Outcomes Of Stereotactic Radiosurgery Research Articles

Stereotactic Radiosurgery for Acromegaly: An International Multicenter Retrospective Cohort Study.

Stereotactic radiosurgery (SRS) is a treatment option for persistent or recurrent acromegaly secondary to a growth hormone secreting pituitary adenoma, but its efficacy is inadequately defined. To assess, in a multicenter, retrospective cohort study, the outcomes of SRS for acromegaly and determine predictors. We pooled and analyzed data from 10 participating institutions of the International Gamma Knife Research Foundation for patients with acromegaly who underwent SRS with endocrine follow-up of ≥6 mo. The study cohort comprised 371 patients with a mean endocrine follow-up of 79 mo. IGF-1 lowering medications were held in 56% of patients who were on pre-SRS medical therapy. The mean SRS treatment volume and margin dose were 3.0 cm3 and 24.2 Gy, respectively. The actuarial rates of initial and durable endocrine remission at 10 yr were 69% and 59%, respectively. The mean time to durable remission after SRS was 38 mo. Biochemical relapse after initial remission occurred in 9%, with a mean time to recurrence of 17 mo. Cessation of IGF-1 lowering medication prior to SRS was the only independent predictor of durable remission (P = .01). Adverse radiation effects included the development of ≥1 new endocrinopathy in 26% and ≥1 cranial neuropathy in 4%. SRS is a definitive treatment option for patients with persistent or recurrent acromegaly after surgical resection. There appears to be a statistical association between the cessation of IGF-1 lowering medications prior to SRS and durable remission.

Factors influencing the outcome of stereotactic radiosurgery in patients with five or more brain metastases

Background Stereotactic radiosurgery (srs) for patients with 5 or more brain metastases (bmets) is a matter of debate. We report our results with that approach and the factors influencing outcome.Methods In the 103 patients who underwent srs for the treatment of 5 or more bmets, primary histology was nonsmall- cell lung cancer (57% of patients). All patients were grouped by Karnofsky performance status and recursive partitioning analysis (rpa) classification. In our cohort, 72% of patients had uncontrolled extracranial disease, and 28% had stable or responding systemic disease. Previous irradiation for 1–4 bmets had been given to 56 patients (54%). The mean number of treated bmets was 7 (range: 5–19), and the median cumulative bmets volume was 2 cm3 (range: 0.06–28 cm3).Results Multivariate analyses showed that stable extracranial disease (p < 0.001) and rpa (p = 0.022) were independent prognostic factors for overall survival (os). Moreover, a cumulative treated bmets volume of less than 6 cm3 (adjusted hazard ratio: 2.54; p = 0.006; 95% confidence interval: 1.30 to 4.99) was associated with better os. The total number of bmets had no effect on survival (p = 0.206). No variable was found to be predictive of local control. The rpa was significant (p = 0.027) in terms of distant recurrence.Conclusions Our study suggests that srs is a reasonable option for the management of patients with 5 or more bmets, especially with a cumulative treatment volume of less than 6 cm3.

Factors influencing the outcome of stereotactic radiosurgery in patients with five or more brain metastases.

Stereotactic radiosurgery (srs) for patients with 5 or more brain metastases (bmets) is a matter of debate. We report our results with that approach and the factors influencing outcome. In the 103 patients who underwent srs for the treatment of 5 or more bmets, primary histology was non-small-cell lung cancer (57% of patients). All patients were grouped by Karnofsky performance status and recursive partitioning analysis (rpa) classification. In our cohort, 72% of patients had uncontrolled extracranial disease, and 28% had stable or responding systemic disease. Previous irradiation for 1-4 bmets had been given to 56 patients (54%). The mean number of treated bmets was 7 (range: 5-19), and the median cumulative bmets volume was 2 cm3 (range: 0.06-28 cm3). Multivariate analyses showed that stable extracranial disease (p < 0.001) and rpa (p = 0.022) were independent prognostic factors for overall survival (os). Moreover, a cumulative treated bmets volume of less than 6 cm3 (adjusted hazard ratio: 2.54; p = 0.006; 95% confidence interval: 1.30 to 4.99) was associated with better os. The total number of bmets had no effect on survival (p = 0.206). No variable was found to be predictive of local control. The rpa was significant (p = 0.027) in terms of distant recurrence. Our study suggests that srs is a reasonable option for the management of patients with 5 or more bmets, especially with a cumulative treatment volume of less than 6 cm3.

