Progressive deterioration of intellect and motor function occurring several decades after cranial irradiation. A new facet in the clinical spectrum of radiation encephalopathy

Primary Central Nervous System Lymphoma in Elderly Patients: Management and Perspectives

The management of elderly patients suffering from primary central nervous system (CNS) lymphoma, who represent a rapidly growing population, is challenging. Despite the advances made in PCNSL treatment, the prognosis in older patients remains unsatisfactory. The high risk of systemic and CNS toxicity induced by a high-dose chemotherapy regimen and radiation therapy, respectively, limits the use of consolidation phase treatments in elderly patients and contributes to the poor outcome of these patients. Here, we review the current treatment strategies and ongoing trials proposed for elderly PCNSL patients.

OAR sparing 3D radiotherapy planning supported by fMRI brain mapping investigations

The human brain as an organ has numerous functions; some of them can be visualized by functional imaging techniques (e.g., functional MRI [fMRI] or positron emission tomography). The localization of the appropriate activity clusters requires sophisticated instrumentation and complex measuring protocol. As the inclusion of the activation pattern in modern self-tailored 3D based radiotherapy has notable advantages, this method is applied frequently. Unfortunately, no standardized method has been published yet for the integration of the fMRI data into the planning process and the detailed description of the individual applications is usually missing. Thirteen patients with brain tumors, receiving fMRI based RT planning were enrolled in this study. The delivered dose maps were exported from the treatment planning system and processed for further statistical analysis. Two parameters were introduced to measure the geometrical distance Hausdorff Distance (HD), and volumetric overlap Dice Similarity Coefficient (DSC) of fMRI corrected and not corrected dose matrices as calculated by 3D planning to characterize similarity and/or dissimilarity of these dose matrices. Statistical analysis of bootstrapped HD and DSC data was performed to determine confidence intervals of these parameters. The calculated confidence intervals for HD and DSC were (5.04, 7.09), (0.79, 0.86), respectively for the 40 Gy and (5.2, 7.85), (0.74, 0.83), respectively for the 60 Gy dose volumes. These data indicate that in the case of HD < 5.04 and/or DSC > 0.86, the 40 Gy dose volumes obtained with and without fMRI activation pattern do not show a significant difference (5% significance level). The same conditions for the 60 Gy dose volumes were HD < 5.2 and/or DSC > 0.83. At the same time, with HD > 7.09 and/or DSC < 0.79 for 40 Gy and HD > 7.85 and/or DSC < 0.74 for 60 Gy the impact of fMRI utilization in RT planning is excessive. The fMRI activation clusters can be used in daily RT planning routine to spare activation clusters as critical areas in the brain and avoid their high dose irradiation. Parameters HD (as distance) and DSC (as overlap) can be used to characterize the difference and similarity between the radiotherapy planning target volumes and indicate whether the fMRI delivered activation patterns and consequent fMRI corrected planning volumes are reliable or not.

The Role of Navigated Transcranial Magnetic Stimulation Motor Mapping in Adjuvant Radiotherapy Planning in Patients With Supratentorial Brain Metastases

Purpose: In radiotherapy (RT) of brain tumors, the primary motor cortex is not regularly considered in target volume delineation, although decline in motor function is possible due to radiation. Non-invasive identification of motor-eloquent brain areas is currently mostly restricted to functional magnetic resonance imaging (fMRI), which has shown to lack precision for this purpose. Navigated transcranial magnetic stimulation (nTMS) is a novel tool to identify motor-eloquent brain areas. This study aims to integrate nTMS motor maps in RT planning and evaluates the influence on dosage modulations in patients harboring brain metastases.

Materials and Methods: Preoperative nTMS motor maps of 30 patients diagnosed with motor-eloquent brain metastases were fused with conventional planning imaging and transferred to the RT planning software. RT plans of eleven patients were optimized by contouring nTMS motor maps as organs at risk (OARs). Dose modulation analyses were performed using dose-volume histogram (DVH) parameters.

