A prediction model for recurrence after translabyrinthine surgery for vestibular schwannoma: toward personalized postoperative surveillance

Purpose The aim of this study is to compute and validate a statistical predictive model for the risk of recurrence, defined as regrowth of tumor necessitating salvage treatment, after translabyrinthine removal of vestibular schwannomas to individualize postoperative surveillance. Methods The multivariable predictive model for risk of recurrence was based on retrospectively collected patient data between 1995 and 2017 at a tertiary referral center. To assess for internal validity of the prediction model tenfold cross-validation was performed. A ‘low’ calculated risk of recurrence in this study was set at < 1%, based on clinical criteria and expert opinion. Results A total of 596 patients with 33 recurrences (5.5%) were included for analysis. The final prediction model consisted of the predictors ‘age at time of surgery’, ‘preoperative tumor growth’ and ‘first postoperative MRI outcome’. The area under the receiver operating curve of the prediction model was 89%, with a C-index of 0.686 (95% CI 0.614–0.796) after cross-validation. The predicted probability for risk of recurrence was low (< 1%) in 373 patients (63%). The earliest recurrence in these low-risk patients was detected at 46 months after surgery. Conclusion This study presents a well-performing prediction model for the risk of recurrence after translabyrinthine surgery for vestibular schwannoma. The prediction model can be used to tailor the postoperative surveillance to the estimated risk of recurrence of individual patients. It seems that especially in patients with an estimated low risk of recurrence, the interval between the first and second postoperative MRI can be safely prolonged.

CSF Upward Motion Is Crucial for ETV Success

Purpose: ETV is indicated for treating obstructions of major CSF pathways. The outcome evaluation often yields success rates of only +- 70% for shunt independency. Hence, compromised CSF absorption seems to occur more often than expected. We searched for parameters suitable to assess the involved CSF dynamics. Material and Methods: This was a prospective study in 58 paediatric patients (7.7 yrs. mean age) between 2000 and 2020 with aqueductal stenosis (11/58), obstruction of the aqueduct due to tumor growth (22/58),and connatal hydrocephalus (9/58). The average follow-up interval was 4.7 years. Head circumferences, Evans- and fronto-occipital horn ratios before and 3 months after ETV were obtained as Delta-indices. Furthermore ETV success score (ETVSS), the patency of the aqueduct pre- and postoperatively as well as of the stoma were assessed by flow void signs on MRI. Evaluation on MRI also included the shape of the floor of the 3rd ventricle and whether or not the septum pellucidum showed signs of perforation. Four patients were analysed pre- and postoperatively via real-time MRI. At least the educational status regarding protected or unprotected education was analyzed. Results:The prevalence of a bowing of the floor of the 3rd ventricle was 72%, and the ETVSS was 71.0%. In 26 children a septal perforations or an open aqueduct prior to ETV (19) could be identified. Mean ER and FOHR were reduced by 0.03 and 0.05 , respectively. Maintained open (flow void on postop MRI) or perforation could successfully be carried out during endoscopic surgery in 44 patients (79%). The disproportionate increase of head circumference abated in 79.4% of patients. New shunt insertion occurred in 16 patients (27.5%). Intraoperatively upward CSF flow was detected in all cases. Statistical analyses(ANOVA) showed significant results for unprotected education, postoperative ER and FOHR but not for open stoma. Conclusion: The identification of flow through the stoma on postoperative MRI seems to be a necessary but not sufficient condition for ETV success. In our study, ventricular volumes were used as parameters to determine success rates as well as unprotected education. Furthermore, enabling upward CSF flow driven by inspiration seems crucial for successful ETV.

Fluorescence-guided craniotomy of glioblastoma using panitumumab-IRDye800

A contrast-enhancing lesion in the left temporal lobe of a 72-year-old woman was biopsied and diagnosed as glioblastoma. Near-infrared (NIR)–labeled epidermal growth factor receptor (EGFR) antibody, panitumumab-IRDye800, was infused 52 hours before craniotomy without pretreatment. Tumor fluorescence was detected through intact dura, and the visual contrast between disease and peritumoral healthy brain was enhanced after tumor exposure. Residual cancerous tissue was identified with strong fluorescence in resection cavity after en bloc tumor removal. Minimal fluorescence remained in the final wound bed, likely from nonenhancing tumor. Fluorescence was heterogeneously distributed at the infiltrative margin in resected tumor pieces imaged ex vivo. Postoperative MRI confirmed gross-total resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21201

Second window ICG predicts postoperative MRI gadolinium enhancement in high grade gliomas and brain metastases

A prospective trial evaluating the utility of second window indocyanine green (SWIG) in predicting postoperative MRI gadolinium enhancement was performed on high-grade gliomas (HGGs) and brain metastases. Compared to white light alone, SWIG demonstrated a higher sensitivity, negative predictive value, and accuracy in predicting residual neoplasm on MRI. The specificity of SWIG for predicting MRI enhancement was higher in HGGs than brain metastases. Clinically, near-infrared (NIR) imaging was better able to predict tumor recurrence than postoperative MRI. These results illustrate how SWIG is able to take advantage of gadolinium-like distribution properties to extravasate into the tumor microenvironment, enabling guidance in surgical resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21204

