Michail Plotkin

Publications of Michail Plotkin

• Contribution of (68)Ga-DOTATOC PET/CT to Target Volume Delineation of Skull Base Meningiomas Treated With Stereotactic Radiation Therapy.

  Authors: Reinhold Graf, Fonyuy Nyuyki, Ingo G Steffen, Roger Michel, Daniel Fahdt, Peter Wust, Winfried Brenner, Volker Budach, Reinhard Wurm, Michail Plotkin

  International journal of radiation oncology, biology, physics. 05/2012;

  PURPOSE: To investigate the potential impact of (68)Ga-DOTATOC positron emission tomography ((68)Ga-DOTATOC-PET) in addition to magnetic resonance imaging (MRI) and computed tomography (CT) forPURPOSE: To investigate the potential impact of (68)Ga-DOTATOC positron emission tomography ((68)Ga-DOTATOC-PET) in addition to magnetic resonance imaging (MRI) and computed tomography (CT) for retrospectively assessing the gross tumor volume (GTV) delineation of meningiomas of the skull base in patients treated with fractionated stereotactic radiation therapy (FSRT). METHODS AND MATERIALS: The study population consisted of 48 patients with 54 skull base meningiomas, previously treated with FSRT. After scans were coregistered, the GTVs were first delineated with MRI and CT data (GTV(MRI/CT)) and then by PET (GTV(PET)) data. The overlapping regions of both datasets resulted in the GTV(common), which was enlarged to the GTV(final) by adding volumes defined by only one of the complementary modalities (GTV(MRI/CT-added) or GTV(PET-added)). We then evaluated the contribution of conventional imaging modalities (MRI, CT) and (68)Ga-DOTATOC-PET to the GTV(final), which was used for planning purposes. RESULTS: Forty-eight of the 54 skull base lesions in 45 patients showed increased (68)Ga-DOTATOC uptake and were further analyzed. The mean GTV(MRI/CT) and GTV(PET) were approximately 21 cm(3) and 25 cm(3), with a common volume of approximately 15 cm(3). PET contributed a mean additional GTV of approximately 1.5 cm(3) to the common volume (16% ± 34% of the GTV(common)). Approximately 4.5 cm(3) of the GTV(MRI/CT) was excluded from the contribution to the common volume. The resulting mean GTV(final) was significantly smaller than both the GTV(MRI/CT) and the GTV(PET). Compared with the initial GTV(MRI/CT), the addition of (68)Ga-DOTATOC-PET resulted in more than 10% modification of the size of the GTV(final) in 32 (67%) meningiomas CONCLUSIONS: (68)Ga-DOTATOC-PET/CT seems to improve the target volume delineation in skull base meningiomas, often leading to a reduction of GTV compared with results from conventional imaging (MRI and CT).

• No correlation of substantia nigra echogenicity and nigrostriatal degradation in Parkinson's disease.

  Authors: Elmar Lobsien, Simon Schreiner, Michail Plotkin, Andreas Kupsch, Stephan J Schreiber, Florian Doepp

  Movement disorders : official journal of the Movement Disorder Society. 01/2012;

  BACKGROUND: Substantia nigra hyperechogenicity assessed by transcranial sonography is a typical finding in up to 90% of patients with idiopathic Parkinson's disease, although its value as a surrogateBACKGROUND: Substantia nigra hyperechogenicity assessed by transcranial sonography is a typical finding in up to 90% of patients with idiopathic Parkinson's disease, although its value as a surrogate marker for disease progression in Parkinson's disease is controversial. (123) I-FP-CIT-single photon emission computed tomography (SPECT) represents an established paraclinical surrogate marker to quantify the nigrostriatal dopaminergic deficit in Parkinson's disease. Whereas most studies found no correlation between extent of substantia nigra echogenicity and the putaminal FP-CIT binding ratio, a more recent analysis reported opposite results. METHODS: In 92 patients with Parkinson's disease the substantia nigra echogenicity was compared with the putaminal FP-CIT binding ratio using an investigator-independent SPECT analysis protocol and with several clinical parameters. RESULTS: No correlation was found between the substantia nigra hyperechogenicity and the FP-CIT binding ratio or the disease severity. CONCLUSIONS: Substantia nigra hyperechogenicity does not reflect the degree of the nigrostriatal degeneration or the clinical state of the disease progression. © 2012 Movement Disorder Society.

