Long-term clinical outcomes of stereotactic radiotherapy for bilateral vestibular schwannomas in neurofibromatosis type 2 patients.

PURPOSE: The evidence for treating patients with neurofibromatosis 2-related vestibular schwannoma (VS-NF2) using hypofractionated stereotactic radiation therapy (HSRT) is limited. This study aimed to investigate clinical outcomes in patients with VS-NF2 treated with Robotic HSRT. METHODS: We retrospectively analyzed 25 NF2 patients with 48 VSs who were treated using Robotic HSRT at Ramathibodi Hospital from January 2009 to January 2020. RESULTS: Median follow-up was 98 months (range, 24-155 months). Median tumor volume was 2.3 cm3 (range, 0.4-28.3 cm3). Median prescribed dose was 18 Gy (range, 18-25 Gy) in three fractions (range, 3-5). The 5- and 10-year local control rates were 87% and 80%, respectively. The 5- and 10-year hearing preservation rates were 59% and 35%, respectively. Three patients developed new symptoms associated with transient volume expansion after treatment: hydrocephalus in one, facial weakness in one, and ataxia in one. No patient developed worsening of trigeminal nerve function. No histologically confirmed of radiation induced malignancy was reported in the study. CONCLUSIONS: Robotic HSRT demonstrated excellent long-term tumor control with a low non-auditory complication rate in patients with VS-NF2. However, preservation of hearing remains a major concern.

Long-term treatment outcomes of pediatric low-grade gliomas treated at a university-based hospital.

PURPOSE: A multimodality approach is generally considered for pediatric low-grade gliomas (LGG); however, the optimal management remains uncertain. The objective of the study was to evaluate treatment outcomes of pediatric LGG, focusing on long-term survival and factors related to outcomes. METHODS: A retrospective review of 77 pediatric LGG cases treated at Ramathibodi Hospital, Thailand between 2000 and 2018 was performed. The inclusion criteria were all pediatric LGG cases aged ≤ 15 years. Diffuse intrinsic pontine gliomas and spinal cord tumors were excluded. RESULTS: The median follow-up time was 8.2 years (range, 0.6-19.7). The median age at diagnosis was 6.2 years (interquartile range, 3.6-11.4). Treatments modality included tumor surgery (93%), chemotherapy (40%), and radiation therapy (14%). The 10-year overall survival (OS) and 10-year progression-free survival were 94% and 59%, respectively, for the entire cohort. The 10-year OS was 100% in three subgroups of patients: pilocytic subtype, WHO grade 1 tumors, and recipient of gross total resection. After multivariable analysis, no tumor surgery had a significantly unfavorable influence on overall survival. CONCLUSIONS: With a multimodality approach, pediatric LGGs had excellent outcome. Gross total resection is the standard primary treatment. Chemotherapy is the alternative standard treatment in incomplete resection cases, unresectable patients, or patients with progressive disease. Radiation therapy should be reserved as a salvage treatment option because of late complications that usually affect patients' quality of life.

Double jeopardy - pituitary apoplexy complicated by ruptured aneurysm of the internal carotid artery within an adenoma: a case report.

BACKGROUND: Sudden onset of severe headache is the most common presentation of a ruptured intracranial aneurysm. Similar symptoms can be caused by pituitary apoplexy, and radiological examination is needed to distinguish between the two. Development of infarction and/or haemorrhage of the hypophysis with concomitant unruptured cerebral aneurysm has been described. However, intratumoural aneurysm within a pituitary adenoma presenting with the ictus of both pathologies is extremely rare. CASE PRESENTATION: A 64-year-old man presented with classic symptoms of pituitary apoplexy. His symptoms improved after a few days, and he was discharged. However, he subsequently developed further episodes of sudden and severe headache together with visual decline and ophthalmoplegia. Radiographs demonstrated an enlarging sellar mass with suspicion of a ruptured internal carotid artery aneurysm, within the apoplectic pituitary macroadenoma. Although an endovascular procedure was planned, the patient developed massive subarachnoid haemorrhage resulting in brain death. CONCLUSION: This case report describes an intratumoural aneurysm of the cavernous internal carotid artery as a potential cause or result of pituitary apoplexy. Despite its rarity, this possible life-threatening complication of pituitary apoplexy should be recognised for prompt diagnosis and early management.