Results: By constraining the dose applied to the nTMS motor maps outside the planning target volume (PTV) to 15 Gy, the mean dose (Dmean) to the nTMS motor maps was significantly reduced by 18.1% from 23.0 Gy (16.9–30.4 Gy) to 18.9 Gy (13.5–28.8 Gy, p < 0.05). The Dmean of the PTV increased by 0.6 ± 0.3 Gy (1.7%).

Conclusion: Implementing nTMS motor maps in standard RT planning is feasible in patients suffering from intracranial metastases. A significant reduction of the dose applied to the nTMS motor maps can be achieved without impairing treatment doses to the PTV. Thus, nTMS might provide a valuable tool for safer application of RT in patients harboring motor-eloquent brain metastases.

Whole brain radiotherapy for brain metastasis

Whole brain radiotherapy (WBRT) is a mainstay of treatment in patients with both identifiable brain metastases and prophylaxis for microscopic disease. The use of WBRT has decreased somewhat in recent years due to both advances in radiation technology, allowing for a more localized delivery of radiation, and growing concerns regarding the late toxicity profile associated with WBRT. This has prompted the development of several recent and ongoing prospective studies designed to provide Level I evidence to guide optimal treatment approaches for patients with intracranial metastases. In addition to defining the role of WBRT in patients with brain metastases, identifying methods to improve WBRT is an active area of investigation, and can be classified into two general categories: Those designed to decrease the morbidity of WBRT, primarily by reducing late toxicity, and those designed to improve the efficacy of WBRT. Both of these areas of research show diversity and promise, and it seems feasible that in the near future, the efficacy/toxicity ratio may be improved, allowing for a more diverse clinical application of WBRT.

Enhanced chemotherapy delivery by intraarterial infusion and blood-brain barrier disruption in the treatment of cerebral metastasis

BACKGROUND

Cerebral metastases are clinically significant in 10% to 30% of patients with neoplasia. Multiple cerebral metastases are typically treated with palliative radiotherapy. There is no consensus on the role of enhanced chemotherapy delivery as an adjuvant treatment modality in this disease. In this report, the authors detailed their experience with intraarterial (IA) chemotherapy infusion with and without blood-brain barrier disruption (BBBD) in patients with multiple cerebral metastases.

METHODS

From November 1999 to May 2005, 38 patients with multiple cerebral metastases were enrolled in a prospective study. Patients were treated with IA carboplatin, except for those with cerebral metastases of systemic lymphoma, who were administered IA methotrexate. Osmotic BBBD was offered to patients without the presence of a significant mass effect. These regimens were coupled with intravenous etoposide and cyclophosphamide. Cycles were repeated every 4 weeks.

RESULTS

Survival was calculated from study entry and radiologic response was based on MacDonald criteria. Kaplan-Meier estimates were generated for all subgroups. Mean and median survival obtained was as follows: 34 and 29.6 months for the whole group; 33.6 and 42.3 months for ovarian carcinoma; 15.3 and 13.5 months for lung adenocarcinomas; 8.3 and 8.8 months for small cell lung carcinoma; 8.9 and 8.1 months for breast carcinoma; and 24.8 and 16.3 months, respectively, for cerebral metastasis from systemic lymphoma.

CONCLUSIONS

Even with a small number of patients in each subgroup, the results obtained seem promising for multiple brain metastasis of ovarian carcinoma, adenocarcinoma of lung, small cell lung carcinoma, and systemic lymphoma.

Cognitive Functions in Brain Tumor Patients

As effective treatment interventions have increased survival rates, there has been greater awareness that many brain tumor patients experience cognitive dysfunction despite adequate disease control. Cognitive difficulties often have an impact on quality of life and interfere with the patient's ability to function at premorbid levels; however, the incidence of cognitive dysfunction in brain tumor patients is unknown, because it has not been investigated systematically. Future prospective clinical trials in neuro-oncology should include cognitive outcome measures to increase understanding of the contribution of the tumor and the delayed effects of treatment to cognitive dysfunction.