• Magnetic resonance imaging, computed tomography, and 68Ga-DOTATOC positron emission tomography for imaging skull base meningiomas with infracranial extension treated with stereotactic radiotherapy - a case series.

  Authors: Reinhold Graf, Michail Plotkin, Ingo G Steffen, Reinhard Wurm, Peter Wust, Winfried Brenner, Volker Budach, Harun Badakhshi

  Head & face medicine. 01/2012; 8(1):1.

  ABSTRACT: Magnetic resonance imaging (MRI) and computed tomography (CT) with 68Ga-DOTATOC positron emission tomography (68Ga-DOTATOC-PET) were compared retrospectively for their ability to delineateABSTRACT: Magnetic resonance imaging (MRI) and computed tomography (CT) with 68Ga-DOTATOC positron emission tomography (68Ga-DOTATOC-PET) were compared retrospectively for their ability to delineate infracranial extension of skull base (SB) meningiomas treated with fractionated stereotactic radiotherapy. Fifty patients with 56 meningiomas of the SB underwent MRI, CT, and 68Ga-DOTATOC PET/CT prior to fractionated stereotactic radiotherapy. The study group consisted of 16 patients who had infracranial meningioma extension, visible on MRI ± CT (MRI/CT) or PET, and were evaluated further. The respective findings were reviewed independently, analyzed with respect to correlations, and compared with each other. Within the study group, SB transgression was associated with bony changes visible by CT in 14 patients (81%). Tumorous changes of the foramen ovale and rotundum were evident in 13 and 8 cases, respectively, which were accompanied by skeletal muscular invasion in 8 lesions. We analysed six designated anatomical sites of the SB in each of the 16 patients. Of the 96 sites, 42 had infiltration that was delineable by MRI/CT and PET in 35 cases and by PET only in 7 cases. The mean infracranial volume that was delineable in PET was 10.1 ± 10.6 cm3, which was somewhat larger than the volume detectable in MRI/CT (8.4 ± 7.9 cm3). 68Ga-DOTATOC-PET allows detection and assessment of the extent of infracranial meningioma invasion. This method seems to be useful for planning fractionated stereotactic radiation when used in addition to conventional imaging modalities that are often inconclusive in the SB region.

• Comparison of F-18 FET-PET with F-18 FDG-PET for biopsy planning of non-contrast-enhancing gliomas.

  Authors: Michail Plotkin, C Blechschmidt, G Auf, F Nyuyki, L Geworski, T Denecke, W Brenner, F Stockhammer

  European radiology. 10/2010; 20(10):2496-502.

  The management of non-contrast-enhancing brain tumours largely depends on biopsy, which allows a differentiation of low-grade gliomas (LGG) from high-grade gliomas (HGG). The aim of this study was toThe management of non-contrast-enhancing brain tumours largely depends on biopsy, which allows a differentiation of low-grade gliomas (LGG) from high-grade gliomas (HGG). The aim of this study was to compare positron emission tomography using 2-[(18)F]-fluoro-2-deoxy-D: -glucose (FDG-PET) and O-(2-[(18)F]-fluoroethyl)-L: -tyrosine (FET-PET) in terms of providing target regions for biopsies. Fifteen consecutive patients with newly diagnosed brain tumours (n = 11) or suspected recurrence of a known LGG (n = 4), in whom MRI demonstrated no contrast enhancement, were studied by both FET-PET and FDG-PET. FET-PET, FDG-PET and MRI data were fused, and then transferred to the neurosurgical navigation system, prior to neurosurgical interventions. Histology showed HGG (WHO grade III) in 6/15 and LGG (WHO grade II) in 9/15 patients. FET-PET revealed an increased intratumoural tracer uptake in 8/9 LGG and in 5/6 HGG. FDG-PET depicted hypermetabolic spots in 2/9 LGG and in 4/6 HGG. In 6 patients we observed an increased intratumoural uptake of both tracers. In 4 of them, the area of highest FET accumulation in the tumour corresponded to the focus of increased FDG uptake. FET-PET appears to be superior to FDG-PET for biopsy planning in non-contrast-enhancing brain tumours. FDG-PET does not provide any additional information in this issue.

• Assessment of histological response of paediatric bone sarcomas using FDG PET in comparison to morphological volume measurement and standardized MRI parameters.

