Repeat Stereotactic Radiosurgery Research Articles

Management approach for recurrent brain metastases following upfront radiosurgery may affect risk of subsequent radiation necrosis

PurposeMany patients treated with stereotactic radiosurgery (SRS) alone as initial treatment require 1 or more subsequent salvage therapies. This study aimed to determine if commonly used salvage strategies are associated with differing risks of radiation necrosis (RN). Methods and materialsAll patients treated with upfront SRS alone for brain metastases at our institution were retrospectively analyzed. Salvage treatment details were obtained for brain failures. Patients who underwent repeat SRS to the same lesion were excluded. RN was determined based on pathological confirmation or advanced brain imaging consistent with RN in a symptomatic patient. Patients were grouped according to salvage treatment and rates of RN were compared via Fisher's exact tests. ResultsOf 284 patients treated with upfront SRS alone, 132 received salvage therapy and 44 received multiple salvage treatments. This included 31 repeat SRS alone, 58 whole brain radiation therapy (WBRT) alone, 28 SRS and WBRT, 7 surgery alone, and 8 surgery with adjuvant radiation. With a median follow-up of 10 months, the rate of RN among all patients was 3.17% (9/284), salvaged patients 4.55% (6/132), and never salvaged patients 1.97% (3/152). Receiving salvage therapy did not significantly increase RN risk (P = .31). Of the patients requiring salvage treatments, the highest RN rate was among patients that had both salvage SRS and WBRT (delivered as separate salvage therapies) (6/28, 21.42%). RN rate in this group was significantly higher than in those treated with repeat SRS alone (0/31), WBRT alone (0/58), surgery alone (0/7), and surgery with adjuvant radiation (0/8). Comparing salvage WBRT doses <30 Gy versus ≥30 Gy revealed no effect of dose on RN rate. Additionally, among patients who received multiple SRS treatments, number of treated lesions was not predictive of RN incidence. ConclusionOur results suggest that initial management approach for recurrent brain metastasis after upfront SRS does not affect the rate of RN. However, the risk of RN significantly increases when patients are treated with both repeat SRS and salvage WBRT. Methods to improve prediction of toxicity and optimize patient selection for salvage treatments are needed.

Repeat stereotactic radiosurgery as salvage therapy for locally recurrent brain metastases previously treated with radiosurgery

OBJECTIVE There are a variety of salvage options available for patients with brain metastases who experience local failure after stereotactic radiosurgery (SRS). These options include resection, whole-brain radiation therapy, laser thermoablation, and repeat SRS. There is little data on the safety and efficacy of repeat SRS following local failure of a prior radiosurgical procedure. This study evaluates the clinical outcomes and dosimetric characteristics of patients who experienced tumor recurrence and were subsequently treated with repeat SRS. METHODS Between 2002 and 2015, 32 patients were treated with repeat SRS for local recurrence of ≥ 1 brain metastasis following initial SRS treatment. The Kaplan-Meier method was used to estimate time-to-event outcomes including overall survival (OS), local failure, and radiation necrosis. Cox proportional hazards analysis was performed for predictor variables of interest for each outcome. Composite dose-volume histograms were constructed for each reirradiated lesion, and these were then used to develop a predictive dosimetric model for radiation necrosis. RESULTS Forty-six lesions in 32 patients were re-treated with a second course of SRS after local failure. A median dose of 20 Gy (range 14-22 Gy) was delivered to the tumor margin at the time of repeat SRS. Local control at 1 year was 79% (95% CI 67%-94%). Estimated 1-year OS was 70% (95% CI 55%-88%). Twelve patients had died at the most recent follow-up, with 8/12 patients experiencing neurological death (as described in Patchell et al.). Eleven of 46 (24%) lesions in 11 separate patients treated with repeat SRS were associated with symptomatic radiation necrosis. Freedom from radiation necrosis at 1 year was 71% (95% CI 57%-88%). Analysis of dosimetric data revealed that the volume of a lesion receiving 40 Gy (V40Gy) was the most predictive factor for the development of radiation necrosis (p = 0.003). The following V40Gy thresholds were associated with 10%, 20%, and 50% probabilities of radiation necrosis, respectively: 0.28 cm3 (95% CI 3%-28%), 0.76 cm3 (95% CI 9%-39%), 1.60 cm3 (95% CI 26%-74%). CONCLUSIONS Repeat SRS appears to be an effective salvage option for patients with brain metastases experiencing local failure following initial SRS treatment. This series demonstrates durable local control and, although rates of radiation necrosis are significant, repeat SRS may be indicated for select cases of local disease recurrence. Because the V40Gy is predictive of radiation necrosis, limiting this value during treatment planning may allow for a reduction in radiation necrosis rates.

