Asymptomatic Postoperative Cerebral Venous Sinus Thrombosis After Posterior Fossa Tumor Surgery: Incidence, Risk Factors, and Therapeutic Options

BACKGROUND

Cerebral venous sinus thrombosis (CVST) is a known complication of posterior fossa surgery near the sigmoid and transverse sinus. The incidence and treatment of postoperative asymptomatic CVST are controversial.

OBJECTIVE

To analyze incidence, risk factors, and management of asymptomatic postoperative CVST after posterior fossa tumor surgery.

METHODS

In this retrospective, single-center study, we included all patients who underwent posterior fossa tumor surgery in the semisitting position between January 2013 and December 2020. All patients underwent preoperative and postoperative imaging using MRI with/without additional computed tomography angiography. We analyzed the effect of demographic and surgical data on the incidence of postoperative CVST. Furthermore, therapeutic anticoagulation or conservative treatment for postoperative CVST and the incidence of intracranial hemorrhage were investigated.

RESULTS

In total, 266 patients were included. Thirty-three of 266 (12.4%) patients developed postoperative CVST. All patients were asymptomatic. Thirteen of 33 patients received therapeutic anticoagulation, and 20 patients did not. Univariate analysis showed that age ( P = .56), sex ( P = .20), American Society of Anesthesiology status ( P = .13), body mass index ( P = .60), and length of surgery ( P = .176) were not statistically correlated with postoperative CVST. Multivariate analysis revealed that meningioma ( P < .001, odds ratio 11.3, CI 95% 4.1-31.2) and vestibular schwannoma ( P = .013, odds ratio 4.4, CI 95% 1.3-16.3) are risk factors for the development of new postoperative CVST. The use of therapeutic anticoagulation to treat postoperative CVST was associated with a higher rate of intracranial hemorrhage (n = 4, P = .017).

CONCLUSION

Tumor entity influences the incidence of postoperative CVST. In clinically asymptomatic patients, careful decision making is necessary whether to initiate therapeutic anticoagulation or not.

Infusion of 5-Azacytidine (5-AZA) into the fourth ventricle or resection cavity in children with recurrent posterior Fossa Ependymoma: a pilot clinical trial

BACKGROUND

DNA methylation inhibitors are logical therapeutic candidates for ependymomas originating in the posterior fossa of the brain. Our objective was to test the safety of infusing 5-Azacytidine (5-AZA), a DNA methylation inhibitor, directly into cerebrospinal fluid (CSF) spaces of the fourth ventricle or tumor resection cavity in children with recurrent ependymoma originating in the posterior fossa.

MATERIALS AND METHODS

In patients with recurrent ependymoma whose disease originated in the posterior fossa, a maximal safe subtotal tumor resection was performed. At the conclusion of the tumor resection, a catheter was surgically placed into the fourth ventricle or tumor resection cavity and attached to a ventricular access device. CSF flow from the posterior fossa to the sacrum was confirmed by CINE phase contrast magnetic resonance imaging (MRI) postoperatively. 12 consecutive weekly 10 milligram (mg) infusions of 5-Azacytidine (AZA) were planned. Disease response was monitored with MRI scans and CSF cytology.

RESULTS

Six patients were enrolled. One patient was withdrawn prior to planned 5-AZA infusions due to surgical complications after tumor resection. The remaining five patients received 8, 12, 12, 12, and 12 infusions, respectively. There were no serious adverse events or new neurological deficits attributed to 5-AZA infusions. All five patients with ependymoma who received 5-AZA infusions had progressive disease. Two of the five patients, however, were noted to have decrease in the size of at least one intraventricular lesion.

CONCLUSION

5-AZA can be infused into the fourth ventricle or posterior fossa tumor resection cavity without causing neurological toxicity. Future studies with higher doses and/or increased dosing frequency are warranted.

Brainstem primitive neuroectodermal tumors (bstPNET): results of treatment with intensive induction chemotherapy followed by consolidative chemotherapy with autologous hematopoietic cell rescue

We have evaluated the response rate and survival utilizing intensified chemotherapy followed by myeloablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) and adjuvant radiation therapy in six young children with newly diagnosed brainstem primitive neuroectodermal tumors (bstPNET). Following maximum surgical resection of the tumor, patients received high dose induction chemotherapy including vincristine, cisplatin, cyclophosphamide, and etoposide. Eligible patients received a single cycle of myeloablative chemotherapy followed by AuHCR. Two patients survive at least 32 months with stable disease. This approach provides an alternative for young patients with bstPNET who in prior reports have had a uniformly fatal prognosis.

