Young Hyun Cho

Endolymphatic Sac Tumors : Report of Four Cases

Endolymphatic sac tumor is rare, locally aggressive hypervascular tumor of papillary structure, arising from the endolymphatic duct or sac in the posterior petrous bone. We present four cases with this tumor. Two patients were male and the other two were female. Age of each patient was 15, 52, 58, and 67 years. Three patients presented with progressive hearing loss and sustained vertigo for months to years and another one was referred for the tumor detected in routine medical check-up. Preoperative embolization was performed in 3 patients. Complete excision of the tumor was achieved in all patients using translabyrinthine or retrosigmoid approach. Herein, we describe the clinical and radiographic features, surgical treatment and pathologic findings with a review of the literature.

Frontal transcortical approach in 12 Central Neurocytomas

BackgroundCentral neurocytomas (CN) are rare intraventricular tumors with benign clinical behavior that typically affect young adults. Although a favorable prognosis is generally expected after adequate management, there is no general consensus on the standard of therapy. We evaluated the efficacy and safety of radical surgery for the management of CN.MethodsBetween 1996 and 2010, 12 patients with CN (eight males and four females; range, 18 to 62xa0years; mean age, 28.5xa0years) were surgically treated in our institution. The initial goal of therapy was complete resection through a frontal transcortical approach, and repeat surgery was done in cases of residual or recurrent disease. The mean follow-up period was 51.2xa0months (range, 14–149xa0months).ResultsComplete resection was achieved in all patients either with primary (nine patients, 75xa0%) or second-look surgery (three patients, 25xa0%). No mortalities occurred and there were four surgery-related complications (two events of transient hemiparesis, one transient aphasia, and onepostoperative subdural hygroma). All patients were alive with normal activities of daily living at the last follow-up. Two patients (16.6xa0%) experienced a single recurrence at 26 and 66xa0months, one of whom underwent redo-surgery.ConclusionFor the management of CN, complete resection is feasible, effective, and safe. Repeat surgery may be a viable option in cases of residual or recurrent disease and the use of radiotherapy can be avoided in this young population.

Is the Complete Resection of Craniopharyngiomas in Adults Feasible Considering Both the Oncologic and Functional Outcomes

Objective To assess the impact of the complete resection of craniopharyngioma (CP) in adults on oncologic and functional outcomes. Methods We retrospectively analyzed 82 patients with CP who were surgically treated by the same neurosurgeon at our institution between January 1994 and December 2012. Results Gross total resection (GTR) was achieved in 71 patients (86.6%), near total resection (NTR) in 7 patients (8.5%), and subtotal resection (STR) in 3 patients (3.7%). The disease-specific overall survival rate was 100% with the exclusion of 2 surgery-related mortalities. The overall recurrence rate was 12.2% (10 of 82 patients), however the recurrence rate according to extent of resection (EOR) was 9.9% (7 of 71 patients) after GTR, 14.3% (1 of 7 patients) after NTR, and 66.7% (2 of 3 patients) after STR. The overall recurrence-free survival (RFS) rates at 5 and 10 years were 87.0% and 76.8%, respectively. Postoperatively, most patients (86.3%) needed hormone replacement for at least 1 hypothalamic-pituitary axis. Vision improved in 56.4% of the patients with preoperative abnormal vision, but deteriorated in 27.4% of patients. Hypothalamic dysfunction developed in 32.9% of patients. There were no significant differences in the risks of pituitary dysfunction, visual deterioration, or hypothalamic dysfunction between the groups with complete vs. incomplete removal. The overall rate of postoperative complications was 22.0%, which did not differ between groups (p=0.053). Conclusion The complete removal of a CP at first surgery can provide a chance for a cure with acceptable morbidity and mortality risks.

Treatment and outcomes for gangliogliomas: a single-center review of 16 patients.