Long-term clinical outcomes of stereotactic radiosurgery and hypofractionated stereotactic radiotherapy using the CyberKnife® robotic radiosurgery system for vestibular schwannoma.

AIM: The study aimed to evaluate the long-term clinical outcomes of patients with vestibular schwannoma (VS) treated with stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HSRT) with frameless robotic whole-body radiosurgery system (CyberKnife® ). METHODS: This retrospective analysis of prospectively collected data included 123 consecutive patients with VS treated at the Radiosurgery center, Ramathibodi Hospital, Bangkok, Thailand. SRS was recommended for patients with unserviceable hearing and Koos grade I-III tumors, and HSRT for patients with serviceable hearing or Koos grade III-IV tumors. Between March 2009 and December 2015, 23 patients (19%) were treated with SRS, whereas 100 (81%) received HSRT. The commonly used regimen was 12 Gy in one fraction for SRS and 18 Gy in three fractions for HSRT. RESULTS: After a median follow-up of 72 months (range: 12-123 months), the 5-year and 8-year progression-free survival (PFS) rates for the whole cohort were 96% and 92%, respectively. The PFS was not significantly different between the SRS and HSRT groups (p = 0.23). Among 28 patients with serviceable hearing in the HSRT group, the 5-year and 8-year hearing preservation rates were 87% and 65%, respectively. The rate of nonauditory complications was 14%. Koos grade III/IV was a predictor of disease progression and was associated with nonauditory complications. CONCLUSION: SRS and HSRT with the CyberKnife® system provided excellent long-term tumor control with a low rate of nonauditory complications. HSRT may result in acceptable hearing preservation rates.

Long-term outcomes of 170 brain arteriovenous malformations treated by frameless image-guided robotic stereotactic radiosurgery: Ramathibodi hospital experience.

ABSTRACT: This study was conducted to report long-term outcomes of the frameless robotic stereotactic radiosurgery (SRS) for brain arteriovenous malformation (AVM) at Ramathibodi Hospital.Retrospective data of patients with brain AVM (bAVM), who underwent CyberKnife SRS (CKSRS) at Ramathibodi Hospital from 2009 to 2014, were examined. Exclusion criteria were insufficient follow-up time (<36 months) or incomplete information. Patients' demographics, clinical presentation, treatment parameters, and results were analyzed. Excellent outcome was defined as AVM obliteration without a new neurological deficit. Risk factors for achieving excellent outcome were assessed.From a total of 277 CKSRS treatments for bAVM during the 6 years, 170 AVMs in 166 patients met the inclusion criteria. One hundred and thirty-nine cases (81.76%) presented with hemorrhages from ruptured bAVMs. Almost two-thirds underwent embolization before radiosurgery. With the median AVM volume of 4.17 mL, three-quarters of the cohort had single-fraction CKSRS, utilizing the median prescribed dose of 15 Gray (Gy). In the multisession group (25.29%), the median prescribed dose and the AVM volume were 27.5 Gy and 22.3 mL, respectively. An overall excellent outcome, at a median follow-up period of 72.45 months, was observed in 99 cases (58.24%). Seven AVMs (4.12%) ruptured after CKSRS but 1 patient suffered a new neurological deficit. Two patients (1.18%) were classified into the poor outcome category but there were no deaths. Negative factors for excellent outcome, by multivariate regression analysis, were the male sex and multisession SRS delivery, but not age, history of AVM rupture, previous embolization, or AVM volume.Despite relatively larger bAVM and utilizing a lower prescribed radiation dose, the excellent outcome was within the reported range from previous literature. This study offers one of the longest follow-ups and the largest cohorts from the frameless image-guided robotic SRS community.

Postoperative Copeptin as a Biomarker for Development of Diabetes Insipidus Following Hypothalamic-Pituitary Surgery.

