Gamma Knife Radiosurgery Using Co-Registration with PET-CT and MRI for Recurrent Nasopharyngeal Carcinoma with Previous Radiotherapy : A Single Center 14-Year Experience

Objective@#: We retrospectively evaluated the efficacy of Gamma Knife radiosurgery (GKS) for recurrent nasopharyngeal carcinoma (NPC) in patients who previously underwent radiotherapy, and analyzed the treatment outcomes over 14 years. @*Methods@#: Ten patients with recurrent NPC who had previously received radiotherapy underwent stereotactic radiosurgery using a Gamma Knife® (Elekta Inc, Atlanta, GA, USA) between 2005 and 2018. The median target volume was 8.2 cm3 (range, 1.7–17.8), and the median radiation dose to the target was 18 Gy (range, 12–30). The median follow-up period was 18 months (range, 6–76 months). Overall and local failure-free survival rates were determined using the Kaplan-Meier method. @*Results@#: The NPCs recurred at the primary cancer site in seven patients (70%), as distant brain metastasis in two (20%), and as an extension into brain in one (10%). The recurrent tumors in seven of the 10 patients (70%) were found on the routine follow-up imaging studies. Two patients presented with headache and one with facial pain. Local failure after GKS occurred in five patients (50%) : two of whom died eight and 6 months after GKS, respectively. No adverse radiation effects were noted after GKS. The 1- and 3-year overall survival rates after GKS were 90% and 77%, respectively. The local failure-free survival rates at 6 months, 1 year, and 3 years after GKS were 80%, 48%, and 32%, respectively. The median interval from GKS to local failure was 8 months (range, 6–12). Univariate analysis revealed that using co-registration with positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI) was associated with a lower local failure rate of recurrent NPC (p=0.027). @*Conclusion@#: GKS is an acceptable salvage treatment option for patients with recurrent NPC who previously received radiation therapy. PET-CT and MRI co-registration for dose planning can help achieve local control of recurrent NPC.

Combined treatment of surgery and sclerotherapyfor sinus pericranii

Sinus pericranii is a rare vascular anomaly characterized by abnormal venous communication betweenthe inner and outer regions of the cranial cavity. Here, we report a case of sinus pericraniiand venous malformations in the right periorbital region of a 2-year-old girl. Radiologic findingsshowed venous malformations in the right parietal region communicating with the superior sagittalsinus in the intracranial region. There were notable improvements following surgical resectionfor the abnormal venous lesions and several sclerotherapies. Presence of a bluish and pulsatingmass on the scalp, which showed bruit on auscultation, may indicate sinus pericranii, whichshould be included in the differential diagnosis.

A Case of Temporal Bone Cholesterol Granuloma Extending to Posterior Cranial Fossa without Middle Ear Involvement / 대한이비인후과학회지

Cholesterol granulomas of the temporal bone can occur in the petrous apex, middle ear, and mastoid cavity. Although cholesterol granulomas in the petrous apex often extend to the middle cranial fossa, cholesterol granulomas in the middle ear and mastoids rarely invade the cranial cavity with bony erosion. We report a case of a large cholesterol granuloma involving the posterior cranial fossa with pneumatic mastoid and not affecting the middle ear. The patient had no otologic or neurologic symptoms, and the mass was found incidentally on a brain MRI included in a regular medical checkup. The mass was removed via a combined transmastoid and suboccipital approach without complications, and characteristic pathology findings demonstrated a cholesterol granuloma.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas Involving the Transverse-Sigmoid Sinus: A Single Center Experience and Review of the Literatures

OBJECTIVE: We retrospectively assessed the efficacy of stereotactic radiosurgery (SRS) for dural arteriovenous fistulas (DAVFs) involving the transverse-sigmoid sinus and analyzed the angiographic and clinical results with our 8-year experience. METHODS: Nine patients with intracranial DAVFs involving the transverse-sigmoid sinus underwent SRS using a Gamma Knife® (Elekta Inc., Atlanta, GA, USA) between 2009 and 2016. Five patients underwent SRS for residual DAVFs after embolization and four patients were treated with SRS alone. The median target volume was 1.9 cm3 (range, 0.8–14.2) and the median radiation dose of the target was 17 Gy (range, 16–20). The median follow-up period was 37 months (range, 7–81). RESULTS: Pulsating tinnitus (33%) was the most common symptom. DAVFs were completely obliterated in four patients (44%) and subtotally obliterated in five (56%). Six patients (67%) showed complete recovery of symptoms or signs, and three (33%) showed incomplete recovery. One patient experienced a recurrent seizure. Adverse radiation effects after SRS occurred in one patient (11%). The total obliteration rates after SRS were 16.7%, 37.5%, and 68.7% at 1, 2, and 3 years, respectively. The median interval from SRS to total obliteration of the fistula was 31 months (range, 12–38). The rates at which the symptoms started to improve were 40% at 1 month and 80% at 2 months after SRS. Symptoms started to improve at a median of 5 weeks after SRS (range, 3–21). CONCLUSION: SRS with or without embolization is a safe and effective treatment to relieve symptoms and obliterate DAVFs on the transverse-sigmoid sinus.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas Involving the Transverse-Sigmoid Sinus: A Single Center Experience and Review of the Literatures

