Cerebral pseudocysts following chemotherapy of glioblastomas

Efficacy and safety of cysto-ventricular catheter implantation for space-occupying cysts arising from glioma and brain metastasis: a retrospective study

BACKGROUND

Cysto-ventricular catheters (CVC) have emerged as promising treatment option for cystic craniopharyngioma and arachnoid cysts, but their effectiveness in treating cysts originating from glioma or brain metastasis (BM) remains limited. This study aimed to analyze the efficacy of CVC in patients with glioma and BM as well as procedure-associated morbidity.

METHODS

This single-center retrospective study included all patients treated with CVC placement for acquired space-occupying cysts deriving from previously treated glioma or BMs between 1/2010 and 12/2021.

RESULTS

A total of 57 patients with a median age of 47 years (IQR 38-63) were identified. Focal neurological deficits were the predominant symptoms in 60% of patients (n = 34), followed by cephalgia in 14% (n = 8), and epileptic seizures in 21.1% (n = 12). Accurate CVC placement was achieved in all but one case requiring revision surgery due to malposition. Three months after CVC implantation, 70% of patients showed symptomatic improvement. Multivariate logistic regression analysis identified the development of space-occupying cysts later in the course of the disease (OR 1.014; p = 0.04) and a higher reduction of cyst-volume postoperatively (OR 1.055; p = 0.05) were significant predictors of postoperative symptomatic improvement following CVC placement. Local cyst recurrence was observed in three cases during follow-up MRI after an average time of 5 months (range 3-9 months). Further complications included secondary malresorptive hydrocephalus in three cases and meningeosis neoplastica in one patient.

CONCLUSIONS

Stereotactic implantation of CVC is an efficient treatment option for patients suffering from symptomatic space-occupying cysts from BMs or glioma, independently from their CNS WHO grade. However, a vigilant approach is crucial regarding potential complications and treatment failures.

Cystic glioblastoma: an evaluation of IDH1 status and prognosis

BACKGROUND

Controversy exists regarding the prognostic significance of cystic features in newly diagnosed glioblastoma multiforme (GBM) and the pathological origin of cystic GBMs.

OBJECTIVE

To determine whether cystic GBMs develop from low-grade gliomas by evaluating IDH1 status and to evaluate the differences in overall survival between patients with cystic and noncystic tumors.

METHODS

We retrospectively reviewed the records of 351 consecutive newly diagnosed adult GBM patients treated at our institution from October 1997 to November 2011; patients with >50% cystic tumor composition were further identified. IDH1 mutation was determined by immunohistochemical staining. Patient characteristics and treatment were reported for cystic and noncystic tumors separately. Overall survival was reported for cystic and noncystic cohorts by using the Kaplan-Meier estimates.

RESULTS

Of 351 patients, 27 (7.7%) had cystic tumors and 324 (92.3%) had noncystic tumors. Tumor samples for patients with cystic GBMs were immunohistochemically analyzed for IDH1 mutations. Two (7.4%) of the 27 tumor samples were documented as having IDH1 mutations. Characteristics such as age, sex, perioperative Karnofsky Performance Status, tumor size, extent of resection, postsurgery radiation, and temozolomide therapy were comparable in the and noncystic cohorts. Patients in the cystic cohort had a median overall survival of 15.0 months compared with 18.2 months for the noncystic cohort (log-rank P = .77).

CONCLUSION

The low frequency of IDH1 mutation status in our cystic cohort strongly suggests that most newly diagnosed cystic GBMs do not arise from malignant transformation of previously undiagnosed low-grade gliomas. Furthermore, there is no difference in overall survival between patients newly diagnosed with cystic and noncystic GBMs.

Brain tumor classification using the diffusion tensor image segmentation (D-SEG) technique

Background

There is an increasing demand for noninvasive brain tumor biomarkers to guide surgery and subsequent oncotherapy. We present a novel whole-brain diffusion tensor imaging (DTI) segmentation (D-SEG) to delineate tumor volumes of interest (VOIs) for subsequent classification of tumor type. D-SEG uses isotropic (p) and anisotropic (q) components of the diffusion tensor to segment regions with similar diffusion characteristics.

Methods

DTI scans were acquired from 95 patients with low- and high-grade glioma, metastases, and meningioma and from 29 healthy subjects. D-SEG uses k-means clustering of the 2D (p,q) space to generate segments with different isotropic and anisotropic diffusion characteristics.