The clinical significance of persistent trigeminal nerve contrast enhancement in patients who undergo repeat radiosurgery.

OBJECTIVE Contrast enhancement of the retrogasserian trigeminal nerve on MRI scans frequently develops after radiosurgical ablation for the management of medically refractory trigeminal neuralgia (TN). The authors sought to evaluate the clinical significance of this imaging finding in patients who underwent a second radiosurgical procedure for recurrent TN. METHODS During a 22-year period, 360 patients underwent Gamma Knife stereotactic radiosurgery (SRS) as their first surgical procedure for TN at the authors' center. The authors retrospectively analyzed the data from 59 patients (mean age 72 years, range 33-89 years) who underwent repeat SRS for recurrent pain at a median of 30 months (range 6-146 months) after the first SRS. The isocenter was 4 mm, and the median maximum doses for the first and second procedures were 80 Gy and 70 Gy, respectively. A neuroradiologist and a neurosurgeon blinded to the treated side evaluated the presence of nerve contrast enhancement on MRI series at the time of the repeat procedure. The authors correlated the presence of this imaging change with clinical outcomes. Pain outcomes and development of trigeminal sensory dysfunction were evaluated with the Barrow Neurological Institute (BNI) Pain Scale and BNI Numbness Scale, respectively. The mean length of follow-up after the second SRS was 58 months (95% CI 49-68 months). RESULTS At the time of the repeat SRS, contrast enhancement of the trigeminal nerve on MRI scans was observed in 31 patients (53%). Five years after the SRS, patients with this enhancement had lower actuarial rates of complete pain relief after the repeat SRS (27% [95% CI 7%-47%]) than patients without the enhancement (76% [95% CI 58%-94%]) (p < 0.001). At the 5-year follow-up, patients with the contrast enhancement also had a higher risk for trigeminal sensory loss after repeat SRS (75% [95% CI 59%-91%]) than patients without contrast enhancement (26% [95% CI 10%-42%]) (p = 0.001). Dysesthetic pain after repeat SRS was observed for 8 patients with and for 2 patients without contrast enhancement. CONCLUSIONS Trigeminal nerve contrast enhancement on MRI scans observed at the time of a repeat SRS for TN was associated with less satisfactory pain control and more frequently detected facial sensory loss. Residual contrast enhancement at the time of a repeat SRS may warrant consideration of dose reduction or further separation of the radiosurgical targets.

Stereotactic radiosurgery for recurrent vestibular schwannoma after previous resection

OBJECTIVE The goal of this retrospective cohort study was to assess long-term outcomes in patients with vestibular schwannoma (VS) who underwent stereotactic radiosurgery (SRS) after initial microsurgical resection. METHODS From the authors' database of 1770 patients with VS, the authors retrospectively analyzed data from 173 Gamma Knife SRS procedures for VS after 1 (128 procedures) or multiple (45 procedures) microsurgical resections. The median length of the interval between the last resection and SRS was 42 months (range 2-329 months). The median length of clinical follow-up was 74 months (range 6-285 months). Progression-free survival after SRS was determined with Kaplan-Meier analysis. RESULTS At the time of SRS, the hearing of 161 patients (93%) was Gardner-Robertson Class V, and 81 patients (47%) had facial neuropathy (i.e., facial function with House-Brackmann [HB] grades of III-VI), 87 (50%) had trigeminal neuropathy, and 71 (41%) reported imbalance or disequilibrium disorders. The median tumor volume was 2.7 cm3 (range 0.2-21.6 cm3), and the median dose to the tumor margin was 13 Gy (range 11-20 Gy). Radiosurgery controlled growth of 163 (94%) tumors. Progression-free survival after SRS was 97% at 3 years, 95% at 5 years, and 90% at 10 years. Four patients with delayed tumor progression underwent repeat SRS at a median of 35 months (range 23-64 months) after the first SRS. Four patients (2.3%) with tumor progression underwent repeat resection at a median of 25 months (range 19-33 months). Among the patients with any facial dysfunction (indicated by HB grades of II-VI), 19% had improvement in this condition after SRS, and 5.5% with some facial function (indicated by HB grades of I-V) developed more facial weakness. Among patients with trigeminal neuropathy, 20% had improvement in this condition, and 5.8% developed or had worsened trigeminal neuropathy after SRS. CONCLUSIONS Stereotactic radiosurgery offered a safe and effective long-term management strategy for VS patients whose tumors remained or recurred after initial microsurgery.