OBJECTIVE: Copeptin is a surrogate marker of arginine vasopressin release with better stability and simplicity of measurement. Postoperative copeptin levels may guide clinicians in stratifying patients who need close monitoring of fluid balance. The objective is to determine whether copeptin is a predictive marker of postoperative diabetes insipidus (DI). METHODS: This is a prospective diagnostic study. Patients who underwent neurosurgical intervention of the sellar-suprasellar regions were recruited. Serum copeptin levels were measured before and after surgery, within 24 hours. Logistic regression analysis and diagnostic performance measures were calculated to determine the relationship between postoperative copeptin levels and DI. RESULTS: Of 82 patients, 26 (31.7%) developed postoperative DI, with 7 patients (8.5%) having permanent DI. The samples for copeptin measurement were taken at 13 ± 2.1 hours postoperatively. From the receiver operating characteristic analysis, low postoperative copeptin levels (<2.5 pmol/L) demonstrated an acceptable ability to predict DI (area under the curve, 0.72; 95% CI, 0.60-0.84). Discriminative power was stronger in the permanent DI group (area under the curve, 0.82; 95% CI, 0.64-1.00). Postoperative copeptin levels <2.5 pmol/L were associated with DI (specificity > 91%). However, postoperative copeptin levels >20 pmol/L were rarely associated with DI, with a negative predictive value of 100%. CONCLUSIONS: In patients undergoing sellar-suprasellar interventions, low postoperative copeptin levels within the first postoperative day predict postoperative DI, whereas high levels exclude it. Copeptin measurement should be applied in the clinical practice of postoperative care in patients following hypothalamic-pituitary surgery. This study may expand the potential use of copeptin, including in the Asian population.

Carboplatin-based regimen in pediatric intracranial germ-cell tumors (IC-GCTs): effectiveness and ototoxicity.

BACKGROUND: Induction chemotherapy with carboplatin followed by radiotherapy has been used for many years for treating intracranial germ-cell tumors (IC-GCTs) in Thailand. The objective of this study was to assess treatment outcomes, focusing on survival and ototoxicity. METHODS: The outcomes of all patients with IC-GCT treated at Ramathibodi Hospital and the Prasat Neurological Institute between 2000 and 2017 were reviewed and analyzed, including all patient characteristics and treatment modalities. Five-year overall survival (OS) and event-free survival (EFS) were analyzed using the Kaplan-Meier method, and factors affecting survival were compared using the log-rank test. RESULTS: Fifty-three patients age 1-14 years (median, 11 years) were included in this study. The median follow-up time was 63 months. The 5-year EFS and OS rates were 94.3% and 96.2% for all patients, respectively. No statistical difference in OS or EFS was observed between the data of recipients in the carboplatin-based and historical cisplatin-based therapies in our institutes. Concerning radiotherapy, omission of radiotherapy or focal irradiation results in worse long-term survival outcomes, but reduction in dose of radiotherapy to less than 40 Gy did not cause any negative impact on survival rates. Furthermore, carboplatin was associated with lower rates of hearing loss than cisplatin (5.7% vs 87.5%). CONCLUSIONS: Induction chemotherapy with carboplatin-based regimens was associated with excellent survival rates and low ototoxicity in patients with IC-GCT. Radiotherapy should be given to all patients with a minimal volume equivalent to whole-ventricular radiotherapy, during which doses of lower than 40 Gy can be effectively used.

Spinal dural sac termination and internal filum terminale fusion: A Study from 80 Cadavers.

Surgery for tethered spinal cord caused by thickened filum terminale (FT) is frequently performed through S1 laminectomy based on the assumption that the internal FT (FTi) fuses with dura mater at S2 vertebral level. Literature on specific study for the site of its fusion and dural sac (DS) termination was rather limited. Moreover, there is no large anatomical study in Asian population. To determine the anatomy, examination of the FTi fusion site, as well as the region at which DS ended, was undertaken. From 80 embalmed cadavers, the majority of FTi fusion occurred at, or below, S1/S2 disk space (62.5%) which was less frequent than previous reports (70%-90%). In addition, there was 11.3% of the fila that fused above S1. Regarding the DS termination, it was found at, or below, S1/S2 disk space in 76.3% with one subject (1.3%) at L5/S1 disk space. With modest differences compared with non-Asian cadaveric data, our results offer pertinent information to surgeons performing tethered cord release. One ought to keep in mind that small, but not negligible, percentage of FTi can fuse with dura mater above S1 level; hence, more rostral laminectomy at L5 may be required. Clin. Anat. 33:558-561, 2020. © 2019 Wiley Periodicals, Inc.