Results

Our results are visualized using a novel RGB color scheme incorporating p, q and T2-weighted information within each segment. The volumetric contribution of each segment to gray matter, white matter, and cerebrospinal fluid spaces was used to generate healthy tissue D-SEG spectra. Tumor VOIs were extracted using a semiautomated flood-filling technique and D-SEG spectra were computed within the VOI. Classification of tumor type using D-SEG spectra was performed using support vector machines. D-SEG was computationally fast and stable and delineated regions of healthy tissue from tumor and edema. D-SEG spectra were consistent for each tumor type, with constituent diffusion characteristics potentially reflecting regional differences in tissue microstructure. Support vector machines classified tumor type with an overall accuracy of 94.7%, providing better classification than previously reported.

Conclusions

D-SEG presents a user-friendly, semiautomated biomarker that may provide a valuable adjunct in noninvasive brain tumor diagnosis and treatment planning.

Stent placement for intracranial cysts by combined stereotactic/endoscopic surgery

OBJECTIVE

The treatment of space-occupying cystic lesions includes percutaneous cyst aspiration, marsupialization, percutaneous ventriculocystotomy, or Rickham catheter implantation. In some patients, the cysts tend to recur and repeated evacuations are necessary. The authors present a new treatment method with internal drainage of cysts into the ventricular system using a balloon-mounted vascular stent.

METHODS

Six patients with cysts of low-grade gliomas, one with monocystic craniopharyngioma, and one with suprasellar arachnoid cyst were treated between September 2003 and May 2005. All patients were symptomatic after multiple previous treatments. Stent implantations were performed under local anesthesia in adults and under general anesthesia in children. In all patients, the stereotactic frame and computed tomographic and magnetic resonance fusion were used for an optimized approach. The treatment was performed in a compassionate manner and the patients were informed about the off-label use of the device.

RESULTS

Stent placement was successful in all eight patients without procedure-related complications. Improvement of clinical symptoms was seen in seven out of eight patients. Seven out of eight cysts decreased in size within a follow-up period of up to 23 months (mean, 17 mo; median, 18 mo; range, 6-23 mo). The first patient showed recurrence of the tumor cyst 3 months after initial treatment with a Herkulink stent (5 x 18 mm), followed by retreatment with an Omnilink stent (6 x 28 mm; Guidant Corp., Santa Clara, CA). Stenting was ineffective in one patient.

CONCLUSION

Treatment of intracranial cystic lesions by internal drainage is possible with the use of stent-assisted ventriculocystostomy.

Pathophysiology of glioma cyst formation

Fluid filled cystic cavities are accompaniments of some cerebral gliomas. These tumoural cysts together with peritumoural vasogenic brain oedema add to the morbid effects of the gliomas in terms of mass effect and increased intracranial pressure. Although different mechanisms have been suggested as to the pathogenesis of glioma-associated cysts, it is still unclear why these cysts appear in only a limited number of cerebral gliomas while brain oedema, a probable precursor of glioma cysts, is a usual accompaniment of most gliomas. Here, the authors present a two-hit hypothesis of brain glioma cyst formation. We suggest that after the formation of vasogenic tumoural brain oedema, microvascular phenomena may lead to the formation of microcysts, which might later become confluent and grow to form macroscopic cysts. Progress in the understanding of pathogenesis of cerebral glioma cysts might set targets for treatment of brain edema and glioma cysts.

Management of tumor bed cysts after chemotherapeutic wafer implantation. Report of four cases

Adjuvant use of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) wafers with surgical resection is becoming common for the treatment of malignant gliomas. Cyst formation in the tumor resection cavity is a recently described complication associated with the use of BCNU wafers. There is currently no report in which successful management of this complication without additional surgical intervention is described. The authors describe four patients in whom postoperative cysts developed in the tumor resection cavity after placement of BCNU wafers. These include a 38-year-old man with a left frontoparietal tumor, a 48-year-old man with a right frontal lobe tumor, a 78-year-old man with a left parietooccipital tumor, and a 61-year-old woman with a left frontotemporal tumor. Histopathological studies of biopsy samples revealed malignant glioma in each patient. All four patients had unremarkable perioperative courses, were discharged within 3 to 8 days of surgery, and subsequently returned with acute neurological deterioration. Follow-up magnetic resonance (MR) imaging demonstrated cyst formation with significant mass effect at the previous resection site. Three patients were treated with high-dose dexamethasone and returned to their neurological baseline over an 8-day period. The fourth patient improved after surgical drainage and biopsy sampling of the cyst, which revealed no evidence of infection or recurrent tumor, but again sought medical care 2 weeks later with cyst recurrence necessitating high-dose steroid therapy. On MR images at least a 30% reduction in cyst size was demonstrated in all four patients, each of whom remained clinically stable at 2, 6, 6, and 4 months of follow-up review. Neurosurgeons should be aware of the potential for postoperative cyst formation accompanied by clinically significant mass effect after BCNU wafer implantation, as well as the potential for successful nonsurgical management leading to clinical and radiological improvement.

