Preoperative 11 C-Methionine PET-MRI in Pediatric Infratentorial Tumors.

PURPOSE: MRI is the main imaging modality for pediatric brain tumors, but amino acid PET can provide additional information. Simultaneous PET-MRI acquisition allows to fully assess the tumor and lower the radiation exposure. Although symptomatic posterior fossa tumors are typically resected, the patient management is evolving and will benefit from an improved preoperative tumor characterization. We aimed to explore, in children with newly diagnosed posterior fossa tumor, the complementarity of the information provided by amino acid PET and MRI parameters and the correlation to histopathological results. PATIENTS AND METHODS: Children with a newly diagnosed posterior fossa tumor prospectively underwent a preoperative 11 C-methionine (MET) PET-MRI. Images were assessed visually and semiquantitatively. Using correlation, minimum apparent diffusion coefficient (ADC min ) and contrast enhancement were compared with MET SUV max . The diameter of the enhancing lesions was compared with metabolic tumoral volume. Lesions were classified according to the 2021 World Health Organization (WHO) classification. RESULTS: Ten children were included 4 pilocytic astrocytomas, 2 medulloblastomas, 1 ganglioglioma, 1 central nervous system embryonal tumor, and 1 schwannoma. All lesions showed visually increased MET uptake. A negative moderate correlation was found between ADC min and SUV max values ( r = -0.39). Mean SUV max was 3.8 (range, 3.3-4.2) in WHO grade 4 versus 2.5 (range, 1.7-3.0) in WHO grade 1 lesions. A positive moderate correlation was found between metabolic tumoral volume and diameter values ( r = 0.34). There was no correlation between SUV max and contrast enhancement intensity ( r = -0.15). CONCLUSIONS: Preoperative 11 C-MET PET and MRI could provide complementary information to characterize pediatric infratentorial tumors.

Brain biomarkers and neuropsychological outcomes of pediatric posterior fossa brain tumor survivors treated with surgical resection with or without adjuvant chemotherapy.

PURPOSE: Children with brain tumors experience cognitive late effects, often related to cranial radiation. We sought to determine differential effects of surgery and chemotherapy on brain structure and neuropsychological outcomes in children who did not receive cranial radiation therapy (CRT). METHODS: Twenty-eight children with a history of posterior fossa tumor (17 treated with surgery, 11 treated with surgery and chemotherapy) underwent neuroimaging and neuropsychological assessment a mean of 4.5 years (surgery group) to 9 years (surgery + chemotherapy group) posttreatment, along with 18 healthy sibling controls. Psychometric measures assessed IQ, language, executive functions, processing speed, memory, and social-emotional functioning. Group differences and correlations between diffusion tensor imaging findings and psychometric scores were examined. RESULTS: The z-score mapping demonstrated fractional anisotropy (FA) values were ≥2 standard deviations lower in white matter tracts, prefrontal cortex gray matter, hippocampus, thalamus, basal ganglia, and pons between patient groups, indicating microstructural damage associated with chemotherapy. Patients scored lower than controls on visuoconstructional reasoning and memory (P ≤ .02). Lower FA in the uncinate fasciculus (R = -0.82 to -0.91) and higher FA in the thalamus (R = 0.73-0.91) associated with higher IQ scores, and higher FA in the thalamus associated with higher scores on spatial working memory (R = 0.82). CONCLUSIONS: Posterior fossa brain tumor treatment with surgery and chemotherapy affects brain microstructure and neuropsychological functioning years into survivorship, with spatial processes the most vulnerable. Biomarkers indicating cellular changes in the thalamus, hippocampus, pons, prefrontal cortex, and white matter tracts associate with lower psychometric scores.

Magnetic resonance-guided laser interstitial thermal therapy for posterior fossa neoplasms.