  Authors: Timm Denecke, Patrick Hundsdörfer, Daniel Misch, Ingo G Steffen, Stefan Schönberger, Christian Furth, Michail Plotkin, Juri Ruf, Hubertus Hautzel, Brigitte Stöver, Regine Kluge, Uta Bierbach, Sylke Otto, James F Beck, Christiane Franzius, Günter Henze, Holger Amthauer

  European journal of nuclear medicine and molecular imaging. 10/2010; 37(10):1842-53.

  The objective of this study was to evaluate positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) in comparison to volumetry and standardized magnetic resonance imaging (MRI)The objective of this study was to evaluate positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) in comparison to volumetry and standardized magnetic resonance imaging (MRI) parameters for the assessment of histological response in paediatric bone sarcoma patients. FDG PET and local MRI were performed in 27 paediatric sarcoma patients [Ewing sarcoma family of tumours (EWS), n = 16; osteosarcoma (OS), n = 11] prior to and after neoadjuvant chemotherapy before local tumour resection. Several parameters for assessment of response of the primary tumour to therapy by FDG PET and MRI were evaluated and compared with histopathological regression of the resected tumour as defined by Salzer-Kuntschik. FDG PET significantly discriminated responders from non-responders using the standardized uptake value (SUV) reduction and the absolute post-therapeutic SUV (SUV2) in the entire patient population (SUV, p = 0.005; SUV2, p = 0.011) as well as in the subgroup of OS patients (SUV, p = 0.009; SUV2, p = 0.028), but not in the EWS subgroup. The volume reduction measured by MRI/CT did not significantly discriminate responders from non-responders either in the entire population (p = 0.170) or in both subgroups (EWS, p = 0.950; OS, p = 1.000). The other MRI parameters alone or in combination were unreliable and did not improve the results. Comparing diagnostic parameters of FDG PET and local MRI, metabolic imaging showed high superiority in the subgroup of OS patients, while similar results were observed in the population of EWS. FDG PET appears to be a useful tool for non-invasive response assessment in the group of OS patients and is superior to MRI. In EWS patients, however, neither FDG PET nor volumetry or standardized MRI criteria enabled a reliable response assessment to be made after neoadjuvant treatment.

• Serotonergic neurotransmission in early Parkinson's disease: a pilot study to assess implications for depression in this disorder.

  Authors: Jan C Beucke, Idun Uhl, Michail Plotkin, Christine Winter, Hans-Jörg Assion, Tanja Endrass, Holger Amthauer, Andreas Kupsch, Georg Juckel

  The world journal of biological psychiatry : the official journal of the World Federation of Societies of Biological Psychiatry. 09/2010; 11(6):781-7.

  Depression, a disease usually accompanied by a serotonergic deficit, has been observed in about 40% of patients suffering from Parkinson's disease (PD). Thus, a serotonergic dysfunction in PD can beDepression, a disease usually accompanied by a serotonergic deficit, has been observed in about 40% of patients suffering from Parkinson's disease (PD). Thus, a serotonergic dysfunction in PD can be assumed. We aimed to investigate the interaction between serotonergic (5-HT) and dopaminergic activity in early PD. We hypothesized a serotonergic as well as a dopaminergic deficit in PD patients. We also assumed a correlation between these neurotransmitters indicating a relationship between dopaminergic and serotonergic function in PD. Nine unmedicated PD patients before and 12 weeks after L-dopa treatment and nine healthy subjects were examined using the loudness dependence of auditory evoked potentials (LDAEP), a promising indicator of central serotonergic function. Dopaminergic transporters (DAT) were collected using (123)I-FP-CIT and single photon emission computer tomography (SPECT). LDAEP values were correlated with (123)I-FP-CIT SPECT data. A significant difference between LDAEP of controls and patients (P= 0.05) suggested lower serotonergic activity in PD. Twelve weeks after initiation of L-dopa treatment this difference was lost between patients and controls (P= 0.20). There was a trend towards a correlation between LDAEP and DAT (r= 0.65; P = 0.057) of the unmedicated patients, suggesting a low serotonergic activity may be related to a dopamine deficit in PD. Our results support the hypothesis that serotonergic neurotransmission is decreased in untreated PD and suggest that a low serotonergic activity may be related to the dopamine pathology in PD. This could be related to the high prevalence of depression in PD.

• Continuous low-dose temozolomide and celecoxib in recurrent glioblastoma.

