Risk Factors Associated with Development of Peritumoral Edema Following Stereotactic Radiosurgery and Radiotherapy for Intracranial Meningioma

PURPOSE/OBJECTIVE(S)

Peritumoral edema (PTE) is a potential adverse effect following radiotherapy for intracranial meningioma. The purpose of this study is to identify which baseline factors may increase risk for PTE.

MATERIALS/METHODS

A retrospective chart review was conducted of 431 patients who underwent primary radiotherapy to 480 radiographically-defined intracranial meningiomas between January 2008 and December 2021 within an integrated health care system. Patients with prior surgical management were excluded. Patients were treated with frameless LINAC-based image-guided single fraction stereotactic radiosurgery (SRS) (32.9%), 5 fraction SRS (FSRS) (30.8%), or fractionated stereotactic radiotherapy (FSRT) (36.3%). Pre- and post-radiotherapy MRI studies were reviewed to evaluate for PTE following treatment. An event was defined as new or worsening PTE compared to pre-radiotherapy imaging or development of new symptoms post-radiotherapy. Univariate and stepwise logistics regression analyses were performed to compare the risk of PTE between groups.

RESULTS

Median follow-up was 85.8 months (IQR: 49.4-125.4). Median patient age was 66 years (IQR: 56-73). Patients treated with SRS (median age: 61 years) were younger than those treated with FSRS/FSRT (median age: 68 years) (p<0.001). Lesions treated with SRS (median volume: 1.33cc) were smaller than those treated with FSRS/FSRT (median volume: 6.36cc) (p<0.001). For all-comers, 68 (14.2%) lesions developed any PTE, and 27 (5.6%) developed symptomatic PTE (SPTE). Of these, 4 patients developed symptoms post-treatment without radiographic evidence of new or worsening PTE. Incidence of PTE/SPTE by site was as follows: base of skull (BOS): 10.3%/6.1%, convexity: 22.7%/7.6%, falcine: 17.6%/4.1%, parasagittal: 27.8%/8.3%, posterior fossa/tentorium 7.0%/0.0%. Incidence of PTE/SPTE by technique was as follows: SRS: 6.3%/3.8%, FSRS: 20.9%/7.4%, FSRT: 15.5%/5.7%. On univariate analysis, age >65 (OR = 2.17 (95% CI: 1.26-3.77) p = 0.006), tumor volume (OR = 1.05 (1.02-1.08), p = 0.003), pre-treatment PTE (OR = 6.82 (95% CI: 3.59-12.94) p<0.001), and convexity/falcine/parasagittal (CFPS) location (OR = 2.52 (95% CI: 1.49-4.23) p<0.001) were associated with increased incidence of PTE. On multivariate analysis, age >65 (OR = 1.91 (95% CI: 1.05-3.45) p<0.03), tumor volume (OR = 1.04 (95% CI: 1.00-1.08) p = 0.03), pre-treatment PTE (OR = 4.64 (95% CI: 2.33-9.24) p<0.001), and CFPS location (OR = 2.53 (95% CI: 1.41-4.52) p = 0.002) were associated with increased incidence of PTE. Two patients with PTE underwent resection for local failure which revealed atypical meningioma.

CONCLUSION

Age >65, larger tumor volume, presence of pre-treatment PTE, and CFPS location were associated with increased incidence of PTE following radiotherapy. Patients with these risk factors should be counseled regarding post-treatment effects. Infrequently, PTE following treatment may be an indicator of higher-grade meningioma.

Clinical Outcomes Following Postoperative Cavity Stereotactic Radiosurgery for Brain Metastases

PURPOSE/OBJECTIVE(S)

We evaluated outcomes of patients with brain metastases (BM) treated with surgical resection and postoperative cavity stereotactic radiosurgery (SRS) to identify which baseline characteristics and treatment factors may increase risk for local recurrence (LR).