Stereotactic radiosurgery in treatment of trigeminal neuralgia

The objective of this study was to analyze the results of treatment in patients with trigeminal neuralgia using the Leksell Gamma Knife system. The results of stereotactic radiosurgery were analyzed in 52 patients (31 females and 21 males aged 31 to 79 years) who had undergone treatment at the Radiosurgical Center of MIBS (St. Petersburg) in 2009-2016. Forty-four patients were diagnosed with typical trigeminal neuralgia; four patients, with atypical neuralgia; and four patients, with symptomatic neuralgia (accompanying multiple sclerosis). Pain severity was assessed using the Visual Analogue Scale (VAS) and the Barrow Neurological Institute Scale (BNIPS) before and after the surgery, as well as during the follow-up period (mean duration, 3 years). Pain was reduced in 38 (86.4%) patients with type 1 neuralgia. The effect usually was not observed immediately after the surgery but was delayed from several weeks to 12 months (median, 2 months; interquartile range) [1, 4]. The surgery was ineffective in 6 (14%) patients. Eight (18%) patients had a relapse on average after 2 years and 5 months. By the end of the follow-up period, score I according to the BNIPS was achieved in 22 (50%) patients; score II or III was achieved in 7 (16%) patients. Primary reduction of pain was achieved in two patients with type 2 neuralgia; one of them had a relapse after 19 months. Among patients with symptomatic neuralgia, the primary effect was achieved in three patients, but two of them later had a relapse. Stereotactic radiosurgery can be used to alleviate pain in most patients with type 1 trigeminal neuralgia, but its results are inferior to those of invasive interventions. According to our findings, 18% of patients had a relapse. For patients with multiple sclerosis accompanied by type 2 and symptomatic trigeminal neuralgia, this method is not sufficiently effective. When both microvascular decompression and stereotactic radiosurgery can be used to treat for type 1 and 2 trigeminal neuralgia, patient's choice is crucial. It is important to inform the patient both about the potential complications of the interventions and about the delayed effect of the surgery and relapse frequency.

Clinical evidence for dose tolerance of the central nervous system in hypofractionated radiotherapy

Stereotactic radiosurgery (SRS), stereotactic body radiotherapy (SBRT), and stereotactic ablative body radiotherapy (SABR) are commonly used in the treatment of central nervous system (CNS) disease. This study has refined the radiation toxicity estimates for some normal tissues of the CNS based on review and analysis of the clinical evidence for single fraction radiosurgery, hypofractionated SBRT, and conventionally fractionated radiation therapy. Published guidelines and protocols are reviewed. In the past, many normal tissue tolerances were compiled based on the experience of the investigators and publications in the literature. Some tolerances were determined by modeling or calculation using the existing biological formulas, in particular the linear quadratic (LQ) model. In the present study, the estimate of risk for each dose tolerance limit in some CNS tissues is provided exclusively with normal tissue complication probability (NTCP). The clinical outcomes are compared to understand the difference in biological effect between radiosurgery and radiotherapy. Normal tissue dose tolerances and the corresponding complication rates are provided for brainstem, optic nerves, cochlea, and spinal cord, including single fraction SRS, five-fraction SBRT, and conventional radiation therapy. Calculation of biologically effective dose (BED) or single fraction equivalent dose (SFED) alone using the LQ model conveys no consensus on the biological effect across different fractionations. Comparison of conventional radiation therapy to brain and spinal cord with single fraction equivalent dose leads to even conflicting clinical outcomes. Effective differences between single fraction SRS and conventional radiotherapy need to be better understood. The existing biological model might not be valid to predict the radiosurgical outcomes based on conventionally fractionated radiotherapy. However, application of the statistical dose response models of clinical SRS and SBRT outcomes data to selected current dose tolerance guidelines into simple tables can be a clinically useful resource.

