Biomedical subjects

Oliver Ganslandt

Publications and source records attributed to Oliver Ganslandt.

At least 19 recordsLinked to original sources

PubMed2006

Diffusion tensor imaging and optimized fiber tracking in glioma patients: Histopathologic evaluation of tumor-invaded white matter structures.

Fiber tracking is increasingly used to plan and guide neurosurgical procedures of intracranial tumors in the vicinity of functionally important areas of the brain. However, valid data concerning the reliability of tracking with respect to the actual pathoanatomical situation are lacking. We retrospectively correlated fiber tracking based on magnetic resonance (MR) DT imaging with the histopathological data of 25 patients with WHO grade II and III gliomas. Fiber tracking using the Fiber Assignment by Continuous Tracking (FACT) method was performed to investigate the integrity of white matter tracts in the surrounding border zone of the lesions. The tracking procedure was stopped when fractional anisotropy (FA) thresholds = 0.1, 0.15, 0.2, 0.25, and 0.3, or a tract turning angle >60 degrees were encountered. In 9 patients we were able to reconstruct brain fiber tracts at biopsy loci (2-32% tumor infiltration) using an FA threshold of 0.15 and 0.2, but not for a threshold of 0.25 or 0.3. The neurological outcome demonstrated potential tumor cell infiltration of functionally intact brain fiber tracts in the range of 2-8%. These findings may be useful in planning therapeutic approaches to gliomas in the vicinity of eloquent brain regions.

Adolescent↗

PubMed2006

International quality control survey of neurochemical dementia diagnostics.

UNLABELLED: Currently, neurochemical dementia diagnostics (NDD) are increasingly entering routine clinical neurochemistry, offering improved early and differential diagnosis of dementias. However, there is an obvious lack of standardization in pre-analytical sample handling and systematic quality surveys. Therefore, in this study, 14 laboratories in Germany, Austria, and Switzerland were given aliquots of a human cerebrospinal fluid (CSF) sample, and were asked to measure Alzheimer's disease (AD) biomarkers (amyloid beta (Abeta) peptides, total Tau protein, and phosphorylated Tau protein (P-tau(181P))) according to their routine protocols. RESULTS: The inter-laboratory coefficients of variation of the results obtained by the laboratories participating in this study were in the range of 20-30%. Although the results of this quality control survey are promising, the quality of measurements has to be further optimized.

Alzheimer Disease↗

PubMed2006

Survival and quality of life after hypofractionated stereotactic radiotherapy for recurrent malignant glioma.

PURPOSE: To prospectively evaluate efficacy, side effects and quality of life in patients with recurrent malignant glioma after hypofractionated stereotactic radiotherapy. METHODS AND MATERIALS: From 1/2003 to 8/2005, 15 patients with recurrent malignant glioma were prospectively scheduled for hfSRT with 5 x 7 Gy (90%-isodose). Median gross tumor volume and planning target volume were 5.75 (range, 0.77-21.94) and 22.4 (range, 4.22-86.79) cc, respectively. Irradiation was performed with the dedicated stereotactic radiosurgery system Novalistrade mark (BrainLAB, Heimstetten, Germany). RESULTS: Rates of remission, no change and progressive disease were 27%, 33%, and 40%, respectively, after a median follow-up of 9 months. Progression-free survival rates at 6 and 12 months were 75% and 53% respectively. Quality of life, measured by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire scores could be kept stable in two thirds of the patients for a median time of 9 months, respectively. CONCLUSION: Hypofractionated stereotactic radiotherapy with 5 x 7 Gy of recurrent high grade glioma is an effective treatment that helps to maintain quality of life for an acceptable period, comparable to the results obtained with current chemotherapy schedules. Combined approaches of radiotherapy, chemotherapy and other targeted therapies deserve further inverstigation.

Adult↗

PubMed2006

Phase II trial of hypofractionated stereotactic radiotherapy for brain metastases: results and toxicity.