MATERIALS/METHODS

From June 2017 to December 2021, 68 patients underwent surgical resection for BM followed by single-fraction SRS (n = 15) or fractionated SRS (FSRS) in 3 (n = 24) or 5 (n = 29) fractions to the postoperative cavity using frameless LINAC-based technique. Patients treated with surgery alone or surgery with postoperative whole brain radiotherapy (WBRT) were excluded. Median prescription doses were 1600 cGy (range: 1440-1875) in 1 fraction, 2400 cGy (range: 2100-2700) in 3 fractions, and 3000 cGy (range: 2500-3000) in 5 fractions. Local control (LC) and overall survival (OS) were estimated by the Kaplan-Meier method. Cox proportional hazards models were used to compare groups.

RESULTS

Median follow-up was 19.5 months (IQR: 9.0-34.7). Median patient age was 62.5 years (range: 24-80), and 38 (55.9%) patients were male. Primary tumors were lung (n = 29), including NSCLC (n = 28) and SCLC (n = 1), melanoma (n = 12), breast (n = 11), and other (n = 16). Median preoperative tumor maximal dimension was 3.5cm (range: 1.1-6.3). Median planning treatment volume (PTV) was larger in the FSRS group (26.2cc (range: 6.5-151.8)) than in the SRS group (7.7cc (range: 1.1-11.5)) (p<0.001). Median number of concurrently treated intact lesions was 0 (range: 0-13). Median time from surgery to SRS was 32 days (range: 14-77). Forty-eight (70.6%) patients were treated with immunotherapy or targeted therapy. Median OS was 22.3 months (95% CI: 14.4-30.9). The 1-year and 2-year OS rates were 70% and 48%, respectively. The 1-year and 2-year LC rates were 86% and 73%, respectively. Median time to LR was 8.4 months (95% CI: 4.4-11.0). Among the 14 patients with LR, 11 had undergone salvage therapy at last follow-up which included repeat SRS (n = 4), WBRT (n = 3), palliative local radiotherapy (n = 2), surgery followed by repeat SRS (n = 1), and systemic therapy (n = 1). Eleven (16.2%) patients ultimately underwent WBRT post-SRS for local and/or distant failure. No difference in LC was observed based on primary tumor, time interval between resection and SRS, PTV volume, prescription dose, or fractionation regimen (SRS v. FSRS). However, all LR in the 3-fraction group occurred in patients who received less than 2700 cGy.

CONCLUSION

Favorable LC and OS outcomes were observed following postoperative cavity SRS for resected BM in a modern cohort with a large percentage of patients receiving immunotherapy or targeted therapy. No prognostic factors were identified for LC which may be attributable to the cohort size and small number of events observed. However, our findings suggest that patients who undergo 3-fraction FSRS should be treated to a total dose of 2700 cGy to maximize LC.

Experience Using the Pterional Keyhole Approach for the Treatment of Ruptured Intracranial Aneurysms of the Anterior Circulation

BACKGROUND

The pterional keyhole approach is a more recently introduced minimally invasive version of the traditional pterional approach for treating aneurysms of the anterior circulation.

METHODS

In this study, we compared operative parameters and clinical outcomes in patients treated with the pterional keyhole approach and historical controls in whom the traditional pterional approach was used. We reviewer records of 356 patients treated with the pterional keyhole approach between 2009 and 2016, along with those of 301 patients treated via the traditional pterional approach at the same period who served as a control group. The clinical manifestations, surgical details, postoperative complications, and modified Rankin Scale scores in the 2 groups were retrospectively compared.

RESULTS

There were 408 aneurysms in the study group and 362 aneurysms in the control group. In the pterional keyhole group, the total clipping ratio was 93.6%, leaving a remnant/wrapping rate of 6.37%, compared with 93.9% and 6.08%, respectively, in the standard pterional group. In the patients treated via the keyhole approach, the mean bone flap diameter was 4 × 3 cm, mean blood loss was 204 ± 100 mL, mean operation time was 160 ± 57 minutes, and mean length of stay was 8.32 ± 2.72 days, compared with control group parameters of 5 × 6 cm, 284 ± 150 mL, 180 ± 49 minutes, and 11.32 ± 2.48 days, respectively. At a 6-month follow-up, 71.1% had a favorable outcome, 25.8% had a poor outcome, and the mortality was 3.09%, compared with 68.1%, 29.9% and 1.99%, respectively, in the control group.

