Central Nervous System Dissemination of Solitary Sporadic Supratentorial Hemangioblastoma:A Case Report and Literature Review

We report a patient with whole neuroaxis dissemination of a sporadic supratentorial hemangioblastoma (HB) for more than 15 years. A 68-year-old female patient presented with severe radiating pain in the right leg. Gadolinium-enhanced lumbar spine MRI showed an intradural mass (2.5 cm in diameter) at the L4 level. The patient had been severely disabled for 22 years after a previous intraventricular brain tumor resection. At that time, the diagnosis was angioblastic meningioma, which was thought to be incorrect. At 14 years after the brain surgery, gamma knife radiosurgery was performed three times for newly developed or recurred supratentorial and infratentorial tumors in the cerebrospinal fluid pathway. The patient underwent lumbar spinal surgery, and a gross total removal of the mass was performed, which confirmed the histopathological diagnosis of HB. We reexamined the old histopathological specimen of the intraventricular tumor from 20 years ago and changed the diagnosis from angioblastic meningioma to supratentorial HB. Six months after spinal surgery, the patient underwent a second spinal surgery and brain surgery, and the histopathological diagnosis was HB following both surgeries, which was the same following the first spinal surgery. Here, we report a sporadic supratentorial HB patient who showed cranial and spinal disseminations for more than two decades along with a literature review

Leksell Frame-Based Stereotactic Biopsy for Infratentorial Tumor : Practical Tips and Considerations

The Leksell frame-based transcerebellar approach was proposed with the arc support frame attached upside down to the Z coordinate. This study presented practical tips and considerations for obtaining adequate tissue samples for deep-seated cerebellar lesions or lower brainstem lesions specifically those accessible via the cerebellar peduncle. For practical insights, the Leksell coordinate frame G was fixed to prevent the anterior screw implantation within the temporalis muscle, to avoid interference with the magnetic resonance (MR)-adapter, and taking into account the magnetic field of MR in close proximity to the tentorium. After mounting of indicator box, the MR imaging evaluation should cover both the indicator box and the infratentorial region that deviated from it. The coordinates [X, Y, Za, Arc0, Ringa0] obtained from Leksell SurgiPlan® software (Elekta, Stockholm, Sweden) with arc 00 located on the patient’s right side were converted to [X, Y, Zb=360–Za, Arc0, Ringb0=Ringa0–1800]. The operation was performed in the prone position under general anesthesia in four patients with deep cerebellar (n=3) and brainstem (n=1) tumors. The biopsy results showed two cases of diffuse large B-cell lymphoma, one metastatic braintumor and one glioblastoma. One patient required frame repositioning as a complication. Drawing upon the methodology outlined in existing literature, we anticipate that imparting supplementary expertise could render the stereotactic biopsy of infratentorial tumors more consistent and manageable for the practitioner, thereby facilitating adequate tissue samples and minimizing patient complications.

Clinical diagnoses of patients showing caloric inversion

Abstract Objectives When air irrigation is used for caloric stimulation in patients with a perforated ear, warm irrigation may elicit a nystagmus that initially beats in the opposite direction of what is expected for warm irrigations, which is referred to as "caloric inversion". This study aimed to investigate the disease group in which caloric inversion appeared in patients who underwent caloric testing and to classify the patterns of caloric inversion. Methods We conducted a retrospective review of bithermal caloric test results that were collected in our dizziness clinic between 2005 and 2022. Caloric inversion was defined when nystagmus induced by caloric stimulation appeared in the opposite direction to that expected. The incidence of caloric inversion among all patients who underwent bithermal caloric tests was calculated. To confirm the clinical diagnoses of the patients with caloric inversion, their clinical records were reviewed. Results Out of 9923 patients who underwent bithermal caloric tests, 29 patients (0.29%) showed a caloric inversion. The most common clinical diagnosis was chronic otitis media (21 of 29, 72%). Of the 21 patients with chronic otitis media, 20 patients showed a caloric inversion by warm air irrigation and one patient showed caloric inversion by cold air stimulation. Patients with clinical diagnoses other than chronic otitis media such as sudden sensorineural hearing loss, benign paroxysmal vertigo of childhood and recurrent vestibulopathy showed caloric inversion by warm air irrigation. Caloric inversion by warm water irrigation was observed in patients with lateral semicircular canal cupulopathy and recurrent vestibulopathy. Two patients (one with Meniere's disease and one with age-related dizziness) showed caloric inversion by cold water irrigation. Conclusion Caloric inversion can be observed in various diseases other than chronic otitis media with tympanic membrane perforation. Special care should be taken in the interpretation of caloric test results. Level of Evidence: Level 4.