Repeat courses of SRS in patients initially treated with SRS alone for brain-metastatic melanoma.

Stereotactic radiosurgery (SRS) is often used in the treatment of brain metastatic melanoma. Little data exist regarding outcomes of repeat course of SRS in this population. We aimed to identify treatment outcomes and toxicities in melanoma patients treated with repeat SRS after upfront SRS. We reviewed ten consecutive patients treated with repeat SRS following upfront SRS alone for brain metastatic melanoma. The median overall survival from initial treatment was 17.5 months. The median overall survival from repeat SRS was 6.7 months with a 6-month local control rate of 80%. The majority of patients progressed systemically before death. Four patients reported six adverse events, all grade 1. Prospective study regarding the safety and efficacy of repeat courses of SRS in patients with brain-metastatic melanoma, especially in combination with novel immunotherapies, is warranted.

The strategy of repeat stereotactic radiosurgery without whole brain radiation treatment for new brain metastases: Outcomes and implications for follow-up monitoring

PurposeStereotactic radiosurgery (SRS) is widely used to treat brain metastases in place of whole brain radiation therapy (WBRT), with the goal of reducing treatment toxicity balanced against the risk of developing new metastases. We evaluated outcomes of repeated courses of SRS in the management of new brain metastases as an alternative to salvage WBRT. Methods and materialsWe conducted a single-institution retrospective review of 239 patients treated with SRS without WBRT for brain metastases from 2004 to 2014. Eighty-six patients received at least 2 courses of SRS for new brain metastases. Outcome metrics included survival, development of symptomatic new brain metastases, neurologic symptoms at death or last follow-up, and ultimate WBRT. ResultsEighty-six patients (median age, 59 years) underwent a median of 2 courses of SRS (range, 2-6), with a median of 2 lesions treated initially and on retreatment. The median interval between SRS treatments was 5.8 months (range, 1.2-69.1). New brain metastases after initial radiosurgery were detected by routine imaging in 87% of cases. Median overall survival from repeat SRS was 13.0 months (range, 0.3-64.5) and from initial brain metastasis diagnosis 25.0 months (range, 2.0-68.1). On multivariate analysis, Eastern Cooperative Oncology Group performance status 0-1 (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.15-0.90; P=.029), controlled extracranial disease (HR, 0.35; 95% CI, 0.13-0.94; P=.038), and interval between initial and second SRS >6 months (HR, 0.49; 95% CI, 0.25-0.96; P=.037) correlated with improved overall survival from brain metastasis diagnosis. A total of 24.7% of patients had symptomatic intracranial metastatic disease at death or last follow-up, and 26.7% ultimately received WBRT. ConclusionRepeated SRS is a reasonable option for patients with new brain metastases, as our results suggest favorable survival outcomes with this approach. New lesions infrequently caused neurologic symptoms before routine imaging detection, and a minority of patients had symptomatic intracranial disease at death or last follow-up.

Stereotactic radiosurgery for intracranial hemangiopericytomas: a multicenter study.