  Authors: Florian Stockhammer, Martin Misch, Arend Koch, Marcus Czabanka, Michail Plotkin, Cristiane Blechschmidt, Jochen Tuettenberg, Peter Vajkoczy

  Journal of neuro-oncology. 05/2010; 100(3):407-15.

  Even after gross tumor resection and combined radiochemotherapy, glioblastomas recur within a few months. Salvage therapy often consists of rechallenging with temozolomide in a dose-intensifiedEven after gross tumor resection and combined radiochemotherapy, glioblastomas recur within a few months. Salvage therapy often consists of rechallenging with temozolomide in a dose-intensified schedule. Previously, low-dose metronomic temozolomide in combination with cyclo-oxigenase 2 inhibitors has had a beneficial effect as first-line treatment for glioblastoma. We report our experience with this procedure in recurrent glioblastomas after standard treatment. From June 2007 to April 2009, 28 patients with recurrent glioblastoma received continuous low-dose temozolomide of 10 mg/m(2) twice daily and 200 mg celecoxib. Before therapy the recurrent tumor was resected in 19 of 28 patients. Microvessel density (MVD) was determined by immunohistochemistry in 19 patients, and MGMT promoter methylation status, using the pyrosequencing method, was determined in 17 patients. In 14/28 patients, positron emission tomography with [F-18]-fluoroethyl)-L-tyrosine (FET-PET) was performed. Tumor progression was defined by the Macdonald criteria on MRI every 8-12 weeks or by clinical deterioration. The median time to progression was 4.2 months. Progression-free survival (PFS) after 6 months was 43%. Except for a lymphopenia in one patient, there was no grade 3 or 4 toxicity. PFS did not correlate with MVD or MGMT status. A high FET uptake correlated with tumor control after 6 months under therapy (P = 0.041, t-test). Low-dose continuous temozolomide in combination with celecoxib seems to have activity in recurrent glioblastoma without relevant toxicity. High FET uptake correlated with a better outcome under metronomic therapy.

• Tumour perfusion assessment during regional hyperthermia treatment: comparison of temperature probe measurement with H(2)(15)O-PET perfusion.

  Authors: Chi-Hee Cho, Geetha Sreenivasa, Michail Plotkin, Hubertus Pietsch, Peter Wust, Lutz Lüdemann

  International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group. 04/2010; 26(4):404-11.

  Hyperthermia treatment might increase tumour oxygenation and perfusion, as has been reported for experimental tumours. The present study was performed to investigate this hypothesis in patientsHyperthermia treatment might increase tumour oxygenation and perfusion, as has been reported for experimental tumours. The present study was performed to investigate this hypothesis in patients undergoing regional hyperthermia treatment. Thirteen patients with primary or recurrent pelvic tumours were included in this study. Prior to and up to one hour after regional hyperthermia, perfusion was quantitatively determined by H(2)(15)O-PET. The fused CT-PET images were used to extract tumour time-activity curves and to identify the catheter position. Perfusion was calculated from the total tumour time-activity curves and for the time-activity curves at the catheter site. Additionally, perfusion was calculated from the temperature-time curves measured using temperature probes. Perfusion values calculated using H(2)(15)O-PET and those deduced from temperature probe measurements are significantly correlated with a correlation coefficient, R = 0.21. The perfusion values deduced from the temperature measured in a body cavity do not provide information about average tumour perfusion. Perfusion values deduced from the temperature are overestimated for very poorly perfused tissues and underestimated for highly perfused tissues. Temperature measurement during hyperthermia may allow only determination of intermediate perfusion values.

• [Quality control in PET/CT systems: experiences and requirements].

  Authors: Lilli Geworski, Cornelia Karwarth, Eduard Fitz, Michail Plotkin, Bernd Knoop

  Zeitschrift für medizinische Physik. 03/2010; 20(1):46-50.