CMET-10. RISK OF RADIATION NECROSIS FOLLOWING REPEAT STEREOTACTIC RADIOSURGERY FOR RECURRENT BRAIN METASTASES

INTRODUCTION Stereotactic radiosurgery (SRS) has become the standard of care for the treatment of many patients with oligo-metastases of the brain with a local control rate of 80–90% and radiation necrosis rate of 7% per lesion. Per patient, the rate of radiation necrosis is 10–15% with half being symptomatic. We sought to determine outcomes of stereotactic radiosurgery for treatment of recurrent brain metastases after failure of initial SRS.

Improved Outcomes with Adjuvant Stereotactic Radiosurgery Compared with Fractionated Stereotactic Radiation Therapy for Resected Intracranial Metastases

Post-operative stereotactic radiosurgery (SRS) is increasingly implemented for patients with resected intracranial metastases, with recent randomized data demonstrating improved cognition and equivalent overall survival compared with adjuvant whole brain radiotherapy (WBRT). Several institutional series have also demonstrated promising local control rates utilizing adjuvant fractionated stereotactic radiotherapy (FSRT) to cavities. Our purpose was to compare our institutional outcomes of linac-based SRS with FSRT for patients with resected brain metastases. We reviewed the medical charts and dosimetric data of 68 patients, treated with either SRS or FSRT to the resection cavity, from February 2002 to May 2017. SRS was delivered in a single fraction of 15 - 21 Gy (BED10 = 37.5 – 65.1 Gy), prescribed to the 60 – 85% isodose line. FSRT was delivered in 5 - 6 fractions of 25 - 36 Gy (BED10 = 37.5 – 57.6 Gy), typically prescribed to the 95% isodose line. Planning target volume was defined on MRI as resection cavity plus 0 - 3 mm. Local control and survival outcomes were estimated using the Kaplan-Meier method and analyzed using the log-rank test and Cox proportional hazards models. Chi-square test was performed to identify factors predicting local failure. Seventy-five intracranial lesions were identified. Median age was 60 years with a median follow-up of 11 months (range: 1-119 months). The majority (92%) of lesions received a gross total resection, with 47% originating from a lung primary. Forty-nine cavities received FSRT, while 26 were treated with linac-based SRS. The median diameter of lesions treated with FSRT and SRS was 2.9 cm and 2.3 cm, respectively (p = 0.3). One-year local control for patients who received SRS compared with FSRT was 91% vs 66%, respectively (HR 5.0 [1.1 - 22.1], p = 0.03). The 1-year local control for patients who received SRS, high dose (≥ 30 Gy) FSRT, and low dose (< 30 Gy) FSRT was 91%, 84%, and 52% (p = 0.007). The majority of recurrences were in-field (88%) for patients treated with FSRT, compared to 50% in-field failure rate for those who received SRS. Resection cavity location (p = 0.9), tumor histology (p = 0.8), and pre-operative tumor size (p = 0.85) did not predict for local failure. The median PTV for cavities that recurred was 22.5 cc compared with 13.0 cc for those that did not (p = 0.16). The 1-year distant brain control with SRS compared with FSRT was 61% vs 41% (p = 0.06). There was no significant difference in overall survival (79% vs 62%, p = 0.2). We observed a significantly higher rate of local control in patients who received adjuvant cavity linac-based SRS compared with FSRT, suggesting that increased biologic effective dose may correspond with improved control for resected brain metastases. These treatments need to be evaluated prospectively to validate the above findings.