Outcome of postoperative radiation therapy for pediatric intracranial ependymoma: a single-institution review.

PURPOSE: To report outcome of postoperative radiotherapy (RT) in both new and recurrent grade II and III intracranial ependymomas in children treated at Ramathibodi Hospital. MATERIALS AND METHODS: Between 2006 and 2017, 24 pediatric intracranial ependymomas treated with postoperative RT were retrospectively reviewed. The median age at diagnosis was 44.5 months (range, 4-165 months). There were 14 (58%) males. Fourteen (58%) patients had infratentorial tumor. The median maximal diameter of tumor at diagnosis was 4.45 cm (range, 2.2-10 cm). Fourteen (58%) patients had anaplastic tumor. Gross total resections were performed in 14 (58%) patients. The median prescribed dose was 54 Gy (range, 45-60 Gy). The median total treatment time was 43 days (range, 37-78 days). RESULTS: The median clinical follow-up time was 44.5 months (range, 1-146 months). There were nine recurrences, five of which occurred at the primary tumor site. The estimated 5-year progression-free survival rate was 56%. The estimated 5-year overall survival rate was 75%. Extent of resection was the only factor associated with improved progression-free survival and overall survival after univariate testing. Six from nine patients with recurrent diseases underwent further surgery or further RT. These six patients had better median overall survival than the three who did not. Acute complication was mostly transient and tolerable. No late radiation effect was found. CONCLUSIONS: Postoperative radiation is an effective treatment. GTR is associated with better PFS and OS. Aggressive salvage local treatments for recurrent patients can result in good overall survival. Longer follow-up is needed in account for late relapse.

Outcomes of the Endoscopic Transsphenoidal Surgery for Resection of Pituitary Adenomas Utilizing Extracapsular Dissection Technique with a Cotton Swab.

PURPOSE: The purpose of this study was to determine the effectiveness and safety of a cotton swab for extracapsular dissection in endoscopic transsphenoidal surgery (ETSS) for pituitary adenoma (PA). MATERIALS AND METHODS: A retrospective review of patients undergoing ETSS for PA from 2014 to 2017 was undertaken. Only patients with extracapsular dissection by cotton swab with the intent to completely remove the tumor were included. Assessment of the prospectively recorded clinical, laboratory, and radiographic presentation as well as the intra- and postoperative data was carried out. Factors influencing the extent of resection were analyzed. RESULTS: Of the 222 patients, one hundred cases met the inclusion criteria. The cohort consisted of 81 nonfunctioning and 19 functioning PAs. Fifty patients presented with visual disturbance and 34 patients had prior surgical treatment. The majority of PAs was macroadenoma (97%) with 73% modified Hardy Stage C and 38% Knosp Grade 4. Intraoperative cerebrospinal fluid (CSF) leakage was the most frequently noted complication (78%). Meningitis occurred in three cases and repeat ETSS for CSF leakage repair was necessary in three patients. No death or vascular injury was observed. At 12 months after ETSS, magnetic resonance imaging scan confirmed 43% complete tumor resection. Previous surgery and Knosp Grade 4 were the strong factors for incomplete PA removal by multivariate logistic regression analysis. For functioning PAs, thirteen patients (68.42%) achieved biochemical remission. CONCLUSION: Cotton swab for extracapsular dissection proved its clinical effectiveness and safety. In spite of the technique, negative predictors for complete PA resection were parasellar extension and previous surgery.

Outcome of newly diagnosed high risk medulloblastoma treated with carboplatin, vincristine, cyclophosphamide and etoposide.