PURPOSE: To prospectively evaluate efficacy and side effects of hypofractionated stereotactic radiotherapy (hfSRT) for irresectable brain metastases not amenable to radiosurgery (SRS). METHODS AND MATERIALS: From 1/2003 to 2/2005, 51 patients with 72 brain metastases were included in a prospective phase II-trial and accepted for treatment at the dedicated stereotactic radiosurgery system Novalis (BrainLAB, Heimstetten, Germany). In case of planned or prior whole brain radiotherapy (WBRT), hfSRT was to be performed with 5 x 6 Gy, otherwise with 5 x 7 Gy. This dose was prescribed to the 90% isodose line which should cover 100% of the planning target volume (PTV). RESULTS: Rates of complete remission (CR), partial remission (PR), no change (NC) and progressive disease (PD) were 66.7%, 18.1%, 12.5% and 2.8%, respectively, after a median follow-up of 7 months. Median survival was 11 months. Disease-specific survival and survival related to brain metastases were strongly associated with the size of gross tumor volume (GTV), the planning target volume (PTV), Karnofsky Performance Score (KPS) and number of metastases. Side effects, i.e., increase in T2w-signal area, duration of steroid intake and size of new or progressive necrotic centre of metastasis, were dependent on the volume of normal brain irradiated with more than 4 Gy per fraction (V(4Gy)). Significantly more patients with a V(4Gy)> or =23 cc developed radiological signs of side effects from hfSRT. CONCLUSION: Hypofractionated stereotactic radiotherapy with 5 x 6-7 Gy is an effective and safe treatment for brain metastases not amenable to single high-dose radiosurgery. The normal brain volume receiving >4 Gy per fraction may not exceed 20 cc.

Adult↗

PubMed2006

Combining fMRI and MEG increases the reliability of presurgical language localization: a clinical study on the difference between and congruence of both modalities.

To avoid neurological impairment during surgery near language-related eloquent brain areas, we performed presurgical functional brain mapping with functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in 172 patients using language tasks. For MEG localizations, we used either a moving equivalent-current dipole fit or a current-density reconstruction using a minimum variance beamformer with a spatial filter algorithm. We localized the Wernicke and Broca language areas for every patient. We integrated the results into a frameless stereotaxy system. To visualize the results in the navigation microscope during surgery, we superimposed the fMRI and MEG findings on the brain surface. MEG and fMRI results differed in 4% of cases, and in 19%, one modality showed activation but not the other. In the vicinity of large gliomas, the BOLD (blood oxygenation level-dependent) effect was suppressed in 53% of our patients. Of the 124 patients who had surgery, only 7 patients (5.6%) experienced a transient language deterioration, which resolved in all cases. We used MEG and fMRI to show different aspects of brain activity and to establish validation between MEG and fMRI. We conclude that measurement by both MEG and fMRI increases the degree of reliability of language area localization and that the combination of fMRI and MEG is useful for presurgical localization of language-related eloquent cortex.

Brain↗

PubMed2006

Application accuracy of automatic registration in frameless stereotaxy.

OBJECTIVE: We compared the application accuracy of an infrared-based neuronavigation system when used with a novel automatic registration with its application accuracy when standard fiducial-based registration is performed. METHODS: The automatic referencing tool is based on markers that are integrated in the headrest holder we routinely use in our intraoperative magnetic resonance imaging (MRI) setting and can be detected by the navigation software automatically. For navigation targeting we used a Plexiglas phantom with 32 notched rods of different heights. The phantom was fixed in the head holder and multiple optimized gradient echo slices containing the clamp-integrated markers were acquired. After that we measured a T1 MPRAGE sequence with a slice thickness of 1.0 mm for navigation. The deepest points of the surface of the rods were defined as target points in image space. In three measurement series we referenced the phantom once with 4, once with 7 fiducials and twice automatically. In one series we performed only one automatic registration. The localization error was measured 3 times per rod and registration. RESULTS: The median localization errors for standard registration with 7 fiducials were between 1.2 and 3.05 mm. With 4 fiducials, medians were in the range from 1.87 to 2.21 mm. For the automatic registration we obtained median localization errors between 0.88 and 2.13 mm. In 6 of the 8 samples that were compared the automatic registration showed an application accuracy that was highly significantly better (p < 0.001 in most cases) than that of fiducial-based standard registration. CONCLUSION: The application accuracy found for automatic referencing is at least not worse than that for standard registration no matter whether 4 or 7 fiducial markers were used. Therefore, its use in the operating room is feasible. In combination with intraoperative MRI it may become a favorable alternative to standard fiducial-based registration especially when an intraoperative update of navigation data is necessary.