PURPOSE: Magnetic resonance-guided laser interstitial thermal therapy (LITT) has been increasingly used to treat a number of intracranial pathologies, though its use in the posterior fossa has been limited to a few small series. We performed a multi-institutional review of targets in the posterior fossa, reporting the efficacy and safety profile associated with laser ablation in this region of the brain. METHODS: A retrospective review of patients undergoing LITT in the posterior fossa was performed from August 2010 to March 2020. Patient demographic information was collected alongside the operative parameters and patient outcomes. Reported outcomes included local control of the lesion, postoperative complications, hospital length of stay, and steroid requirements. RESULTS: 58 patients across four institutions underwent LITT in the posterior fossa for 60 tumors. The median pre-ablation tumor volume was 2.24 cm3. 48 patients (50 tumors) were available for follow-up. An 84% (42/50) overall local control rate was achieved at 9.5 months median follow up. There were two procedural complications, including insertional hemorrhage and laser misplacement and 12/58 (21%) patients developed new neurological deficits. There was one procedure related death. The median length of hospital stay was 1 day, with 20.7% of patients requiring discharge to a rehabilitation facility. CONCLUSIONS: LITT is an effective approach for treating pathology in the posterior fossa. The average target size is smaller than what has been reported in the supratentorial space. Care must be taken to prevent injury to surrounding structures given the close proximity of critical structures in this region.

Finite element analysis of Tumor Treating Fields in a patient with posterior fossa glioblastoma.

INTRODUCTION: Tumor Treating Fields (TTFields) are alternating electric fields at 200 kHz that disrupt tumor cells as they undergo mitosis. Patient survival benefit has been demonstrated in randomized clinical trials but much of the data are available only for supratentorial glioblastomas. We investigated a series of alternative array configurations for the posterior fossa to determine the electric field coverage of a cerebellar glioblastoma. METHODS: Semi-automated segmentation of neuro-anatomical structures was performed while the gross tumor volume (GTV) was manually delineated. A three-dimensional finite-element mesh was generated and then solved for field distribution. RESULTS: Compared to the supratentorial array configuration, the alternative array configurations consist of posterior displacement the 2 lateral opposing arrays and inferior displacement of the posteroanterior array, resulting in an average increase of 46.6% electric field coverage of the GTV as measured by the area under the curve of the electric field-volume histogram (EAUC). Hotspots, or regions of interest with the highest 5% of TTFields intensity (E5%), had an average increase of 95.6%. Of the 6 posterior fossa configurations modeled, the PAHorizontal arrangement provided the greatest field coverage at the GTV when the posteroanterior array was placed centrally along the patient's posterior neck and horizontally parallel, along the longer axis, to the coronal plane of the patient's head. Varying the arrays also produced hotspots proportional to TTFields coverage. CONCLUSIONS: Our finite element modeling showed that the alternative array configurations offer an improved TTFields coverage to the cerebellar tumor compared to the conventional supratentorial configuration.

Postural balance in pediatric posterior fossa tumor survivors: Through impairments to rehabilitation possibilities.

BACKGROUND: The rehabilitation after pediatric brain tumors is a pressing issue in current neuro-oncology. The purpose of this study was to reveal the peculiarities of postural stability in pediatric posterior fossa tumor survivors as compared to the healthy controls. Additionally, we aimed to determine the feasibility of the balance biofeedback training for these patients. METHODS: We measured 6 postural stability parameters with the eyes opened and closed in 35 patients and 25 healthy controls aged 7-17. Further, the patients were divided into two groups: the intervention and waitlist. The intervention group was the first to undergo a 2-week biofeedback training designed to enhance balance control, while the waitlist group performed only the usual exercises. Then the groups were interchanged. Pre- and post-stability scores were measured in each condition. FINDINGS: The current results suggest the pronounced deficiency of stability in the patients. Their results in both opened and closed eyes conditions were similar. The post-training measurements revealed that some stability parameters were improved: ellipse square and mean root square oscillations in the frontal and sagittal planes. INTERPRETATION: The patients predictably demonstrated the significantly worse stability measurements as compared to the healthy controls. Moreover, they were shown not to use visual information to correct postural balance thus prompting us to assume severe deficits of the eye movements control due to the cerebellar pathology. This specificity, as well as the post-training significant improvement, emphasizes the clinical necessity to consider them when designing the rehabilitation protocols for posterior fossa tumor survivors.

Laser Interstitial Thermal Therapy to the Posterior Fossa: Challenges and Nuances.

