The role of radical microsurgical resection in multimodal treatment for skull base meningioma

Object Because resection followed by timely stereotactic radiosurgery (SRS) is becoming a standard strategy for skull base meningiomas, the role of initial surgical tumor reduction in this combined treatment should be clarified. Methods This study examined 161 patients with benign skull base meningiomas surgically treated at Osaka City University between January 1985 and December 2005. The mean follow-up period was 95.3 months. Patients were categorized into 3 groups based on the operative period and into 4 groups based on tumor location. Maximal resection was performed as first therapy throughout all periods. In the early period (1985–1994), in the absence of SRS, total excision of the tumor was intentionally performed for surgical cure of the disease. In the mid and late periods (1995–2000 and 2001–2005), small parts of the tumor invading critical neurovascular structures were left untouched to obtain good functional results. Residual tumors with high proliferation potential (Ki 67 index > 4%) or with progressive tendencies were treated with SRS. The extent of initial tumor resection, recurrence rate, Karnofsky Performance Scale score, and complication rate were investigated in each group. Results The mean tumor equivalent diameter of residual tumors was 3.67 mm in the no-recurrence group and 11.7 mm in the recurrence group. The mean tumor resection rate (TRR) was 98.5% in the no-recurrence group and 90.1% in the recurrence group. A significant relationship was seen between postoperative tumor size, TRR, and recurrence rate (p < 0.001), but the recurrence rate showed no significant relationship with any other factors such as operative period (p = 0.48), tumor location (p = 0.76), or preoperative tumor size (p = 0.067). The mean TRR was maintained throughout all operative periods, but the complication rate was lowest and postoperative Karnofsky Performance Scale score was best in the late period (p < 0.001 each). Late-period results were as follows: mean TRR, 97.9%; mortality rate, 0%; and severe morbidity rate, 0%. Stereotactic radiosurgery procedures were added in 27 cases (16.8%) across all periods. Throughout all follow-up periods, 158 tumors were satisfactorily controlled by maximal possible excision alone or in combination with adequate SRS. Conclusions The combination of maximal possible resection and additional SRS improves functional outcomes in patients with skull base meningioma. A TRR greater than 97% in volume can be achieved with satisfactory functional preservation and will lead to excellent tumor control in combined treatment of skull base meningioma.

Download Full-text

Quantitative and qualitative 5-aminolevulinic acid–induced protoporphyrin IX fluorescence in skull base meningiomas

Neurosurgical FOCUS ◽

10.3171/2011.2.focus1112 ◽

2011 ◽

Vol 30 (5) ◽

pp. E8 ◽

Cited By ~ 49

Author(s):

Kimon Bekelis ◽

Pablo A. Valdés ◽

Kadir Erkmen ◽

Frederic Leblond ◽

Anthony Kim ◽

...

Keyword(s):

Skull Base ◽

Aminolevulinic Acid ◽

Tumor Resection ◽

Protoporphyrin Ix ◽

Complete Resection ◽

Qualitative Assessment ◽

Neoplastic Tissue ◽

Surgical Microscope ◽

Skull Base Meningioma ◽

Skull Base Meningiomas

Object Complete resection of skull base meningiomas provides patients with the best chance for a cure; however, surgery is frequently difficult given the proximity of lesions to vital structures, such as cranial nerves, major vessels, and venous sinuses. Accurate discrimination between tumor and normal tissue is crucial for optimal tumor resection. Qualitative assessment of protoporphyrin IX (PpIX) fluorescence following the exogenous administration of 5-aminolevulinic acid (ALA) has demonstrated utility in malignant glioma resection but limited use in meningiomas. Here the authors demonstrate the use of ALA-induced PpIX fluorescence guidance in resecting a skull base meningioma and elaborate on the advantages and disadvantages provided by both quantitative and qualitative fluorescence methodologies in skull base meningioma resection. Methods A 52-year-old patient with a sphenoid wing WHO Grade I meningioma underwent tumor resection as part of an institutional review board–approved prospective study of fluorescence-guided resection. A surgical microscope modified for fluorescence imaging was used for the qualitative assessment of visible fluorescence, and an intraoperative probe for in situ fluorescence detection was utilized for quantitative measurements of PpIX. The authors assessed the detection capabilities of both the qualitative and quantitative fluorescence approaches. Results The patient harboring a sphenoid wing meningioma with intraorbital extension underwent radical resection of the tumor with both visibly and nonvisibly fluorescent regions. The patient underwent a complete resection without any complications. Some areas of the tumor demonstrated visible fluorescence. The quantitative probe detected neoplastic tissue better than the qualitative modified surgical microscope. The intraoperative probe was particularly useful in areas that did not reveal visible fluorescence, and tissue from these areas was confirmed as tumor following histopathological analysis. Conclusions Fluorescence-guided resection may be a useful adjunct in the resection of skull base meningiomas. The use of a quantitative intraoperative probe to detect PpIX concentration allows more accurate determination of neoplastic tissue in meningiomas than visible fluorescence and is readily applicable in areas, such as the skull base, where complete resection is critical but difficult because of the vital structures surrounding the pathology.