CONCLUSIONS

The pterional keyhole approach offers shorter operative times, less blood loss, shorter length of stay, and improved cosmesis without sacrificing outcomes compared with traditional pterional craniotomy.

Simultaneous cerebrospinal fluid and hematologic metastases in a high-grade ependymoma

Background

Ependymomas are relatively uncommon tumors that constitute about 7% of all primary intracranial neoplasms. Among these, high-grade ependymomas are locally aggressive and recur most commonly at the primary site following resection. Ependymomas are also known to be the one glial neoplasm that tends to frequently metastasize inside and outside the central nervous system (CNS) that complicates workup and management. Metastasis due to surgical manipulation is common and neurosurgeons should be well-versed in the most effective methods to remove these tumors in order to avoid such metastases.

Case Description

Here, we report a case of a 28-year-old female who initially presented with a parenchymal World Health Organization (WHO) grade III anaplastic ependymoma of the occipital lobe without metastasis. After multiple resections, the patient showed no evidence of disease recurrence for 2 years. During follow-up, new metastasis to the frontal lobe as well as to the lung were discovered 2 years after the initial surgery, without recurrence at the tumor's primary site.

Conclusions

While uncommon, this case demonstrates the possibility for ependymomas to metastasize via cerebrospinal fluid to other locations within the CNS and hematologically to extraneural locations without recurring locally.

Neurenteric cyst of the conus medullaris

Background:

Neurenteric cysts (NECs) are rare developmental malformations of the central nervous system (CNS) which originate as benign congenital lesions. They originate from developmental foregut precursors, and are presumed to be the result of abnormal partitioning of the embryonic notochord plate. Such NECs predominantly arise in the cervical region in patients around 6 years of age or in their twenties or thirties. Notably, NECs of the conus medullaris are exceedingly rare, especially in patients of advanced age.

Case Description:

A 70-year-old male presented with bilateral upper thigh and leg pain of over 20 years duration. His pain worsened over the past 3 years, and he sought surgical management. Although his neurological exam was normal, the lumbar magnetic resonance imaging revealed an intradural, nonenhancing, thin-walled, cystic lesion at L1/conus medullaris. The lesion was successfully resected without any adverse sequelae.

Conclusions:

NECs are rare congenital legions that involve the spine. Here, an L1 intradural extramedullay neuroenteric cyst of the conus medullaris was resected without complications.

Surgical nuances of partial sacrectomy for chordoma

Background:

Sacral chordomas are rare, slow growing, locally aggressive tumors. Unfortunately, aggressive surgical resection is often associated with increased neurological morbidity.

Methods:

This technical note focuses on the utilization of partial sacrectomy for the resection of complex spinal chordomas.

Results:

The case presented documents the potential range of postoperative morbidity seen in patients undergoing partial sacrectomy for chordomas. Despite iatrogenic morbidity and tumor recurrence, with the cooperation of medical and surgical spine specialists, majority of patients can achieve good long-term outcomes.

Conclusions:

Sacral chordomas are rare lesions and pose a therapeutic challenge for spinal surgeons and oncologists. En-bloc surgical resection (e.g., partial sacrectomy) is the treatment of choice for these lesions, and the cooperation between subspecialists can lead to good neurologic outcomes, particularly if gross total resection is achieved.

Adult sacrococcygeal teratoma with coccygectomy: A case report with a review of the literature

Background:

Saccrococcygeal teratomas (SCT) are derived from embryonic germ cell layers. They frequently present at the base of the coccyx within the pelvis. While these tumors are common in children, they are exceedingly rare in adults. In adults, a majority of these tumors are intrapelvic and associated with a low risk of malignant transformation. Therefore, this contributes to a good prognosis following resection of mostly benign lesions.

Case Description:

An adult female with chronic pelvic pain presented with a sacral teratoma. She failed conservative treatment and underwent a coccygectomy with an en-bloc excision of the tumor. Microscopic histological analysis showed no evidence of immature or malignant elements, confirming the diagnosis of a mature, benign, cystic SCT.