Automation↗

PubMed2006

Preoperative grading of gliomas by using metabolite quantification with high-spatial-resolution proton MR spectroscopic imaging.

PURPOSE: To evaluate proton magnetic resonance (MR) spectroscopic imaging with high spatial resolution for preoperative grading of suspected World Health Organization grades II and III gliomas. MATERIALS AND METHODS: Institutional ethics committee approval and informed consent were obtained for control subjects but were not required for the retrospective component involving patients. Twenty-six patients (10 women, 16 men; mean age, 37.5 years) suspected of having gliomas and 26 age- and sex-matched control subjects underwent proton MR spectroscopy. Absolute metabolite concentrations for choline-containing compounds (Cho), creatine (Cr), and N-acetylaspartate (NAA)-N-acetylaspartylglutamate (total NAA [tNAA]) were calculated by using a user-independent spectral fit program. Metabolic maps of Cho/tNAA ratios were calculated, segmented, and used for MR spectroszpcopy-guided stereotactic brain biopsy. Two-sided paired Student t tests were used to test for statistical significance. RESULTS: Significantly lower Cho levels (P = .002) and higher tNAA levels (P = .010) were found in grade II tumors (n = 9) compared with grade III tumors (n = 17). The average Cho/tNAA ratio over the voxels in the tumor center showed a distinct difference (P < .001) between grade II and III gliomas at a threshold of 0.8 (with ratios <0.8 for grade II). The maximum Cr concentration in the tumor showed a clear-cut threshold between grade III oligodendrogliomas and oligoastrocytomas (Cr level, <7 mmol/L) and grade III astrocytomas (Cr level, >7 mmol/L; P = .020). Comparison between the histopathologic findings from the MR spectroscopy-guided biopsy samples (76 biopsies from 26 patients) and molar metabolite values in corresponding voxels located at the biopsy sampling points showed a negative linear correlation for tNAA (r = -0.905) and a positive exponential correlation for Cho (r = 0.769) and Cho/tNAA (r = 0.885). CONCLUSION: Proton MR spectroscopic imaging with high spatial resolution allows preoperative grading of gliomas.

Adolescent↗

PubMed2006

Dose escalation in large anterior skull-base tumors by means of IMRT. First experience with the Novalis system.

PURPOSE: To evaluate the feasibility and tolerance of dose escalation with stereotactic intensity-modulated radiotherapy (sIMRT) for skull-base tumors. PATIENTS AND METHODS: Between 01/2003 and 12/2004, twelve patients were treated. Nine were exclusively treated at the Novalis site with one planning target volume (PTV) field boost, three were administered boost IMRT treatment (two with each one PTV-shrinking field, one with single PTV) after conventional three-dimensional conformal radiotherapy. This resulted in 23 PTVs with a median volume of 93.63 cm3 (range, 88.58-125.88 cm3). Dose calculation was done by the pencil-beam algorithm. Median total doses of 66.6, 77.4, and 63.9 Gy were prescribed for sIMRT alone, sIMRT after 3-D conformal irradiation of the nasopharynx and cervical lymph nodes with 59.4 Gy, and for reirradiation, respectively. RESULTS: 95% isodose PTV coverage was reached in 86.5% (range, 80-93%). Homogeneity (Dmax/Dref) was 1.11, 1.09, and 1.08. Median total doses to 50% of chiasm, right and left optic nerve were 16.21, 16.82 and 10.23 Gy. 11/12 patients are locally controlled with a median follow-up of 11 months (range, 3-23 months), one has died of pulmonary embolism after cerebrospinal dissemination of retinal adenocarcinoma. CONCLUSION: SIMRT enables dose escalation to tumors located close to critical organs. Inverse planning for micro-multileaf collimator stereotactic irradiation is practicable in the daily routine irradiation program. SIMRT needs special verification and still, the following parameters have to be standardized: IMRT dose specification, dose maxima, length of radiation delivery time.