Multi-institution prospective trial of reduced-dose craniospinal irradiation (23.4 Gy) followed by conformal posterior fossa (36 Gy) and primary site irradiation (55.8 Gy) and dose-intensive chemotherapy for average-risk medulloblastoma

PURPOSE

Limiting the neurocognitive sequelae of radiotherapy (RT) has been an objective in the treatment of medulloblastoma. Conformal RT to less than the entire posterior fossa (PF) after craniospinal irradiation might reduce neurocognitive sequelae and requires evaluation.

METHODS AND MATERIALS

Between October 1996 and August 2003, 86 patients, 3-21 years of age, with newly diagnosed, average-risk medulloblastoma were treated in a prospective, institutional review board-approved, multi-institution trial of risk-adapted RT and dose-intensive chemotherapy. RT began within 28 days of definitive surgery and consisted of craniospinal irradiation (23.4 Gy), conformal PF RT (36.0 Gy), and primary site RT (55.8 Gy). The planning target volume for the primary site included the postoperative tumor bed surrounded by an anatomically confined margin of 2 cm that was then expanded with a geometric margin of 0.3-0.5 cm. Chemotherapy was initiated 6 weeks after RT and included four cycles of high-dose cyclophosphamide, cisplatin, and vincristine.

RESULTS

At a median follow-up of 61.2 months (range, 5.2-115.0 months), the estimated 5-year event-free survival and cumulative incidence of PF failure rate was 83.0% +/- 5.3% and 4.9% +/- 2.4% (+/- standard error), respectively. The targeting guidelines used in this study resulted in a mean reduction of 13% in the volume of the PF receiving doses >55 Gy compared with conventionally planned RT. The reductions in the dose to the temporal lobes, cochleae, and hypothalamus were statistically significant.

CONCLUSION

This prospective trial has demonstrated that irradiation of less than the entire PF after 23.4 Gy craniospinal irradiation for average-risk medulloblastoma results in disease control comparable to that after treatment of the entire PF.

Radiotherapy in pediatric medulloblastoma: Quality assessment of Pediatric Oncology Group Trial 9031

PURPOSE

To evaluate the potential influence of radiotherapy quality on survival in high-risk pediatric medulloblastoma patients.

METHODS AND MATERIALS

Trial 9031 of the Pediatric Oncology Group (POG) aimed to study the relative benefit of cisplatin and etoposide randomization of high-risk patients with medulloblastoma to preradiotherapy vs. postradiotherapy treatment. Two-hundred and ten patients were treated according to protocol guidelines and were eligible for the present analysis. Treatment volume (whole brain, spine, posterior fossa, and primary tumor bed) and dose prescription deviations were assessed for each patient. An analysis of first site of failure was undertaken. Event-free and overall survival rates were calculated. A log-rank test was used to determine the significance of potential survival differences between patients with and without major deviations in the radiotherapy procedure.

RESULTS

Of 160 patients who were fully evaluable for all treatment quality parameters, 91 (57%) had 1 or more major deviations in their treatment schedule. Major deviations by treatment site were brain (26%), spinal (7%), posterior fossa (40%), and primary tumor bed (17%). Major treatment volume or total dose deviations did not significantly influence overall and event-free survival.

CONCLUSIONS

Despite major treatment deviations in more than half of fully evaluable patients, underdosage or treatment volume misses were not associated with a worse event-free or overall survival.

Hyperfractionated radiotherapy and chemotherapy for childhood ependymoma: final results of the first prospective AIEOP (Associazione Italiana di Ematologia-Oncologia Pediatrica) study

PURPOSE

A postsurgical "stage-based" protocol for ependymoma was designed.

METHODS AND MATERIALS

Children were given: (1) focal hyperfractionated radiotherapy (HFRT) if with no evidence of disease (NED), or (2) 4 courses with VEC followed by HFRT for residual disease (ED). HFRT dose was 70.4 Gy (1.1 Gy/fraction b.i.d.); VEC consisted of VCR 1.5 mg/m2 1/w, VP16 100 mg/m2/day x 3, CTX 3 g/m2 d 1. When feasible, second-look surgery was recommended.