Effect of Advanced Age on Stereotactic Radiosurgery Outcomes for Brain Arteriovenous Malformations: A Multicenter Matched Cohort Study

The effect of age on adult brain arteriovenous malformation (AVM) outcomes after stereotactic radiosurgery (SRS) remains unclear. The aim of this study is to compare AVM outcomes between elderly (age ≥60 years) and nonelderly adult patients. We retrospectively reviewed pooled data comprising patients who underwent SRS for AVMs between 1987 and 2014 at 8 centers participating in the International Gamma Knife Research Foundation. Adult (age ≥18 years) patients with ≥12 months follow-up were dichotomized into elderly and nonelderly cohorts, and matched in a 1:1 ratio. Favorable outcome was AVM obliteration without permanent symptomatic radiation-induced changes (RIC) or post-SRS hemorrhage. The study cohort consisted of 1845 patients (188 elderly vs. 1657 nonelderly) who met the inclusion criteria, and subsequent matching resulted in 181 patients in each cohort. In the matched cohorts, rates of obliteration (54.7% vs. 64.6%; P= 0.054) favorable outcome (51.4% vs. 61.3%; P= 0.056) were no different between the elderly and nonelderly cohorts. The rates of post-SRS hemorrhage (9.9% vs. 5.5%; P= 0.115), RIC (26.5% vs. 30.9%; P= 0.353), symptomatic RIC (9.4% vs. 9.4%; P= 1.000), and permanent symptomatic RIC (3.3% vs. 2.2%; P= 0.750) were also not significantly different between the elderly and nonelderly cohorts. Elderly patients with AVM did have a significantly higher rate of all-cause mortality (27.7% vs. 5.5%; P < 0.001). Advanced age does not seem to significantly affect obliteration or complication rates after SRS for AVMs. Although the decision to recommend intervention for AVMs in the elderly population is multifactorial, SRS may be a viable modality when treatment is deemed appropriate.

Gamma Knife stereotactic radiosurgery for cavernous sinus meningioma: long-term follow-up in 200 patients.

The authors of this study evaluate the long-term outcomes of stereotactic radiosurgery (SRS) for cavernous sinus meningioma (CSM). The authors retrospectively assessed treatment outcomes 5-18 years after SRS in 200 patients with CSM. The median patient age was 57 years (range 22-83 years). In total, 120 (60%) patients underwent Gamma Knife SRS as primary management, 46 (23%) for residual tumors, and 34 (17%) for recurrent tumors after one or more surgical procedures. The median tumor target volume was 7.5 cm3 (range 0.1-37.3 cm3), and the median margin dose was 13.0 Gy (range 10-20 Gy). Tumor volume regressed in 121 (61%) patients, was unchanged in 49 (25%), and increased over time in 30 (15%) during a median imaging follow-up of 101 months. Actuarial tumor control rates at the 5-, 10-, and 15-year follow-ups were 92%, 84%, and 75%, respectively. Of the 120 patients who had undergone SRS as a primary treatment (primary SRS), tumor progression was observed in 14 (11.7%) patients at a median of 48.9 months (range 4.8-120.0 months) after SRS, and actuarial tumor control rates were 98%, 93%, 85%, and 85% at the 1-, 5-, 10-, and 15-year follow-ups post-SRS. A history of tumor progression after microsurgery was an independent predictor of an unfavorable response to radiosurgery (p = 0.009, HR = 4.161, 95% CI 1.438-12.045). Forty-four (26%) of 170 patients who had presented with at least one cranial nerve (CN) deficit improved after SRS. Development of new CN deficits after initial microsurgical resection was an unfavorable factor for improvement after SRS (p = 0.014, HR = 0.169, 95% CI 0.041-0.702). Fifteen (7.5%) patients experienced permanent CN deficits without evidence of tumor progression at a median onset of 9 months (range 2.3-85 months) after SRS. Patients with larger tumor volumes (≥ 10 cm3) were more likely to develop permanent CN complications (p = 0.046, HR = 3.629, 95% CI 1.026-12.838). Three patients (1.5%) developed delayed pituitary dysfunction after SRS. This long-term study showed that Gamma Knife radiosurgery provided long-term tumor control for most patients with CSM. Patients who underwent SRS for progressive tumors after prior microsurgery had a greater chance of tumor growth than the patients without prior surgery or those with residual tumor treated after microsurgery.

