Yong-Kwang Tu

National Taiwan University Hospital, Taipei, Taipei, Taiwan

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Publications (54)108.99 Total impact

  • Article: Single-Incision Laparoscopic Surgery (SILS) for Ventriculoperitoneal Shunt Placement.
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    ABSTRACT: Background Single-incision laparoscopic surgery (SILS) may facilitate safer shunt placement and lower distal obstruction rate than is seen in conventional surgery.Objective We reviewed our 2-year experience in SILS for ventriculoperitoneal shunt placement to evaluate its usefulness and safety.Materials and Methods In this retrospective study, we enrolled patients older than 18 years with dilated ventricle and syndromes of hydrocephalus. A total of 31 patients underwent 31 primary ventriculoperitoneal shunt placement surgery and two underwent revision surgery. All the procedures were performed by the SILS technique.Results The entire duration of ventriculoperitoneal shunt implantation ranged from 45 to 80 minutes, with mean operation time of 65 ± 15.3 minutes. No major laparoscopy-related complications were noted. Shunt infection, peritonitis, and distal catheter malfunction occurred in one case (3.2%), proximal malfunction in one case (3.2%), and subcutaneous emphysema occurred in two cases (6.4%). The emphysema resolved within 2 days. Cosmetic results were "very good to good" in 17 patients (54.8%) and "satisfactory" in 14 patients (45.2%). The abdominal scars in most cases were nearly invisible.Conclusion SILS is a safe and effective technique for ventriculoperitoneal shunt placement and can be accomplished with no higher risk of shunt infection and distal malfunction. Without an additional port, SILS allows good visualization of the peritoneal cavity to avoid major intra-abdominal complications. Only one 6-mm incision at the umbilicus area is required and is almost invisible after wound healing.
    Journal of neurological surgery. Part A, Central European neurosurgery. 02/2013;
  • Article: Hyperacute cerebral aneurysm rerupture during CT angiography.
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    ABSTRACT: The object of this study was to identify the clinical features and outcomes of a subgroup of patients with aneurysmal subarachnoid hemorrhage (SAH) who had active contrast extravasation from a ruptured aneurysm during initial cerebral CT angiography (CTA). The authors performed a retrospective study of spontaneous SAH cases involving patients treated at their institute. They identified 9 cases in which active contrast extravasation was evident on the initial CT angiogram. Another 12 similar cases were also identified in a literature review and data was gathered from these cases to evaluate the outcomes. Analysis of all 21 cases revealed that the overall outcomes in cases characterized by active aneurysmal bleeding during CTA were poor. Seventy-six percent of patients had unfavorable results. Patients who showed poor neurological status at presentation died no matter what kind of treatment they received. In contrast, patients who presented with good neurological status initially had a chance of favorable outcome. Among the patients with good initial neurological status, most demonstrated rapid deterioration of their condition during the CTA examination; only those who received immediate and effective decompressive surgery and aneurysm obliteration had good results. Active aneurysmal rebleeding during CTA is an uncommon but devastating event. Though the mortality of this distinct group of patients remains high, a clinical subgroup may benefit from immediate surgery. Patients with good initial neurological status who show rapid neurological deterioration may still have a favorable outcome if they undergo timely and successful decompressive surgery and proper aneurysm obliteration. Patients who present with poor neurological status do badly, and there is no effective treatment for such patients.
    Journal of Neurosurgery 03/2012; 116(6):1244-50. · 2.96 Impact Factor
  • Article: Treatment of patients with traumatic subdural effusion and concomitant hydrocephalus.