Distinct Specialized Center of Excellence, the Story of Hwasun Neurosurgery at Chonnam National University Hwasun Hospital

The paper provides a comprehensive overview of the growth and development of Hwasun Neurosurgery at Chonnam National University Hwasun Hospital over the past 18 years. As the first brain tumor center in Korea when it was established in April 2004, Hwasun Neurosurgery has since become one of the leading institutions in brain tumor education and research in the country. Its impressive clinical and basic research capabilities, dedication to professional education, and numerous academic achievements have all contributed to its reputation as a top-tier institution. We hope this will become a useful guide for other brain tumor centers or educational institutions by sharing the story of Hwasun Neurosurgery.

A 14-year-old male with rhabdomyolysis associated with psychogenic polydipsia and hyponatremia

Rhabdomyolysis associated with psychogenic polydipsia and hyponatremia is a rare condition that can cause substantial morbidity and mortality. We report a 14-year-old boy with psychogenic polydipsia who experienced recurrent hyponatremia and subsequent rhabdomyolysis. Treatment involved intravenous fluids and restriction of oral water intake. This case emphasizes the importance of early recognition and management of this condition. The possibility of rhabdomyolysis should be considered in patients with hyponatremia who have myalgia.

Lorlatinib Therapy for Rapid and Dramatic Control of Brain and Spinal Leptomeningeal Metastases From ALK-Positive Lung Adenocarcinoma

We report a patient with severe neurological deterioration due to leptomeningeal metastases involving brain and spinal cord from anaplastic lymphoma kinase (ALK)-positive lung adenocarcinoma, managed rapidly and successfully with lorlatinib therapy. A 48-year-old male patient presented with acute mental deterioration, severe headache, and weakness of both legs. The patient’s previous medical history included cerebral metastases from ALK-positive lung adenocarcinoma, which had been successfully managed via whole brain radiation therapy and gamma knife radiosurgery one year and three months before, respectively. Physical examination revealed neck stiffness and paraparesis with motor grade I.Gadolinium-enhanced brain MRI showed newly developed leptomeningeal enhancement along cerebellar folia, and whole spine MRI revealed similar leptomeningeal metastasis along the whole spinal axis. Lorlatinib was started orally with a dose of 100 mg/day. The patient showed rapid clinical improvement after one week. The patient was alert and the headache disappeared, while the paraparesis improved to normal ambulatory status. Two months of lorlatinib treatment resulted in almost complete disappearance of previous leptomeningeal enhancement of brain and spinal cord, and absence of newly developed metastatic lesions in the central nervous system, based on MRI results. The patient had been regularly followed with ongoing lorlatinib therapy for 5 months without any systemic complications or neurological abnormality. Conclusively, lorlatinib could be a rapid and effective treatment for patients with central nervous system leptomeningeal metastases arising from ALK-positive lung cancer.

The Tumor Control According to Radiation Dose of Gamma Knife Radiosurgery for Small and Medium-Sized Brain Metastases from Non-Small Cell Lung Cancer

Objective@#: The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). @*Methods@#: We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1–3 and 3–5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. @*Results@#: After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0–17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150–0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5–11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. @*Conclusion@#: The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

Utility of sentinel lymph node biopsy in papillary thyroid microcarcinoma

Purpose@#There are many studies on sentinel lymph node (SLN) biopsy in thyroid carcinoma but SLN biopsy (SLNB) in papillary thyroid carcinoma (PTC) remains open to debate. Therefore in this retrospective study, the usefulness of SLNB in thyroid carcinoma patients who had micro-PTC without cervical lymphadenopathy was assessed. @*Methods@#SLNB was performed in 114 patients who were diagnosed with micro-PTC in a single lobe without palpable or ultrasound-detected lymph node at the tertiary center between January 2012 and December 2013. After SLNB, all patients underwent total thyroidectomy and central neck dissection or thyroid lobectomy and central neck dissection of the single side. @*Results@#SLNs were identified in 112 of 114 patients with 41 positive SLNs and 71 negative SLNs on intraoperative frozen sections. However, eight negative patients were found to be positive in the final pathology. Sentinel node identification rate and false negative value of SLNB were 98.2% and 11.3%, respectively. In the univariate analysis, higher lymph node metastasis was detected in men than in women. Higher detection number of SLN showed higher probability of lymph node metastasis. @*Conclusion@#SLNB may be helpful in papillary thyroid cancer, especially in male patients. Also, it is useful for the staging of nodal status and clearance of persistent disease.