Download Full-text

Multivariate risk factor analysis and literature review of postoperative deterioration in Karnofsky Performance Scale score in elderly patients with skull base meningioma

Neurosurgical FOCUS ◽

10.3171/2018.1.focus17730 ◽

2018 ◽

Vol 44 (4) ◽

pp. E14 ◽

Cited By ~ 6

Author(s):

Manish Kolakshyapati ◽

Fusao Ikawa ◽

Masaru Abiko ◽

Takafumi Mitsuhara ◽

Yasuyuki Kinoshita ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Prognostic Factors ◽

Elderly Patients ◽

Skull Base ◽

Karnofsky Performance Scale ◽

Preoperative Risk ◽

Skull Base Meningioma ◽

The Mean ◽

Performance Scale

OBJECTIVEElderly patients are particularly at risk for severe morbidity following surgery. Among the various risk factors, age and skull base location of meningioma are known to be poor prognostic factors in meningioma surgery. The authors conducted this study to analyze significant preoperative risk factors in elderly patients with skull base meningioma.METHODSA total of 265 elderly patients (≥ 65 years old) with meningioma were surgically treated at the authors’ institute and affiliated hospitals between 2000 and 2016, and these cases were reviewed. Among them, 57 patients with skull base meningioma were evaluated. Among the various risk factors, the authors analyzed age, sex, Karnofsky Performance Scale (KPS) score, American Society of Anesthesiologists score, and tumor size, location, and pathology. Body mass index (BMI) and serum albumin were investigated as the frailty factors. The authors also reviewed 11 surgical studies of elderly patients ≥ 60 years old with meningioma.RESULTSThe mean age was 72.4 ± 5.7 years, and 42 patients were female (73.6%). The mean size of meningioma was 36.6 ± 14.8 mm at the maximum diameter, and the mean follow-up period was 31.1 ± 31.5 months. (The continuous variables are expressed as the mean ± SD.) Histopathological investigation revealed a higher incidence (71.9%) of WHO Grade I. The rates of deterioration after surgery, at 3 months, and at 1 year were 33.3%, 37.3%, and 39.1%, respectively. Univariate analysis revealed location, preoperative KPS score, BMI level 2, and serum albumin level (p = 0.010, 0.017, 0.0012, and 0.0019, respectively) to be poor prognostic factors. Multivariate analysis revealed that location (p = 0.038) and BMI (p = 0.035) were risk factors for KPS score deterioration immediately after surgery. According to the 11 papers reviewed, the median rate (25th–75th percentile) of skull base–related location was 43.5% (39.6–47.75); for asymptomatic status the mean was 24%; and for mortality at 3 months and 1 year the medians were 6.3% (0.7–7.1) and 8% (4.8–9.4), respectively.CONCLUSIONCareful preoperative assessment based on the frailty concept was essential for better outcome in elderly patients with skull base meningioma. The BMI is appropriate as a quantitative factor for measure of frailty, particularly in elderly individuals with skull base meningioma. Further prospective randomized controlled trials are necessary to validate frailty as a preoperative risk factor. Not only patient selection but also surgical timing was an important factor.

Download Full-text

Short diameter may be a useful simple indicator of the tumor response in skull base meningiomas after conventionally fractionated stereotactic radiotherapy

European Radiology ◽

10.1007/s00330-021-07707-1 ◽

2021 ◽

Author(s):

Keiichi Takehana ◽

Daisuke Nakamura ◽

Alshaymaa Abdelghaffar ◽

Megumi Uto ◽

Tomohiro Katagiri ◽

...