  Today, in most cases PET examinations are performed using PET/CT hybrid systems. While acceptance testing and routine control of the basic modalities PET and CT, respectively, are described byToday, in most cases PET examinations are performed using PET/CT hybrid systems. While acceptance testing and routine control of the basic modalities PET and CT, respectively, are described by appropriate regulations, corresponding instructions with regard to the interface connecting both are still missing. This interface includes the adjustment of gantries and patient bed to each other as well as the energy scaling of attenuation coefficients from CT energy to 511 keV. Measurements checking the mechanical adjustment (determination of off-set parameters) are performed following manufacturer's recommendation, with a typical frequency twice a year. On a Biograph 16 (Siemens, Inc.), these measurements were systematically extended to a weekly frequency over an observation period of 10 months, supplemented by measurements with additional load to the patient bed (up to 135 kg), and different vertical bed positions. The results show, that for the construction tested additional off-set measurements for routine control extending well beyond manufacturer's recommendation are not necessary. The energy scaling of attenuation coefficients is depending on methodological aspects and software implementation, and therefore is not part of routine control. On the contrary, the development of appropriate methods for acceptance testing to assess and to determine the mechanical adjustment in all its degrees of freedom as well as the accuracy of attenuation corrected emission data is urgently needed.

• Combined correction of recovery effect and motion blur for SUV quantification of solitary pulmonary nodules in FDG PET/CT.

  Authors: Ivayla Apostolova, Rafael Wiemker, Timo Paulus, Sven Kabus, Thomas Dreilich, Jörg van den Hoff, Michail Plotkin, Janos Mester, Winfried Brenner, Ralph Buchert, Susanne Klutmann

  European radiology. 03/2010; 20(8):1868-77.

  We evaluate a fully data-driven method for the combined recovery and motion blur correction of small solitary pulmonary nodules (SPNs) in F-18 fluorodeoxyglucose (FDG) positron emission tomographyWe evaluate a fully data-driven method for the combined recovery and motion blur correction of small solitary pulmonary nodules (SPNs) in F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT). The SPN was segmented in the low-dose CT using a variable Hounsfield threshold and morphological constraints. The combined effect of limited spatial resolution and motion blur in the SPN's PET image was then modelled by an effective Gaussian point-spread function (psf). Both isotropic and non-isotropic psfs were used. To validate the method, PET/CT measurements of the NEMA/IEC spheres phantom were performed. The method was applied to 50 unselected SPNs <or=30 mm from routine patient care. Recovery of standardised uptake value (SUV) in the phantom image was significantly improved by combined recovery and motion blur correction compared with recovery-only correction, particularly with the non-isotropic model (residual average error 10%). In the patient images, automated segmentation and fit of the effective psf worked properly in all cases. Volume-equivalent diameter ranged from 4.9 to 27.8 mm. Uncorrected maximum SUV ranged from 0.9 to 13.3. Compared with recovery-only correction, combined correction with the non-isotropic model resulted in a 'relevant' (>or=30%) SUV increase in 47 SPNs (94%). Correction of both recovery and motion blur is mandatory for accurate SUV quantification of SPNs.

• Multiple system atrophy masking multiple sclerosis.

  Authors: Carsten Finke, Eberhard Siebert, Michail Plotkin, Gregor K Wenning, Uwe Reuter

  Clinical neurology and neurosurgery. 10/2009;

  Multiple system atrophy (MSA) and multiple sclerosis (MS) are progressive neurological disorders with overlapping clinical signs and symptoms. However, due to the course of the disease and the age ofMultiple system atrophy (MSA) and multiple sclerosis (MS) are progressive neurological disorders with overlapping clinical signs and symptoms. However, due to the course of the disease and the age of onset both disorders are rarely differential diagnosis for each other. We here report the remarkable association of the two diseases in one patient. As MSA dominated the clinical presentation, diagnosis and therapy of MS were delayed. We discuss the clinical symptoms in our patient and highlight the features that allow to differentiate both diseases.

• Imaging of hypoxic-ischemic penumbra with (18)F-fluoromisonidazole PET/CT and measurement of related cerebral metabolism in aneurysmal subarachnoid hemorrhage.

  Authors: Asita S Sarrafzadeh, Alexandra Nagel, Marcus Czabanka, Timm Denecke, Peter Vajkoczy, Michail Plotkin

  Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. 09/2009;