Background Ganglioglioma is a rare and slowly growing benign tumor. We investigated the outcomes of patients who underwent different combination treatments. Methods Between 1998 and 2012, 16 patients, including 11 men and 5 women, with a median age of 12.5 years (range, 2.5-65 years) were treated for intracranial gangliogliomas at our institution. The median follow-up period was 5.7 years (range, 48 days-15.6 years). Fifteen cases were included in the outcome assessment because one patient was lost to follow-up. Complete resection was achieved in 8 (53%) patients. Six (40%) patients underwent incomplete resection with or without adjuvant radiotherapy, and one patient with a brainstem tumor underwent only stereotactic biopsy. Results Gangliogliomas predominantly affected young (87.5%), male patients and most frequently presented with seizures (64%). Of eight patients who underwent complete resection, seven did not show recurrence, whereas only three of six with incomplete resection showed no recurrence. Four patients with recurrence received salvage treatments (two repeat surgeries and two radiosurgeries). A tumor control rate of 93% (14/15) was achieved at the last follow-up. No recurrence or malignant changes were observed after a median follow-up of 12 and 4.5 years in four patients who received gamma knife (GK) radiosurgery as adjuvant and salvage treatment. Conclusion Complete resection produced the best outcomes and incomplete resection followed by adjuvant or salvage treatments showed favorable outcomes. In patients who are not eligible for complete resection because of tumor location or potential neurologic deficits following surgery, GK radiosurgery should be considered for the treatment of residual or recurrent tumors.

Fiducial-free CyberKnife radiosurgery for residual metastatic spinal tumor after decompression and instrumentation

Stereotactic spinal radiotherapy is a promising technology for use in the multidisciplinary management of benign and malignant spinal tumors. We present two patients with residual metastatic spinal tumors and their treatment with CyberKnife (Accuray, Sunnyvale, CA, USA) after decompression and instrumentation, one of which was successful and the other not. A 73-year-old male patient was admitted with bilateral extremity weakness (Grade IV) and voiding difficulty that had developed 2 days previously. CyberKnife treatment for the residual tumor after surgery with decompression and instrumentation was attempted, but could not be performed due to imaging interference caused by the instrumentation. A second patient, a 49-year-old male, was admitted with right extremity weakness and voiding difficulty that had developed 5 months previously. In this patient, we were able to perform CyberKnife treatment on the residual tumor after decompression and instrumentation. Based on these two patients, we believe that fiducial-free CyberKnife treatment is not suitable for treatment of residual metastatic spinal tumors at the upper thoracic levels, after decompression with instrumentation. This is due to the difficulties in matching digitally reconstructed radiographs with live radiographic images, as a result of the larger inclination and smaller vertebral body surface at the upper thoracic level.

Anatomical Origin of Tuberculum Sellae Meningioma: Off-Midline Location and Its Clinical Implications

OBJECTIVEnTuberculum sellae meningiomas (TSM) arise from the dura mater of tuberculum sellae, limbus sphenoidale, and chiasmatic sulcus and cause asymmetric visual disturbances. In this study, we analyzed the laterality of the origin of TSM and discussed its clinical implications on immediate and long-term visual outcomes.nnnMETHODSnBetween 1994 and 2013, TSM was diagnosed in 100 patients after microsurgical resection. The medical records, radiologic features, and operative findings were retrospectively reviewed and analyzed in these patients.nnnRESULTSnVisual disturbances were evident in 95 patients (95%) after neuro-ophthalmologic testing. Among them, 89 patients (89%) showed marked asymmetric visual field defect, and 6 patients (6%) had relatively symmetric visual field defect. On intraoperative inspection, the origin of TSM was at the one lateral end portion of the tuberculum sellae in 85 patients (85%). In 15 patients (15%), the TSM originated from the midline region, including the central portion of the tuberculum sellae (nxa0= 13) and diaphragm sellae (nxa0= 2). Optic canal involvement was observed in 73 patients (73%). Preexisting visual field defects were improved in 70 patients (70%), were stationary in 25 patients (25%), and aggravated in 5 patients (5%) during postoperative follow-up (mean 58 months, 24∼122 months). The preoperative symptom duration, the laterality of the origin of TSM, and optic disc atrophy were associated with long-term poor visual outcomes.nnnCONCLUSIONSnMost TSMs that originated from the dura of one lateral end portion of the tuberculum sellae correlated with asymmetric visual symptoms and poor visual outcomes. This microsurgical feature should be considered in the planning of optimal surgical strategy to achieve favorable outcomes.