The role of stereotactic cyst aspiration for glial and metastatic brain tumors

OBJECTIVE

To evaluate the role of stereotactic cyst aspiration in the context of multimodality management of cystic glial and metastatic tumors, we retrospectively reviewed our experience with 38 patients during a 10-year interval.

METHODS

All 38 patients had one or more computed tomography or magnetic resonance imaging guided stereotactic cyst aspirations. Twenty-seven patients had glial neoplasms and 11 had metastatic brain tumors. Twenty-two patients underwent cyst aspiration as the initial treatment modality while 15 patients had cyst aspiration following previous treatments.

RESULTS

In the immediate postoperative period, 19 of the 27 (70%) patients with gliomas and nine of the 11 (82%) patients with metastatic tumors experienced symptomatic improvement. No procedure-related morbidity was encountered. Twelve patients (31.5%) eventually required a catheter-reservoir system. Thirty-seven percent of patients with cystic glial neoplasms and 18% of patients with metastatic tumors had delayed cytoreductive surgery by craniotomy subsequent to stereotactic cyst aspiration. Reduction in tumor volume following aspiration facilitated Gamma knife radiosurgery in seven patients.

CONCLUSION

Single stereotactic aspiration is a low risk procedure that provides immediate relief of symptoms in patients with cystic brain tumors. It appears to be valuable together with the use of other therapeutic strategies.

Differential diagnosis of supratentorial cystic intracranial lesions by CT-scanning

Although CT scanning has considerably improved diagnostic accuracy, problems remain in establishing a precise preoperative diagnosis in cases of intracranial lesions especially when a cyst is present. Five cases of cystic lesions are presented to illustrate these problems. The CT features of cystic lesions as well as the pathophysiological processes that lead to their formation are discussed. The pertinent literature on this topic is reviewed.

Treatment of cystic astrocytomas with intracavitary phosphorus 32

Cyst formation by astrocytomas can cause progressive neurological deficit and can necessitate multiple surgical procedures. Before the advent of computed tomography (CT) preoperative diagnosis of cystic astrocytomas was difficult and stereotactic management of these lesions was limited. CT-guided stereotaxy provides a safe approach to all cystic astrocytomas including brain stem lesions. Based upon the experience of intracavitary radiation of craniopharyngioma cysts, the authors treated nine patients presenting with cystic astrocytomas utilizing colloidal chromium phosphorus 32 (32P). Control of cyst formation was achieved in eight patients. Our preliminary data suggest that intracavitary 32P may provide a significant adjunctive therapy in the management of cystic astrocytomas.

Correction factors for gravimetric measurement of peritumoural oedema in man

The water content of samples of normal and oedematous brain in lobectomy specimens from 16 patients with cerebral tumours has been measured by gravimetry and by wet and dry weighing. Uncorrected gravimetry underestimated the water content of oedematous peritumoural cortex by a mean of 1.17%, and of oedematous peritumoural white matter by a mean of 2.52%. Gravimetric correction equations calculated theoretically and from an animal model of serum infusion white matter oedema overestimate peritumoural white matter oedema in man, and empirical gravimetric error correction factors for oedematous peritumoural human white matter and cortex have therefore been derived. These enable gravimetry to be used to accurately determine peritumoural oedema in man.

Status spongiosus in the course of treatment of malignant gliomas

Two cases of fatal encephalopathy which appeared in the course of treatment of malignant gliomas are described. CT scan showed diffuse, low density, non-enhanced lesions of the white matter. Pathological findings showed that the CT scan aspects corresponded to status spongiosus without demyelination. We were unable to find similar reports in the literature.