  This study aimed to characterize hypoxic, but salvageable, tissue imaged by (18)F-fluoromisonidazole ((18)F-FMISO), combining with perfusion-computed tomography (PCT) for regional cerebral blood flowThis study aimed to characterize hypoxic, but salvageable, tissue imaged by (18)F-fluoromisonidazole ((18)F-FMISO), combining with perfusion-computed tomography (PCT) for regional cerebral blood flow (rCBF) measurement and metabolism by microdialysis (MD) in aneurysmal subarachnoidal hemorrhage (SAH) patients. (18)F-FMISO positron-emission tomography (PET)/CT was performed within the period of possible vasospasm (day 6.8+/-3 after SAH) in seven SAH patients. In parallel, rCBF was determined within the MD region of interest (MD-ROI) (n=5). The MD catheter was inserted into the brain parenchyma with highest risk for ischemia; extracellular levels of glutamate and energy metabolites were registered at time of PET and hourly for 10 days. Twelve-month outcome was evaluated. In asymptomatic patients (n=3) no hypoxia was detected and glutamate levels were low (<10 mmol/L), whereas symptomatic patients had higher glutamate concentrations (P<0.001). Increased (18)F-FMISO uptake within the MD-ROI (n=3) was related to higher glutamate levels, while rCBF was above the ischemic range. Hypoxia (increased (18)F-FMISO uptake) was present in symptomatic patients and associated with relevant metabolic derangement of extracellular glutamate levels, whereas energy metabolism and rCBF were preserved. This technique has the potential to improve our understanding of the role of cellular hypoxia in aneurysmal SAH.Journal of Cerebral Blood Flow & Metabolism advance online publication, 23 September 2009; doi:10.1038/jcbfm.2009.199.

• Potential impact of (68)Ga-DOTATOC PET/CT on stereotactic radiotherapy planning of meningiomas.

  Authors: Fonyuy Nyuyki, Michail Plotkin, Reinhold Graf, Roger Michel, Ingo Steffen, Timm Denecke, Lilli Geworski, Daniel Fahdt, Winfried Brenner, Reinhard Wurm

  European journal of nuclear medicine and molecular imaging. 09/2009;

  PURPOSE: Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with (68)Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planningPURPOSE: Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with (68)Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planning radiotherapy. We investigated the input of (68)Ga-DOTATOC-PET/CT on the definition of the "gross tumour volume" (GTV) in meningiomas, in order to assess the potential value of this method. METHODS: Prior to radiotherapy, 42 patients with meningiomas (26 f, 16 m, mean age 55) underwent MRI and (68)Ga-DOTATOC-PET/CT examinations. History: operated n = 24, radiotherapy n = 1, operation and radiotherapy n = 8, no treatment n = 9. PET/CT and MRI data were co-registered using a BrainLAB workstation. For comparison, the GTV was defined first under consideration of CT and MRI data, then using PET data. RESULTS: 3/42 patients were excluded from the analysis (two with negative PET results, one with an extensive tumour, not precisely delineable by MRI or PET/CT). The average GTV(CT/MRI) was 22(+/-19)cm(3); GTV(PET) was 23(+/-20)cm(3). Additional GTV, obtained as a result of PET was 9(+/-10)cm(3) and was observed in patients with osseous infiltration. In some pre-treated patients there were intratumoural areas (as identified in CT/MRI) without SR-expression (7(+/-11)cm(3)). Common GTV as obtained by both CT/MRI and PET was 15(+/-14)cm(3). The mean bi-directional difference between the GTV(CT/MRI) and GTV(PET) accounted to 16(+/-15)cm(3) (93%, p < 0.001). In a subgroup of seven patients with multiple meningiomas, PET showed a total of 19 lesions; nine of them were not recognizable by CT or MRI. CONCLUSION: (68)Ga-DOTATOC-PET enables delineation of SR-positive meningiomas and delivers additional information to both CT and MRI regarding the planning of stereotactic radiotherapy. The acquisition on a PET/CT scanner helps to estimate the relation of PET findings to anatomical structures and is especially useful for detection of osseous infiltration. (68)Ga-DOTATOC-PET also allows detection of additional lesions in patients with multiple meningiomas.

• Association of F18-fluoro-ethyl-tyrosin uptake and 5-aminolevulinic acid-induced fluorescence in gliomas.