Treatment-related neurotoxicity

Two challenges need to be addressed to improve the outcome of patients with primary central nervous system lymphoma. The first challenge is to develop therapies that result in less toxicity and improved long-term outcome. The second challenge is to develop interventions to help those patients who develop treatment-related neurotoxicity; ongoing collaborative efforts are required to improve communication and understanding of this complication. Long-term follow up of prospective therapeutic studies should report on both disease control and the development of neurotoxicity. New protocols should include prospective longitudinal measures of neurocognitive function.

White Matter Lesions Detected by Magnetic Resonance Imaging After Radiotherapy and High-Dose Chemotherapy in Children With Medulloblastoma or Primitive Neuroectodermal Tumor

Purpose

White matter lesions (WMLs) have been described as a delayed effect of cranial irradiation in children with brain tumors, or a transient subacute effect characterized by an intralesional or perilesional reaction. We report the occurrence of subacute WMLs detected by magnetic resonance imaging (MRI) in children treated for medulloblastoma or primitive neuroectodermal tumor (PNET) and document the associated clinical, radiologic, and neurocognitive findings.

Patients and Methods

Among 134 patients with medulloblastoma or supratentorial PNET treated prospectively with risk-adjusted craniospinal irradiation and conformal boost to the tumor bed, followed by four high-dose chemotherapy (HDC) cycles with stem-cell rescue, 22 developed WMLs on T1-weighted imaging with and without contrast and/or T2-weighted imaging on MRI. Patients had ≥ 12 months of follow-up. Neurocognitive assessments included intelligence quotient (IQ) tests and tests of academic achievement.

Results

Twenty-two patients developed WMLs at a median of 7.8 months after starting therapy (range, 1.9 to 13.0 months). Lesions were predominantly in the pons (n = 8) and cerebellum (n = 6). Sixteen patients (73%) had WML resolution at a median of 6.2 months (range, 1.68 to 23.5 months) after onset; two patients developed necrosis and atrophy. Three developed persistent neurologic deficits. Cumulative incidence of WMLs at 1 year was 15% ± 3%. Patients with WMLs had a significant decline in estimated IQ (−2.5 per year; P = .03) and math (−4.5 per year; P = .003) scores.

Conclusion

WMLs in medulloblastoma or PNET patients treated with conformal radiotherapy and HDC are typically transient and asymptomatic, and may mimic early tumor recurrence. A minority of patients with WMLs develop permanent neurologic deficits and imaging changes. Overall, the presence of WMLs is associated with greater neurocognitive decline.

Central nervous system lymphoma

Central nervous system involvement with malignant lymphoma whether primary or secondary is an uncommon but not rare complication observed in the management of patients with hematological malignancy. Its importance lies in the considerable morbidity and mortality with which it is associated and the inadequacy of therapy. In Section I, Dr. Lauren Abrey addresses the totality of the problem of primary central nervous system lymphoma, with emphasis on strategies increasingly dependent on systemic chemotherapy. In Section II, Dr. John Sandlund reviews the success of sequential clinical trials of overall therapy for acute lymphoblastic leukemia in childhood, identifying those patients at high risk of central nervous system leukemia and the development of a rational therapeutic strategy for prevention. In Section III, Dr. Andrew Lister discusses the issue of secondary central nervous system involvement with lymphoma and the indications for prophylaxis.

Akinetic mutism caused by bilateral infiltration of the fornix in a patient with astrocytoma

In a 59-year-old female patient, a World Health Organization (WHO) grade II astrocytoma had been diagnosed 16 years ago, which finally progressed into WHO grade III. Several right frontal neurosurgical resections, local radiation and a local radioimplant had been applied. Despite this long record, she was reported alert with a Karnofsky index of 90% until admission. Within a few weeks she rapidly developed akinetic mutism. Upon admission, computed tomography (CT) scan showed a large cystic right frontal defect and a suggested small tumor recurrence. White matter of the frontal lobe appeared to be translucent and compatible with previous radiation. The severe mental changes were initially attributed to a delayed radiation encephalopathy. Neuropathologically, the white matter of the frontal lobe showed mild elevated cell density consistent with gliosis; however, a tumor recurrence invading the tip of the corpus callosum and invading the entire length both fornices appeared. From the neuropathological findings of massive local tumor recurrence in both fornices, together with the acute clinical onset, it seems unlikely that the sequel of radiotherapy caused akinetic mutism, but the symmetric and severe involvement of the limbic system. We conclude that the rapid progression from a state of alertness to a full clinical picture of akinetic mutism was because of infiltration of both fornices.