Medulloblastoma is the most common malignant brain tumor among children. Although molecular study has been included in the new classification, in developing countries with limited resources the previous Chang staging system is still used. Therefore, treatment with postoperative radiation and chemotherapy remains the standard treatment. One common complication after treatment is ototoxicity, mainly due to radiation and cisplatinum. We report a revised chemotherapy protocol, replacing cisplatinum with carboplatin in newly diagnosed medulloblastoma cases. All 23 patients in this study had high risk medulloblastoma. Mean (SD) age was 9.5 ±â€¯3.1 years. The 5-year progression free survival (PFS), 5-year overall survival (OS), and 10-year OS were 41.8 ±â€¯12.2%, 60.0 ±â€¯11.2%, and 48.0 ±â€¯14.0 respectively. Most patients had grade 3-4 hematologic toxicity. Twelve patients had hearing tests, with 11 patients having grade 0 and 1 patient having grade 1 according to the Brock criteria.

Clinical outcomes of perioptic tumors treated with hypofractionated stereotactic radiotherapy using CyberKnife® stereotactic radiosurgery.

INTRODUCTION: Stereotactic radiation technique is widely reported as an effective treatment for various types of benign intracranial tumors. However, single fraction radiosurgery (SRS) is not recommended for tumors located close to the optic apparatus due to the restricted radiation tolerance dose of the optic pathway. Recent advances in radiotherapy include advanced frameless radiosurgery using hypofractionated stereotactic radiotherapy (HSRT), and this has become an attractive treatment option for perioptic tumors within 2-3 mm of the optic pathway. Accordingly, the aim of this study was to investigate the clinical outcomes of perioptic tumors treated with HSRT using CyberKnife® (CK) robotic radiosurgery system relative to tumor control, vision preservation and toxicity. METHODS: This retrospective analysis of prospectively collected data included consecutive 100 patients that were diagnosed with and treated for perioptic tumor at the Radiosurgery center, Ramathibodi Hospital during the January 2009 to December 2012 study period. RESULTS: The median tumor volume was 6.81 cm3 (range 0.37-51.6), and the median prescribed dose was 25 Gy (range 20-35) in 5 fractions (range 3-5). After the median follow-up time of 37.5 months (range 21-103), two patients developed tumor progression at 6 and 34 months post-HSRT. The 5-year overall survival was 97%, and the 5-year local control was 97.5%. At the last follow-up, no vision deterioration or newly developed hypopituitarism was detected in our study. CONCLUSIONS: Although a longer follow-up is needed, HSRT yields a high level of local control and vision preservation, and should be considered a treatment of choice for perioptic tumor located close to the optic apparatus.

Evolution of Technique in Endoscopic Transsphenoidal Surgery for Pituitary Adenoma: A Single Institution Experience from 220 Procedures.

Introduction Endoscopic transsphenoidal surgery (ETSS) for pituitary adenoma (PA) has been a recent shift from the traditional microscopic technique. Although some literature demonstrated superiority of ETSS over the microscopic method and some evaluated mono- vs. binostril access within the ETSS, none had explored the potential influence of dedicated instrument, as this procedure had evolved, on patients' outcomes when compared to traditional microscopic tools. Objective To investigate our own clinical and radiographic outcomes of ETSS for PA with its technical evolution over time as well as a significance of, having vs. lacking, the special endoscopic tools. Methods Included patients underwent ETSS for PA performed by the first author (AH). Prospectively recorded patients' data concerning pre-, intra- and postoperative clinical and radiographic assessments were subject to analysis. The three groups of differently evolving ETSS techniques, beginning with mononostril (MN) to binostril ETSS with standard microsurgical instruments (BN1) and, lastly, binostril ETSS with specially-designed endoscopic tools (BN2), were examined for their impact on the intra- and, short- and long-term, postoperative results. Also, the survival after ETSS for PA, as defined by the need for reintervention in each technical group, was appraised. Results From January 2006 to 2012, there were 47, 101 and 72 ETSS, from 183 patients, in the MN, BN1 and BN2 cohorts, respectively. Significant preoperative findings were greater proportion of patients with prior surgery (p=0.01) and tumors with parasellar extension (p=0.02) in the binostril (BN1&2) than the MN group. Substantially shorter operative time and less amount of blood loss were evident as our technique had evolved (p<0.001). Despite higher incidence, and more advanced grades, of cerebrospinal fluid leakage in the binostril groups (p < 0.001), the requirement for post-ETSS surgical repair was less than the mononostril cohort (p=0.04). At six-month follow-up (n=214), quantitative radiographic outcome analysis was markedly superior in BN2. Consequently, long-term result was better in this latest technical group. Important negative risk factors, from multivariate Cox regression analysis, were prior surgery, Knosp grade, and firm tumor while BN1, BN2 and percentages of anteroposterior dimension PA removal had positive effect on longer survival. Conclusion The evolution of technique for ETSS for PA from MN to BN2 has shown its efficacy by improving intra- and postoperative outcomes in our study cohorts. Based on our results, not only that a neurosurgeon, wishing to start performing ETSS, should enroll in a formal fellowship training but he/she should also utilize advanced endoscopic tools, as we have proved its superior results in dealing with PA.