Analysis of the results of recurrent intracranial meningiomas treated with re-radiosurgery

OBJECTSnMeningioma is the most common intracranial neoplasm, comprising approximately 30% of all primary intracranial tumors (Claus et al., 2005) [1]. Treatment options include observation, microsurgical resection, stereotactic radiosurgery (SRS), and whole brain radiation therapy (WBRT). Gamma knife radiosurgery (GKRS) is a very effective treatment for intracranial meningiomas; previous studies showed the tumor control rate at 5-10 years of follow-up as 84.3%-100% in all cases (Feigl et al., 2005; Linskey et al., 2005; Malik et al., 2005; Aichholzer et al., 2000; Hakim et al., 1998; Chang and Adler 1997; Lunsford, 1994; Ganz et al., 1993) [2-9]. Many studies have discussed issues like optimal dose, conformal configurations, and adverse effects to improve the treatment result with GKRS (Malik et al., 2005; Kenai et al., 2005; Rowe et al., 2004; Shrieve et al., 2004) [4,10-12]. There are some cases in which the radiosurgery result is unfavorable and perhaps further treatment is needed. In these cases, re-radiosurgery can be an option. However, there have not been comprehensive studies discussing the issues of re-radiosurgery. Therefore, we analyzed the result of re-radiosurgery for recurrent meningiomas and their impact on clinical outcomes.nnnMETHODSnFrom 1995 to 2015, we retrospectively reviewed 1163 patients who underwent GKRS for intracranial meningioma at the Asan Medical Center. Patients with multiple meningiomas or a follow-up with a period of less than a year were excluded from this study. Finally, 865 patients were enrolled in this study. Clinical symptoms and brain magnetic resonance imaging (MRI) scans were assessed by neurosurgeons. When tumor size increased together with newly developed neurologic symptoms, further management, such as microsurgical resection or SRS, was considered. Histologic analysis of the resected tumors was performed by neuropathologists. Clinical data, including patients sex, age, and tumor locations were recorded. Treatment data included tumor volume, tumor grade, radiation dose, and presence of edema. Final outcome data including follow-up period, time to progression, interval between first and second radiosurgery courses and interval between microsurgery and radiosurgery were obtained.nnnRESULTSnAmong 865 patients, tumor recurrence was found in 63 patients (7.28%). Seven patients showed transient tumor growth after GKRS. These patients have been under close observation without any further treatments. Fifty-six patients (6.47%) showed permanent tumor growth on follow-up MRI. Thirty-three patients from this group underwent repeated radiosurgery owing to tumor growth, resulting in a re-irradiation rate of 3.82% at our radiosurgery center. The other 23 patients were treated using methods other than re-radiosurgery. Among the 33 patients, 25 underwent microsurgical resection prior to their initial course of GKRS, and the other 8 were treated with re-radiosurgery only. An analysis was performed to determine factors that may have a role in treatment results. Of the many variables, tumor grade (p=0.004, Fishers exact test) was the only significant factor for progression-free survival (PFS). Thirteen patients with unbiopsied or benign meningioma showed stable tumor size, while there was tumor growth in 8 patients. Among high-grade meningioma patients, 3 and 9 showed stable disease and tumor growth, respectively. As a result of re-radiosurgery, 11 out of 17 patients showed tumor growth and needed further treatments; this involved a third GKRS for 4 patients, microsurgical resection for 6 patients, and cyber knife radiosurgery (CKRS) for 1 patient. Four patients from this group were also treated with WBRT.nnnCONCLUSIONnWe analyzed the results of re-radiosurgery for recurrent meningiomas and observed that World Health Organization (WHO) grade II and III was significantly associated with a lower PFS rate compared with low-grade meningiomas (p=0.004). Conversely, patients with benign meningioma or unbiopsied tumors had much better results. Hence, re-radiosurgery is recommended for patients with unknown or benign meningiomas if their first GKRS result is unsatisfactory. However, re-radiosurgery should be considered carefully for recurrent high-grade tumors. Owing to the small number of recurrent meningioma patients treated with re-radiosurgery, further studies are required to delineate the role of this treatment.