Adult↗

PubMed2006

Usefulness of 1H-MRS in the diagnosis of contrast enhancing cystic lesions: A case report.

The clinical and radiological features of brain abscesses can sometimes imitate those of necrotic tumors or metastasis. Whereas the approach and urgency of surgical intervention differs enormously, further diagnostic features are necessary in order to establish the correct preoperative diagnosis. We report on two patients who presented with septated ring-enhancing lesions in the right parieto-temporat hemisphere with perifocal edema and discuss the role of 1H-magnetic resonance spectroscopy (MRS) in the diagnosis of contrast enhancing cystic lesions.

Adult↗

PubMed2006

Gliomas: histopathologic evaluation of changes in directionality and magnitude of water diffusion at diffusion-tensor MR imaging.

PURPOSE: To retrospectively correlate changes in fractional anisotropy (FA) and mean diffusivity in gliomas at diffusion-tensor magnetic resonance (MR) imaging with the degree of tumor cell infiltration determined histologically. MATERIALS AND METHODS: The institutional review board required neither ethics committee approval nor patient informed consent for this study. Twenty patients (eight women, 12 men; age range, 18-53 years) with glioma (seven World Health Organization grade II and 13 grade III tumors) underwent diffusion-tensor MR imaging at 1.5 T. Diffusion-tensor data were obtained with an echo-planar imaging sequence with six diffusion directions (b = 1000 sec/mm(2)), isotropic 1.9-mm voxels, and five averages. FA and mean diffusivity values were calculated from diffusion-tensor data. Coregistration with a three-dimensional MR imaging data set (used for stereotactic brain biopsies) enabled correlation of FA and mean diffusivity values with the histopathologic findings total cell number (CN), tumor CN, and percentage tumor infiltration (TI) by using linear, exponential, and logarithmic models. Student t and Mann-Whitney U tests were performed. RESULTS: Histopathologic findings of 77 MR image-guided stereotactic biopsies in all 20 patients were correlated with FA and mean diffusivity values at the biopsy locus. For FA and mean diffusivity, a logarithmic model showed strongest correlation with tumor CN and total CN; a linear model showed strongest correlation with percentage TI. For FA there were negative logarithmic (R = -0.802, P < .001) and linear (R = -0.796, P < .001) correlations with tumor CN and percentage TI, respectively. For mean diffusivity there were positive logarithmic (R = 0.557, P < .001) and linear correlations (R = 0.521, P < .001) with tumor CN and percentage TI, respectively. Differences between correlations for FA and mean diffusivity versus tumor CN (P < .001) and percentage TI (P < .001) were significant. CONCLUSION: FA is better than mean diffusivity for assessment and delineation of different degrees of pathologic changes (ie, TI) in glioma.

Adolescent↗

PubMed2006

Intraoperative visualization for resection of gliomas: the role of functional neuronavigation and intraoperative 1.5 T MRI.