Fourth ventricle neurocysticercosis presenting with Bruns’ syndrome: A case report

Background: Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system. We present a case of the fourth ventricle NCC that presented with Bruns’ syndrome (with headaches worsened by head movements, gait ataxia, and vomiting) and the operative technique used for cyst removal. Case Description: A 39-year-old woman was admitted to the emergency department with moderate-to-severe headaches that got worse in the afternoon and were triggered by head movements, relieved on prone position, and were associated with gait ataxia and vomiting. A brain magnetic resonance imaging (MRI) showed a fourth ventricle cyst, with an eccentric enhancing nodule compatible with a larvae scolex and associated obstructive hydrocephalus. The patient was positioned prone and underwent a microsurgical resection of the cyst without rupture through a telovelar approach to the fourth ventricle. The postoperative MRI confirmed complete cyst removal and resolution of the hydrocephalus. At 12-month follow-up, the patient remains with no signs of disease recurrence. Conclusion: In this report, we depict a case of intraventricular NCC successfully treated with a single surgery, allowing intact cyst removal and achieving effective hydrocephalus treatment with no need to resort to cerebrospinal fluid diversion techniques.

Cerebral venous thrombosis with a catch

Background: Cerebral venous thrombosis (CVT) is a rare entity typically occurring in patients in hypercoagulable states. They can also occur in cases of trauma. The symptoms are nonspecific. Case Description: A 28-year-old male presented to the emergency department with a head injury. During the necessary imaging, it was found that he had a depressed skull fracture and other signs of traumatic brain injury. Unbeknownst to the patient and the patient party, it was also revealed that the patient only had one kidney. Wound debridement and excision of the depressed fracture were performed. A postoperative MRI revealed that the patient had CVT. Conclusion: There should be a high index of suspicion for CVT in case of traumatic head injuries. The surgeon should plan management according to the patient’s comorbidities.

Postoperative GH and Degree of Reduction in IGF-1 Predicts Postoperative Hormonal Remission in Acromegaly

PurposeDetermine predictive factors for long-term remission of acromegaly after transsphenoidal resection of growth hormone (GH)-secreting pituitary adenomas.MethodsWe identified 94 patients who had undergone transsphenoidal resection of GH-secreting pituitary adenomas for treatment of acromegaly at the USC Pituitary Center from 1999-2019 to determine the predictive value of postoperative endocrine lab values.ResultsPatients underwent direct endoscopic endonasal (60%), microscopic transsphenoidal (38%), and extended endoscopic approaches (2%). The cohort was 63% female and 37% male, with average age of 48.9 years. Patients presented with acral enlargement (72, 77%), macroglossia (40, 43%), excessive sweating (39, 42%), prognathism (38, 40%) and frontal bossing (35, 37%). Seventy-five (80%) were macroadenomas and 19 (20%) were microadenomas. Cavernous sinus invasion was present in 45%. Available immunohistochemical data demonstrated GH staining in 88 (94%) and prolactin in 44 (47%). Available postoperative MRI demonstrated gross total resection in 63% of patients and subtotal resection in 37%. Most patients (66%) exhibited hormonal remission at 12 weeks postoperatively. Receiver operating characteristic (ROC) curves demonstrated postoperative day 1 (POD1) GH levels ≥1.55ng/mL predicted failure to remit from surgical resection alone (59% specificity, 75% sensitivity). A second ROC curve showed decrease in corrected insulin-like growth factor-1 (IGF-1) levels of at least 37% prognosticated biochemical control (90% sensitivity, 80% specificity).ConclusionPOD1 GH and short-term postoperative IGF-1 levels can be used to successfully predict immediate and long-term hormonal remission respectively. A POD1 GH cutoff can identify patients likely to require adjuvant therapy to emphasize clinical follow-up.

Quantification of Liver Fat Content after Radiofrequency Ablation for Liver Cancer: Correlation with Hepatic Perfusion Disorders