OBJECTIVE: We retrospectively assessed the efficacy of stereotactic radiosurgery (SRS) for dural arteriovenous fistulas (DAVFs) involving the transverse-sigmoid sinus and analyzed the angiographic and clinical results with our 8-year experience.METHODS: Nine patients with intracranial DAVFs involving the transverse-sigmoid sinus underwent SRS using a Gamma Knife® (Elekta Inc., Atlanta, GA, USA) between 2009 and 2016. Five patients underwent SRS for residual DAVFs after embolization and four patients were treated with SRS alone. The median target volume was 1.9 cm3 (range, 0.8–14.2) and the median radiation dose of the target was 17 Gy (range, 16–20). The median follow-up period was 37 months (range, 7–81).RESULTS: Pulsating tinnitus (33%) was the most common symptom. DAVFs were completely obliterated in four patients (44%) and subtotally obliterated in five (56%). Six patients (67%) showed complete recovery of symptoms or signs, and three (33%) showed incomplete recovery. One patient experienced a recurrent seizure. Adverse radiation effects after SRS occurred in one patient (11%). The total obliteration rates after SRS were 16.7%, 37.5%, and 68.7% at 1, 2, and 3 years, respectively. The median interval from SRS to total obliteration of the fistula was 31 months (range, 12–38). The rates at which the symptoms started to improve were 40% at 1 month and 80% at 2 months after SRS. Symptoms started to improve at a median of 5 weeks after SRS (range, 3–21).CONCLUSION: SRS with or without embolization is a safe and effective treatment to relieve symptoms and obliterate DAVFs on the transverse-sigmoid sinus.

Expression of Aquaporin 1 and 4 in the Choroid Plexus and Brain Parenchyma of Kaolin-Induced Hydrocephalic Rats / 대한신경손상학회지

OBJECTIVE: Aquaporin (AQP) is a recently discovered protein that regulates water homeostasis. The present study examines changes in AQP 1 and 4 in kaolin induced experimental hydrocephalic rats to elucidate the pathophysiology of water homeostasis in the disease. METHODS: Hydrocephalus was induced by percutaneous intracisternal injection of kaolin. The brain parenchyma and choroid plexus were obtained at 3, 7, 14 and 30 days after injection. Protein expressions of AQP 1 and 4 were measured by western blot, immunohistochemistry (IHC) and immunofluorescence (IF) stains. RESULTS: In the choroid plexus of the kaolin-induced hydrocephalus group, AQP 1 expression identified by western blot exhibited sharp decrease in the early stage (55% by the 3rd day and 22% by the 7th day), but indicated a 2.2-fold increase in the later stage (30th day) in comparison with control groups. In the parenchyma, a quantitative measurement of AQP 4 expression revealed variable results on the 3rd and 7th days, but indicated expression 2.1 times higher than the control in the later stage (30th day). In addition, the IHC and IF findings supported the patterns of expression of AQP 1 in the choroid plexus and AQP 4 in the parenchyma. CONCLUSION: Expression of AQP 1 decreased sharply in the choroid plexus of acute hydrocephalus rats and increased at later stages. Expression of AQP 4 in the brain parenchyma was variable in the early stage in the hydrocephalus group, but was higher than in the control in the later stage. These findings suggest a compensating role of AQPs in water physiology in hydrocephalus.