Neurologic complications of transplantation

BACKGROUND

Organ transplantation is one of the most dynamic fields in medicine and has evolved into a life-saving option for thousands of patients with previously fatal conditions. The posttransplantation clinical course is frequently associated with neurologic complications that are usually related to pretransplant morbidity, the surgical procedure of transplantation, immunosuppression, and opportunistic infection.

REVIEW SUMMARY

Neurologic complications of organ transplantation may be divided into complications common to all types of allografts and complications that are specific for a particular type of organ transplantation. The most common complications include seizures, opportunistic central nervous system (CNS) infection, metabolic encephalopathy, stroke, intracranial hemorrhage, and drug-related adverse events. Opportunistic CNS infection may have a subtle presentation and should not be overlooked, as the consequences of delayed treatment may be grave. Neurotoxicity of immunosuppressive agents is also a frequent cause of neurologic complications and may occur in the setting of normal serum drug levels. The clinical course of transplant patients is frequently complex, requiring close cooperation between the transplant team and specialty consultants. Prolonged survival of transplant patients will shift the focus of neurologic complications from acute, perioperative to chronic complications of immunosuppression.

CONCLUSIONS

Neurologic complications of organ transplantation are commonly related to opportunistic infection or neurotoxicity of immunosuppressive agents, requiring careful titration of immunosuppression. Timely diagnosis of CNS infection or other causes of neurologic dysfunction may significantly improve recovery and outcome in these patients.

Een zeldzame oorzaak van dementie: de bestralingsencephalopathie

We describe the clinical history of a 49-year old woman, who demonstrated progressive personality changes more than twenty years after radiation of a pituitary adenoma (prolactinoma), with apathy, loss of initiative, memory deficits, postural instability, dysarthria and faecal incontinence. Neuropsychological assessment showed impulsivity, loss of overview, desinhibition, fluctuating deficits of attention, and memory disturbances. MRI-scanning of the brain revealed a cystic lesion along the right ventricle. The clinical picture and the findings of the other investigations are typical for dementia due to radiation encephalopathy. Such a long period between radiation and cognitive deterioration is rare, although it has been described before.

Radiation-induced blood-brain barrier damage in astrocytoma: relation to elevated gelatinase B and urokinase

Successful management of brain tumors prolongs life, raising the risk of delayed injury secondary to the treatment. Radiation therapy, a mainstay of brain tumor treatment, can damage the cerebral blood vessels. Acutely a breakdown of the blood-brain barrier (BBB) may be seen, but fibrosis complicates radiation injury in the chronic phase. Matrix metalloproteinases (MMPs) and plasminogen activators are two matrix-degrading proteolytic enzymes, which are induced by radiation. They disrupt the basal lamina around cerebral capillaries and open the BBB. We report a patient with an astrocytoma managed by partial resection and external beam irradiation to maximal tolerable doses. The patient later developed malignant brain edema shortly after stereotactic radiosurgery. Tissue obtained during surgical debulking to control the edema showed very high levels of gelatinase B (92 kDa type IV collagenase) and urokinase-type plasminogen activator (uPA). Tumor cells were absent from the biopsy and subsequent autopsy specimens, but necrosis with fibrosis of the blood vessels was seen. If abnormal matrix enzyme function participates in the expression of radiation injury, then inhibitors to such enzymes may provide one strategy for controlling cerebrovascular damage after therapeutic brain radiation.

Klüver-Bucy syndrome in a patient with nasopharyngeal carcinoma: a late complication of radiation brain injury

We report a patient with dementia and Klüver-Bucy syndrome who presented 17 years after radiotherapy for nasopharyngeal carcinoma. Computerized tomography of the brain revealed bilateral temporal lobe atrophy. The possibility of delayed effects of radiation brain injury in causing the human Klüver-Bucy syndrome is discussed.