Clinical Outcomes of Intracranial Nonvestibular Schwannomas Treated with LinacBased Stereotactic Radiosurgery and Radiotherapy.

BACKGROUND: Intracranial nonvestibular schwannomas arising from various cranial nerves excluding CN VIII are uncommon. Recently, stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) have been widely reported as effective treatment modalities for nonvestibular schwannomas. The purpose of this study was to study the long term clinical outcome for nonvestibular schwannomas treated with both XKnife and CyberKnife (CK) radiosurgery at one institution. MATERIALS AND METHODS: From 2004 to 2013, fiftytwo nonvestibular schwannoma patients were included in this study, 33 patients (63%) were treated with CK, and 19 (37%) were treated with XKnife. The majority of the tumors were jugular foramen schwannomas (38%) and trigeminal schwannomas (27%). HSRT was given for 45 patients (86%), whereas CSRT was for 6 (12%) and SRS for 1 (2%). RESULTS: The median pretreatment volume was 9.4 cm3 (range, 0.5752 cm3). With the median follow up time of 36 months (range, 3135), the 3 and 5 year progression free survival was 94 % and 88%, respectively. Tumor size was decreased in 13 (25%), stable in 29 (56%), and increased in 10 (19%). Among the latter, 3 (30%) required additional treatment because of neurologic deterioration. No patient was found to develop any new cranial nerve deficit after SRS/SRT. CONCLUSIONS: These data confirmed that SRS/ SRT provide high tumor control rates with low complications. Large volume tumors and cystic expansion after radiation should be carefully followed up with neurological examination and MRI, because it may frequently cause neurological deterioration requiring further surgery.

The Clinical Outcome of Hypofractionated Stereotactic Radiotherapy With CyberKnife Robotic Radiosurgery for Perioptic Pituitary Adenoma.

Stereotactic radiation technique including single fraction radiosurgery and conventional fractionated stereotactic radiotherapy is widely reported as an effective treatment of pituitary adenomas. Because of the restricted radiation tolerance dose of the optic pathway, single fraction radiosurgery has been accepted for small tumor located far away from the optic apparatus, while fractionated stereotactic radiotherapy may be suitable for larger tumor located close to the optic pathway. More recently, hypofractionated stereotactic radiotherapy has become an alternative treatment option that provides high rate of tumor control and visual preservation for the perioptic lesions within 2 to 3 mm of the optic pathway. The objective of the study was to analyze the clinical outcomes of perioptic pituitary adenomas treated with hypofractionated stereotactic radiotherapy. From 2009 to 2012, 40 patients with perioptic pituitary adenoma were treated with CyberKnife robotic radiosurgery. The median tumor volume was 3.35 cm3 (range, 0.82-25.86 cm3). The median prescribed dose was 25 Gy (range, 20-28 Gy) in 5 fractions (range, 3-5). After the median follow-up time of 38.5 months (range, 14-71 months), 1 (2.5%) patient with prolactinoma had tumor enlargement, 31 (77.5%) were stable, and the remaining 8 (20%) tumors were smaller in size. No patient's vision deteriorated after hypofractionated stereotactic radiotherapy. Hormone normalization was observed in 7 (54%) of 13 patients. No newly developed hypopituitarism was detected in our study. These data confirmed that hypofractionated stereotactic radiotherapy achieved high rates of tumor control and visual preservation. Because of the shorter duration of treatment, it may be preferable to use hypofractionated stereotactic radiotherapy over fractionated stereotactic radiotherapy for selected pituitary adenomas immediately adjacent to the optic apparatus.