Conclusions:

Mature SCTs in adults are rare malignant lesions. In this case, the patient was cured following primary surgical excision requiring en-bloc coccygectomy.

Efficacy of systemic adoptive transfer immunotherapy targeting NY-ESO-1 for glioblastoma

BACKGROUND

Immunotherapy is an ideal treatment modality to specifically target the diffusely infiltrative tumor cells of malignant gliomas while sparing the normal brain parenchyma. However, progress in the development of these therapies for glioblastoma has been slow due to the lack of immunogenic antigen targets that are expressed uniformly and selectively by gliomas.

METHODS

We utilized human glioblastoma cell cultures to induce expression of New York-esophageal squamous cell carcinoma (NY-ESO-1) following in vitro treatment with the demethylating agent decitabine. We then investigated the phenotype of lymphocytes specific for NY-ESO-1 using flow cytometry analysis and cytotoxicity against cells treated with decitabine using the xCelligence real-time cytotoxicity assay. Finally, we examined the in vivo application of this immune therapy using an intracranially implanted xenograft model for in situ T cell trafficking, survival, and tissue studies.

RESULTS

Our studies showed that treatment of intracranial glioma-bearing mice with decitabine reliably and consistently induced the expression of an immunogenic tumor-rejection antigen, NY-ESO-1, specifically in glioma cells and not in normal brain tissue. The upregulation of NY-ESO-1 by intracranial gliomas was associated with the migration of adoptively transferred NY-ESO-1-specific lymphocytes along white matter tracts to these tumors in the brain. Similarly, NY-ESO-1-specific adoptive T cell therapy demonstrated antitumor activity after decitabine treatment and conferred a highly significant survival benefit to mice bearing established intracranial human glioma xenografts. Transfer of NY-ESO-1-specific T cells systemically was superior to intracranial administration and resulted in significantly extended and long-term survival of animals.

CONCLUSION

These results reveal an innovative, clinically feasible strategy for the treatment of glioblastoma.

Cytokine responsiveness of CD8(+) T cells is a reproducible biomarker for the clinical efficacy of dendritic cell vaccination in glioblastoma patients

Background

Immunotherapeutic approaches, such as dendritic cell (DC) vaccination, have emerged as promising strategies in the treatment of glioblastoma. Despite their promise, however, the absence of objective biomarkers and/or immunological monitoring techniques to assess the clinical efficacy of immunotherapy still remains a primary limitation. To address this, we sought to identify a functional biomarker for anti-tumor immune responsiveness associated with extended survival in glioblastoma patients undergoing DC vaccination.

Methods

28 patients were enrolled and treated in two different Phase 1 DC vaccination clinical trials at UCLA. To assess the anti-tumor immune response elicited by therapy, we studied the functional responsiveness of pre- and post-vaccination peripheral blood lymphocytes (PBLs) to the immunostimulatory cytokines interferon-gamma (IFN-γ) and interleukin-2 (IL-2) in 21 of these patients for whom we had adequate material. Immune responsiveness was quantified by measuring downstream phosphorylation events of the transcription factors, STAT-1 and STAT-5, via phospho-specific flow cytometry.

Results

DC vaccination induced a significant decrease in the half-maximal concentration (EC-50) of IL-2 required to upregulate pSTAT-5 specifically in CD3⁺CD8⁺ T lymphocytes (p < 0.045). Extended survival was also associated with an increased per cell phosphorylation of STAT-5 in cytotoxic T-cells following IL-2 stimulation when the median post/pre pSTAT-5 ratio was used to dichotomize the patients (p = 0.0015, log-rank survival; hazard ratio = 0.1834, p = 0.018). Patients whose survival was longer than two years had a significantly greater pSTAT-5 ratio (p = 0.015), but, contrary to our expectations, a significantly lower pSTAT-1 ratio (p = 0.038).

Conclusions

Our results suggest that monitoring the pSTAT signaling changes in PBL may provide a functional immune monitoring measure predictive of clinical efficacy in DC-vaccinated patients.