SU‐F‐P‐60: Optimization of Cyberknife Treatment Planning Using a Dose‐Limiting Auto‐Shells Method for Brain Metastases

PURPOSEnIn pursuit of high precision in target localization and steeper dose fall-off in stereotactic radiosurgery, we investigated the impact of optimizing dose-limiting auto-shell function on the quality of Cyberknife (CK) plans in treating brain metastases (BMs).nnnMETHODSnNineteen BMs previously treated using CK were selected for this study. The original CK plans (CK_original) had been produced using one to three dose-limiting auto-shells at prescription dose (PD) level and low dose levels of 10 to 30% of PD. In each case, a modified CK plan (CK_modified) was generated using five dose-limiting shells at PD level, intermediate dose level of 50% of PD, and low dose levels with an optimal shell-dilation size based on our experience. In addition, a Gamma Knife plan (GK) was also produced using the original contour set. Thus, a triplet data set of dosimetric parameters was generated and analyzed.nnnRESULTSnWhile no differences in conformity index (mean±SD 1.22 ± 0.1, 1.18 ± 0.1, and 1.24 ± 0.1 in CK_original, CK_modified, and GK, respectively; over all P > 0.05) and tumor coverage (mean±SD 99.5 ± 0.4%, 99.5 ± 0.3%, and 99.4 ± 0.2% in CK_original, CK_modified, and GK, respectively; over all P > 0.05) were observed among the plans, the normal tissue volume receiving 50% of PD was significantly decreased in CK_modified and GK compared with CKoriginal by 1.28 and 1.27-fold, respectively (P < 0.001, each). No significant differences in dose fall-off were observed between CK_modified and GK (P = 0.345).nnnCONCLUSIONnBy optimizing auto-shell function, a significantly steeper dose fall-off can be achieved in CK system, while maintaining high precision in target localization.

Analysis the causes of radiosurgical failure in intracranial meningiomas treated with radiosurgery

OBJECTIVESnSurgical resection is a primary indication for intracranial meningioma. Radiosurgery is also an excellent treatment modality for postoperative residual tumors, or tumors in high-risk locations, such as the skull base. Despite multimodality treatments, there are some cases in which radiosurgery fails and surgical resection or re-radiosurgery is required. However, there has not been a comprehensive study focusing on the causes of secondary treatment for local recurrence or a new mass that develops outside the target area after radiosurgery. Hence, we analyzed the causes of radiosurgical failure in patients with meningioma.nnnMETHODSnFrom 2000 to 2015, we retrospectively reviewed 1086 patients who underwent gamma knife radiosurgery (GKRS) for intracranial meningioma at the Asan Medical Center. Multiple meningiomas or tumors with a volume greater than 7000mm3 were excluded. All patients had a minimum follow-up of 12 months. Finally, 771 patients were enrolled in this study. Clinical symptoms and brain MRI findings were assessed by neurosurgeons. When the tumor size increased and was accompanied by newly developed neurological symptoms, further management was considered (e.g. microsurgical resection and stereotactic radiosurgery). Histological analyses of the resected tumors were performed by neuropathologists.nnnRESULTSnAmong the 771 patients, tumor growth was observed in 60 patients (7.78%). Seven patients showed transient tumor growth after GKRS. These patients have been under close observation without any further treatment. Thirty patients (3.89%) underwent re-radiosurgery for tumor control. Another 23 patients underwent procedures other than re-radiosurgery; 8 underwent microsurgical resection, 3 underwent cyber knife radiosurgery (CKRS), 1 underwent radiation therapy, and 8 were closely followed-up. Three patients visited other clinics or were lost to follow-up. Of the remaining 30 patients, 22 (group 1) underwent microsurgical resection prior to their initial course of GKRS and the other 8 (group 2) were treated only with re-radiosurgery. In group 1, recurrence rates after radiosurgery were 2.47% (n=19) and 0.39% (n=3) for local and distant recurrence, respectively. In group 2, recurrence rates after radiosurgery were 0.52% (n=4) and 0.52% (n=4) for local and distant recurrence, respectively. An analysis was performed to determine the factors that may result in differences between the two groups. Of the many variables, local recurrence (p=0.0331, Fishers exact test) was the only significant factor.nnnCONCLUSIONnWe analyzed the causes of radiosurgical failure in meningioma patients and observed that microsurgery before radiosurgery was significantly associated with a high local recurrence rate compared with primary radiosurgery. Furthermore, the percentage of local recurrence cases that required secondary radiosurgery was as low as 2.98%. This result is comparable with that of microsurgical resection, which is the mainstay of treatment for meningioma.