BACKGROUND: Posterior fossa tumors are rare in adults and pose a challenge to treat due to the bony contour of the posterior fossa, complex anatomical structures including deep venous sinuses, and the proximity of the fourth ventricle and brain stem. We describe our experience with laser interstitial thermal therapy (LITT) for the management of brain metastases and radiation necrosis of the posterior fossa. METHODS: We retrospectively analyzed 13 patients with metastases and radiation necrosis of the posterior fossa managed with LITT. RESULTS: Thirteen patients with histopathologically confirmed radiation necrosis (n = 5) and metastases (n = 8) of the posterior fossa underwent LITT. The median preoperative tumor was 4.66 cm3, and median postoperative ablation cavity volume was 6.29 cm3. The median volume of the ablation cavity was decreased to 2.90 cm3 at a 9-month follow-up. The median volume of peritumoral edema was 12.25 cm3, which fell to a median of 5.77 cm3 at 1-month follow-up. The median progression-free survival was 7 months (range, 3-14 months) and the mean overall survival was 40 months (range, 2-49 months) after LITT. There were no intraoperative complications. One patient experienced palsy of the seventh and eighth cranial nerves on follow-up, attributable to LITT. CONCLUSIONS: Lesions of the posterior fossa are challenging to treat given their proximity to the dura and venous sinuses. Our findings demonstrate that LITT ablation may be a safe and feasible option for metastases and radiation necrosis of the posterior fossa. Larger studies are needed to confirm the efficacy of this approach.

Neuroimaging of the component white matter connections and structures within the cerebellar-frontal pathway in posterior fossa tumor survivors.

INTRODUCTION: In posterior fossa tumor survivors, lower white matter integrity (WMI) in the right cerebellar-left frontal pathway has been well documented and appears to be related to proximity to the cerebellum, radiation treatment, as well as time since treatment in both cranial radiation and surgery-only treatment groups. The current study investigated theories of transneural degeneration following cerebellar tumor resection that may underlie or relate to reductions in WMI and regional brain volumes using correlations. We hypothesized a positive relationship between the volume of the right cerebellum and known white matter output pathways, as well as with the volume of structures that receive cerebellar projections along the pathway. METHODS: Adult survivors of childhood brain tumors were recruited (n = 29; age, M = 22 years, SD = 5; 45% female). Age- and gender-matched controls were also included (n = 29). Participants completed 3 T diffusion-weighted and T1 MPRAGE MRI scans. Brain structure volume relative to intracranial vault served as regional volumetric measures. Fractional anisotropy (FA) and radial diffusivity (RD) served as WMI measures. In the survivor group, partial correlations between WMI and regional volume included controlling for disease severity. RESULTS: In posterior fossa tumor survivors, the volumes of the cerebellum, thalamus, and frontal lobe were correlated with WMI of the thalamic-frontal segment of the cerebellar-frontal pathway (r = 0.41-0.49, p < .05). Cerebellar atrophy was correlated with reduced WMI in the cerebellar-rubral segment (FA, r = -0.32 p > .05; RD, r = 0.53, p < .01). In the no-radiation survivor group, the regional volume of each structure along the pathway was associated with WMI in the cerebellar-rubral segment. In the radiation survivor group, significant correlations were found between the regional brain volume of each structure and the thalamic-frontal segment of the pathway. DISCUSSION: The results of this multimodal neuroimaging study provide correlational evidence that the mechanism of injury subsequent to brain tumor treatment may be different depending on type of treatment(s). Without radiation, the primary mechanism of injury is cerebellar tumor growth, resection, and hydrocephalus. Therefore, the most proximal connection to that injury (cerebellar-rubral pathway) was correlated with reductions in volume along the pathway. In contrast, the survivor group treated with radiation may have had possible radiation-induced demyelination of the thalamic-frontal portion of the pathway, based on a strong correlation with volume loss in the cerebellum, red nucleus, thalamus, and frontal lobe.

Novel Use of the Leksell Gamma Frame for Stereotactic Biopsy of Posterior Fossa Lesions.