Stereotactic Radiosurgery in the Management of Patients With Brain Metastases of Non-Small Cell Lung Cancer: Indications, Decision Tools and Future Directions.

Brain metastases (BM) frequently occur in non-small cell lung cancer (NSCLC) patients. Most patients with BM have a limited life expectancy, measured in months. Selected patients may experience a very long progression-free survival, for example, patients with a targetable driver mutation. Traditionally, whole-brain radiotherapy (WBRT) has been the cornerstone of the treatment, but its indication is a matter of debate. A randomized trial has shown that for patients with a poor prognosis, WBRT does not add quality of life (QoL) nor survival over the best supportive care. In recent decades, stereotactic radiosurgery (SRS) has become an attractive non-invasive treatment for patients with BM. Only the BM is irradiated to an ablative dose, sparing healthy brain tissue. Intracranial recurrence rates decrease when WBRT is administered following SRS or resection but does not improve overall survival and comes at the expense of neurocognitive function and QoL. The downside of SRS compared with WBRT is a risk of radionecrosis (RN) and a higher risk of developing new BM during follow-up. Currently, SRS is an established treatment for patients with a maximum of four BM. Several promising strategies are currently being investigated to further improve the indication and outcome of SRS for patients with BM: the effectivity and safety of SRS in patients with more than four BM, combining SRS with systemic therapy such as targeted agents or immunotherapy, shared decision-making with SRS as a treatment option, and individualized isotoxic dose prescription to mitigate the risk of RN and further enhance local control probability of SRS. This review discusses the current indications of SRS and future directions of treatment for patients with BM of NSCLC with focus on the value of SRS.

Radiosurgery of Glomus Tumors of Temporal Bone: a Meta-analysis.

1) Perform a meta-analysis of the available data on the outcomes of stereotactic radiosurgery (SRS) for the treatment of temporal bone glomus tumors (GT), and 2) evaluate the collective outcomes of SRS treatment with respect to tumor control. A thorough literature search of the published English-language literature from 2011 to 2016 was performed in PubMed, Ovid, and Cochrane databases using the keywords ("Gamma Knife" or "CyberKnife" or "linear accelerator" or "radiosurgery") and ("glomus jugulare" or "jugular paraganglioma" or "glomus tympanicum"). Studies reporting outcomes of SRS for temporal bone GT were included. Of 45 articles found, 15 studies met our inclusion and exclusion criteria and were selected for qualitative and quantitative analyses totaling 511 patients. Average margin dose, modality, isodose line, volume decrease, follow-up duration, and tumor control rate data were extracted and analyzed. Gamma Knife was the most commonly implemented radiosurgery modality and was used in eight studies. The mean marginal dose varied between 13.2 and 20 Gy. The pooled tumor control rate was 95.4% (95% CI: 93.6-97.2%) over a median follow-up duration ranging between 27.4 and 148 months. Clinical data on outcomes of SRS for the treatment of GTs are sparse and primarily limited to single institutional analyses, with considerable variation in tumor volume and follow-up duration. This meta-analysis provides an in-depth analysis of the available data in the literature and reviews the reported outcomes. Future studies on SRS for GT should include data on tumor growth before radiation as well as follow-up periods sufficiently long to identify true tumor control.

Tolerance and outcomes of stereotactic radiosurgery combined with anti-programmed cell death-1 (pembrolizumab) for melanoma brain metastases.