OBJECTIVE: To investigate how functional neuronavigation and intraoperative high-field magnetic resonance imaging (MRI) influence glioma resection. METHODS: One hundred and thirty-seven patients [World Health Organization (WHO) grade I: 20; II: 19; III: 41; IV: 57] underwent resection for supratentorial gliomas in an operative suite equipped with intraoperative high-field MRI and microscope-based neuronavigation. Besides standard anatomical image data including T1- and T2-weighted sequences, various functional data from magnetoencephalography (n=37), functional MRI (n=65), positron emission tomography (n=8), MR spectroscopy (n=28) and diffusion tensor imaging (n=55) were integrated in the navigational setup. RESULTS: Intraoperative MRI showed primary complete resection in 27% of all patients (I: 50%; II: 53%; III: 2%; IV: 28%). In 41% of all patients (I: 40%; II: 26%; III: 66%; IV: 28%) the resection was extended owing to intraoperative MRI increasing the percentage of complete resections to 40% (I: 70%; II: 58%; III: 17%; IV: 40%). Integrated application of functional navigation resulted in low post-operative morbidity with a transient new neurological deficit in 10.2% (paresis: 8.8% and speech disturbance: 1.4%) decreasing to a permanent deficit in 2.9% (four of 137 patients with a new or increased paresis). CONCLUSIONS: The combination of intraoperative MRI and functional navigation allows safe extended resections in glioma surgery. However, despite extended resections, still in the majority of the grade III and IV gliomas no gross total resection could be achieved owing to the extension of the tumor into eloquent brain areas. Intraoperative MRI data can be used to localize the tumor remnants reliably and compensate for the effects of brain shift.

Adolescent↗

PubMed2006

Implementation of fiber tract navigation.

OBJECTIVE: To implement fiber tracking in a common neuronavigation environment for routine clinical use to visualize major white matter tracts intraoperatively. METHODS: A single-shot, spin-echo diffusion weighted echo planar imaging sequence with six diffusion directions on a 1.5 T magnetic resonance scanner was used for diffusion tensor imaging. For three-dimensional (3-D) tractography, we applied a knowledge-based multiple volume of interest approach. Tracking was initiated in each voxel of the initial seed volume in retrograde and orthograde directions according to the direction of the major eigenvector by applying a tensor deflection algorithm. Tractography results were displayed as streamlines assigned direction encoding color. After selecting the fiber tract bundle of interest by defining inclusion and exclusion volumes, a 3-D object was generated automatically by wrapping the whole fiber tract bundle. This 3-D object was displayed along with other contours representing tumor outline and further functional data with the microscope heads-up display. RESULTS: In 16 patients (three cavernomas, 13 gliomas), major white matter tracts (pyramidal tract, n = 14; optic radiation, n = 2) were visualized intraoperatively with a standard navigation system. Three patients developed a postoperative paresis, which resolved in two in the postoperative course. Additional planning time for tractography amounted to up to 10 minutes. Comparing the tractography results with a fiber bundle generated on a different platform by applying a distortion-free sequence revealed a good congruency of the defined 3-D outlines in the area of interest. CONCLUSION: Fiber tract data can be reliably integrated into a standard neuronavigation system, allowing for intraoperative visualization and localization of major white matter tracts such as the pyramidal tract or optic radiation.

Adolescent↗

PubMed2006

Intraoperative high-field magnetic resonance imaging in transsphenoidal surgery of hormonally inactive pituitary macroadenomas.