OBJECTIVE Hemangiopericytomas (HPCs) are rare tumors widely recognized for their aggressive clinical behavior, high recurrence rates, and distant and extracranial metastases even after a gross-total resection. The authors report a large multicenter study, through the International Gamma Knife Research Foundation (IGKRF), reviewing management and outcome following stereotactic radiosurgery (SRS) for recurrent or newly discovered HPCs. METHODS Eight centers participating in the IGKRF participated in this study. A total of 90 patients harboring 133 tumors were identified. Patients were included if they had a histologically diagnosed HPC managed with SRS during the period 1988-2014 and had a minimum of 6 months' clinical and radiological follow-up. A de-identified database was created. The patients' median age was 48.5 years (range 13-80 years). Prior treatments included embolization (n = 8), chemotherapy (n = 2), and fractionated radiotherapy (n = 34). The median tumor volume at the time of SRS was 4.9 cm3 (range 0.2-42.4 cm3). WHO Grade II (typical) HPCs formed 78.9% of the cohort (n = 71). The median margin and maximum doses delivered were 15 Gy (range 2.8-24 Gy) and 32 Gy (range 8-51 Gy), respectively. The median clinical and radiographic follow-up periods were 59 months (range 6-190 months) and 59 months (range 6-183 months), respectively. Prognostic variables associated with local tumor control and post-SRS survival were evaluated using Cox univariate and multivariate analysis. Actuarial survival after SRS was analyzed using the Kaplan-Meier method. RESULTS Imaging studies performed at last follow-up demonstrated local tumor control in 55% of tumors and 62.2% of patients. New remote intracranial tumors were found in 27.8% of patients, and 24.4% of patients developed extracranial metastases. Adverse radiation effects were noted in 6.7% of patients. During the study period, 32.2% of the patients (n = 29) died. The actuarial overall survival was 91.5%, 82.1%, 73.9%, 56.7%, and 53.7% at 2, 4, 6, 8, and 10 years, respectively, after initial SRS. Local progression-free survival (PFS) was 81.7%, 66.3%, 54.5%, 37.2%, and 25.5% at 2, 4, 6, 8, and 10 years, respectively, after initial SRS. In our cohort, 32 patients underwent 48 repeat SRS procedures for 76 lesions. Review of these 76 treated tumors showed that 17 presented as an in-field recurrence and 59 were defined as an out-of-field recurrence. Margin dose greater than 16 Gy (p = 0.037) and tumor grade (p = 0.006) were shown to influence PFS. The development of extracranial metastases was shown to influence overall survival (p = 0.029) in terms of PFS; repeat (multiple) SRS showed additional benefit. CONCLUSIONS SRS provides a reasonable rate of local tumor control and a low risk of adverse effects. It also leads to neurological stability or improvement in the majority of patients. Long-term close clinical and imaging follow-up is necessary due to the high probability of local recurrence and distant metastases. Repeat SRS is often effective for treating new or recurrent HPCs.

BMET-17REPEAT RADIOSURGERY FOR LOCALLY-RECURRENT BRAIN METASTASES WITH EXTENSIVE PERI-LESIONAL EDEMA: INCREASED RISK OF RADIATION-RELATED TOXICITY?

BACKGROUND: Extensive peri-lesional edema of brain metastases following stereotactic radiosurgery (SRS) is highly associated with radiation injury confirmed by surgical resection. We hypothesized that repeat SRS (rSRS) to the same lesion would have a higher risk of symptomatic radiation-related toxicity when extensive peri-lesional edema (ExPLE) is present. METHODS: We analyzed the records of 87 patients (105 brain metastases) who were initially treated with SRS followed by rSRS to the same lesion for suspected local-recurrence between 2004-2014. We defined ExPLE as a ratio of edema-volume/tumor-volume of >10. For 98 lesions (93%), MR imaging was available for review, including T1 post-contrast, T2, Fluid-attenuated inversion recovery (FLAIR), and thin-slice contrast-enhanced spoiled gradient recalled acquisition in steady state sequences. Lesion volumes and FLAIR edema volumes were manually contoured and measured by an investigator blinded to the clinical outcome. Alpha/Beta of 10 was used for biological effective dose (BED). Toxicities and local recurrences were captured from clinical charts; the latter defined by increase in size or re-emergence on serial imaging. Student's t-test and Cox proportional hazards regression were used in assessing statistical significance at p < 0.05. RESULTS: The median follow-up from time of rSRS was 12.7 months (IQR 5.3-27). Median time between SRS and rSRS was 10.1 months (IQR 7.1-16.0). Thirty-seven (38%) of the lesions had ExPLE. Median tumor volumes and doses were 2.5/2.9cc (p = 0.520) and 57.4/59.1 BED (p = 0.444) for the tumors with/without ExPLE, respectively. There were 10 (9.5%) grade 3 radiation-toxicity events following rSRS for local-recurrence with no grade 4 or 5 toxicities. Using univariate analysis, ExPLE was not statistically associated to a higher risk of radiation-related toxicity (p = 0.651) or to a higher risk of local failure (p = 0.932) following rSRS. CONCLUSIONS: Repeat radiosurgery to locally-recurrent brain metastases with ExPLE did not increase the risk of radiation injury compared to lesions with low peri-lesional edema.