Anti-programmed cell death-1 (anti-PD1) antibodies are currently the first-line treatment for patients with metastatic BRAF wild-type melanoma, alone or combined with the anti-CTLA4 monoclonal antibody, ipilimumab. To date, data on safety and the outcomes of patients treated with the anti-PD1 monoclonal antibodies, pembrolizumab (PB), or nivolumab, combined with stereotactic radiosurgery (SRS), for melanoma brain metastases (MBM) are scarce. We retrospectively reviewed all patients with MBM treated with PB combined with SRS between 2012 and 2015. The primary endpoint was neurotoxicity. The secondary endpoints were local, distant intracranial controls and overall survival (OS). Among 74 patients with MBM treated with SRS, 25 patients with a total of 58 MBM treated with PB combined with SRS within 6 months were included. Radiation necrosis, occurring within a median time of 6.5 months, was observed for four MBM (6.8%) in four patients. No other significant SRS-related adverse event was observed. After a median follow-up of 8.4 months, local control was achieved in 46 (80%) metastases and 17 (68%) patients. Perilesional oedema and intratumour haemorrhage appearing or increasing after SRS were associated with local progression (P<0.001). The median OS was 15.3 months (95% confidence interval: 4.6-26). The timing between SRS and PB administration did not seem to influence the risk of radiation necrosis, intracranial control or OS. SRS combined with PB was well tolerated and achieved local control in 80% of the lesions. Prolonged OS was observed compared with that currently yielded in this population of patients. Prospective studies are required to explore further the optimal ways to combine immunotherapy and SRS.

Stereotactic Radiosurgery for Benign (World Health Organization Grade I) Cavernous Sinus Meningiomas-International Stereotactic Radiosurgery Society (ISRS) Practice Guideline: A Systematic Review.

Stereotactic radiosurgery (SRS) has become popular as a standard treatment for cavernous sinus (CS) meningiomas. To summarize the published literature specific to the treatment of CS meningioma with SRS found through a systematic review, and to create recommendations on behalf of the International Stereotactic Radiosurgery Society. Articles published from January 1963 to December 2014 were systemically reviewed. Three electronic databases, PubMed, EMBASE, and The Cochrane Central Register of Controlled Trials, were searched. Publications in English with at least 10 patients (each arm) were included. Of 569 screened abstracts, a total of 49 full-text articles were included in the analysis. All studies were retrospective. Most of the reports had favorable outcomes with 5-yr progression-free survival (PFS) rates ranging from 86% to 99%, and 10-yr PFS rates ranging from 69% to 97%. The post-SRS neurological preservation rate ranged from 80% to 100%. Resection can be considered for the treatment of larger (>3 cm in diameter) and symptomatic CS meningioma in patients both receptive to and medically eligible for open surgery. Adjuvant or salvage SRS for residual or recurrent tumor can be utilized depending on factors such as tumor volume and proximity to adjacent critical organs at risk. The literature is limited to level III evidence with respect to outcomes of SRS in patients with CS meningioma. Based on the observed results, SRS offers a favorable benefit to risk profile for patients with CS meningioma.

Awake craniotomy for excision of arteriovenous malformations? A qualitative comparison study with stereotactic radiosurgery

Treatment of arteriovenous malformations (AVM) located at the eloquent area has been a challenge. Awake brain mapping allows identification of a non-eloquent gyrus for intervention and can potentially facilitate resection with preservation of functions. An alternative treatment option is stereotactic radiosurgery (SRS). The objective of this study was to perform a qualitative comparison of the treatment outcome of awake AVM excision versus SRS. We conducted a 13-year retrospective review of AVM excision under awake craniotomy performed at Prince of Wales Hospital, Hong Kong, from 2003 to 2016. Patients’ presentation, Spetzler-Martin (SM) grading, rate of obliteration and complication were reviewed and analyzed with the modified radiosurgery-based AVM score (RS score). Six patients had excision of AVM under awake mapping during this period of time. Two were SM Grade II and four were SM Grade III. Five located at the peri-rolandic region while one at the temporal language area. None had failed mapping. Five out of six achieved complete obliteration (83.3%). Qualitative comparative analysis had revealed better treatment outcome with awake AVM excision as compared to SRS with the obliteration rate of 100% versus 96% for RS score ≤1.00, 100% versus 78% for RS score 1.01–1.50, and 66% versus 50% for RS score >2.00 respectively. In conclusion, awake mapping and excision of AVMs at the eloquent area is feasible. Qualitative comparative analysis had revealed higher obliteration rate with awake AVM excision as compared to SRS.