Initial Experience with Ultra-Low-Field Intraoperative Magnetic Resonance Imaging in Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenoma at Ramathibodi Hospital.

Objective: To report our initial experience using ultra-low-field 0.15 Tesla PoleStar N-30 (Medtronic, Louisville, CO, USA) intraoperative magnetic resonance imaging (iMRI) in endoscopic endonasal transsphenoidal surgery (eTSS) for pituitary adenoma (PA) at the Faculty of Medicine Ramathibodi Hospital. Material and Method: From September 2013 to August 2014, information from patients who underwent eTSS for PA with ultra-low-field iMRI was prospectively collected. Data of the scans, at the three point-of-times (before, during and after the eTSS), from the iMRI in these patients were subject to our analysis. Results: A total of the 11 patients successfully underwent eTSS with iMRI during the study period. Two patients were found to have residual PA despite surgeon's opinion of complete resection of the tumor. Further resection yielded complete removal in one and subtotal removal in the other patient. No serious intra- or postoperative complication occurred in association with iMRI. Conclusion: This is the first report of eTSS for PA with Polestar N-30 iMRI. Our results are similar to those previously published series utilizing earlier versions of, PoleStar N-10 and N-20, ultra-low-field iMRI. These findings, again, confirm the added value of iMRI for the extent of surgical resection in eTSS for PA. Step-by-step illustrations of the iMRI procedure are described.

Outcomes for Pituitary Adenoma Patients Treated with Linac- Based Stereotactic Radiosurgery and Radiotherapy: a Long Term Experience in Thailand.

BACKGROUND: The study analyzed the long term clinical outcomes of pituitary adenoma cases treated with the first Thailand installation of a dedicated Linac-based stereotactic radiation machine (X-Knife). MATERIALS AND METHODS: A retrospective review of 115 consecutive pituitary adenoma patients treated with X-Knife at the Faculty of Medicine, Ramathibodi Hospital, Bangkok, Thailand from 1997 to 2003 was performed. Stereotactic radiosurgery (SRS) was selected for 21 patients (18%) including those with small tumors (≤3 cm) located ≥5 mm. from the optic apparatus, whereas the remaining 94 patients (82%) were treated with fractionated stereotactic radiotherapy (FSRT). RESULTS: With a median follow-up time of 62 months (range, 21-179), the six-year progression free survival was 95% (93% for SRS and 95% for FSRT). The overall hormone normalization at 3 and 5 years was 20% and 30%, respectively, with average time required for normalization of approximately 16 months for SRS and 20 months for FSRT. The incidence of new hypopituitarism was 10% in the SRS group and 9% in the FSRT group. Four patients (5%) developed optic neuropathy (1 in the SRS group and 3 in the FSRT group). CONCLUSIONS: Linac-based SRS and FSRT achieved similar high local control rates with few complications in pituitary adenoma cases. However, further well designed, randomized comparative studies between SRS versus FSRT particularly focusing on hormone normalization rates are required.

The clinical outcome of intracranial hemangioblastomas treated with linac-based stereotactic radiosurgery and radiotherapy.

Recent publications have reported stereotactic radiosurgery as an effective and safe treatment for intracranial hemangioblastomas. However, because of the low incidence of these particular tumors, reports on large patient number studies have not yet been available. The objective of this study was to analyze the clinical results of 14 patients with 56 intracranial hemangioblastomas treated with linear accelerator (linac)-based stereotactic radiosurgery (SRS) and radiotherapy (SRT) in the same institute. The median age of patients was 41 years (range, 28-73 years). Nine of the patients (64%) had von Hippel-Lindau disease. A total of 39 lesions (70%) were treated with CyberKnife (CK), and 17 lesions (30%) were treated with X-Knife. The median pretreatment volume was 0.26 cm(3) (range, 0.026-20.4 cm(3)). The median marginal dose was 20 Gy (range, 10-32 Gy) in 1 fraction (range, 1-10 fractions). The median follow-up time was 24 months (range, 11-89 months). At the last follow-up, 47 tumors (84%) were stable, 7 (13%) decreased and 2 (4%) increased. The 1-, 2- and 6-year local control rates were 98%, 88% and 73%, respectively. No radiation complications were observed in this study. There was a trend toward local failure only in cystic tumors, but this trend was not found to be statistically significant. SRS/SRT achieved a high local control rate in intracranial hemangioblastomas without radiation-induced complications.