Traumatic Brain Injury in Children under Age 24 Months: Analysis of Demographic Data, Risk Factors, and Outcomes of Post-traumatic Seizure

OBJECTIVE: Traumatic brain injury (TBI) in children under age 24 months has characteristic features because the brain at this age is rapidly growing and sutures are opened. Moreover, children this age are completely dependent on their parents. We analyzed the demographic data and risk factors for outcomes in TBI patients in this age group to elucidate their clinical characteristics. METHODS: We retrospectively reviewed the medical records and radiological films of children under 24 months who were admitted to Kyungpook National University Hospital from January 2004 to December 2013 for TBI. Specifically, we analyzed age, cause of injury, initial Glasgow coma scale (GCS) score, radiological diagnosis, seizure, hydrocephalus, subdural hygroma, and Glasgow outcome scale (GOS) score, and we divided outcomes into good (GOS 4–5) or poor (GOS 1–3). We identified the risk factors for post-traumatic seizure (PTS) and outcomes using univariate and multivariate analyses. RESULTS: The total number of patients was 60, 39 males and 21 females. Most common age group was between 0 to 5 months, and the median age was 6 months. Falls were the most common cause of injury (n=29, 48.3%); among them, 15 were falls from household furniture such as beds and chairs. Ten patients (16.7%) developed PTS, nine in one week; thirty-seven patients (61.7%) had skull fractures. Forty-eight patients had initial GCS scores of 13–15, 8 had scores of 12–8, and 4 had scored 3–7. The diagnoses were as follows: 26 acute subdural hematomas, 8 acute epidural hematomas, 7 focal contusional hemorrhages, 13 subdural hygromas, and 4 traumatic intracerebral hematomas larger than 2 cm in diameter. Among them, two patients underwent craniotomy for hematoma removal. Four patients were victims of child abuse, and all of them had PTS. Fifty-five patients improved to good-to-moderate disability. Child abuse, acute subdural hematoma, and subdural hygroma were risk factors for PTS in univariate analyses. Multivariate analysis found that the salient risk factor for a poor outcome was initial GCS on admission. CONCLUSION: The most common cause of traumatic head injury in individuals aged less than 24 months was falls, especially from household furniture. Child abuse, moderate to severe TBI, acute subdural hematoma, and subdural hygroma were risk factors for PTS. Most of the patients recovered with good outcomes, and the risk factor for a poor outcome was initial mental status.

Multiple Cerebral Infarctions due to Unilateral Traumatic Vertebral Artery Dissection after Cervical Fractures / 대한신경손상학회지

We report a case of multiple symptomatic cerebral infarctions from a traumatic vertebral artery dissection (VAD) after cervical fractures. A 73-year-old man was admitted with stuporous mentality and left hemiparesis after a motor-vehicle accident. A brain computed tomography (CT) scan at admission showed a traumatic subarachnoid hemorrhage on the left parietal lobe. A cervical CT scan showed left lateral mass fractures on C2, C5, and C6, involving the transverse foramen. Cervical spine magnetic resonance imaging (MRI) revealed loss of signal void on the left vertebral artery. Neck CT angiography showed left VAD starting at the C5 level. Brain MRI revealed acute, multiple cerebral infarctions involving the pons, midbrain, thalamus, corpus callosum, and parietal and frontal lobes on diffusion weighted images. The patient was treated conservatively at the intensive care unit in the acute stage to prevent extent of stroke. Aspirin was started for antiplatelet therapy in the chronic stage. The possibility of symptomatic cerebral infarctions due to traumatic VAD following cervical fracture should be considered.

Asymmetric and Upper Body Parkinsonism in Patients with Idiopathic Normal-Pressure Hydrocephalus

BACKGROUND AND PURPOSE: Our aims were to analyze the characteristics of parkinsonian features and to characterize changes in parkinsonian motor symptoms before and after the cerebrospinal fluid tap test (CSFTT) in idiopathic normal-pressure hydrocephalus (INPH) patients. METHODS: INPH subjects were selected in consecutive order from a prospectively enrolled INPH registry. Fifty-five INPH patients (37 males) having a positive response to the CSFTT constituted the final sample for analysis. The mean age was 73.7±4.7 years. The pre-tap mean Unified Parkinson's Disease Rating Scale motor (UPDRS-III) score was 24.5±10.2. RESULTS: There was no significant difference between the upper and lower body UPDRS-III scores (p=0.174). The parkinsonian signs were asymmetrical in 32 of 55 patients (58.2%). At baseline, the Timed Up and Go Test and 10-meter walking test scores were positively correlated with the total motor score, global bradykinesia score, global rigidity score, upper body score, lower body score, and postural instability/gait difficulties score of UPDRS-III. After the CSFTT, the total motor score, global bradykinesia score, upper body score, and lower body score of UPDRS-III significantly improved (p<0.01). There was a significant decrease in the number of patients with asymmetric parkinsonism (p<0.05). CONCLUSIONS: In the differential diagnosis of elderly patients presenting with asymmetric and upper body parkinsonism, we need to consider a diagnosis of INPH. The association between gait function and parkinsonism severity suggests the involvement of similar circuits producing gait and parkinsonian symptoms in INPH.