BACKGROUND: Stereotactic transcerebellar biopsies of brainstem tumors have often been reported. The Leksell frame or Cosman-Roberts-Wells frame is often used in transcerebellar approaches. However, to access lesions via the cerebellum, these frames should be secured as inferiorly on the cranium as possible, which can require exaggerated neck flexion and limit the flexible trajectory to the target. To overcome these disadvantages, we have devised a new way to use the Leksell frame for transcerebellar approaches. METHODS: The frame was fixed to the upper part of the head and arc support by attaching the frame upside down, which gives surgeons a wide operative field and permits flexible trajectory planning. RESULTS: Under local anesthesia, the surgery was performed in a sitting position. Air was observed in the target site on postoperative computed tomography and magnetic resonance imaging, which confirmed that a specimen had been successfully sampled from the site as planned. CONCLUSIONS: Our devised transcerebellar approach provided a generous operative field and a flexible trajectory, which enabled minimally invasive biopsy of a posterior fossa lesions to be performed in a short amount of time with the patient under local anesthesia.

Endoscopic third ventriculostomy through lamina terminalis: A feasible alternative to standard endoscopic third ventriculostomy.

CONTEXT: Endoscopic third ventriculostomy (ETV), wherein a stoma is created in the floor of the third ventricle, has now become the standard procedure for noncommunicating hydrocephalus across the world. However, in certain situations, this procedure may pose technical difficulties. These include a narrow prepontine space, vascularized third ventricular floor, the presence of prominent blood vessels traversing within the prepontine space, significant basal exudates, thickened and ill-defined third ventricular floor, and distorted floor anatomy. In such situations, an endoscopic lamina terminalis opening may provide a safer and more effective alternative to the standard technique. AIMS: The paper aims to discuss the different indications, technical nuances, and outcome of endoscopic third ventriculostomy through the lamina terminalis (ETV LT) utilizing the standard transventricular transforaminal route. SETTINGS AND DESIGN: A total of 240 patients underwent ETV between January 2007 and January 2014. Of these patients, 8 patients required an EVT LT and these patients formed the subset of patients for the present study. In all the 8 patients, the decision to perform fenestration of the LT during the endoscopic procedure was taken intraoperatively. We qualified a procedure to be a success when a second procedure was not required subsequently. RESULTS: Of the eight patients in whom ETV LT was done, four had aqueductal stenosis (including one case of post-primary ETV), three patients were diagnosed with post-meningitic hydrocephalus, and the remaining patient had a posterior fossa tumor. The procedure was successful in 6 of our patients who did not require a second procedure till the last follow-up. CONCLUSIONS: Endoscopic transventricular transforaminal LT fenestration with a flexible neuroendoscope is a feasible alternative to the standard ETV when technical difficulties precludes safe performance of the latter procedure.

The efficacy of P6 acupressure with sea-band in reducing postoperative nausea and vomiting in patients undergoing craniotomy: a randomized, double-blinded, placebo-controlled study.

BACKGROUND: Postoperative nausea and vomiting (PONV) is a multifactorial problem after general anesthesia. Despite antiemetic prophylaxis and improved anesthetic techniques, PONV still occurs frequently after craniotomies. P6 stimulation is described as an alternative method for preventing PONV. The primary aim of this study was to determine whether P6 acupressure with Sea-Band could reduce postoperative nausea after elective craniotomy. Secondary aims were to investigate whether the frequency of vomiting and the need for antiemetics could be reduced. METHODS: In this randomized, double-blinded, placebo-controlled study, patients were randomized into either a P6 acupressure group (n=43) or a sham group (n=52). Bands were applied unilaterally at the end of surgery, and all patients were administered prophylactic ondansetron. Postoperative nausea was evaluated with a Numerical Rating Scale, 0 to10, and the frequency of vomiting was recorded for 48 hours. RESULTS: We found no significant effect from P6 acupressure with Sea-Band on postoperative nausea or vomiting in patients undergoing craniotomy. Nor was there any difference in the need for rescue antiemetics. Altogether, 67% experienced PONV, and this was especially an issue at >24 hours in patients recovering from infratentorial surgery compared with supratentorial surgery (55% vs. 26%; P=0.014). CONCLUSIONS: Unilateral P6 acupressure with Sea-Band applied at the end of surgery together with prophylactic ondansetron did not significantly reduce PONV or the need for rescue antiemetics in patients undergoing craniotomy. Our study confirmed that PONV is a common issue after craniotomy, especially after infratentorial surgery.