Pharmacokinetic properties and bioequivalence of gefitinib 250 mg in healthy Korean male subjects

Gefitinib is an anti-cancer drug used to treat non-small cell lung cancer. The objective of this study was to compare the pharmacokinetics and evaluate the bioequivalence of 2 orally administered gefitinib 250 mg tablets in healthy Korean subjects. A randomized, openlabel, single-dose, crossover bioequivalence study was conducted. A total of 50 healthy male volunteers were randomized into 2 sequence groups. During each treatment, the subjects received the test or reference formulation of 250 mg gefitinib with a washout period of 21 days. The plasma samples were collected at pre-dose and up to 144 hours post-dose, and plasma drug concentrations were measured using validated liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated, and the formulations were considered as bioequivalent if the 90% confidence intervals (CIs) of the geometric mean ratios were within the bioequivalence limits of 0.8 to 1.25. Forty-one subjects completed the study and were included in the pharmacokinetic analysis. The 90% CIs of the geometric mean ratios of the test formulation to the reference formulation were 0.8115 to 0.9993 for maximum plasma concentration and 0.9119 to 1.0411 for area under the plasma concentration versus time curve from dosing to the last measurable concentration. There were no serious or unexpected adverse events during the study. In healthy Korean adult subjects, the test and reference formulations of gefitinib 250 mg had similar pharmacokinetic parameters and similar plasma concentration-time profiles. The test formulation of gefitinib met the regulatory criteria for assuming bioequivalence. Both formulations were safe and well-tolerated.

Are the Outcomes of Breast Conservation Surgery Inferior to Those of Mastectomy in Patients with Stage II-IIIA Triple-Negative Breast Cancer?

Purpose@#Breast conserving surgery (BCS) is generally not considered for breast cancer because of concerns about the poor prognosis of triple negative breast cancer (TNBC). We assessed the outcomes of BCS and mastectomy for patients with stage II-IIIA TNBC. @*Methods@#The data of 172 breast cancer patients diagnosed with stage II-IIIA TNBC who underwent treatment at Pusan National University Hospital and Pusan National University Yangsan Hospital from 2010 to 2014 were retrospectively analyzed. The patients were divided into the following two groups: patients who underwent BCS (n=101) and those who underwent mastectomy (n=71). The Cox regression model was used to examine the outcomes of both treatments. The median follow-up period was 71 months in the BCS group, and 67 months in the mastectomy group. @*Results@#The median age of the 172 patients was 51 years (range, 22-82 years). In the BCS group, radiation therapy and chemotherapy (p<0.001 and p=0.007, respectively) were performed more frequently. The BCS group had more patients with a high Ki-67 index (p=0.006), while the mastectomy group included more patients with a higher pathologic T (pT) stage (p=0.005). The 5-year loco-regional recurrence-free, disease-free, and overall survival rates of the BCS group versus the mastectomy group were 93.8% versus 95.3%, 89.8% versus 90.7%, and 90.8% versus 86.3%, respectively, but the differences were not statistically significant. Lymphovascular invasion was a risk factor for disease-free survival and advanced stage was an important risk factor for overall survival. @*Conclusion@#In stage II-IIIA TNBC, BCS was not inferior to mastectomy in locoregional recurrence rates, disease-free survival rates, or overall survival rates.