Update of Diagnostic Evaluation of Craniosynostosis with a Focus on Pediatric Systematic Evaluation and Genetic Studies

Most craniosynostoses are sporadic, but may have an underlying genetic basis. Secondary and syndromic craniosynostosis accompanies various systemic diseases or associated anomalies. Early detection of an associated disease may facilitate the interdisciplinary management of patients and improve outcomes. For that reason, systematic evaluation of craniosynostosis is mandatory. The authors reviewed systematic evaluation of craniosynostosis with an emphasis on genetic analysis.

Change in Plasma Vascular Endothelial Growth Factor after Gamma Knife Radiosurgery for Meningioma: A Preliminary Study

OBJECTIVE: The purpose of this study was to investigate changes in the plasma level of vascular endothelial growth factor (VEGF) after Gamma Knife radiosurgery (GKRS) for the treatment of meningioma. METHODS: Fourteen patients with meningiomas had peripheral venous blood collected at the time of GKRS and at 1 week, 1 month, 3 month and 6 month visits. Plasma VEGF levels were measured using commercially available enzyme-linked immunosorbent assay. For controls, peripheral blood samples were obtained from 20 healthy volunteers. RESULTS: The mean plasma VEGF level (29.6 pg/mL) in patients with meningiomas before GKRS was significantly lower than that of the control group (62.4 pg/mL, p=0.019). At 1 week after GKRS, the mean plasma VEGF levels decreased to 23.4 pg/mL, and dropped to 13.9 pg/mL at 1 month, 14.8 pg/mL at 3 months, then increased to 27.7 pg/mL at 6 months. Two patients (14.3%) with peritumoral edema (PTE) showed a level of VEGF 6 months after GKRS higher than their preradiosurgical level. There was no significant association found in an analysis of correlation between PTE and tumor size, marginal dose, age, and sex. CONCLUSION: Our study is first in demonstrating changes of plasma VEGF after stereotactic radiosurgery (SRS) for meningioma. This study may provide a stimulus for more work related to whether measurement of plasma level has a correlation with tumor response after SRS for meningioma.

Cerebrospinal Fluid Tap Test in Idiopathic Hydrocephalus Patient with an Evans' Index Less Than 0.3

A 73-year-old man presented with progressive gait impairment. He exhibited slow, shuffling, and unstable gait. A formal neuropsychological evaluation revealed memory deficits with frontal dysfunction. Brain MRI revealed communicating hydrocephalus with an Evans' index of 0.27. After cerebrospinal fluid (CSF) removal by lumbar puncture, the patient exhibited a marked improvement in gait. A CSF tap test after careful clinical examination may need to be considered in the diagnosis of idiopathic hydrocephalus with an Evans' index of <0.3.

A Retrospective Analysis of Ventriculoperitoneal Shunt Revision Cases of a Single Institute

OBJECTIVE: Ventriculoperitoneal (VP) shunt complication is a major obstacle in the management of hydrocephalus. To study the differences of VP shunt complications between children and adults, we analyzed shunt revision surgery performed at our hospital during the past 10 years. METHODS: Patients who had undergone shunt revision surgery from January 2001 to December 2010 were evaluated retrospectively by chart review about age distribution, etiology of hydrocephalus, and causes of revision. Patients were grouped into below and above 20 years old. RESULTS: Among 528 cases of VP shunt surgery performed in our hospital over 10 years, 146 (27.7%) were revision surgery. Infection and obstruction were the most common causes of revision. Fifty-one patients were operated on within 1 month after original VP shunt surgery. Thirty-six of 46 infection cases were operated before 6 months after the initial VP shunt. Incidence of shunt catheter fracture was higher in younger patients compared to older. Two of 8 fractured catheters in the younger group were due to calcification and degradation of shunt catheters with fibrous adhesion to surrounding tissue. CONCLUSION: The complications of VP shunts were different between children and adults. The incidence of shunt catheter fracture was higher in younger patients. Degradation of shunt catheter associated with surrounding tissue calcification could be one of the reasons of the difference in facture rates.

