum of 36 months, or less if obliteration was documented before 36 months had elapsed. Of the 33 patients, 9 underwent embolization and 1 underwent microsurgery before radiosurgery. Nine patients required a second radiosurgery. The mean AVM target volume was 4.35 cc, and the average radiation dose to the AVM margin was 20 Gy. The median follow-up was 36 months (range, 10-91 mo), and angiographic follow-up of eligible patients was performed 24 or 36 months after radiosurgery. RESULTS: Results were stratified by radiosurgical target volumes: less than 3 cc (Group 1), 3 to 10 cc (Group 2), and greater than 10 cc (Group 3). Overall (including second radiosurgery), 13 (87%) of 15 patients in Group 1 had complete obliteration confirmed by angiography. Nine (64%) of 14 patients in Group 2 exhibited nidus obliteration, and one (25%) of four patients in Group 3 demonstrated obliteration on a magnetic resonance imaging scan. Eight patients (24%) underwent second-stage radiosurgery after angiography revealed a persistent AVM nidus; three patients demonstrated complete obliteration on follow-up angiography. The obliteration rate was higher (87%) for AVMs with less than 3 cc target volume and lower (56%) for those with target volumes larger than 3 cc. One patient experienced worsening neurological function after radiosurgery, and one died from delayed AVM hemorrhage during the latency period. No patient bled after angiographically confirmed AVM obliteration. CONCLUSION: Stereotactic radiosurgery is a successful and safe management option for patients with motor cortex AVMs. The obliteration of AVMs and the attendant low morbidity rates indicate a primary role for radiosurgery in these patients. Staged radiosurgery may be necessary to increase obliteration rates for larger AVMs or for those that are not obliterated after the first procedure.     

Stereotactic radiosurgery as an alternative to fractionated radiotherapy for patients with recurrent or residual nonfunctioning pituitary adenomas

OBJECTIVE: To evaluate tumor control rates and complications after stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas. METHODS: Between 1992 and 2000, 33 patients underwent radiosurgery for treatment of nonfunctioning pituitary adenomas. Thirty-two patients (97%) had undergone one or more previous tumor resections. Twenty-two patients (67%) had enlarging tumors before radiosurgery. The median tumor margin dose was 16 Gy (range, 12-20 Gy). The median follow-up period after radiosurgery was 43 months (range, 16-106 mo). RESULTS: Tumor size decreased for 16 patients, remained unchanged for 16 patients, and increased for 1 patient. The actuarial tumor growth control rates at 2 and 5 years after radiosurgery were 97%. No patient demonstrated any decline in visual function. Five of 18 patients (28%) with anterior pituitary function before radiosurgery developed new deficits, at a median of 24 months after radiosurgery. The actuarial risks of developing new anterior pituitary deficits were 18 and 41% at 2 and 5 years, respectively. No patient developed diabetes insipidus. CONCLUSION: Stereotactic radiosurgery safely provides a high tumor control rate for patients with recurrent or residual nonfunctioning pituitary adenomas. However, despite encouraging early results, more long-term information is needed to determine whether radiosurgery is associated with lower risks of new endocrine deficits and radiation-induced neoplasms, compared with fractionated radiotherapy.     

Brain metastases treated with radiosurgery alone: an alternative to whole brain radiotherapy?

OBJECTIVE: Whole brain radiotherapy (WBRT) provides benefit for patients with brain metastases but may result in neurological toxicity for patients with extended survival times. Stereotactic radiosurgery in combination with WBRT has become an important approach, but the value of WBRT has been questioned. As an alternative to WBRT, we managed patients with stereotactic radiosurgery alone, evaluated patients' outcomes, and assessed prognostic factors for survival and tumor control. METHODS: One hundred seventy-two patients with brain metastases were managed with radiosurgery alone. One hundred twenty-one patients were evaluable with follow-up imaging after radiosurgery. The median patient age was 60.5 years (age range, 16-86 yr). The mean marginal tumor dose and volume were 18.5 Gy (range, 11-22 Gy) and 4.4 ml (range, 0.1-24.9 ml). Eighty percent of patients had solitary tumors. RESULTS: The overall median survival time was 8 months. The median survival time in patients with no evidence of primary tumor disease or stable disease was 13 and 11 months. The local tumor control rate was 87%. At 2 years, the rate of local control, remote brain control, and total intracranial control were 75, 41, and 27%, respectively. In multivariate analysis, advanced primary tumor status (P = 0.0003), older age (P = 0.008), lower Karnofsky Performance Scale score (P = 0.01), and malignant melanoma (P = 0.005) were significant for poorer survival. The median survival time was 28 months for patients younger than 60 years of age, with Karnofsky Performance Scale score of at least 90, and whose primary tumor status showed either no evidence of disease or stable disease. Tumor volume (P = 0.02) alone was significant for local tumor control, whereas no factor affected remote or intracranial tumor control. Eleven patients developed complications, six of which were persistent. Nineteen (16.5%) of 116 patients in whom the cause of death was obtained died as a result of causes related to brain metastasis. CONCLUSION: Brain metastases were controlled well with radiosurgery alone as initial therapy. We advocate that WBRT should not be part of the initial treatment protocol for selected patients with one or two tumors with good control of their primary cancer, better Karnofsky Performance Scale score, and younger age, all of which are predictors of longer survival.     

Grading of vestibular schwannomas and corresponding tumor volumes: ramifications for radiosurgery

Background

Patients with vestibular schwannomas (VS) are either assigned to watchful waiting, microsurgical resection, or radiosurgery. Decision making on how to proceed is based on parameters such as age, tumor growth, loss of hearing, and the tumor’s Koos grading.