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    ABSTRACT: Traumatic subdural effusion (TSE) is a common sequela of traumatic brain injury. Surgical intervention is suggested only when TSE exerts mass effect. The authors have found that many patients with TSE exerting mass effect have concomitant hydrocephalus. Patient experiencing this occurrence were studied, and the pathogenesis of this phenomenon was discussed in the context of recent advances in the understanding of CSF circulation. During a 2-year period, the authors' institution treated 14 patients with TSE who developed hydrocephalus, after 1 of the patients suffered subdural drainage and other 13 received subdural peritoneal shunt (SPSs). Thirteen of those who had SPSs received programmable ventriculoperitoneal shunts (VPSs) for the hydrocephalus. The clinical characteristics as well as the imaging and operative findings of these patients were reviewed. All patients with symptomatic TSE exerting mass effect received SPSs. All of these patients had a modified Frontal Horn Index of more than 0.33 at presentation, and high opening pressure on durotomy. Following a brief period (4-7 days) of clinical improvement, the condition of all patients deteriorated due to hydrocephalus. Programmable VPSs were inserted with the initial pressure set at approximately 8-10 cm H(2)O according to opening pressure at ventriculostomy. Shunt valve pressure was gradually decreased to 5-7 cm H(2)O, according to clinical and radiological follow-up. Elevated modified Frontal Horn Index in patients with TSE is suggestive of concomitant hydrocephalus. The authors propose that tearing of the dura-arachnoid plane following trauma contributes to TSE and may also impede CSF circulation, causing hydrocephalus. Shunt pressure was adjusted to relative low pressure, indicating the old age of the patients and poor reexpansion of brain parenchyma after the mass effect. Subdural peritoneal shunts and VPSs are indicated in those patients with TSE exerting mass effect with concomitant hydrocephalus.
    Journal of Neurosurgery 12/2011; 116(3):558-65. · 2.96 Impact Factor
  • Article: Risk Profile of Patients with Poor-Grade Aneurysmal Subarachnoid Hemorrhage Using Early Perfusion Computed Tomography.
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    ABSTRACT: OBJECTIVE: To determine whether perfusion computed tomography (CT) is useful for identifying patients with poor-grade subarachnoid hemorrhage (SAH) with reversible etiologies and whether early obliteration in patients with poor-grade aneurysmal SAH leads to favorable outcomes. METHODS: Patients with new-onset aneurysmal SAH in World Federation of Neurological Surgeons (WFNS) grade IV or V neurologic condition who had perfusion CT performed at admission were eligible for the study. The study retrospectively enrolled 38 patients seen between January 2007 and July 2009. The decision to perform an early obliteration was made by the family after a discussion with the neurosurgeons, neurointensivists, and interventional radiologists. The functional outcomes were correlated with the Glasgow Outcome Scale (GOS) at 6 months, and quantitative perfusion CT data were collected. RESULTS: This study included 10 (26%) grade IV and 28 (74%) grade V patients. Favorable outcomes occurred in 19 (50%) patients, and 11 (29%) patients died. After a multivariate logistic regression analysis of the parameters, older age (odds ratio 1.104, P = 0.0317), bilateral prolonged mean transient time (MTT) at the thalami (odds ratio 4.155, P = 0.0362), and early obliteration (odds ratio 0.098, P = 0.003) were predictive of poor outcome. CONCLUSIONS: Early bilateral prolonged MTT at the thalami and old age are associated with a poor outcome. Early obliteration benefits a significant portion of SAH patients.
    World Neurosurgery 12/2011; · 0.68 Impact Factor
  • Article: Early parenchymal contrast extravasation predicts subsequent hemorrhage progression, clinical deterioration, and need for surgery in patients with traumatic cerebral contusion.
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    ABSTRACT: This study aimed to identify early radiologic signs that are predictive of hemorrhage progression and clinical deterioration in patients with traumatic cerebral contusion. We hypothesized that contrast extravasation (CE) and blood-brain barrier disruption might be associated with hemorrhage progression, brain edema, and clinical deterioration in these patients. Twenty-two patients with traumatic cerebral contusion (diagnosed on initial noncontrast head computed tomography [CT]) who initially did not require surgical intervention were enrolled in this study. Contrast-enhanced and perfusion CT scans were performed within 6 hours of injury, and follow-up noncontrast CT scans were performed at 24 hours and 72 hours. In each noncontrast CT scan, the volumes of the contusion hemorrhage and edema were calculated using computerized planimetric techniques. The initial Glasgow Coma Scale, hemorrhage progression, clinical deterioration, and the need for subsequent surgery were recorded. The early radiologic findings were compared with these parameters and functional outcome at 6 months to identify predictive radiologic signs. CE was present in 9 of 22 patients (41%) and was highly associated with hemorrhage progression (p < 0.05), clinical deterioration (p < 0.01), and need for subsequent surgery (p < 0.01). In addition, patients with CE had a greater volume of edema at 24 hours (p < 0.01) and 72 hours (p < 0.01) than those who did not have CE. However, CE was not found to be associated with poor outcome. Early parenchymal CE is associated with hemorrhage progression, cerebral edema, clinical deterioration, and need for subsequent surgery. These patients should be monitored closely, and early surgery may be needed if deterioration occurs. Further elucidation of the pathophysiology is needed to formulate effective treatment for these high-risk patients.