Keyword(s):

Skull Base ◽

Stereotactic Radiotherapy ◽

Tumor Volume ◽

Tumor Response ◽

Fractionated Stereotactic Radiotherapy ◽

Skull Base Meningioma ◽

Skull Base Meningiomas ◽

Simple Indicator ◽

Conventionally Fractionated

Abstract Objectives The purpose of this study was to assess the radiological change patterns in skull base meningiomas after conventionally fractionated stereotactic radiotherapy (CFSRT) to determine a simple and valid method to assess the tumor response. Materials and methods Forty-one patients with a benign skull base meningioma treated by CFSRT from March 2007 to August 2015 were retrospectively evaluated. We measured tumor volume (TV), long-axis diameter (LD), and short-axis diameter (SD) on both pre-treatment images and follow-up images of 1, 3, and 5 years after CFSRT, respectively. The paired t test was used to detect differences in the LD and SD change rates. Spearman’s correlation coefficients were calculated to evaluate relationships between the TV and the diameters changes. Results The number of available follow-up MRIs that was performed at 1, 3, and 5 years after the CFSRT was 41 (100%), 34 (83%), and 23 (56%), respectively. The change rates of SD were significantly higher than those of LD at every time point and more strongly correlated with the change rates of tumor volume at 3 and 5 years after CFSRT. Conclusions SD may be useful as a simple indicator of the tumor response for skull base meningioma after CFSRT. Key Points • The change rate in short-axis diameter is a useful and simple indicator of the response of skull base meningioma to conventionally fractionated stereotactic radiotherapy. • Conventionally fractionated stereotactic radiotherapy for skull base meningioma achieved excellent 5-year local control.

Download Full-text

Preservation of nasal turbinates in endoscopic, anterior skull base surgery—yes, we can!

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-021-06856-9 ◽

2021 ◽

Author(s):

Axel Wolf ◽

Alexandros Andrianakis ◽

Peter Valentin Tomazic ◽

Michael Mokry ◽

Georg Clarici ◽

...

Keyword(s):

Skull Base ◽

Skull Base Surgery ◽

Tumor Resection ◽

Tumor Location ◽

Anterior Skull Base ◽

Tumor Diameter ◽

Tumor Type ◽

Preoperative Information ◽

Medical University ◽

Significant Factors

Abstract Objective To evaluate the frequency, type and indications of nasal turbinate (NT) resection during endoscopic, anterior skull base surgery and to analyze factors that may have an impact on the need of NT removal. Methods In this retrospective cohort study, 306 subjects (150 males and 156 females, mean age 55.4 ± 15.3 years) who underwent multidisciplinary, transnasal, endoscopic tumor surgery of the anterior skull base using 4-handed techniques between 2011 and 2019 at the Department of Otorhinolaryngology, Medical University of Graz, were included. Results In the majority of interventions (n = 281/306; 91.8%), all NT were preserved. Significant factors influencing the need of NT resections turned out to be type of endoscopic approach (p < 0.001; V = 0.304), sagittal (p = 0.003; d = 0.481) and transversal (p = 0.017; d = 0.533) tumor diameter, tumor type (p < 0.001; V = 0.355) and tumor location (p < 0.001; V = 0.324). Conclusions NT can be preserved in the majority of patients undergoing tumor resection in anterior, transnasal, skullbase surgery and routine resection of NT should be avoided. Variables that have an impact on the need of NT resections are types of endoscopic approaches, sagittal and transversal tumor extension and tumor type. These factors should be considered in planning of surgery and preoperative information of patients.

Download Full-text

Surgically resected skull base meningiomas demonstrate a divergent postoperative recurrence pattern compared with non–skull base meningiomas

Journal of Neurosurgery ◽

10.3171/2015.7.jns15546 ◽

2016 ◽

Vol 125 (2) ◽

pp. 431-440 ◽

Cited By ~ 20

Author(s):

Alireza Mansouri ◽

George Klironomos ◽

Shervin Taslimi ◽

Alex Kilian ◽

Fred Gentili ◽

...

Keyword(s):