  Authors: Florian Stockhammer, Martin Misch, Peter Horn, Arend Koch, Nyuyki Fonyuy, Michail Plotkin

  Acta neurochirurgica. 07/2009;

  PURPOSE: Malignant gliomas are highly infiltrative tumours with a fatal prognosis. F18-fluoroethyl-tyrosine (FET)-positron emission tomography (PET) often reveals a broader extension of these tumoursPURPOSE: Malignant gliomas are highly infiltrative tumours with a fatal prognosis. F18-fluoroethyl-tyrosine (FET)-positron emission tomography (PET) often reveals a broader extension of these tumours compared with contrast-enhanced magnetic resonance imaging (MRI). Complete resection of the contrast-enhancing lesion is aspired. Fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) improved the extent of resection. In this study, we investigated whether the FET uptake correlates with the extent of resection using 5-ALA-induced fluorescence. METHODS: Thirteen patients who underwent preoperative and postoperative MRI, FET-PET and fluorescence-guided neuronavigated resection were included in this study. The areas in which intraoperative fluorescence terminated the resection were marked. After fusion of PET and MRI, the standardized uptake value (SUV) of FET related to normal brain (SUV(R)) was measured in regions of interest corresponding to resected and remaining tissue, respectively. Receiver-operating characteristic (ROC) curve analysis determined the optimal threshold of the relative SUV anticipating 5-ALA-induced fluorescence. RESULTS: During resection a vivid fluorescence was present in all patients. Histology revealed glioblastomas in 11 cases, an anaplastic astrocytoma in one case and a low-grade astrocytoma in one case. The median FET SUV(R) was higher in areas corresponding to the fluorescent tumour compared with the non-fluorescent normal brain (2.321 vs 1.142, p < 0.0001, t-test). A SUV(R) greater than 1.374 predicted the fluorescence with a sensitivity of 0.87 [95% confidence interval (CI): 0.74-0.94] and a specificity of 0.94 (CI: 0.84-0.99). The area under the ROC curve was 0.9656 (CI: 0.9364-0.9948). CONCLUSIONS: FET uptake predicts the 5-ALA-induced fluorescence in glioma patients. Thus, FET-PET provides useful information for planning glioma resection.

• Planning transarterial radioembolization of colorectal liver metastases with Yttrium 90 microspheres: evaluation of a sequential diagnostic approach using radiologic and nuclear medicine imaging techniques.

  Authors: Timm Denecke, Ricarda Rühl, Bert Hildebrandt, Lars Stelter, Christian Grieser, Heiner Stiepani, Michael Werk, Pietr Podrabsky, Michail Plotkin, Holger Amthauer, Jens Ricke, Enrique Lopez Hänninen

  European radiology. 06/2008; 18(5):892-902.

  The purpose of the study was to establish a diagnostic approach to the preparation of patients with colorectal liver metastases considered for transarterial radioembolization (RE). Twenty-twoThe purpose of the study was to establish a diagnostic approach to the preparation of patients with colorectal liver metastases considered for transarterial radioembolization (RE). Twenty-two patients sequentially underwent computed tomography (CT; thorax/abdomen), magnetic resonance imaging (MRI; liver; hepatocyte-specific contrast), positron emission tomography (PET/PET-CT; F18-fluoro-desoxy-glucose), and angiography with perfusion scintigraphy [planar imaging; tomography with integrated CT (SPECT-CT)]. The algorithm was continued when no contraindication or alternative treatment option was found. The impact of each test on the therapy decision and RE management was recorded. Patient evaluation using CT revealed contraindications for RE in 4/22 patients (18%). Of the remaining 18 patients, 2 were excluded and 3 were assigned to locally ablative treatment based on MRI and PET results (28%). The remaining 13 patients entered the planning algorithm: SPECT-CT revealed gastrointestinal tracer accumulations in 4 (31%) patients [SPECT, 2 (15%)], making a modified application necessary. In five patients (38%), planar scintigraphy revealed relevant hepatopulmonary shunting. Therapy was finally administered to all 13 patients without therapy-related pulmonary or gastrointestinal morbidity. Each part of the diagnostic algorithm showed a relevant impact on patient management. The sequential approach appears to be suitable and keeps the number of unnecessary treatments and therapy risks to a minimum.

• Correlation of F-18-fluoro-ethyl-tyrosin uptake with vascular and cell density in non-contrast-enhancing gliomas.