Volumetric analysis of intracranial arteriovenous malformations contoured for CyberKnife radiosurgery with 3-dimensional rotational angiography vs computed tomography/magnetic resonance imaging.

BACKGROUND: Accurate target delineation has significant impact on brain arteriovenous malformation (AVM) obliteration, treatment success, and potential complications of stereotactic radiosurgery. OBJECTIVE: We compare the nidal contouring of AVMs using fused images of contrasted computed tomography (CT) and magnetic resonance imaging (MRI) with matched images of 3-dimensional (3-D) cerebral angiography for CyberKnife radiosurgery (CKRS) treatment planning. METHODS: Between May 2009 and April 2012, 3-D cerebral angiography was integrated into CKRS target planning for 30 consecutive patients. The AVM nidal target volumes were delineated using fused CT and MRI scans vs fused CT, MRI, and 3-D cerebral angiography for each patient. RESULTS: The mean volume of the AVM nidus contoured with the addition of 3-D cerebral angiography to the CT/MRI fusion (9.09 cm(3), 95% confidence interval: 5.39 cm(3)-12.8 cm(3)) was statistically smaller than the mean volume contoured with CT/MRI fused scans alone (14.1 cm(3), 95% confidence interval: 9.16 cm(3)-19.1 cm(3)), with a mean volume difference of δ = 5.01 cm(3) (P = .001). Diffuse AVM nidus was associated with larger mean volume differences compared with a compact nidus (δ = 6.51 vs 2.11 cm(3), P = .02). The mean volume difference was not statistically associated with the patient's sex (male δ = 5.61, female δ = 5.06, P = .84), previous hemorrhage status (yes δ = 5.69, no δ = 5.23, P = .86), or previous embolization status (yes δ = 6.80, no δ = 5.95, P = .11). CONCLUSION: For brain AVMs treated with CKRS, the addition of 3-D cerebral angiography to CT/MRI fusions for diagnostic accuracy results in a statistically significant reduction in contoured nidal volume compared with standard CT/MRI fusion-based contouring.

Cochlea radiation dose correlates with hearing loss after stereotactic radiosurgery of vestibular schwannoma.

OBJECTIVE: For multisession radiosurgery, no published data relate the volume and dose of cochlear irradiation to quantified risk of hearing loss. We conducted a retrospective, dosimetric study to evaluate the relationship between hearing loss after stereotactic radiosurgery (SRS) and the dose-volume of irradiated cochlea. METHODS: Cochlear dose data were retrospectively collected on consecutive patients who underwent SRS (18 Gy in 3 sessions) for vestibular schwannoma between 1999 and 2005 at Stanford University Hospital. Inclusion criteria included Gardner-Robertson (GR) grade I or II hearing prior to radiosurgical treatment, complete audiograms, and magnetic resonance imaging (MRI) follow-up. A cochlea dose-volume histogram was generated for each of the 94 patients who qualified for this study. RESULTS: GR grade I-II hearing posttreatment was maintained in 74% of patients (70/94). Median time to last follow-up audiogram was 2.4 years (range 0.4-8.9) and to last MRI was 3.6 years (range 0.5-9.4). Each higher level of cochlear irradiation was associated with increased risk of hearing loss. Larger cochlear volume was associated with lower risk of hearing loss. Controlling for differences in cochlear volume among subjects, each additional mm(3) of cochlea receiving 10 to 16 Gy (single session equivalent doses of 6.6-10.1 Gy3) significantly increased the odds of hearing loss by approximately 5%. CONCLUSIONS: Larger cochlear volume is associated with lower risk of hearing loss following trisession SRS for vestibular schwannoma. Controlling for this phenomenon, higher radiation dose and larger irradiated cochlear volume are significantly associated with higher risk of hearing loss. This study confirms and quantifies the risk of hearing loss following trisession SRS for vestibular schwannoma.