Correlation of the Beta-Trace Protein and Inflammatory Cytokines with Magnetic Resonance Imaging in Chronic Subdural Hematomas : A Prospective Study

OBJECTIVE: Magnetic resonance imaging (MRI) of chronic subdural hematoma (CSDH) detects various patterns, which can be attributed to many factors. The purpose of this study was to measure the level of interleukin-6 (IL-6), interleukin-8 (IL-8), and highly specific protein [beta-trace protein (betaTP)] for cerebrospinal fluid (CSF) in CSDHs, and correlate the levels of these markers with the MRI findings. METHODS: Thirty one patients, treated surgically for CSDH, were divided on the basis of MRI findings into hyperintense and non-hyperintense groups. The concentrations of IL-6, IL-8, and betaTP in the subdural fluid and serum were measured. The betaTP was considered to indicate an admixture of CSF to the subdural fluid if betaTP in the subdural fluid (betaTP(SF))/betaTP in the serum (betaTP(SER))>2. RESULTS: The mean concentrations of IL-6 and IL-8 of the hyperintense group (n=17) of T1-WI MRI were 3975.1+/-1040.8 pg/mL and 6873.2+/-6365.4 pg/mL, whereas them of the non-hyperintense group (n=14) were 2173.5+/-1042.1 pg/mL and 2851.2+/-6267.5 pg/mL (p<0.001 and p=0.004). The mean concentrations of betaTP(SF) and the ratio of betaTP(SF)/betaTP(SER) of the hyperintense group (n=13) of T2-WI MRI were 7.3+/-2.9 mg/L and 12.6+/-5.4, whereas them of the non-hyperintense group (n=18) were 4.3+/-2.3 mg/L and 7.5+/-3.9 (p=0.011 and p=0.011). CONCLUSION: The hyperintense group on T1-WI MRI of CSDHs exhibited higher concentrations of IL-6 and IL-8 than non-hyperintense group. And, the hyperintese group on T2-WI MRI exhibited higher concentrations of betaTP(SF) and the ratio of betaTP(SF)/betaTP(SER) than non-hyperintense group. These findings appear to be associated with rebleeding and CSF admixture in the CSDHs.

Analysis of Circulating Endostatin and Vascular Endothelial Growth Factor in Patients with Pituitary Adenoma Treated by Stereotactic Radiosurgery: A Preliminary Study

BACKGROUND: The purpose of this study was to investigate plasma levels of endostatin and vascular endothelial growth factor (VEGF) in normal subjects and in patients with pituitary adenoma and to evaluate change in these levels following stereotactic radiosurgery (SRS) for pituitary adenoma. METHODS: Peripheral venous blood was collected from five patients with pituitary adenoma before SRS using Gamma Knife and at the 1 week and 1 month follow-up visits. Plasma endostatin and VEGF levels were measured using commercially available enzyme-linked immunosorbent assay kits. Peripheral blood samples were obtained from 10 healthy volunteers as controls. RESULTS: Mean baseline plasma endostatin level (105.3 ng/mL, range, 97.0-120.2 ng/mL) in patients with pituitary adenoma was higher than that of the healthy controls (86.6 ng/mL, range, 71.3-98.2 ng/mL) (p=0.001). Mean plasma VEGF level was 89.5 pg/mL (range, 24.1-171.8 pg/mL) in patients with pituitary adenoma at baseline and 29.3 pg/mL (range, 9.2-64.3 pg/mL) in the control group (p=0.050). Plasma endostatin level changed to 106.6 ng/mL 1 week after SRS and decreased to 95.9 ng/mL after 1 month. Plasma VEGF level following SRS decreased to 74.1 pg/mL after 1 week and 79.0 pg/mL after 1 month. There was a trend toward decreased plasma endostatin and VEGF concentrations 1 month after SRS compared to baseline levels (p=0.195, p=0.812, respectively). CONCLUSION: Plasma endostatin and VEGF levels in patients with pituitary adenoma were significantly elevated over controls at baseline, which decreased from baseline to 1 month after SRS for pituitary adenomas.