Cerebral space-occupying cysts following radiation and chemotherapy of malignant gliomas

Eight cases of cerebral cyst formation among 50 patients (= 16%) with malignant supratentorial gliomas treated by surgery, megavoltage radiation, and multiple-agent chemotherapy are reported. Five of them developed signs of intracranial hypertension or progressive neurological deficit, while in three patients cerebral cysts were detected by CT without clinical deterioration. At operation or autopsy, or both, the large fluid-filled, smooth-walled cysts were lined by glio-mesenchymal scar tissue with no or little tumour recurrence in five, while three patients showed large recurrent tumour masses associated with necrosis and cyst formation. Clinical signs or CT evidence, or both, of cerebral cysts developed 4 to 12 months (average 10 months) after the first craniotomy, and 3 to 9 months after termination of radiotherapy, usually after the second to fourth course of polychemotherapy. The cystic cavities which are attributed to increased necrosis and other effects of radiation and cytostatic treatment, may mimic tumour progression or recurrence, and cerebral abscess, but are usually recognized by CT. Surgical treatment produced transient clinical improvement in 5 patients, but usually did not prevent the fatal outcome of the disease, which in these paticrosis and other effects of radiation and cytostatic treatment, may mimic tumour progression or recurrence, and cerebral abscess, but are usually recognized by CT. Surgical treatment produced transient clinical improvement in 5 patients, but usually did not prevent the fatal outcome of the disease, which in these paticrosis and other effects of radiation and cytostatic treatment, may mimic tumour progression or recurrence, and cerebral abscess, but are usually recognized by CT. Surgical treatment produced transient clinical improvement in 5 patients, but usually did not prevent the fatal outcome of the disease, which in these patients occurred 3 weeks to 6 months after surgical treatment of cyst formation, their life span ranging from 9 to 22 months. The pathogenesis and clinical problems related to cerebral cysts arising following multimodality treatment of malignant brain tumours are discussed.

Cysts in malignant gliomas. Identification by computerized tomography

The clinical course, computerized tomography (CT) scans, and postmortem reports for 265 patients treated for malignant brain tumors were reviewed. Forty-one patients underwent reoperation for tumor recurrence and one had needle aspiration as a diagnostic procedure; of these patients, seven (3% of 265 and 17% of 42) were diagnosed as harboring tumor cysts and 10 (25% of 41) as having necrotic tumor centers. The CT scans on the 17 patients harboring tumors with surgically confirmed cysts and necrotic centers were reviewed; criteria for distinguishing between cysts and central necrosis are suggested. The relative benefits of repeated aspiration and surgical therapy for these cystic lesions are discussed.

Malignant gliomas treated after surgery by combination chemotherapy and delayed irradiation. Part I: Analysis of results

Forty-six patients with gliomas were introduced after surgery into a therapeutic programme of six cycles of combination chemotherapy with VM26 and CCNU, followed by delayed irradiation six months after surgery with an average dose of 5,800 rads. After irradiation the same preradiation chemotherapy was readministered for an average of four cycles. The results were compared to those from another group of 28 patients treated only by the same chemotherapy (CRC and C groups sucessively). Twelve patients (26%) died before irradiation in the CRC group, six patients (13%) had recurrences at the time of irradiation, and 28 patients (61%) had no clinical or radiological signs of recurrence at the time of irradiation. For the total of treated patients the median survival after surgery was 17 months, and 46% of the patients were surviving at 18 months. The percentage of survivors at 18 months was significantly more elevated in the group treated by combination chemotherapy and delayed irradiation than in a control group treated by the same combination chemotherapy alone. This result suggests that in approximately 50% of cases combination chemotherapy after surgery, and delayed irradiation six months after surgery, cumulated their effects on survival time.

Malignant gliomas treated after surgery by combination chemotherapy and delayed radiation therapy. Part II. Tolerance to irradiation after chemotherapy

34 patients operated on for malignant gliomas were successively treated by combination chemotherapy with VM26 and CCNU and conventional radiation therapy with an average dosage of 5,800 Rads, six months after surgery. The general and haematological tolerance of delayed irradiation after chemotherapy was satisfactory. Twelve patients developed neurological complications during or after irradiation. The complications were early in 10 cases, and delayed in 2. They were probably due to tumour growth in five cases, and secondary to irradiation in seven. In four of the seven cases the preradiation chemotherapy seemed to potentiate the radiation effect on the central nervous system.