Management Approach for Recurrent Brain Metastases Following Upfront Radiosurgery May Affect Risk of Subsequent Radiation Necrosis

Purpose Many patients treated with stereotactic radiosurgery (SRS) alone as initial treatment require 1 or more subsequent salvage therapies. This study aimed to determine if commonly used salvage strategies are associated with differing risks of radiation necrosis (RN). Methods and materials All patients treated with upfront SRS alone for brain metastases at our institution were retrospectively analyzed. Salvage treatment details were obtained for brain failures. Patients who underwent repeat SRS to the same lesion were excluded. RN was determined based on pathological confirmation or advanced brain imaging consistent with RN in a symptomatic patient. Patients were grouped according to salvage treatment and rates of RN were compared via Fisher's exact tests. Results Of 284 patients treated with upfront SRS alone, 132 received salvage therapy and 44 received multiple salvage treatments. This included 31 repeat SRS alone, 58 whole brain radiation therapy (WBRT) alone, 28 SRS and WBRT, 7 surgery alone, and 8 surgery with adjuvant radiation. With a median follow-up of 10 months, the rate of RN among all patients was 3.17% (9/284), salvaged patients 4.55% (6/132), and never salvaged patients 1.97% (3/152). Receiving salvage therapy did not significantly increase RN risk (P = .31). Of the patients requiring salvage treatments, the highest RN rate was among patients that had both salvage SRS and WBRT (delivered as separate salvage therapies) (6/28, 21.42%). RN rate in this group was significantly higher than in those treated with repeat SRS alone (0/31), WBRT alone (0/58), surgery alone (0/7), and surgery with adjuvant radiation (0/8). Comparing salvage WBRT doses <30 Gy versus ≥30 Gy revealed no effect of dose on RN rate. Additionally, among patients who received multiple SRS treatments, number of treated lesions was not predictive of RN incidence. Conclusion Our results suggest that initial management approach for recurrent brain metastasis after upfront SRS does not affect the rate of RN. However, the risk of RN significantly increases when patients are treated with both repeat SRS and salvage WBRT. Methods to improve prediction of toxicity and optimize patient selection for salvage treatments are needed.

Adverse radiation effect after stereotactic radiosurgery for brain metastases: incidence, time course, and risk factors.

The authors sought to determine the incidence, time course, and risk factors for overall adverse radiation effect (ARE) and symptomatic ARE after stereotactic radiosurgery (SRS) for brain metastases. All cases of brain metastases treated from 1998 through 2009 with Gamma Knife SRS at UCSF were considered. Cases with less than 3 months of follow-up imaging, a gap of more than 8 months in imaging during the 1st year, or inadequate imaging availability were excluded. Brain scans and pathology reports were reviewed to ensure consistent scoring of dates of ARE, treatment failure, or both; in case of uncertainty, the cause of lesion worsening was scored as indeterminate. Cumulative incidence of ARE and failure were estimated with the Kaplan-Meier method with censoring at last imaging. Univariate and multivariate Cox proportional hazards analyses were performed. Among 435 patients and 2200 brain metastases evaluable, the median patient survival time was 17.4 months and the median lesion imaging follow-up was 9.9 months. Calculated on the basis of 2200 evaluable lesions, the rates of treatment failure, ARE, concurrent failure and ARE, and lesion worsening with indeterminate cause were 9.2%, 5.4%, 1.4%, and 4.1%, respectively. Among 118 cases of ARE, approximately 60% were symptomatic and 85% occurred 3-18 months after SRS (median 7.2 months). For 99 ARE cases managed without surgery or bevacizumab, the probabilities of improvement observed on imaging were 40%, 57%, and 76% at 6, 12, and 18 months after onset of ARE. The most important risk factors for ARE included prior SRS to the same lesion (with 20% 1-year risk of symptomatic ARE vs 3%, 4%, and 8% for no prior treatment, prior whole brain radiotherapy [WBRT], or concurrent WBRT) and any of these volume parameters: target, prescription isodose, 12-Gy, or 10-Gy volume. Excluding lesions treated with repeat SRS, the 1-year probabilities of ARE were < 1%, 1%, 3%, 10%, and 14% for maximum diameter 0.3-0.6 cm, 0.7-1.0 cm, 1.1-1.5 cm, 1.6-2.0 cm, and 2.1-5.1 cm, respectively. The 1-year probabilities of symptomatic ARE leveled off at 13%-14% for brain metastases maximum diameter > 2.1 cm, target volume > 1.2 cm(3), prescription isodose volume > 1.8 cm(3), 12-Gy volume > 3.3 cm(3), and 10-Gy volume > 4.3 cm(3), excluding lesions treated with repeat SRS. On both univariate and multivariate analysis, capecitabine, but not other systemic therapy within 1 month of SRS, appeared to increase ARE risk. For the multivariate analysis considering only metastases with target volume > 1.0 cm(3), risk factors for ARE included prior SRS, kidney primary tumor, connective tissue disorder, and capecitabine. Although incidence of ARE after SRS was low overall, risk increased rapidly with size and volume, leveling off at a 1-year cumulative incidence of 13%-14%. This study describes the time course of ARE and provides risk estimates by various lesion characteristics and treatment parameters to aid in decision-making and patient counseling.