Bi-Coronal Separated Skull Fracture: A Unique and Fatal Type of Traumatic Head Injury in Infancy: A Case Report / 대한신경손상학회지

The infantile skull is malleable, and its sutures are tightly adhering to the underlying dura and venous sinus. These characteristics, in association with the small amount of total blood volume, can result in a specific fatal type of skull fracture, which is unique to infancy. The authors report a case of this injury, and stress the need to pay attention to the possibility of massive bleeding during operation in infants. A 23-month-old female baby presented with semicomatose mentality after sustaining injuries by falling from a second-floor. Plain skull films showed bi-frontal skull fracture crossing the midline. Computed tomography revealed an acute subdural hematoma along the right convexity with severe brain edema. In the emergency operation, the scalp incision exposed massive bleeding from the fracture site. The bleeding was identified as arising from the lacerated and widely separated sagittal sinus beneath the fracture. The patient entered hypovolemic shock immediately after the scalp incision, and died from severe brain edema two days after the trauma and surgery. This case implies that special care should be paid during the operation of patients that have skull fracture overlying the venous sinus, especially when the fracture line is separated.

Idiopathic Normal-Pressure Hydrocephalus Patient With an Ataxic Gait as the Predominant Presenting Manifestation

A 43-year-old man presented with progressive ataxic gait of 5 months duration. His gait speed was almost normal, and he did not exhibit shuffling, freezing, or festination. A formal neuropsychological evaluation revealed a deficit in visuospatial function and memory with mild frontal dysfunctions. Brain MRI revealed communicating hydrocephalus with an Evans' ratio of 0.32. After CSF removal by lumbar puncture the patient showed a marked improvement in gait as well as frontal lobe functions, and was finally diagnosed as having idiopathic normal-pressure hydrocephalus.

Shunt-Responsive Idiopathic Normal Pressure Hydrocephalus Patient with Delayed Improvement after Tap Test

The cerebrospinal fluid tap test (CSFTT) is recommended as a key step in the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). While there is no generally accepted evaluation period for ascertaining a CSFTT responder, a substantial number of patients are evaluated only once within 24 hours of the test for improvement in gait. We report an iNPH patient with a favorable response to shunt surgery, who was first judged a non-responder by this standard, though subsequently was judged a responder in virtue of repetitively testing gait over 7 days. A 68-year-old man presented with progressive impairment of gait, balance, and memory. He was diagnosed as iNPH with an Evans' ratio of 0.35. At first hospitalization, change in gait was evaluated 24 hours after the CSFTT. He didn't show any significant improvement and was judged as a non-responder. However, at the second CSFTT, we repetitively tested his change in gait over seven days. Forty-eight hours after the tap, he showed significant improvement in his gait. He was then confirmed as a responder. After the operation, the gait difficulties were almost fully resolved. Further studies developing the standard procedure of the CSFTT should be considered.

Co-Occurrence of Syringomyelia and Hydrocephalus in a Patient Without Chiari Malformation in Her 50's

Syringomyelia rarely accompanies hydrocephalus in the aged person except for the cases with a typical Chiari malformation. A 59-year-old woman developed progressive generalized weakness and gait disturbance for 9 years. MRI demonstrated marked enlargement of the cerebral ventricles and the longitudinal dilatation of central canal involving the entire spinal cord, whereas a typical Chiari malformation was absent. She was successfully treated by ventriculoperitoneal shunting. We report a hydrocephalic patient in her 50's accompanied by syringomyelia without a typical Chiari malformation.

The Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in the Treatment of Brain Abscess

OBJECTIVE: The purpose of this study was to evaluate whether 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) can be used to assess the therapeutic response of brain abscess. METHODS: A study was conducted on 10 consecutive patients with brain abscess. Magnetic resonance imaging (MRI) with diffuse-weighted imaging (DWI) was performed at 3 and 6 weeks after surgical treatment and intravenous antibiotics therapy and FDG-PET at 6 weeks after treatment. The extent of the abscess, signal changes on MRI, and FDG-PET standardized uptake values were analyzed and correlated with the response to therapy. RESULTS: Aspiration or craniotomy with excision of the abscess followed by intravenous antibiotics for 6-8 weeks resulted in good recovery with no recurrence. In 10 patients, two had low signal intensity on the DWI; one had no uptake on FDG-PET imaging after 6 weeks antibiotics and discontinued intravenous treatment, but the other patient had diffuse, increased uptake on FDG-PET imaging after 6 weeks antibiotics and underwent an additional 2 weeks of intravenous antibiotics. The remaining eight patients had high signals on the DWI. Four had no uptake on FDG-PET imaging and the treatment period varied from 6 to 8 weeks (mean, 6.75 weeks). Among the other four patients, FDG was accumulated in a diffuse or local area corresponding to a high signal area within the DWI and 2 weeks of intravenous antibiotics was added. CONCLUSION: MRI plus FDG-PET improved the accuracy of assessing therapeutic responses to antibiotics treatment of brain abscess and aided in optimizing therapy.