OBJECTIVE: The aim of the study was to evaluate the effect of intraoperative, high-field (1.5 T) magnetic resonance imaging (MRI) on the results of transsphenoidal surgery of hormonally inactive pituitary macroadenomas. METHODS: One hundred six patients (tumor size, 29.9 +/- 10.1 mm; minimum, 11.3 mm; maximum, 57.2 mm) with hormonally inactive pituitary macroadenoma were investigated by intraoperative high-field MRI during transsphenoidal surgery. If intraoperative imaging depicted an accessible tumor remnant, resection was continued. RESULTS: Among the 85 patients in whom complete tumor removal was intended preoperatively, intraoperative imaging revealed definite tumor remnants or suspicious findings in 36 (42%) patients. Imaging led to an extended resection in 29 (34%) patients of this group. Among them, resection could be completed in 21. This increased the rate of complete tumor removal from 58% (49 out of 85) to 82% (70 out of 85). In the group of patients with intended partial removal (n = 21), resection was extended in 38% (eight out of 21) because of intraoperative imaging. Comparison with scanning 3 months after surgery did not reveal any false-negative findings of intraoperative MRI; in six cases, intraoperative MRI was suspicious for some minor remnant that could not be reproduced in the postoperative control. CONCLUSION: The extent of resection in transsphenoidal surgery can be reliably assessed using intraoperative high-field MRI. In addition to the suprasellar compartment, intra- and parasellar structures are also visualized in great detail. Intraoperative imaging acts as an immediate intraoperative quality control, allowing one to not only increase the extent of resection, but to also increase the percentage of complete removals.

Adenoma↗

PubMed2005

Intraoperative visualization of the pyramidal tract by diffusion-tensor-imaging-based fiber tracking.

Functional neuronavigation allows intraoperative visualization of cortical eloquent brain areas. Major white matter tracts, such as the pyramidal tract, can be delineated by diffusion-tensor-imaging based fiber tracking. These tractography data were integrated into 3-D datasets applied for neuronavigation by rigid registration of the diffusion images with standard anatomical image data so that their course could be superimposed onto the surgical field during resection of gliomas. Intraoperative high-field magnetic resonance imaging was used to compensate for the effects of brain shift, which amounted up to 8 mm. Despite image distortion of echo planar images, which was identified by non-linear registration techniques, navigation was reliable. In none of the 19 patients new postoperative neurological deficits were encountered. Intraoperative visualization of major white matter tracts allows save resection of gliomas near eloquent brain areas. A possible shifting of the pyramidal tract has to be taken into account after major tumor parts are resected.

Adult↗

PubMed2005

Intraoperative functional MRI: implementation and preliminary experience.

For a non-invasive identification of eloquent brain areas in neurosurgical procedures up to now only preoperative functional brain mapping techniques are available. These are based, e.g., on preoperative functional magnetic resonance imaging (fMRI) investigations in awake patients. The aim of this study was to investigate the feasibility to perform fMRI during neurosurgical procedures in anesthetized patients. For that purpose, a passive stimulation paradigm with peripheral nerve stimulation was applied. A 1.5-T MR scanner placed in a radiofrequency-shielded operating room with an adapted operating table was used for intraoperative fMRI. The fMRI data were analyzed during acquisition by an online statistical evaluation package installed on the MR scanner console. In addition, phase reversal of somatosensory evoked potentials was used for verification of intraoperative fMRI. In four anesthetized patients with lesions in the vicinity of the central region a total of 11 fMRI measurements were successfully acquired and analyzed online. Activation was found in the somatosensory cortex, which could be confirmed by intraoperative phase reversal for each measurement. Furthermore, statistical parametric mapping (SPM) was employed for an extensive offline data analysis. We did not observe any neurological deterioration or complications due to the stimulation technique. Intraoperative fMRI is technically feasible allowing a real-time identification of eloquent brain areas despite brain shift.

Adult↗

PubMed2005

Observation of unaveraged giant MEG activity from language areas during speech tasks in patients harboring brain lesions very close to essential language areas: expression of brain plasticity in language processing networks?

We describe a series of 12 patients who suffered from lesions adjacent to the classic Broca and Wernicke areas and were examined by magnetoencephalography (MEG) for presurgical language localization while performing a protocol of different language tasks. In these patients very large MEG activity of up to 5pT was observed, which was located not only in the adjacent language processing brain areas but also in more distant areas, which are part of the language processing neuronal network. The high amplitude and the focal spatial extent of this activity allowed MEG source localization from the unaveraged data. In nine patients sources of this high amplitude activity were even found in the homologous language areas on the contralateral, the nondominant side of the brain. The physiological interrelationship of these large MEG changes needs to be investigated in more detail in further studies especially in the context of possible mechanisms for brain plasticity to overcome inhibitory activity of the impaired language area.