MR imaging evaluation of inferior olivary nuclei: comparison of postoperative subjects with and without posterior fossa syndrome.

BACKGROUND AND PURPOSE: Posterior fossa syndrome is a severe postoperative complication occurring in up to 29% of children undergoing posterior fossa tumor resection; it is most likely caused by bilateral damage to the proximal efferent cerebellar pathways, whose fibers contribute to the Guillain-Mollaret triangle. When the triangle is disrupted, hypertrophic olivary degeneration develops. We hypothesized that MR imaging patterns of inferior olivary nucleus changes reflect patterns of damage to the proximal efferent cerebellar pathways and show association with clinical findings, in particular the presence or absence of posterior fossa syndrome. MATERIALS AND METHODS: We performed blinded, randomized longitudinal MR imaging analyses of the inferior olivary nuclei of 12 children with and 12 without posterior fossa syndrome after surgery for midline intraventricular tumor in the posterior fossa. The Fisher exact test was performed to investigate the association between posterior fossa syndrome and hypertrophic olivary degeneration on MR imaging. The sensitivity and specificity of MR imaging findings of bilateral hypertrophic olivary degeneration for posterior fossa syndrome were measured. RESULTS: Of the 12 patients with posterior fossa syndrome, 9 had bilateral inferior olivary nucleus abnormalities. The 12 patients without posterior fossa syndrome had either unilateral or no inferior olivary nucleus abnormalities. The association of posterior fossa syndrome and hypertrophic olivary degeneration was statistically significant (P < .0001). CONCLUSIONS: Hypertrophic olivary degeneration may be a surrogate imaging indicator for damage to the contralateral proximal efferent cerebellar pathway. In the appropriate clinical setting, bilateral hypertrophic olivary degeneration may be a sensitive and specific indicator of posterior fossa syndrome.

Time-dependent structural changes of the dentatothalamic pathway in children treated for posterior fossa tumor.

BACKGROUND AND PURPOSE: Injury to the dentatothalamic pathway that originates in the cerebellum has been suggested as a mechanism for neurologic complications in children treated for posterior fossa tumors. We hypothesized that time-dependent changes occur in the dentatothalamic pathway. MATERIALS AND METHODS: Diffusion tensor evaluation was performed in 14 children (median age, 4.1 years; age range, 1-20 years) who underwent serial MR imaging at 3T as part of routine follow-up after posterior fossa tumor resection with or without adjuvant therapy. Tensor metrics were obtained in the acute (≤1 week), subacute (1 to <6 months), and chronic (≥6 months) periods after surgery. We evaluated the following dentatothalamic constituents: bilateral dentate nuclei, cerebellar white matter, and superior cerebellar peduncles. Serial dentate nuclei volumes were also obtained and compared with the patient's baseline. RESULTS: The most significant tensor changes to the superior cerebellar peduncles and cerebellar white matter occurred in the subacute period, regardless of the tumor pathology or therapy regimen, with signs of recovery in the chronic period. However, chronic volume loss and reduced mean diffusivity were observed in the dentate nuclei and did not reverse. This atrophy was associated with radiation therapy and symptoms of ataxia. CONCLUSIONS: Longitudinal diffusion MR imaging in children treated for posterior fossa tumors showed time-dependent tensor changes in components of the dentatothalamic pathway that suggest evolution of structural damage with inflammation and recovery of tissue directionality. However, the dentate nuclei did not show tensor or volumetric recovery, suggesting that the injury may be chronic.

Eurythmy therapy in the aftercare of pediatric posterior fossa tumour survivors--a pilot study.