RESULTS

Sixty-three consecutive children were enrolled: 46 NED, 17 ED; the tumor was infratentorial in 47 and supratentorial in 16, with spinal metastasis in 1. Of NED patients, 35 of 46 have been treated with HFRT; 8 received conventionally fractionated radiotherapy, and 3 received no treatment. Of the 17 ED patients, 9 received VEC + HFRT; violations due to postsurgical morbidity were as follows: HFRT only (2), conventionally fractionated radiotherapy (3) + VEC (2), and no therapy (1). Objective responses to VEC were seen in 54%; objective responses to RT were seen in 75%. Overall survival and progression-free survival at 5 years for all 63 children were 75% and 56%, respectively; for the NED subgroup, 82% and 65%; and for the ED subgroup, 61% and 35%, respectively. All histologies were centrally reviewed. At multivariate analysis, grading, age, and site proved significant for prognosis.

CONCLUSIONS

HFRT, despite the high total dose adopted, did not change the prognosis of childhood ependymoma as compared to historical series: New radiotherapeutic approaches are needed to improve local control. Future ependymoma strategies should consider grading when stratifying treatment indications.

Concurrent chemotherapy and reduced-dose cranial spinal irradiation followed by conformal posterior fossa tumor bed boost for average-risk medulloblastoma: efficacy and patterns of failure

PURPOSE

To review the efficacy and patterns of failure in average-risk medulloblastoma patients treated with concurrent chemotherapy and reduced-dose cranial spinal irradiation and a conformal tumor bed boost.

METHODS AND MATERIALS

Thirty-three patients with average risk (defined as < or =1.5 cm(2) of residual tumor after resection, age >3 years, and no involvement of the cerebrospinal fluid or spine [M0]) medulloblastoma were diagnosed at our institution between January 1994 and December 2001. They were enrolled in an institutional pilot protocol consisting of concurrent chemotherapy (vincristine), reduced-dose cranial spinal irradiation (2340 cGy), a conformal primary tumor bed boost (3240 cGy), followed by eight cycles of chemotherapy (vincristine, cisplatin, and lomustine or cyclophosphamide). The median age at diagnosis of the 33 patients was 7 years (range, 3-21 years). The male/female patient ratio was 2.4:1. The median follow-up of the entire group was 37 months (range, 6-96 months), and the median follow-up of the survivors was 44 months (range, 10-96 months).

RESULTS

The 5-year estimated disease-free survival rate, as determined by Kaplan-Meier plots, was 86% (+/-12.6%, 95% confidence interval). The 5-year estimated disease-free posterior fossa control and primary tumor bed control rates were both 94% (+/-8.2%, 95% confidence interval). The patterns of failure included 2 patients with distant central nervous system failure only, 1 patient who developed local primary tumor bed failure, posterior fossa failure, and diffuse leptomeningeal spread simultaneously, and 1 patient with failure in the high-dose, primary tumor bed field. No patient experienced isolated posterior fossa failure outside the high-dose boost region.

CONCLUSION

The treatment of average-risk medulloblastoma with chemotherapy, reduced-dose cranial spinal irradiation, and a conformal tumor bed boost results in survival rates and local control rates comparable to those in contemporary studies. A reduction in the amount of posterior fossa treated to the high dose is possible. These results need to be corroborated in a large, cooperative group study.

Fatal toxicity following radio- and chemotherapy of medulloblastoma in a child with unrecognized Nijmegen breakage syndrome

BACKGROUND

In large-scale pediatric chemo- and radiotherapy trials a proportion of patients as high as 10-15% is usually reported as having severe treatment related toxicity occasionally resulting in toxic death. Little is known on the underlying predisposition of the individual child. Several hereditary disorders including immunodeficiency (ID) syndromes or repair disorders, Ataxia Telangiectasia (AT), and Nijmegen breakage syndrome (NBS) were associated with an elevated risk for severe treatment related toxicity.

PROCEDURE

This report involves the case of a 7-year-old boy with medulloblastoma who suffered from remarkably severe side effects during and after postoperative radio- and chemotherapy. Several months following craniospinal radiation with a total dose of 36 Gy, late normal tissue side effects were observed within the treated volume. Eighteen months after initiation of treatment the patient died due to protracted cardiopulmonary failure.

RESULTS

To quantify the intrinsic radiation sensitivity, lymphoblastoid cells were used to examine chromosomal aberrations by fluorescence in situ hybridization detecting between two to ninefold higher chromosomal breakage rates in comparison to cells of average cancer patients. Skin fibroblasts showed in the clonogenic survival assays a twofold increased sensitivity. Western blotting demonstrated a typical lack of Nbs1. PCR-SSCP analysis followed by direct sequencing of positive samples revealed a homozygous truncating mutation of the NBS1 gene (657del5).