Repeat Courses of Stereotactic Radiosurgery (SRS), Deferring Whole-Brain Irradiation, for New Brain Metastases After Initial SRS

Toreport the outcomes of repeat stereotactic radiosurgery (SRS), deferring whole-brain radiation therapy (WBRT), for distant intracranial recurrences and identify factors associated with prolonged overall survival (OS). We retrospectively identified 652 metastases in 95 patients treated with 2 or more courses of SRS for brain metastases, deferring WBRT. Cox regression analyzed factors predictive for OS. Patients had a median of 2 metastases (range, 1-14) treated per course, with a median of 2 courses (range, 2-14) of SRS per patient. With a median follow-up after first SRS of 15months (range, 3-98months), the median OS from the time of the first and second course of SRS was 18 (95% confidence interval [CI] 15-24) and 11months (95% CI 6-17), respectively. On multivariate analysis, histology, graded prognostic assessment score, aggregate tumor volume (but not number of metastases), and performance status correlated with OS. The 1-year cumulative incidence, with death as a competing risk, of local failure was 5% (95% CI 4-8%). Eighteen (24%) of 75 deaths were from neurologic causes. Nineteen patients (20%) eventually received WBRT. Adverse radiation events developed in 2% of SRS sites. Multiple courses of SRS, deferring WBRT, for distant brain metastases after initial SRS, seem to be a safe and effective approach. The graded prognostic assessment score, updated at each course, and aggregate tumor volume may help select patients in whom the deferral of WBRT might be most beneficial.

Tumor bed radiosurgery following resection and prior stereotactic radiosurgery for locally persistent brain metastasis.

Despite advances in multimodality management of brain metastases, local progression following stereotactic radiosurgery (SRS) can occur. Often, surgical resection is favored, as it frequently provides immediate symptom relief as well as pathological characterization of any residual tumor. Should the pathological specimen contain viable tumor cells, further radiation therapy is an option to sterilize the tumor bed. We evaluated the use of repeat SRS (rSRS) in lieu of whole-brain radiation therapy (WBRT) as a means of improving local control (LC) while minimizing potential toxicity and dose to the normal brain. A retrospective review was performed to identify patients with brain metastases who underwent SRS and then surgical resection for locally recurrent or persistent disease. From 2004 to 2014, 13 consecutive patients or 15 lesions were treated with rSRS after resection, either post-operatively to the tumor bed (n = 10, 66.6%) or after a second local recurrence (n = 5, 33.3%). LC, distant brain failure (DBF), and radiation toxicity were determined using patient records, RECIST criteria v1.1, and CTCAE v4.03. At a median follow-up interval of 9.0 months (range 1.8-54.9 months) from time of rSRS, five patients remain alive. Following rSRS, 13 of the 15 (86.6%) lesions were locally controlled with an estimated 100% LC at 6 months and 75% LC at 1 year. However, 11 of the 15 (73.3%) treated lesions developed DBF after rSRS with 3 of 13 patients proceeding to WBRT. Two of 15 (13.3%) resulted in either grade 2 radionecrosis with grade 3 seizures or grade 3 radionecrosis. Repeat SRS represents a potential salvage therapy for patients with locally recurrent brain metastases, providing additional tumor control with acceptable toxicity, even in the setting of prior SRS and surgical resection. rSRS may be reasonable to use as an alternative to WBRT in this setting.