Methods

In order to correlate Koos grading with tumor volume, patient records of 235 patients with VS who underwent Gamma Knife radiosurgery (GKRS) were retrospectively reviewed.

Results

From 1994 to 2009, 235 consecutive patients underwent GKRS for sporadic VS at the Zurich Gamma Knife Center. Median follow up was 62.8 ± 33.0 months. Of the 235 tumors, 32 (13.6 %) were graded Koos I with a volume of 0.25 ± 0.3 cc; 71 (30.2 %) were graded Koos II with a volume of 0.57 ± 0.54 cc; 70 (29.8 %) were graded Koos III with a volume of 1.82 ± 1.88 cc; and 62 (26.4 %) were graded Koos IV with a volume of 4.17 ± 2.75 cc. Tumor progression was defined as a volume increase > 20 % at 2 years or later following GKRS. Overall tumor progression occurred in 21/235 (8.9 %) patients at 3.4 ± 0.9 years. Tumor progression did not differ statistically significantly in the various Koos grades: 1/32 (3.1 %) patients with VS Koos Grade I, 7/71 (9.8 %) patients with VS Koos Grade II, 6/70 (8.6 %) patients with VS Koos Grade III, and 7/62 (11.3 %) patients with VS Koos Grade IV.

Conclusion

To our knowledge, this is the first work correlating the various Koos grades of VS to their respective tumor volumes. In our patients, tumor volumes of VS Koos Grade IV were limited because all of our patients were eligible for radiosurgery. In our series, the outcome following GKRS for patients with VS Koos Grade IV tumors did not differ from patients with VS Koos Grades I–III. We therefore suggest to limit Koos Grade IV VS to tumor volumes < 6 cc that may be eligible for radiosurgery, and introduce an additional VS Grade V for large VS with tumor volumes of > 6 cc that may not be eligible for radiosurgery.     

The role of radiosurgery for the treatment of pineal parenchymal tumors

OBJECTIVE: Radiosurgery is an appealing alternative management strategy for selected patients with biopsy-proved pineal parenchymal tumors. The purpose of this report was to clarify its role in conjunction with other surgical, radiation, and medical approaches. METHODS: We retrospectively evaluated 16 patients who had undergone radiosurgery as the primary or adjuvant treatment for pineal parenchymal tumors. Ten patients (62.5%) had pineocytomas, two (12.5%) had mixed pineocytoma and pineoblastoma, and four (25%) had pineoblastomas. The mean marginal dose was 15 Gy, and the mean tumor volume was 5.0 cm(3). The mean follow-up periods from the time of diagnosis or the time of radiosurgery were 61 and 52 months, respectively. RESULTS: The overall actuarial 2- and 5-year survival rates after diagnosis were 75.0 and 66.7%, respectively. In 14 patients who were evaluated with imaging, 4 (29%) demonstrated complete remission, 8 (57%) had partial remission, 2 (14%) had no change, and no patient had local progression. The local tumor control rate (complete remission, partial remission, or no change) was 100%. Five patients died during follow-up. One patient with a pineocytoma and three patients with pineoblastomas died secondary to leptomeningeal or extracranial spread tumor. No cause of death was established for one patient. Two patients developed adverse radiation effects after radiosurgery. CONCLUSION: Our initial experience suggests that stereotactic radiosurgery is a valuable primary management modality for patients with pineocytomas. As adjuvant therapy, radiosurgery may be used to boost local tumor dose during multimodality management of malignant pineal parenchymal tumors.     

Linac Radiosurgery for Skull Base Meningiomas

Summary  Introduction. Skull base meningiomas present a difficult surgical challenge because of the high potential morbidity of radical surgical extirpation and their low potential for incapacitating symptomatology. The focal character of meningiomas makes stereotactic radiosurgery an attractive adjuvant treatment modality to resection. The purpose of this study was to evaluate the local control rates and complications in 56 patients with base of skull meningiomas undergoing radiosurgery.  Methods. Patients underwent radiosurgery using the dedicated stereotactic linear accelerator at the Brigham and Women's Hospital. Minimal peripheral doses of radiosurgery ranged from 12 to 18.5 Gy (mean 15 Gy). Doses were designed to conform to the frequently irregular tumor volumes using the X-Knife treatment planning system. Multiple isocenters were used when required to increase conformality of dose. For 36 patients (64%), radiosurgery was used as an adjunct to surgery; for 20 patients (36%) it was the primary treatment.  Results. Median followup was five years. Nineteen patients (34%) were improved clinically at follow-up; 32 (57%) were unchanged; and 5 patients (9%) developed new or worsened neurologic deficits. Serial imaging studies after radiosurgery showed a reduction in tumor volume in 23 patients (41%); 30 (54%) showed stable disease; 3 patients (5%) had tumors which increased in size (2 being outside the radiosurgery treatment site). The actuarial freedom from progression rate (defined as further tumor growth) was thus 95%, with a median imaging follow-up of 26 months (range, 6–66 months).  Although further follow-up is necessary, the results of this series clearly demonstrate that these lesions are feasible for treatment by modern radiosurgical techniques. Linac radiosurgery can stabilize skull base meningiomas, with decreased or unchanged tumor volumes on radiologic follow-up in approximately 95% of patients. Radiosurgery is a low-morbidity, effective technique as adjunct and sometimes primary treatment of small to moderate-sized meningiomas of the skull base.