A comparative study of the clinical characteristics and outcomes of HR-positive HER2-negative breast cancer patients over and under 65 years old

Purpose@#The purpose of this study was to compare the clinical characteristics and outcomes of hormone receptor-positive (HR+) human epidermal growth factor 2-negative (HER2–) breast cancer among elderly patients (over 65 years old) and younger patients. @*Methods@#This was a retrospective cohort study of 328 patients who were treated for breast cancer at Pusan National University Yangsan Hospital between January 2009 and December 2014. Tumor characteristics, surgical methods, and survival outcomes were compared between the two age groups (<65 and ≥65 years old). Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were also constructed according to the age groups. @*Results@#Among the 328 patients with HR+ HER2– breast cancer, 184 (56.1%) were <65 years old and 144 (43.9%) were ≥65 years old. Breast cancer stages were similar between the two age groups, but the older patients were treated less often with chemotherapy (81% vs. 66%, P=0.002). During the follow-up period, 17 deaths and 36 cases of recurrence or metastasis were reported. There was no difference in DFS between the two groups (P=0.840); however, the OS of the older age group was significantly lower than that of the younger age group (P=0.015). @*Conclusion@#This study suggested that HR+ HER2– breast cancer patients belonging to the two age groups had no significant difference in DFS. However, older age is an independent factor affecting OS rate. Therefore, even if patients are old, but their physical condition is satisfactory, standard and active treatment may be necessary, similar to that given to younger patients.

A comparative study of the clinical characteristics and outcomes of HR-positive HER2-negative breast cancer patients over and under 65 years old

Purpose@#The purpose of this study was to compare the clinical characteristics and outcomes of hormone receptor-positive (HR+) human epidermal growth factor 2-negative (HER2–) breast cancer among elderly patients (over 65 years old) and younger patients. @*Methods@#This was a retrospective cohort study of 328 patients who were treated for breast cancer at Pusan National University Yangsan Hospital between January 2009 and December 2014. Tumor characteristics, surgical methods, and survival outcomes were compared between the two age groups (<65 and ≥65 years old). Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were also constructed according to the age groups. @*Results@#Among the 328 patients with HR+ HER2– breast cancer, 184 (56.1%) were <65 years old and 144 (43.9%) were ≥65 years old. Breast cancer stages were similar between the two age groups, but the older patients were treated less often with chemotherapy (81% vs. 66%, P=0.002). During the follow-up period, 17 deaths and 36 cases of recurrence or metastasis were reported. There was no difference in DFS between the two groups (P=0.840); however, the OS of the older age group was significantly lower than that of the younger age group (P=0.015). @*Conclusion@#This study suggested that HR+ HER2– breast cancer patients belonging to the two age groups had no significant difference in DFS. However, older age is an independent factor affecting OS rate. Therefore, even if patients are old, but their physical condition is satisfactory, standard and active treatment may be necessary, similar to that given to younger patients.

Treatment Outcome of Gamma Knife Radiosurgery for Petroclival Meningiomas: Retrospective Analysis of a Single Institution Experience

Background@#Although Gamma Knife radiosurgery (GKRS) has been widely used for intracranial meningiomas as an alternative or adjuvant treatment, guidelines have not been established for the selection of patients with petroclival meningioma (PCM) for GKRS. In this study, we reported the factors related to tumor progression and postoperative complications in PCM patients treated by GKRS, with a review of the literatures. @*Methods@#Between 2004 and 2019, 64 patients (52 patients for alternative and 12 patients for adjuvant treatment) with PCM underwent GKRS in our institution. The clinical and radiological factors were retrospectively analyzed. The mean radiologic follow-up duration was 58.4 months (range, 6-164 months). The mean tumor volume and diameter before GKRS were 13.4㎤ and 2.9 cm, respectively.The median marginal dose was 12 Gy (range, 10-14 Gy) with a 50% median isodose line. Fractionation was used in 19 cases (29%, two fractionations in 5 cases & three fractionations in 14 cases). @*Results@#Progression was noted in 7 cases (10.9%) and the progression-free survival rates were 91.1% at 5 years and 69.6% at 10 years. Although large in volume, moderate to severe peritumoral edema and male gender were somewhat related to progression, they did not reach statistical significance. Ten patients (15.6%) developed complications after GKRS. The most common complication was cranial nerve deficit (n=8), followed by hemiparesis, cognitive dysfunction, and hydrocephalus. Large size (maximal diameter ≥5 cm) [hazard ratio (HR) 0.091, 95% confidence interval (CI) 0.014-0.608;p=0.013] and multiplicity (HR 0.102, 95% CI 0.018-0.573; p=0.009) were independent factors for developing complications after GKRS. @*Conclusion@#GKRS can be considered an effective and safe treatment for large-volume PCM. However, for patients with large size or multiple masses, the treatment method should be determined with caution because the probability of complications after GKRS may increase.