Is stereotactic radiosurgery a rational treatment option for brain metastases from small cell lung cancer? A retrospective analysis of 70 consecutive patients.

BackgroundBecause of the high likelihood of multiple brain metastases (BM) from small cell lung cancer (SCLC), the role of focal treatment using stereotactic radiosurgery (SRS) has yet to be determined. We aimed to evaluate the efficacy and limitations of upfront and salvage SRS for patients with BM from SCLC.MethodsThis was a retrospective and observational study analyzing 70 consecutive patients with BM from SCLC who received SRS. The median age was 68 years, and the median Karnofsky performance status (KPS) was 90. Forty-six (66%) and 24 (34%) patients underwent SRS as the upfront and salvage treatment after prophylactic or therapeutic whole brain radiotherapy (WBRT), respectively. Overall survival (OS), neurological death-free survival, remote and local tumor recurrence rates were analyzed.ResultsNone of our patients were lost to follow-up and the median follow-up was 7.8 months. One-and 2-year OS rates were 43% and 15%, respectively. The median OS time was 7.8 months. One-and 2-year neurological death-free survival rates were 94% and 84%, respectively. In total, 219/292 tumors (75%) in 60 patients (86 %) with sufficient radiological follow-up data were evaluated. Six-and 12-month rates of remote BM relapse were 25% and 47%, respectively. Six-and 12-month rates of local control failure were 4% and 23%, respectively. Repeat SRS, salvage WBRT and microsurgery were subsequently required in 30, 8 and one patient, respectively. Symptomatic radiation injury, treated conservatively, developed in 3 patients.ConclusionsThe present study suggested SRS to be a potentially effective and minimally invasive treatment option for BM from SCLC either alone or after failed WBRT. Although repeat salvage treatment was needed in nearly half of patients to achieve control of distant BM, such continuation of radiotherapeutic management might contribute to reducing the rate of neurological death.

Gamma knife radiosurgery for the management of cerebral metastases from non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the most frequent cancer that metastasizes to brain. Stereotactic radiosurgery (SRS) has become the management of choice for most patients with such metastatic tumors. Therefore, the authors endeavored to elucidate the survival and SRS outcomes for patients with NSCLC metastasis at their center. In this single-institution retrospective analysis, the authors reviewed their experience with NSCLC metastasis during a 10-year period from 2001 to 2010. Seven hundred twenty patients underwent Gamma Knife radiosurgery. A total of 1004 SRS procedures were performed, and 3143 tumors were treated. The NSCLC subtype was adenocarcinoma in 386 patients, squamous cell carcinoma in 111 patients, and large cell carcinoma in 34 patients. The median aggregate tumor volume was 4.5 cm(3) (range 0.1-88 cm(3)). The median survival time after diagnosis of brain metastasis from NSCLC was 12.6 months, and the median survival after SRS was 8.5 months. The 1-, 2-, and 5-year survival rates after SRS were 39%, 21%, and 10%, respectively. Postradiosurgery survival was decreased in patients treated with prior whole-brain radiation therapy compared with SRS alone (p = 0.003). Aggregate tumor volume was inversely related to survival after SRS (p < 0.001), and the histological subgroups demonstrated significant survival differences (p = 0.023). The overall local tumor control rate in the entire group was 92.8%. One hundred seventy-four patients (24%) underwent repeat SRS for new or resistant metastatic deposits. Stereotactic radiosurgery is an effective means of providing local control for NSCLC metastases. Neurological function and survival benefit from serial patient monitoring and repeat SRS for new tumors.

Stereotactic radiosurgery for arteriovenous malformations of the postgeniculate visual pathway.