Purpose: To quantitatively investigate the correlation between liver fat content and hepatic perfusion disorders (HPD) after radiofrequency ablation (RFA) for liver cancer using magnetic resonance imaging (MRI)-determined proton density fat fraction (PDFF). Materials and methods: A total of 150 liver cancer patients underwent liver MRI examination within one month after RFA and at four months after RFA. According to the liver fat content, they were divided into non-, mild, moderate, and severe fatty liver groups. The liver fat content and hepatic perfusion disorders were determined using PDFF images and dynamic contrast-enhanced MRI images. The relationship between the liver fat content and HPD was investigated. Results: At the first postoperative MRI examination, the proportion of patients in the nonfatty liver group with hyperperfused foci (11.11%) was significantly lower than that in the mild (30.00%), moderate (42.86%), and severe fatty liver (56.67%) groups (p < 0.05), whereas the proportions of patients with hypoperfused foci (6.67%, 7.5%, 5.71%, and 6.67%, respectively) were not significantly different among the four groups (p > 0.05). In the nonfatty liver group, the liver fat content was not correlated with hyperperfusion abnormalities or hypoperfusion abnormalities. By contrast, in the three fatty liver groups, the liver fat content was correlated with hyperperfusion abnormalities but was not correlated with hypoperfusion abnormalities. At the second postoperative MRI examination, six patients in the nonfatty liver group were diagnosed with fatty liver, including two patients with newly developed hyperperfusion abnormalities and one patient whose hypoperfusion abnormality remained the same as it was in the first postoperative MRI examination. Conclusion: There was a high correlation between the liver fat content and hyperperfusion abnormalities after RFA for liver cancer. The higher the liver fat content was, the higher the was risk of hyperperfusion abnormalities. However, there was little correlation between liver fat content and hypoperfusion abnormalities, and the increase in postoperative liver fat content did not induce or alter the presence of hypoperfused foci.

Postoperative MRI Findings Following Conventional and Extralevator Abdominoperineal Excision in Low Rectal Cancer

Aim: The disparity in outcomes for low rectal cancer may reflect differences in operative approach and quality. The extralevator abdominoperineal excision (ELAPE) was developed to reduce margin involvement in low rectal cancers by widening the excision of the conventional abdominoperineal excision (c-APE) to include the posterior pelvic diaphragm. This study aimed to determine the prevalence and localization of inadvertent residual pelvic diaphragm on postoperative MRI after intended ELAPE and c-APE.Methods: A total of 147 patients treated with c-APE or ELAPE for rectal cancer were included. Postoperative MRI was performed on 51% of the cohort (n = 75) and evaluated with regard to the residual pelvic diaphragm by a radiologist trained in pelvic MRI. Patient records, histopathological reports, and standardized photographs were assessed. Pathology and MRI findings were evaluated independently in a blinded fashion. Additionally, preoperative MRIs were evaluated for possible risk factors for margin involvement.Results: Magnetic resonance imaging-detected residual pelvic diaphragm was identified in 45 (75.4%) of 61 patients who underwent ELAPE and in 14 (100%) of 14 patients who underwent c-APE. An increased risk of margin involvement was observed in anteriorly oriented tumors with 16 (22%) of 73 anteriorly oriented tumors presenting with margin involvement vs. 7 (9%) of 74 non-anteriorly oriented tumors (p = 0.038).Conclusion: Residual pelvic diaphragm following abdominoperineal excision can be depicted by postoperative MRI. Inadvertent residual pelvic diaphragm (RPD) was commonly found in the series of patients treated with the ELAPE technique. Anterior tumor orientation was a risk factor for circumferential resection margin (CRM) involvement regardless of surgical approach.

BRMP-03. Pituitary carcinoma: a case of dramatic response to immunotherapy (ipilimumab + nivolumab) after failure with temozolomide

INTRODUCTION Pituitary carcinoma (PC) accounts for just 0.1% of all pituitary tumors, often recurs following resection, and has a median reported survival of 1 year. Current treatment guidelines are not standardized but combine surgical resection, radiation therapy, and chemotherapy [1]. Temozolomide is the only chemotherapeutic with documented effectiveness, and the only recommended agent for aggressive pituitary carcinomas in ESE clinical guidelines [3]. CASE: A 57-year-old male presented with visual deterioration over a three-month period. Ophthalmologic evaluation revealed bitemporal visual field deficits. MRI brain W/WO demonstrated a sellar mass suspected to be pituitary macroadenoma with displacement of the stalk and optic nerve impingement (Figure 1a). The patient underwent stereotactic endoscopic transsphenoidal resection of the mass [2]. Postoperative MRI demonstrated gross total resection (Figure 1b). Pathology revealed a sparsely granulated corticotroph-adenoma with malignant transformation (early in-situ PC). Immunohistochemistry showed LOE of MLH1 and PMS2 in the tumor cells; Genetic analysis revealed MGMT methylation. Proton therapy was recommended given the elevated Ki67 index (75%) and p53 positivity. Before radiotherapy, there was no evidence of residual tumor or metastasis radiographically. He received 6600cGy of radiation over 33 fractions. Surveillance MRI showed recurrence at 21 months postoperatively, and temozolomide was initiated. However, MRI demonstrated marked progression after 3 cycles, and at 44 months, he developed a new 6th nerve palsy (Figure1c). Next-generation sequencing using the MSK-IMPACT platform identified somatic mutations in MLH1 Y548lfs*9 and TP53 R337C[4]. Immunotherapy with ipilimumab/nivolumab was initiated [5], and the patient noted resolution of his third nerve palsy soon after. MRI demonstrated a dramatic response with only minimal residual tumor burden (Figure1d). CONCLUSION PC is a rare tumor with frequent recurrence and a short median expected length of survival. Here we demonstrate the utility of immunotherapy in a single case report of PC. This treatment helped our patient survive well beyond the expected median life expectancy of this aggressive disease.