Repeat stereotactic radiosurgery for Cushing’s disease: outcomes of an international, multicenter study

Stereotactic radiosurgery (SRS) is frequently used for Cushing's disease (CD) after failed pituitary surgery. Management of patients with persistent CD after failed SRS is complex, as the alternative therapeutic options harbor significant risks. The outcomes of repeat pituitary radiosurgery, however, have not been described. We sought to determine the outcomes of repeat SRS in patients with CD. We pooled data from five institutions participating in the International Gamma Knife Research Foundation for patients with recurrent or persistent CD ≥ 12months after initial SRS. Patients were included in the study if they had ≥ 6months endocrine follow-up after repeat SRS. Twenty patients were included in the study. Repeat single-session SRS was performed 1.3-9.7years after initial SRS. Median endocrine follow-up was 6.6years (1.4-19.1years). Median margin dose was 20Gy (range 10.8-35Gy). Endocrine remission after second SRS was noted in 12 patients (60%), with a median time to remission of 6months (range 2-64months). Biochemical recurrence occurred in two patients (17%) after initial remission. Overall, the cumulative rates of durable endocrine remission at 5 and 10years were 47 and 53%, respectively. Two patients (10%) experienced adverse radiation effects, including transient visual loss and permanent diplopia. Repeat SRS achieves lasting biochemical remission in approximately half of patients with CD refractory to both prior microsurgery and SRS. Because of the morbidity of refractory or recurrent CD, repeat SRS should be considered for carefully selected patients with hypercortisolism confirmed one or more years after initial SRS.

130 - Outcomes of stereotactic radiosurgery (SRS) in non-small cell lung cancer (NSCLC) patients with CNS metastasis – validating current guidance in a UK single centre

130 - Outcomes of stereotactic radiosurgery (SRS) in non-small cell lung cancer (NSCLC) patients with CNS metastasis – validating current guidance in a UK single centre

Effect of treatment period on outcomes after stereotactic radiosurgery for brain arteriovenous malformations: an international multicenter study.

The role of and technique for stereotactic radiosurgery (SRS) in the management of arteriovenous malformations (AVMs) have evolved over the past four decades. The aim of this multicenter, retrospective cohort study was to compare the SRS outcomes of AVMs treated during different time periods. The authors selected patients with AVMs who underwent single-session SRS at 8 different centers from 1988 to 2014 with follow-up ≥ 6 months. The SRS eras were categorized as early (1988-2000) or modern (2001-2014). Statistical analyses were performed to compare the baseline characteristics and outcomes of the early versus modern SRS eras. Favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation-induced changes (RICs). The study cohort comprised 2248 patients with AVMs, including 1584 in the early and 664 in the modern SRS eras. AVMs in the early SRS era were significantly smaller (p < 0.001 for maximum diameter and volume), and they were treated with a significantly higher radiosurgical margin dose (p < 0.001). The obliteration rate was significantly higher in the early SRS era (65% vs 51%, p < 0.001), and earlier SRS treatment period was an independent predictor of obliteration in the multivariate analysis (p < 0.001). The rates of post-SRS hemorrhage and radiological, symptomatic, and permanent RICs were not significantly different between the two groups. Favorable outcome was achieved in a significantly higher proportion of patients in the early SRS era (61% vs 45%, p < 0.001), but the earlier SRS era was not statistically significant in the multivariate analysis (p = 0.470) with favorable outcome. Despite considerable advances in SRS technology, refinement of AVM selection, and contemporary multimodality AVM treatment, the study failed to observe substantial improvements in SRS favorable outcomes or obliteration for patients with AVMs over time. Differences in baseline AVM characteristics and SRS treatment parameters may partially account for the significantly lower obliteration rates in the modern SRS era. However, improvements in patient selection and dose planning are necessary to optimize the utility of SRS in the contemporary management of AVMs.