    The Journal of trauma 12/2011; 71(6):1593-9. · 2.48 Impact Factor
  • Article: Fornix hemorrhage after mild head injury.
    Shao-Yu Tsai, Yong-Kwang Tu, Lu-Ting Kuo
    The Journal of trauma 08/2011; 71(2):E41. · 2.48 Impact Factor
  • Article: Contemporary surgical outcome for skull base meningiomas.
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    ABSTRACT: Although surgical excision of meningioma and its dural base is the most common primary management, skull base meningiomas are quite different, and contemporary management usually consists of multimodal treatment with the aim of achieving the best possible functional outcome and quality of life (QOL) for these patients. As surgery plays an important role in the treatment of skull base meningiomas, it is crucial for neurosurgeons to appreciate the surgical outcome and QOL after meningioma surgery. Outcome is usually measured for meningiomas in terms of morbidity, mortality, time to recurrence, and QOL. The extent of resection, tumor grade, proliferative markers, and tumor location are significant factors in predicting the surgical outcome. Therefore, we address each of these factors in detail in this review. Advances in recent decades in microsurgical techniques, neuroimaging modalities, neuroanesthesia, and perioperative intensive care have substantially improved the surgical outcome; therefore, most surgical outcomes discussed in this review are cited from contemporary literature (2000 to the present) in order to depict the surgical outcome of contemporary microsurgery.
    Neurosurgical Review 07/2011; 34(3):281-96; discussion 296. · 2.04 Impact Factor
  • Article: Intraoperative sonography for detection of contralateral acute epidural or subdural hematoma after decompressive surgery.
    The Journal of trauma 06/2011; 70(6):1578-9; author reply 1579. · 2.48 Impact Factor
  • Article: Early endoscope-assisted hematoma evacuation in patients with supratentorial intracerebral hemorrhage: case selection, surgical technique, and long-term results.
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    ABSTRACT: Currently, the effectiveness of minimally invasive evacuation of intracerebral hemorrhage (ICH) utilizing the endoscopic method is uncertain and the technique is considered investigational. The authors analyzed their experience with this method in terms of case selection, surgical technique, and long-term results. The authors performed a retrospective analysis of the clinical and radiographic data obtained in 68 patients treated with endoscope-assisted ICH evacuation. Rebleeding, morbidity, and mortality were recorded as primary end points. Hematoma evacuation rate was calculated by comparing the pre- and postoperative CT scans. Glasgow Coma Scale scores and scores on the extended Glasgow Outcome Scale (GOSE) were recorded at the 6-month postoperative follow-up. The technical aspect of this report explains details of the procedure, the instruments that are used, the methods for hemostasis, and the role of hemostatic agents in the management of intraoperative hemorrhage. The pertinent literature was reviewed and summarized. All surgeries were performed within 12 hours of ictus, and 84% of the surgeries were performed within 4 hours. The mortality rate was 5.9%, and surgery-related morbidity occurred in 3 cases (4.4%). The hematoma evacuation rate was 93% overall-96% in the putaminal group, 86% in the thalamic group, and 98% in the subcortical group. The rebleeding rate was 1.5%. The mean operative time was 85 minutes, and the average blood loss was 56 ml. The mean GOSE score was 4.9 at 6-month follow-up. The authors acknowledge the limitations of these preliminary results in a small number of patients. The data suggest that early endoscope-assisted ICH evacuation is safe and effective in the management of supratentorial ICH. The rebleeding, morbidity, and mortality rates are low compared with rates reported in the literature for the traditional craniotomy method. This study also showed that early and complete evacuation of ICH may lead to improved outcomes in selected patients. However, the safety and efficacy of endoscope-assisted ICH evacuation should be further investigated in a large, prospective, randomized trial.