BACKGROUND: Pediatric posterior fossa brain tumour survivors are burdened with extensive neurologic, emotional, behavioral and mental impairments. Even long-term common remediation therapies such as conventional physical therapy and occupational therapy do not warrant full recovery. Innovative complementary therapy strategies offer a new option that needs evaluation. EYT is a movement therapy that belongs to the field of mind-body therapies (MBTs). This holistic approach aims to promote self-regulation and self-healing powers e.g. in cancer patients. This pilot study is a first attempt to assess the feasibility, treatment adherence and impact of eurythmy therapy (EYT) in pediatric neurooncology. METHODS: Seven posterior fossa tumour survivors who each participated in 25 EYT interventions over 6 months were followed for an additional 6 months. The outcome parameters cognitive functioning, neuromotor functioning and visuomotor integration were assessed at baseline as well as six and 12 months afterwards. RESULTS: We found good adherence and improvements in cognitive and neuromotor functioning in all children and better visuomotor integration in 5/7 children after 6 months. After 12 months, neuromotor functioning and visuomotor integration diminished again to some extent. CONCLUSION: EYT in pediatric cerebellar tumour survivors is feasible and patients may profit from this new approach.

The effects of P6 electrical acustimulation on postoperative nausea and vomiting in patients after infratentorial craniotomy.

BACKGROUND: Postoperative nausea and vomiting (PONV) are frequent and harmful complications after neurosurgery. Current pharmacy-based treatment is the standard of care; it, however, lacks efficiency. Invasive and noninvasive acupuncture at the P6 meridian point has been shown to be effective in the prevention of PONV. We evaluated the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) at P6 for the prophylaxis of PONV in patients undergoing infratentorial craniotomy. METHODS: In this prospective, blind, and randomized study, patients received TEAS at P6 on the dominant side starting 30 minutes before the induction of anesthesia and up to 24 hours after surgery or sham acustimulation at P6. The anesthesia was maintained with sevoflurane/remifentanil and intermittent fentanyl/cisatracurium. Antiemetics with 4 mg ondansetron and 10 mg dexamethasone were administered intraoperatively. Data documenting postoperative episodes of nausea and vomiting and the need for antiemetic rescue (10 mg metoclopramide intramuscularly) were collected. Statistical analysis was performed using the χ test. P<0.05 was considered to be significant. RESULTS: Of the 130 patients enrolled, 119 patients completed the study. The 24-hour cumulative incidence of vomiting was significantly lower in the TEAS group than in the control group (22% vs. 41%, P=0.025). The cumulative incidences of nausea at 6 hours (27% vs. 47%, P=0.019) and 24 hours (33% vs. 58%, P=0.008) after surgery were also significantly lower in the TEAS group compared with the control group. The overall requirements of rescue antiemetics were similar between the groups. CONCLUSION: Perioperative TEAS at P6 may be an effective adjunct to the standard antiemetic drug therapy for the prevention of PONV after infratentorial craniotomy.

Accessing escalators: a central vestibular disorder after posterior fossa tumor removal.

About 20% of childhood tumors originate within the central nervous system. Progress in assessment and treatment of these lesions has led to improved survival rates. We describe a patient with a posterior fossa ependymoma who despite a remarkable recovery following treatment has been frustrated by difficulty in using escalators. Such symptom selectivity is explained by specific vertical visuomotor and high-frequency vestibular deficits disrupting the execution of this complex motor act.

Cerebello-thalamo-cerebral connections in pediatric brain tumor patients: impact on working memory.

Brain tumors are the leading cause of death and disability from childhood disease in developed countries. Pediatric posterior fossa tumors are often effectively controlled with a combination of surgery, radiation, and chemotherapy, depending on tumor type. White matter injury following resection of tumor and radiation treatment is associated with cognitive declines, including working memory deficits. We investigated how brain injury following treatment for posterior fossa tumors results in deficits in working memory. We used diffusion tensor imaging and probabilistic tractography to examine the structural integrity of cerebello-thalamo-cerebral tracts in patients and healthy children. We also compared working memory outcome in patients versus controls, and related this function to integrity of cerebello-thalamo-cerebral tracts. Bilateral cerebello-thalamo-cerebral tracts were delineated in all participants. Patients treated with a combination of surgery and radiation had lower mean anisotropy and higher mean radial diffusivity within the cerebellar regions of the cerebello-thalamo-cerebral tract compared to patients treated with surgery only and healthy controls. Poorer working memory scores were observed for the cranial radiation group relative to controls. Reduced anisotropy and higher radial diffusivity within the entire cerebello-thalamo-cerebral pathway predicted lower working memory. Our finding that working memory function is related to the integrity of cerebello-thalamo-cerebral connections is a novel contribution to the understanding of cerebral-cerebellar communication. Identifying differences in the structural integrity of white matter for specific pathways is an essential step in attempting to localize the effects of posterior fossa tumors and their treatment methods.