What predicts better prognosis in elderly breast cancer patients?

Purpose@#As we enter an aging society, the number of elderly patients with breast cancer is increasing. We assessed the prognostic factors for breast cancer recurrence or metastasis in patients over the age of 65 years by analyzing tumor characteristics and long-term clinical outcomes. @*Methods@#In this retrospective study, the data of 286 breast cancer patients aged 65 years and older, who underwent treatment at the Pusan National University Hospital and Pusan National University Yangsan Hospital from 2008 to 2014, were analyzed. The patients were divided into two groups: those with recurrence or metastasis and those without. Cox-regression model was used to analyze the risk factors for recurrence or metastasis. Kaplan-Meier method was used to analyze survival rates by the log-rank test. @*Results@#Among the 286 patients with invasive breast cancer, 43 patients (15.0%) had recurrence or distant metastasis during a median follow-up period of 61 months. Advanced stages of breast cancer and patients who are not adapted to endocrine therapy were associated with poor prognosis. @*Conclusion@#In this study, advanced stages of breast cancer and endocrine therapy were the prognostic factors for breast cancer recurrences or metastases. Early detection of elderly breast cancer generally increases the possibility of diagnosis at an earlier stage, which can lead to a better prognosis. Moreover, endocrine therapy should be administered to elderly patients who manifest favorable intrinsic subtypes of breast cancer.

Thyrotropin suppression therapy for papillary thyroid carcinoma with a huge recurred neck lymph node

Differentiated thyroid cancer (DTC) originating from thyroid tissue is affected by thyrotropin (TSH). TSH suppression therapy is usually recommended after thyroidectomy in cases of DTC. A 57-year-old woman who harbored a very huge recurred lymph node underwent TSH suppression therapy because of the risk of surgical complications. After TSH suppression, the huge neck lymph node exhibited a response and decreased in size. She had been followed up for 144 months. TSH suppression therapy could be considered as an alternative treatment option in a recurred DTC patient with a high perioperative risk.

Thyrotropin suppression therapy for papillary thyroid carcinoma with a huge recurred neck lymph node

Differentiated thyroid cancer (DTC) originating from thyroid tissue is affected by thyrotropin (TSH). TSH suppression therapy is usually recommended after thyroidectomy in cases of DTC. A 57-year-old woman who harbored a very huge recurred lymph node underwent TSH suppression therapy because of the risk of surgical complications. After TSH suppression, the huge neck lymph node exhibited a response and decreased in size. She had been followed up for 144 months. TSH suppression therapy could be considered as an alternative treatment option in a recurred DTC patient with a high perioperative risk.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors. METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Dexamethasone Downregulates Expressions of 14-3-3β and γ-Isoforms in Mice with Eosinophilic Meningitis Caused by Angiostrongylus cantonensis Infection

Steroids are commonly used in patients with eosinophilic meningitis caused by A. cantonensis infections. The mechanism steroids act on eosinophilic meningitis remains unclear. In this mouse experiments, expressions of 14-3-3 isoform β and γ proteins significantly increased in the CSF 2–3 weeks after the infection, but not increasedin the dexamethasone-treated group. Expression of 14-3-3 β, γ, ɛ, and θ isoforms increased in brain meninges over the 3-week period after infection and decreased due to dexamethasone treatment. In conclusion, administration of dexamethasone in mice with eosinophilic meningitis decreased expressions of 14-3-3 isoform proteins in the CSF and in brain meninges.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors.METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors.RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images.CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Treatment Decisions of World Health Organization Grade II and III Ependymomas in Molecular Era

Surgery and radiotherapy are mainstays of treatment for ependymomas (EPNs). Recent molecular subgrouping could be superior to histopathological grading for predicting the prognosis of patients with EPNs. Gross total resection is an effective treatment approach regardless of its locations or pathologic grades. Adjuvant therapeutic strategies could be decided based on molecular subgrouping with risk-stratification. Information of histologic-molecular biology is now providing clues to therapeutic insights.