    Neurosurgical FOCUS 04/2011; 30(4):E9. · 2.87 Impact Factor
  • Article: Progressive PCA steno-occlusive changes after revascularization for moyamoya disease: a neglected phenomenon.
    Abel Po-Hao Huang, Yong-Kwang Tu
    Neurosurgery 12/2010; 67(6):E1865-6; author reply E1866. · 2.79 Impact Factor
  • Article: Giant serpentine aneurysm mimics cerebral arteriovenous malformation on angiography.
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    ABSTRACT: A serpentine aneurysm is defined as a thrombosed giant aneurysm with internal channel, which mimics a giant arteriovenous malformation on angiography. We report a case of serpentine aneurysm and its radiological characters.
    British Journal of Neurosurgery 12/2010; 24(6):716-7. · 0.88 Impact Factor
  • Article: Use of the "mortise and tenon" principle in the augmentation of autologous cranioplasty using bone cement in a child.
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    ABSTRACT: We report the case of a 20-month-old boy with autologous bone graft resorption that resulted in a floating bone graft and progressive asymmetric deformity of the skull. The patient had undergone decompressive craniectomy for acute subdural hematoma at the age of 13 months after a fall, followed by cranioplasty 1 month later with an autologous bone graft, which was stored in a freezer immediately after surgery. We used the mortise and tenon principle to replace the screws and plates to join a polymethylmethacrylate prosthesis to the skull, augmenting the resorbed autologous bone graft. The cosmetic effect was maintained and craniocerebral protection was restored. It is thought that this technique could be used for bone defects of various sizes in patients of any age in cases where screws and plates are not suitable.
    Child s Nervous System 12/2010; 26(12):1807-11. · 1.54 Impact Factor
  • Article: Clinical outcome of mild head injury with isolated oculomotor nerve palsy.
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    ABSTRACT: Isolated oculomotor nerve palsy after mild head injury is rare. Only a few case reports have described the clinical presentation of these patients, and clinical and functional outcome have not been discussed in depth. The outcome of 10 patients with mild head injury in whom imaging studies ruled out other possible causes of oculomotor palsy was assessed during follow-up using the Glasgow Outcome Scale-Extended (GOSE). We suggest that limited eye movement is a major factor that negatively affects functional status after mild head injury.
    Journal of neurotrauma 11/2010; 27(11):1959-64. · 4.25 Impact Factor
  • Article: A large cystic intrasellar and suprasellar tumor.
    Journal of Clinical Neuroscience 10/2010; 17(10):1305, 1358. · 1.25 Impact Factor
  • Article: Perfusion computed tomographic imaging and surgical selection with patients after poor-grade aneurysmal subarachnoid hemorrhage.
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    ABSTRACT: Patients with ruptured aneurysms who present in coma have already experienced significant brain injury, require intensive resuscitation, have aneurysms that are difficult to treat, and generally fare poorly despite aggressive intervention. To determine whether surgical outcomes in comatose patients with ruptured aneurysms in a modern series might be better than previously reported because of changing surgical indications and multidisciplinary management, and to determine whether perfusion computed tomography (PCT) imaging might help select patients for surgery. A consecutive series of 78 patients with poor-grade aneurysms treated surgically was reviewed. Management consisted of resuscitation, early surgery, intracranial pressure control, comprehensive intensive care, and endovascular therapy for vasospasm. Cerebral blood flow (CBF), volume (CBV), and mean transit time (MTT) were measured on admission PCT studies and correlated with outcomes. Among 58 grade IV patients (74%) and 20 grade V patients (26%), 44 patients (56%) had favorable outcomes (Glasgow Outcome Scale 5 and 4), and 34 patients (44%) had unfavorable outcomes. Favorable outcomes among grade IV patients were observed in 71%, whereas mortality among grade V patients was 60%. Sixteen patients (89%) with normal cerebral perfusion had favorable outcomes and all 13 patients with hemispheric or global hypoperfusion had unfavorable outcomes. PCT provides physiological data that are immediately applicable and can guide decisions to aggressively manage comatose patients with ruptured aneurysms. Grade IV patients with normal or focally abnormal perfusion are good candidates for treatment, whereas grade V patients with hemispheric or global hypoperfusion are poor candidates. Surgery effectively excludes aneurysms with complex anatomy and relieves increased intracranial pressure with hematoma evacuation, lobectomy, and/or hemicraniectomy. Modern neurosurgical, endovascular, and neurointensive critical care produces favorable outcomes in a substantial percentage of carefully selected patients.