CONCLUSIONS

This case highlights that severe treatment related complications in pediatric cancer patients may be the result of increased intrinsic radio- and chemosensitivity due to NBS, AT, and other ID syndromes. It is suggested to exclude such conditions in all patients with anthropometric parameters below the 3rd centile and other signs suggestive for repair disorders or ID syndromes.

Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

PURPOSE

Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury.

METHODS AND MATERIALS

The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n = 20 patients) vs. hyperfractionated radiotherapy (Group B, n = 12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET).

RESULTS

The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p < 0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients.

CONCLUSIONS

The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction.

Paclitaxel for the treatment of progressive or recurrent childhood brain tumors: a pediatric oncology phase II study

PURPOSE

To assess the efficacy and define the toxicity of paclitaxel given at a dosage of 350 mg/m2 every 3 weeks as a 24-hour continuous infusion to children with recurrent or progressive primary brain tumors.

PATIENTS AND METHODS

Seventy-three eligible patients, ages 4 months to 19 years, with progressive or recurrent primary brain tumors were treated according to a Pediatric Oncology Group (POG) phase II protocol with paclitaxel (POG 9330). Tumor histologic strata included: astrocytoma (n = 4), malignant glioma (n = 13), medulloblastoma (n = 16), brain stem glioma (n = 15), ependymoma (n = 13), and miscellaneous histologies (n = 12). All patients had previous histologic confirmation of a primary intracranial or spinal cord tumor with magnetic resonance imaging or computed tomography documentation of unequivocally measurable progressive or recurrent disease. All patients had received previous therapy including surgery, radiation therapy, and/or chemotherapy, but no patient had been previously treated on more than one phase II trial. Paclitaxel was administered as a 24-hour intravenous infusion at a dosage of 350 mg/m2 every 3 weeks. Neurologic and neuroradiologic reevaluations were performed after every second course. Patients were allowed to continue therapy for a total of 18 cycles in the absence of progressive disease or unacceptable toxicity.

RESULTS

Seventy-five patients were enrolled onto the POG 9330 protocol; two ineligible patients were removed from the study before receiving any therapy. Of the 73 eligible patients, 72 were evaluable for toxicity and 70 were either fully or partially evaluable for disease response. There was one complete response and three partial responses (5.7%). Twenty patients had stable disease for more than 2 months. Toxicities included mild nausea, central nervous system toxicity, myelosuppression, and febrile neutropenia, including one septic death. One grade 2 and two grade 3 allergic reactions occurred. No cardiac toxicities or arthralgias were reported.

CONCLUSION

Paclitaxel is well tolerated in children with recurrent or progressive brain tumors at this dosage and schedule and may result in short-term disease stabilization in this patient population. The lack of a significant number of patients with measurable disease regression, however, precludes it from being identified as an active agent when administered as a single agent by 24-hour continuous infusion.