Skull Base ◽

Recurrence Rate ◽

Postoperative Recurrence ◽

Prior History ◽

Skull Base Tumors ◽

Who Grade ◽

Predictors Of Recurrence ◽

History Of ◽

Skull Base Meningiomas

OBJECTIVE The objective of this study was to identify the natural history and clinical predictors of postoperative recurrence of skull base and non–skull base meningiomas. METHODS The authors performed a retrospective hospital-based study of all patients with meningioma referred to their institution from September 1993 to January 2014. The cohort constituted both patients with a first-time presentation and those with evidence of recurrence. Kaplan-Meier curves were constructed for analysis of recurrence and differences were assessed using the log-rank test. Cox proportional hazard regression was used to identify potential predictors of recurrence. RESULTS Overall, 398 intracranial meningiomas were reviewed, including 269 (68%) non–skull base and 129 (32%) skull base meningiomas (median follow-up 30.2 months, interquartile range [IQR] 8.5–76 months). The 10-year recurrence-free survival rates for patients with gross-total resection (GTR) and subtotal resection (STR) were 90% and 43%, respectively. Skull base tumors were associated with a lower proliferation index (0.041 vs 0.062, p = 0.001), higher likelihood of WHO Grade I (85.3% vs 69.1%, p = 0.003), and younger patient age (55.2 vs 58.3 years, p = 0.01). Meningiomas in all locations demonstrated an average recurrence rate of 30% at 100 months of follow-up. Subsequently, the recurrence of skull base meningiomas plateaued whereas non–skull base lesions had an 80% recurrence rate at 230 months follow-up (p = 0.02). On univariate analysis, a prior history of recurrence (p < 0.001), initial WHO grade following resection (p < 0.001), and the inability to obtain GTR (p < 0.001) were predictors of future recurrence. On multivariate analysis a prior history of recurrence (p = 0.02) and an STR (p < 0.01) were independent predictors of a recurrence. Assessing only patients with primary presentations, STR and WHO Grades II and III were independent predictors of recurrence (p < 0.001 for both). CONCLUSIONS Patients with skull base meningiomas present at a younger age and have less aggressive lesions overall. Extent of resection is a key predictor of recurrence and long-term follow-up of meningiomas is necessary, especially for non–skull base tumors. In skull base meningiomas, recurrence risk plateaus approximately 100 months after surgery, suggesting that for this specific cohort, follow-up after 100 months can be less frequent.

Download Full-text

Level I to III craniofacial approaches based on Barrow classification for treatment of skull base meningiomas: surgical technique, microsurgical anatomy, and case illustrations

Neurosurgical FOCUS ◽

10.3171/2011.3.focus1110 ◽

2011 ◽

Vol 30 (5) ◽

pp. E5 ◽

Cited By ~ 8

Author(s):

Emel Avcı ◽

Erinç Aktüre ◽

Hakan Seçkin ◽

Kutluay Uluç ◽

Andrew M. Bauer ◽

...

Keyword(s):

Surgical Technique ◽

Skull Base ◽

Surgical Anatomy ◽

Microsurgical Anatomy ◽

Middle Point ◽

The Mean ◽

The Right ◽

Skull Base Meningiomas ◽

Supraorbital Foramen ◽

Ethmoidal Foramen

Object Although craniofacial approaches to the midline skull base have been defined and surgical results have been published, clear descriptions of these complex approaches in a step-wise manner are lacking. The objective of this study is to demonstrate the surgical technique of craniofacial approaches based on Barrow classification (Levels I–III) and to study the microsurgical anatomy pertinent to these complex craniofacial approaches. Methods Ten adult cadaveric heads perfused with colored silicone and 24 dry human skulls were used to study the microsurgical anatomy and to demonstrate craniofacial approaches in a step-wise manner. In addition to cadaveric studies, case illustrations of anterior skull base meningiomas were presented to demonstrate the clinical application of the first 3 (Levels I–III) approaches. Results Cadaveric head dissection was performed in 10 heads using craniofacial approaches. Ethmoid and sphenoid sinuses, cribriform plate, orbit, planum sphenoidale, clivus, sellar, and parasellar regions were shown at Levels I, II, and III. In 24 human dry skulls (48 sides), a supraorbital notch (85.4%) was observed more frequently than the supraorbital foramen (14.6%). The mean distance between the supraorbital foramen notch to the midline was 21.9 mm on the right side and 21.8 mm on the left. By accepting the middle point of the nasofrontal suture as a landmark, the mean distances to the anterior ethmoidal foramen from the middle point of this suture were 32 mm on the right side and 34 mm on the left. The mean distance between the anterior and posterior ethmoidal foramina was 12.3 mm on both sides; the mean distance between the posterior ethmoidal foramen and distal opening of the optic canal was 7.1 mm on the right side and 7.3 mm on the left. Conclusions Barrow classification is a simple and stepwise system to better understand the surgical anatomy and refine the techniques in performing these complex craniofacial approaches. On the other hand, thorough anatomical knowledge of the midline skull base and variations of the neurovascular structures is crucial to perform successful craniofacial approaches.