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.

Auditory agnosia caused by a tectal germinoma.

The authors describe a patient with auditory agnosia caused by a tectal germinoma. Despite having normal audiometric tests, the patient failed to recognize words and musical characters. On head MRI, the inferior colliculi were infiltrated by tumor. Neuropsychological tests revealed severe impairment in recognition of environmental sounds and words, defective musical perception, and stop consonant-vowel discrimination. Inferior colliculus may play a role in the analysis of sound properties.

Osteopenia in children who have undergone posterior fossa or craniospinal irradiation for brain tumors.

OBJECTIVES: To determine lumbar spine and total body bone mineral density (BMD) in pediatric patients who have undergone cranial or craniospinal irradiation for posterior fossa tumors, specifically medulloblastoma and ependymoma and to analyze the association between degree of osteopenia and factors that may affect BMD. METHODS: Retrospective and prospective data collection included medical record review and examination, including pubertal, dietary, and activity assessment. Lumbar spine and total body BMD were measured by means of dual energy x-ray absorptiometry. Patients were routinely observed by the endocrinology department, and hormone deficiencies were corrected promptly. A subset of patients received calcium and vitamin D supplementation and underwent repeat BMD measurement 1 year later. RESULTS: Of 24 patients aged 4 to 20 years, 11 of whom were male, recruited from 1996 through 1999, 19 had medulloblastoma. All 19 underwent craniospinal radiotherapy plus a boost to the posterior fossa (mean +/- SD of 5410 +/- 130 rad [54.1 +/- 1.3 Gy] to the posterior fossa, mean +/- SD of 3470 +/- 460 rad [34.7 +/- 4.6 Gy] to the whole brain and spinal axis), and 8 of 19 underwent chemotherapy. The remaining 5 patients had ependymoma and underwent irradiation to the posterior fossa only (mean +/- SD of 5680 +/- 720 rad [56.8 +/- 7.2 Gy]). Therefore, there were 3 treatment groups: craniospinal irradiation and chemotherapy, only craniospinal irradiation, and only posterior fossa irradiation. Bone mineral studies were performed a mean +/- SD of 5.42 +/- 3.23 years after therapy. Our patients had lower total body BMD (mean z score, -0.47; 95% confidence interval, -0.85 to -0.09) and lumbar spine BMD (mean z score, -1.27; 95% confidence interval, -1.81 to -0.73) as compared with those of the the general population. There was no significant difference in mean lumbar spine BMD between patients in the 3 groups. Our patients consumed a diet deficient in vitamin D and calcium (mean +/- SD 53.6% +/- 24.1% and 70.0% +/- 37.4% of the amount recommended, respectively). Of 7 patients who underwent measurements 1 year later, 5 had in increase in BMD that was parallel to normal curves, with no compensatory increase. Four patients were hypothyroid, 6 were growth hormone deficient, and 6 were both. All hormones were replaced, with the exception of growth hormone in 1 patient. By using regression analysis, the factors that affected lumbar spine BMD, protectively in both cases, were calcium intake (beta = 0.015, 95% confidence interval, 0.001-0.029) and female sex (beta = 1.422, 95% confidence interval, 0.456-2.388). CONCLUSIONS: Children who have undergone irradiation for posterior fossa tumors have diminished total body and lumbar spine BMD, as compared with those of the general population. This reduction was similar within all 3 treatment groups, which suggests that chemotherapy did not play a major role and that localized irradiation may have systemic effects. This population often has balance and gait problems, so the risk of falling, coupled with osteopenia, may place them at considerably increased risk of fractures.