Adult medulloblastoma: multiagent chemotherapy

In this study, the records of 17 adult patients with medulloblastoma treated with craniospinal radiation and 1 of 2 multiagent chemotherapy protocols were reviewed for progression-free survival, overall survival, and toxicity, and the patients were compared with each other and with similarly treated children and adults. Records of patients treated at 3 institutions were reviewed. Seventeen medulloblastoma patients (11 female, 6 male) with a median age of 23 years (range, 18-47 years) were treated with surgery, craniospinal radiation (CSRT) plus local boost, and 1 of 2 adjuvant chemotherapy regimens. All tumors were infratentorial (10 in 4th ventricle and 7 in left or right hemisphere). Ten patients presented with hydrocephalus, and 7 of them were shunted. Eight patients had gross total resection, 7 had subtotal resection (>50% removed), and 2 had partial resection (<50% removed). Postoperatively, 3 patients had positive cytology and 3 had positive spinal MRI. Five patients were classified as good risk and 12 were classified as poor risk (Chang staging system). Ten patients were treated with the "Packer protocol," consisting of CSRT plus weekly vincristine followed by 8 cycles of cisplatin, lomustine, and vincristine. Seven patients were treated with the Pediatric Oncology Group (POG) protocol, consisting of alternating courses of cisplatin/etoposide and cyclophosphamide/vincristine, followed by CSRT. Eight of 17 patients relapsed, with all 8 relapsing at the primary site. Other relapse sites included the leptomeninges (5), bone (1), and brain (1). The estimated median relapse-free survival (Kaplan-Meier) for all patients was 48 months (95% confidence interval, >26 months to infinity). Median relapse-free survival for patients on the Packer protocol was 26 months, and for those on the POG regimen was 48 months (P = 0.410). Five of 10 on the Packer protocol were relapse-free, while 4 of 7 were relapse-free on the POG regimen. Two patients relapsed during chemotherapy and 6 relapsed after completing all therapy at 18, 18, 26, 30, 40, and 48 months. The estimated median survival of all patients was 56 months (95% confidence interval, 27 to infinity) with 11 patients alive; for the Packer protocol, median survival was 36 months, and for the POG protocol, it was 57 months (P = 0.058). The hazard ratio was 0 (95% confidence interval, 0 to infinity). Toxicity during the Packer protocol was moderately severe, with only 1 of 10 patients able to complete all therapy. Two patients had severe abdominal pain during CSRT + vincristine, and 5 had peripheral neuropathy during vincristine therapy. Hearing loss (>20 dB) occurred in 7, neutropenia (<500 microl) in 6, thrombocytopenia (<50,000 microl) in 6, nephrotoxicity (>25% decrease by creatinine clearance) in 2, and decreased pulmonary function (diffusing capacity for carbon monoxide decrease >40%) in 1. On the POG protocol, only 1 patient had persistent nausea and vomiting, 2 had peripheral neuropathy, and 3 had hearing deficit (>20 dB) or tinnitus. The POG and Packer protocols did not have a statistically significant difference in relapse-free or overall survival because of the small sample size. The POG protocol seemed to have less nonhematologic toxicity. Adults on the Packer protocol appeared to have shorter median survival and greater toxicity than did children. To know whether adding adjuvant chemotherapy to craniospinal radiation in adult therapy increases relapse-free and overall survival, we must await the results of a larger randomized controlled clinical trial.

Combined postoperative irradiation and chemotherapy for anaplastic ependymomas in childhood: results of the German prospective trials HIT 88/89 and HIT 91

PURPOSE

To evaluate the outcome in children with anaplastic ependymomas after surgery, irradiation, and chemotherapy; and to identify prognostic factors for survival.

METHODS AND MATERIALS

Fifty-five children (n = 27 girls, 28 boys; median age at diagnosis, 6.2 years) with newly diagnosed anaplastic ependymomas were treated in the multicenter, prospective trials HIT 88/89 and HIT 91. Macroscopic complete resection was achieved in 28 patients; 27 patients underwent incomplete resection. All patients received chemotherapy before (n = 40) or after irradiation (n = 15). The irradiation volume encompassed either the neuraxis followed by a boost to the primary tumor site (n = 40) or the tumor region only (n = 13). No radiotherapy was administered in two patients.

RESULTS

Median follow-up was 38 months. The overall survival rate at 3 years after surgery was 75.6%. Disease progression occurred in 25 children with local progression occurring in 20. The median time to disease progression was 45 months. The only significant prognostic factor was the extent of resection (estimated progression-free survival [EPFS] after 3 years was 83.3% after complete resection and 38.5% after incomplete resection) and the presence of metastases at the time of diagnosis (0% vs. 65.8% 3-year EPFS in localized tumors). Age, sex, tumor site, mode of chemotherapy, and irradiation volume did not influence survival.

CONCLUSIONS

Treatment centers should be meticulous about surgery and diagnostic workup. Because the primary tumor region is the predominant site of failure it is important to intensify local treatment. Dose escalation by hyperfractionation or stereotactic radiotherapy might be a promising approach in macroscopically residual disease. The role of adjuvant chemotherapy requires further study.

Methotrexate osteopathy in infants with tumors of the central nervous system

Methotrexate osteopathy, previously reported as a complication of maintenance-therapy for acute lymphoblastic leukemia, is characterized by osteopenia, particularly involving the lower extremities, thick, dense provisional zones of calcification, growth arrest lines, and corner fractures resembling scurvy. In attempts to postpone radiotherapy in infants under three years of age, the multicentric German therapy protocol for childhood central nervous system tumors (HIT-89 protocol) has employed high cumulative methotrexate doses. Here we describe osteopathy in three patients as a toxic side effect after administration of cumulative methotrexate doses of 20 g/m2, 80 g/m2 and 135 g/m2. The high prevalence of this adverse effect in infants with tumors of the central nervous system may be attributed to the long-term therapy with high cumulative methotrexate-doses. Both factors may favor intracellular accumulation of methotrexate and formation of methotrexate-polyglutamates and may be responsible for bone toxicity. Apparently the susceptibility of the rapidly growing skeletal structures of infants under three years of age to this toxic side effect of methotrexate is remarkably high.