Download Full-text

Usefulness of Imaging Fusion for Therapeutic Planning in Skull Base Lesions

Rivista di Neuroradiologia ◽

10.1177/197140090301600210 ◽

2003 ◽

Vol 16 (2) ◽

pp. 299-305

Author(s):

E. Puglielli ◽

R. Galzio ◽

A. Ricci ◽

A. Splendiani ◽

F. Iannessi ◽

...

Keyword(s):

Skull Base ◽

Posterior Fossa ◽

Foramen Magnum ◽

Mean Value ◽

Trigeminal Schwannoma ◽

Correct Definition ◽

Skull Base Lesions ◽

The Mean ◽

Planum Sphenoidale ◽

Skull Base Meningiomas

We propose critical considerations on the usefulness of CT, MRI, and fMRI imaging fusion for the treatment of skull base lesions evaluating 41 cases (24 meningiomas: six petroclival, seven clinoidal, four olfactory, two in the foramen magnum, two spheno-petro-clival, one in the planum sphenoidale, one in the posterior pyramid and one in the PCA; five acoustic schwannomas, three epidermoids, two pituitary adenomas, two craniopharingiomas, two posterior fossa aneurysms, one trigeminal schwannoma, one dermoid and one juvenile angiofibroma). Data were collected, fused, integrated and reconstructed by a dedicated Stealth-Station system for Neuronavigation. CT images were acquired on axial non-overlapping slices, 1–3 mm thick; MRI images were obtained with a 1.5 T system, same FOV and thickness. During surgery the Mean Fiducially Error measured at 6 cm depth and anatomical distortion due to CSF loss was evaluated. Neuronavigation was possible in all cases and successfully applied in preoperative planning and during surgical procedures. The Mean Fiducially Error at 6 cm was 1.7 mm. CSF loss during surgery produced modifications on planned anatomy in a mean value of 0.6 mm. In all cases, imaging fusion for pre and intra-operative neuronavigation provided great advantages in the choice of the best approach, placing of bone flap, correct definition of tumour boundaries and meningeal implant, relationship with functional areas, early identification and real-time correction of the surgical route with respect of deep normal or distorted anatomic or pathologic structures and their eventual encasement or involvement by the pathologic primary process. Neuronavigation appeared ideal for skull base meningiomas making surgical manoeuvres safer, more effective and less invasive. In skull base lesions, CSF loss appeared not significant due to the fact that posterior fossa structures are strictly connected to each other and to the bone, thus are poorly affected by surgical deliquoration. We propose the possible extension of imaging fusion technique with the aim of optimizing the target in radiotherapy for intracranial tumours.

Download Full-text

Lateral skull base malignancies

Neurosurgical FOCUS ◽

10.3171/foc.2002.12.5.9 ◽

2002 ◽

Vol 12 (5) ◽

pp. 1-4 ◽

Cited By ~ 6

Author(s):

Benjamin M. McGrew ◽

C. Gary Jackson ◽

Raquel A. Redtfeldt

Keyword(s):

Skull Base ◽

Postoperative Radiotherapy ◽

Survival Rates ◽

Tumor Resection ◽

Surgical Techniques ◽

Local Tumor Control ◽

Tumor Control ◽

Lateral Skull Base ◽

The Mean ◽

Poor Outcomes

Object Historically poor outcomes have been characteristic in patients with lateral skull base malignancies. As advances in skull base surgical techniques have been made, complete resection has increasingly been achieved. This has resulted in improved survival rates and local tumor control. Methods The authors performed a retrospective review of 95 patients treated for lateral skull base malignancies. The mean age of the patients was 49.4 years. There were 44 females and 51 males. The mean follow-up period was 50 months. Resection was performed in all patients, and postoperative radiotherapy was undertaken in 54% of the cases. Local disease control was maintained in 73% of the patients. Tumor involvement of the facial nerve and intracranial tumor extension did not jeopardize the rate of local control. Conclusions Despite the fact that technical advances in skull base surgery have resulted in a higher incidence of complete tumor resection and improved survival rates, a respect for the poor prognosis historically associated with lateral skull base malignancies should be maintained and treatment should be appropriately aggressive.