A visual field deficit resulting from the management of an arteriovenous malformation (AVM) significantly impacts a patient's quality of life. The present study was designed to investigate the clinical and radiological outcomes of stereotactic radiosurgery (SRS) performed for AVMs involving the postgeniculate visual pathway. In this retrospective single-institution analysis, the authors reviewed their experience with Gamma Knife surgery for postgeniculate visual pathway AVMs performed during the period between 1987 and 2009. During the study interval, 171 patients underwent SRS for AVMs in this region. Forty-one patients (24%) had a visual deficit prior to SRS. The median target volume was 6.0 cm3 (range 0.4-22 cm3), and 19 Gy (range 14-25 Gy) was the median margin dose. Obliteration of the AVM was confirmed in 80 patients after a single SRS procedure at a median follow-up of 74 months (range 5-297 months). The actuarial rate of total obliteration was 67% at 4 years. Arteriovenous malformations with a volume<5 cm3 had obliteration rates of 60% at 3 years and 79% at 4 years. The delivered margin dose proved significant given that 82% of patients receiving ≥22 Gy had complete obliteration. The AVM was completely obliterated in an additional 18 patients after they underwent repeat SRS. At a median of 25 months (range 11-107 months) after SRS, 9 patients developed new or worsened visual field deficits. One patient developed a complete homonymous hemianopia, and 8 patients developed quadrantanopias. The actuarial risk of sustaining a new visual deficit was 3% at 3 years, 5% at 5 years, and 8% at 10 years. Fifteen patients had hemorrhage during the latency period, resulting in death in 9 of the patients. The annual hemorrhage rate during the latency interval was 2%, and no hemorrhages occurred after confirmed obliteration. Despite an overall treatment mortality of 5%, related to latency interval hemorrhage, SRS was associated with only a 5.6% risk of new visual deficit and a final obliteration rate close to 80% in patients with AVMs of the postgeniculate visual pathway.

Re-treatment of Brain Metastases Using Stereotactic Radiosurgery

The outcomes of repeat stereotactic radiosurgery (SRS) to the same lesion after failure of previous SRS are not well understood. While repeat SRS may offer durable local tumor control, treatment toxicity may be unacceptable. We report our overall experience using SRS for the retreatment of locally recurrent brain metastases.

Repeat Stereotactic Radiosurgery Is an Appropriate Approach for New/Recurrent Brain Metastases

Repeat Stereotactic Radiosurgery Is an Appropriate Approach for New/Recurrent Brain Metastases

Repeat Stereotactic Radiosurgery (SRS) for Brain Metastases Locally Recurrent Following Initial SRS

Repeat Stereotactic Radiosurgery (SRS) for Brain Metastases Locally Recurrent Following Initial SRS

Repeat Stereotactic Radiosurgery (SRS) for New Brain Metastases Following Initial SRS: Accumulated Tumor Volume and Graded Prognostic Assessment (GPA) Score Calculated at Each Course Correlate With Overall Survival

Repeat Stereotactic Radiosurgery (SRS) for New Brain Metastases Following Initial SRS: Accumulated Tumor Volume and Graded Prognostic Assessment (GPA) Score Calculated at Each Course Correlate With Overall Survival

P08.17 * REPEAT STEREOTACTIC RADIOSURGERY (SRS) FOR RECURRENT BRAIN METASTASES

OBJECTIVES: SRS for brain metastases is an effective treatment for brain metastases with a reported survival of 7-14 months. Local control is in the range of 70-90% at 12 months, with a proportion of patients who recurs locally we have evaluate the efficacy of repeat stereotactic radiosurgery (SRS) as salvage treatment in patients with recurrent brain metastases. PATIENTS AND METHODS: Between May 2008 and December 2012, twenty-seven patients received repeat SRS for a recurrent brain metastasis at University of Rome Sapienza, Sant'Andrea Hospital. All patients had Karnofsky Performance Score ≥ 60 and were previously treated with single-fraction SRS. The median time interval between primary SRS and reirradiation was 13.5 months. At the time of recurrence all patients received multi-fraction SRS (7-8 Gy x 3) RESULTS: Median overall and 12-month survival rates after repeat multifraction SRS were 10.3 months and 37%, respectively. Six patients were alive at the of analysis. The 6-month and 12-month local control rates were 90% and 72%. KPS > 70 (p = 0.04) and presence of extracranial disease (p = 0.01) were significant prognostic factor associated with longer survival. In general the treatment was well tolerated with relatively low treatment-related toxicity. Radionecrosis occurred in 7 reirradiated lesions, and was associated with neurological deterioration in 3 of them. CONCLUSION: Multi-fraction SRS is a feasible treatment option associated with good local control and acceptable radiation-induced toxicity in selected patients with recurrent brain metastases.