    Neurosurgery 10/2010; 67(4):964-74; discussion 975. · 2.79 Impact Factor
  • Article: Differential CT features of acute lentiform subdural hematoma and epidural hematoma.
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    ABSTRACT: Acute subdural hematoma (SDH) normally appears as a panhemispheric collection of blood with a crescent configuration. However, a number of SDH show lentiform appearances, mimicking acute epidural hematoma (EDH). In this study, we reported our experiences with this special disease entity. Radiological features that aided in the accurate localization of the hematoma were also addressed. From among 51 acute SDH cases who were surgically treated between July 2007 and April 2008, five cases whose SDH had a localized convex appearance were enrolled. Surgical records and CT images were retrospectively reviewed. Important CT features that could differentiate lentiform SDH from EDH were especially analyzed. Subdural adhesions were major causes of localized SDH in four out of five patients, all of whom had previous neurosurgical interventions or radiotherapy. Though those hematomas appeared as biconvex on CT scans, four differential features could be identified in favor of SDH. These included a crescentic tail, an obtuse angle at the margin of the hematoma, a dural line above the hematoma and a direct connection to the underlying intracerebral hematomas. Biconvex localized SDH might be misinterpreted as acute EDH if the diagnosis is based on the shape of the hematoma alone. This study emphasized that a detailed evaluation of surgical histories and CT features are mandatory in differentiating lentiform SDH and EDH.
    Clinical neurology and neurosurgery 09/2010; 112(7):552-6. · 1.30 Impact Factor
  • Article: Sarcoma of the cervical spine after radiation treatment for thyroid cancer.
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    ABSTRACT: Case report. We report a rare case of postradiation sarcoma of the cervical spine 30 years after treatment for thyroid cancer. The reported case is a 66-year-old man with a history of thyroid cancer treated with surgery and radiotherapy at the age of 36 years. He was disease-free for 30 years, but then developed left upper limb weakness and numbness. Magnetic resonance imaging showed a homogeneously enhanced mass lesion with cystic parts involving the C4 vertebral body and occupying the left side of the spinal canal with extension to the paraspinal space through the neural foramen. Using staged posterior and anterior approaches, gross total tumor excision, C4 corpectomy, and spinal fusion were achieved. The histologic diagnosis revealed sarcoma that was immunoreactive to vimentin and focally to S100 and O13 antibodies. Radiation-induced sarcoma should be suspected in patients who have received radiation treatment previously and present with new neurologic symptoms and signs in the irradiated area. The patient's muscle power returned to 5/5, except for the left upper extremity, which reached 2/5; he was free from recurring symptoms during the follow-up period. Because of advancements in diagnostic techniques and therapeutic methods, more patients survive primary cancer, and therefore an increase in the number of cases of postradiation sarcoma is expected. Postradiation sarcomas have extremely long latent periods, and one should therefore always keep in mind such a complication of previous radiation treatment.
    Spine 04/2010; 35(9):E363-7. · 2.08 Impact Factor
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    Article: Brain stem cavernous malformations.