Download Full-text

Radiosurgery for large-volume (> 10 cm3) benign meningiomas

Journal of Neurosurgery ◽

10.3171/2009.8.jns09703 ◽

2010 ◽

Vol 112 (5) ◽

pp. 951-956 ◽

Cited By ~ 34

Author(s):

Jonathan M. Bledsoe ◽

Michael J. Link ◽

Scott L. Stafford ◽

Paul J. Park ◽

Bruce E. Pollock

Keyword(s):

Skull Base ◽

Large Volume ◽

Tumor Control ◽

Skull Base Tumors ◽

Who Grade ◽

Average Tumor Volume ◽

The Mean ◽

Skull Base Meningiomas ◽

Supratentorial Tumors

Object Stereotactic radiosurgery (SRS) has proven to be a safe and effective treatment for many patients with intracranial meningiomas. Nevertheless, the morbidity associated with radiosurgery of larger meningiomas is poorly understood. Methods The authors performed a retrospective review of 116 patients who underwent SRS for meningiomas (WHO Grade I) > 10 cm3 between 1990 and 2007, with a minimum follow-up of 12 months. Patients with atypical or malignant meningiomas and those who received prior radiotherapy were excluded. The average tumor volume was 17.5 cm3 (range 10.1–48.6 cm3); the average tumor margin dose was 15.1 Gy (range 12–18 Gy); and the mean follow-up duration was 70.1 months (range 12–199 months). Results Tumor control was 99% at 3 years and 92% at 7 years after radiosurgery. Thirty complications after radiosurgery were noted in 27 patients (23%), including 7 cases of seizures, 6 cases of hemiparesis, 5 cases of trigeminal injury, 4 cases of headaches, 3 cases of diplopia, 2 cases each of cerebral infarction and ataxia, and 1 case of hearing loss. Patients with supratentorial tumors experienced a higher complication rate compared with patients with skull base tumors (44% compared with 18%) (hazard ratio 2.9, 95% CI 1.3–6.7, p = 0.01). Conclusions The morbidity associated with SRS for patients with benign meningiomas > 10 cm3 is greater for supratentorial tumors compared with skull base tumors. Whereas radiosurgery is relatively safe for patients with large-volume skull base meningiomas, resection should remain the primary disease management for the majority of patients with large-volume supratentorial meningiomas.

Download Full-text

Long-Term Results of Stereotactic Radiosurgery for Skull Base Meningiomas

Neurosurgery ◽

10.1227/neu.0000000000001045 ◽

2015 ◽

Vol 79 (1) ◽

pp. 58-68 ◽

Cited By ~ 24

Author(s):

Or Cohen-Inbar ◽

Cheng-chia Lee ◽

David Schlesinger ◽

Zhiyuan Xu ◽

Jason P. Sheehan

Keyword(s):

Skull Base ◽

Tumor Volume ◽

World Health ◽

Tumor Control ◽

Karnofsky Performance Scale ◽

Health Organization ◽

Skull Base Meningiomas ◽

Performance Scale

Abstract BACKGROUND: Gamma knife radiosurgery (GKRS) is well established in the management of inaccessible, recurrent, or residual benign skull base meningiomas. Most series report clinical outcome parameters and complications in the short intermediate period after radiosurgery. Reports of long-term tumor control and neurological status are still lacking. OBJECTIVE: To report the presentation, treatment, and long-term outcome of skull base meningiomas after GKRS. METHODS: From a prospectively collected institutional review board-approved database, we selected patients with a World Health Organization grade I skull base meningioma treated with a single-session GKRS and a minimum of 60 months follow-up. One hundred thirty-five patients, 54.1% males (n = 73), form the cohort. Median age was 54 years (19–80). Median tumor volume was 4.7 cm3 (0.5–23). Median margin dose was 15 Gy (7.5–36). Median follow-up was 102.5 months (60.1–235.4). Patient and tumor characteristics were assessed to determine the predictors of neurological function and tumor progression. RESULTS: At last follow-up, tumor volume control was achieved in 88.1% (n = 119). Post-GKRS clinical improvement or stability was reported in 61.5%. The 5-, 10-, and 15-year actuarial progression-free survival rates were 100%, 95.4%, and 68.8%, respectively. Favorable outcome (both tumor control and clinical preservation/improvement) was attained in 60.8% (n = 79). Pre-GKRS performance status (Karnofsky Performance Scale) was shown to influence tumor progression (P = .001) and post-GKRS clinical improvement/preservation (P = .003). CONCLUSION: GKRS offers a highly durable rate of tumor control for World Health Organization grade I skull base meningiomas, with an acceptably low incidence of neurological deficits. The Karnofsky Performance Scale at the time of radiosurgery serves as a reliable long-term predictor of overall outcome.

Download Full-text