Factors Influencing Long-Term Outcomes of Single-Session Gamma Knife Radiosurgery in Large-Volume Meningiomas >10 cc.

INTRODUCTION: Meningiomas are the most common primary intracranial tumour. Gamma knife radiosurgery (GKRS) is a frequently employed non-invasive method of treatment, with good remission rates and low morbidity in literature. However, the role of GKRS in the management of "large" meningiomas is unclear, with reported outcomes that vary by centre. We aimed to assess the factors that influence long-term outcomes following GKRS in meningiomas >10 cc in volume. METHODS: A retrospectively analysed all patients with meningiomas exceeding 10 cc in volume who underwent GKRS between January 2006 and December 2021 at the National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru. Demographic, clinical, radiological, and follow-up data were acquired, and factors associated with progression following GKRS were assessed. RESULTS: The cohort comprised 76 patients 29 males (38.2%) and 47 females (61.8%) with a mean age of 46.3 ± 11.02 years. Thirty-nine patients had been previously operated (51.3%). Meningiomas were most frequently located in the parasagittal region (26 tumours, 34.2%) and sphenopetroclival region (23 tumours, 30.3%), with mean lesion volume of 12.55 ± 5.22 cc, ranging 10.3 cc-25 cc. The mean dose administered to the tumour margin was 12.5 Gy ± 1.2 Gy (range 6-15 Gy). The median duration of clinical follow-up was 48 months, over which period radiological progression occurred in 14 cases (20%), with unchanged tumour volume in 20 cases (28.6%) and reduction in size of the tumour in 36 cases (51.4%). Progression-free survival after GKRS was 72% at 5 years, was significantly poorer among meningiomas with tumour volume >14 cc (log-rank test p = 0.045), tumours presenting with limb motor deficits (log-rank test p = 0.012), and tumours that underwent prior Simpson grade 3 or 4 excision (log-rank test p = 0.032). CONCLUSIONS: Meningiomas >10 cc in volume appear to display a high rate of progression and subsequent need for surgery following GKRS. Primary surgical resection, when not contraindicated, may be considered with GKRS serving an adjuvant role, especially in tumours exceeding 14 cc in volume, and presenting with limb motor deficits. Long-term clinical and radiological follow-up is essential following GKRS as the response of large meningiomas may be unpredictable.

Surgical outcomes of Supra- Infra Tentorial Extradural Hematoma (SIEDH): A retrospective study from a single institution.

INTRODUCTION: Bicompartmental Supra plus Infratentorial Extra Dural Hematoma (SIEDH) is an uncommon yet important category of Extradural Hematoma (EDH) straddling the transverse sinus. It requires quick decision making and proper surgical evacuation. METHODS: We did a retrospective chart review of all SIEDH cases from prospectively maintained operative database in our institute between 2011 & 2017. Clinical status at discharge and follow up were used to assess outcome. Ordinal regression analysis was used for analysis of factors predicting the outcome. We also describe the surgical procedure we follow at our high-volume trauma center for this unique entity. RESULTS: We had 61 operated cases of SIEDH in our series. The median age of the cohort was 30 years (IQR: 21.5-42). Road Traffic Accident was the most common mode of injury (67.2 %). Median pre-operative GCS was 12 (IQR: 9-12). The median volume of SIEDH was 50cc (IQR: 40-70). Mass effect on 4thventricle and brainstem was seen in 47 and 34 patients respectively. An associated fracture was seen in 54 patients. Sinus injury related bleed was noted intra-operatively in 57 % (N = 35). Follow up was available for 60 cases with a median of 130 days. On evaluating with ordinal regression analysis, we found that, the GCS at presentation, pupillary asymmetry, volume of SIEDH, infratentorial volume, blood loss and mass effect on 4thventricle were statistically significant factors affecting GCS at discharge. However, the GCS at presentation, infratentorial volume and blood loss were the only factors determining GOS at follow-up. CONCLUSION: SIEDH are uncommon yet important type of injury type which requires prompt attention and appropriate nuanced approach. Large SIEDH are commonly associated with sinus injury, and large volume blood loss may be anticipated. In addition, SIEDH may be associated with other traumatic brain injuries which may require surgical evacuation.