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    ABSTRACT: We retrospectively reviewed the clinical experience of 30 patients with brain stem cavernous malformations (BSCM) treated operatively and non-operatively at our hospital between 1983 and 2005 to elucidate the natural history of BSCM and the factors that affect surgical outcome. Inpatient charts, imaging studies, operative records, and follow-up results were evaluated. The average follow up was 48.5 months. Twenty-two patients (73.3%) received surgical extirpation and of these 86.4% improved or stabilized and 13.6% deteriorated with permanent or severe morbidity. There was no mortality. Size, preoperative status, and surgical timing were factors related to surgical outcome. In the non-operative group, 50% of the patients were the same or better, 25% deteriorated, and 25% died. With appropriate patient selection, resection of BSCM can be achieved with acceptable morbidity compared with the ominous natural history of these lesions.
    Journal of Clinical Neuroscience 12/2009; 17(1):74-9. · 1.25 Impact Factor
  • Article: Prediction of early secondary complications in patients with spontaneous subarachnoid hemorrhage based on accelerated sympathovagal ratios.
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    ABSTRACT: The development of secondary complications following spontaneous subarachnoid hemorrhage (SAH) largely depends on sympathetic overexcitation. The roles of vagal activities, however, are poorly defined. Because both components of the autonomic nervous system can be explored in the frequency domain of heart rate variability (HRV), the present study aimed to determine the dynamic evolution of autonomic activities and to identify patients at high risk for complications following hemorrhage. Thirty patients with SAH were enrolled in our study. Those who suffered from symptomatic vasospasm, cerebral infarction, neurogenic pulmonary edema, or early mortality within 1 week of ictus were categorized into the complication group. Spectral analysis of HRV explored three important indices of sympathetic and vagal modulations: low-frequency (LF), high-frequency (HF), and LF/HF ratios. Patterns of HRV dynamics within the first 3 days were compared between complication and non-complication groups. The group trends, estimated by the slopes of HRV changes, were determined for further univariate and multivariate analysis. Our study showed that daily HRV in the complication group exhibited an approximately 2.7-fold increase of sympathovagal ratio (denoted by LF/HF). This resulted from reciprocal changes of sympathoexcitation (LF) and vagal withdrawal (HF). Multivariate analysis revealed that LF/HF slope, an indicator of the trend of sympathovagal change, was an independent variable significantly associated with the development of complications. This study confirmed that during early SAH period, patients with and without complications presented different patterns of sympathovagal changes. LF/HF slope during the first 3 days was a significant predictor of secondary complications after SAH.
    Acta Neurochirurgica 10/2009; 151(12):1631-7. · 1.52 Impact Factor
  • Article: O(6)-Methylguanine-DNA methyltransferase expression and prognostic value in brain metastases of lung cancers.
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    ABSTRACT: O(6)-Methylguanine-DNA methyltransferase (MGMT) is critical for repairing pro-mutagenic DNA bases and is correlated with response to alkylating agents in cancers. Since there is great interest in pursuing the potential role of temozolomide, a novel alkylating agent, in the treatment of brain metastases, this study aimed to evaluate MGMT expression as well as its prognostic value in this devastating disease. We studied the expression and methylation status of MGMT in 86 brain metastases of lung cancers. Twenty of them had matched primary lung tumor tissues available for direct comparison. MGMT expression was assessed by immunohistochemistry (IHC); the methylation status of MGMT promoter was analyzed by nested methylation-specific PCR (MSP) and validated by quantitative real-time PCR analysis. Positive nuclear MGMT expression was detected more frequently in brain metastases as compared with primary lung cancers (83% versus 50%, P=0.004). The discordance in MGMT expression persisted in the 20 paired primary and metastatic tumors (P=0.031). MGMT promoter hypermethylation was highly correlated with loss of MGMT expression. Both univariate and multivariate analyses showed that median overall survival was significantly longer in patients with positive MGMT expression in brain metastases (16.5 versus 3.5 months, P<0.001). In conclusion, MGMT expression was enhanced in brain metastases as compared with the primary lung cancers. MGMT expression in brain metastases was significantly correlated with better survival.
    Lung cancer (Amsterdam, Netherlands) 09/2009; 68(3):484-90. · 3.14 Impact Factor