Adult↗

PubMed2005

Radiosurgery of small skull-base lesions. No advantage for intensity-modulated stereotactic radiosurgery versus conformal arc technique.

BACKGROUND AND PURPOSE: Intensity-modulated stereotactic radiotherapy (IMSRT) has shown the ability to conform the dose to concavities and to better avoid critical organs for large tumors. Given the availability of an electronically driven micro-multileaf collimator, both intensity-modulated stereotactic radiosurgery (IMSRS) and dynamic conformal arc (DCA) technique (DCA) can be performed at the Novalis Shaped Beam Surgery Center, University of Erlangen-Nuremberg, Germany, since 12/2002. This study evaluates both techniques in small skull-base tumors treated with radiosurgery. MATERIAL AND METHODS: Between 12/2002 and 04/2004, a total of 109 radiosurgical procedures were performed in 77 patients, equally distributed between patients with acoustic neuroma (AN), pituitary adenoma (PA) and meningeoma (M). Six index patients (n = 2 AN, n = 1 PA, n = 3 M) routinely planned for dynamic arc stereotactic radiosurgery were replanned using the IMSRS approach (BrainScan, BrainLAB, Heimstetten, Germany). The RTOG radiosurgery quality assurance guidelines, isodose volumes, doses to organs at risk (OAR), and dose delivery criteria were compared. RESULTS: DCA was superior to IMSRS for homogeneity and coverage. IMSRS could keep the high-dose-irradiated volumes (90% isodose volume) lower than DCA in the PA and AN with very small volumes, but all other lower dose volumes were larger for IMSRS. Dose maxima to OAR were higher for IMSRS. Treatment delivery time for IMSRS would clearly exceed treatment time for DCA by a factor of 2-3. The integral absorbed dose to the brain was much higher in the IMSRS than in the DCA approach (factor 2-3). CONCLUSION: RTOG radiosurgery guidelines were best met by the DCA rather than IMSRS approach for the treatment of small skull-base lesions. The IMSRS approach will increase the time for planning, dose delivery and integral dose to the brain. Thus, IMSRT techniques are recommended for fractionated stereotactic radiotherapy to larger volumes rather than for radiosurgery in small skull-base lesions.

Adenoma↗

PubMed2005

Prolonged oral hydroxyurea and concurrent 3d-conformal radiation in patients with progressive or recurrent meningioma: results of a pilot study.

PURPOSE: Treatment of recurrent and progressive meningiomas remains a challenge in clinical neurooncology. This study was designed to evaluate the efficacy of the simultaneous application of 3d-conformal radiotherapy and chemotherapy with hydroxyurea (HU). PATIENTS AND METHODS: Twenty-one patients with recurrent or progressive meningiomas (13 benign, 4 atypical and malignant, 4 with unproven histology) received treatment by fractionated 3d-conformal radiation (55.8-59.4 Gy) and concurrent HU, administered for a median time of three months with a daily dosage of 20 mg/kg. Response was evaluated using clinical and neuro-imaging data. RESULTS: Disease stabilization was achieved in 14/21 patients (pts). Three pts had significant improvement of tumor associated neurological symptoms with imaging criteria of minor response. Progression free survival rates 1 year and 2 years after the initiation of radio-chemotherapy were 84% and 77%, respectively. At the time of analysis a total of 6/21 pts presented with progressive disease with a median time to progression of 59 weeks. Documented radio- and chemotherapy associated toxicity was minimal; only one patient discontinued HU treatment due to gastrointestinal symptoms such as anorexia and weight loss. CONCLUSION: Results obtained in this study indicate that treatment with HU and simultaneous radiotherapy is safe and effective with disease stabilization in the majority of patients. Randomized trials comparing radiosurgery versus radiochemotherapy versus fractionated radiotherapy are warranted.

Administration, Oral↗