Stereotactic radiosurgery for jugular foramen schwannomas: an international multicenter study.

For some jugular foramen schwannomas (JFSs), complete resection is possible but may be associated with significant morbidity. Stereotactic radiosurgery (SRS) is a minimally invasive alternative or adjunct to microsurgery for JFSs. The authors reviewed clinical and imaging outcomes of SRS for patients with these tumors. Nine participating centers of the International Gamma Knife Research Foundation identified 92 patients who underwent SRS between 1990 and 2013. Forty-one patients had prior subtotal microsurgical resection. The median interval between previous surgery and SRS was 15 months (range 0.5-144 months). Eighty-four patients had preexisting cranial nerve (CN) symptoms and signs. The median tumor volume was 4.1 cm3 (range 0.8-22.6 cm3), and the median margin dose was 12.5 Gy (range 10-18 Gy). Patients with neurofibromatosis were excluded from this study. The median follow-up was 51 months (range 6-266 months). Tumors regressed in 47 patients, remained stable in 33, and progressed in 12. The progression-free survival (PFS) was 93% at 3 years, 87% at 5 years, and 82% at 10 years. In the entire series, only a dumbbell shape (extension extracranially via the jugular foramen) was significantly associated with worse PFS. In the group of patients without prior microsurgery (n = 51), factors associated with better PFS included tumor volume < 6 cm3 (p = 0.037) and non-dumbbell-shaped tumors (p = 0.015). Preexisting cranial neuropathies improved in 27 patients, remained stable in 51, and worsened in 14. The CN function improved after SRS in 12% of patients at 1 year, 24% at 2 years, 27% at 3 years, and 32% at 5 years. Symptomatic adverse radiation effects occurred in 7 patients at a median of 7 months after SRS (range 5-38 months). Six patients underwent repeat SRS at a median of 64 months (range 44-134 months). Four patients underwent resection at a median of 14 months after SRS (range 8-30 months). Stereotactic radiosurgery proved to be a safe and effective primary or adjuvant management approach for JFSs. Long-term tumor control rates and stability or improvement in CN function were confirmed.

Does Advanced Age Affect the Outcomes of Stereotactic Radiosurgery for Cerebral Arteriovenous Malformation?

Stereotactic radiosurgery (SRS) is generally considered a minimally invasive treatment modality. However, definitive evidence of the efficacy of SRS in the elderly population is still not available. The outcomes of 561 elderly and nonelderly patients who underwent SRS for AVM at our institution between 1990 and 2013 were reviewed, analyzed, and compared. Elderly patients were defined as those age ≥60 years at the time of SRS. The elderly cohort comprised 55 patients; the nonelderly cohort, 506. In the elderly cohort, the median age was 65 years, and the duration of follow-up was 91 months. The actuarial obliteration rates were 47% at 3 years, 70% at 4 years, and 76% at 5 years in the elderly cohort, and 57% at 3 years, 76% at 4 years, and 83% at 5 years in the nonelderly cohort. In the elderly cohort, the hemorrhage rates during the post-SRS latent phase were 5.2%/year in patients with hemorrhagic onset and 0%/year in those with nonhemorrhagic onset, and event-free survival (EFS) was 93% at 6 years and 89% at 12 years. The obliteration rate, mortality, and EFS rate were not significantly different between the 2 cohorts, whereas the rate of perifocal edema was significantly lower (P= 0.021) in the elderly cohort. The pre-SRS and post-SRS hemorrhage rates were slightly higher in the elderly cohort, albeit without statistical significance. Therapeutic effects and outcomes of SRS are similar in elderly and nonelderly patients. Treatment-related neurologic deficits are rare, and longer EFS can be expected.

Outcomes of Stereotactic Radiosurgery As Primary Interventional Therapy for the Treatment of Trigeminal Neuralgia in Patients with Multiple Sclerosis

Outcomes of Stereotactic Radiosurgery As Primary Interventional Therapy for the Treatment of Trigeminal Neuralgia in Patients with Multiple Sclerosis