  Authors: Florian Stockhammer, Michail Plotkin, Holger Amthauer, Frank van Landeghem, Christian Woiciechowsky

  Journal of neuro-oncology. 04/2008;

  Objective Even without contrast enhancement on MRI scans gliomas can show histological features of anaplasia. These tumors are heterogeneous regarding anaplastic and non-anaplastic areas. IncreasedObjective Even without contrast enhancement on MRI scans gliomas can show histological features of anaplasia. These tumors are heterogeneous regarding anaplastic and non-anaplastic areas. Increased amino acid uptake was shown to be associated with dismal prognosis in gliomas. We investigated histological correlates of tumor grading in biopsies obtained from regions with maximum amino acid uptake revealed by F-18-fluoro-ethyl-tyrosin positron emission tomography (FET-PET). Methods We included 22 patients with non-contrast enhancing lesions on MRI scans. PET was performed 10 min after FET injection, and the area of maximum FET uptake was chosen as the biopsy target. In 13 patients neuronavigated biopsies were obtained during tumor resection. Nine patients had a stereotactic biopsy. The ratio of maximum standardized uptake value (SUV) to background was calculated. Histological specimens were classified and graded according to world health organization (WHO) criteria. We investigated cell and vascular density, mitotic activity, proliferation index, microvascular proliferation, nuclear pleomorphism, necrosis and immunoreactivity of LAT1 (SLC7A5), an amino acid transporter with prognostic impact in gliomas. Results 12 of the 22 non-contrast enhancing gliomas corresponded to anaplastic astrocytomas WHO grade III. Vascular and cellular density was correlated highly to the SUV ratio (P = 0.0015 and P = 0.0021, respectively), but with no nuclear pleomorphism, mitotic activity, Mib-1 immunoreactivity, or microvascular proliferation. Thus, no correlation was found between FET uptake and tumor grade. Conclusion FET-PET correlates with vascular and cell density in non-contrast enhancing gliomas. Although tumor grade cannot be predicted, clinical use of FET PET as an indicator for neovascularization should be addressed in future studies.

• Brain tumor perfusion: Comparison of dynamic contrast enhanced magnetic resonance imaging using T(1), T(2), and T(2)(*) contrast, pulsed arterial spin labeling, and H(2)(15)O positron emission tomography.

  Authors: Lutz Lüdemann, Carsten Warmuth, Michail Plotkin, Annette Förschler, Matthias Gutberlet, Peter Wust, Holger Amthauer

  European journal of radiology. 04/2008;

  OBJECTIVES: Different techniques for measuring of perfusion are clinically available, but these are usually applied to healthy brain tissue. MATERIAL AND METHODS: Five different techniques were usedOBJECTIVES: Different techniques for measuring of perfusion are clinically available, but these are usually applied to healthy brain tissue. MATERIAL AND METHODS: Five different techniques were used here in 12 patients with brain tumors to investigate the impact of tumor vascularization on the perfusion signal: three qualitative dynamic contrast-enhanced/susceptibility-contrast magnetic resonance imaging (DCE-MRI/DSC-MRI) techniques exploiting T(1), T(2), T(2)(*) contrast, and two quantitative techniques, pulsed arterial spin labeling (PASL) and H(2)(15)O positron emission tomography (H(2)(15)O-PET). RESULTS: In a first approximation, a linear correlation was found between all five imaging modalities regarding the perfusion signal of both, normal brain tissue and tumor. The estimated values for tumor perfusion differed significantly between the techniques (1=methodical mean in arbitrary units): PASL: 0.83, H(2)(15)O-PET: 0.62, T(1)-DCE: 1.73, T(2)-DCE: 0.69, T(2)(*)-DSC: 0.89. CONCLUSIONS: The tumor perfusion values, determined with different techniques are not comparable. The T(2)(*)-DSC, here applied with contrast agent presaturation of extravascular space, and PASL depict median perfusion most reliably.

• Brain parenchyma sonography and 123I-FP-CIT SPECT in Parkinson's disease and essential tremor.

  Authors: Florian Doepp, Michail Plotkin, Lara Siegel, Anatol Kivi, Doreen Gruber, Elmar Lobsien, Andreas Kupsch, Stephan J Schreiber

  Movement disorders : official journal of the Movement Disorder Society. 03/2008; 23(3):405-10.

  We aimed to investigate the accuracy of transcranial brain parenchyma sonography (TCS) for differentiation between idiopathic Parkinson's disease (PD) and essential tremor (ET) in comparison toWe aimed to investigate the accuracy of transcranial brain parenchyma sonography (TCS) for differentiation between idiopathic Parkinson's disease (PD) and essential tremor (ET) in comparison to (123)I-FP-CIT SPECT (FP-CIT SPECT). Seventy-four patients, in whom PD or ET was suspected on the basis of clinical criteria, were analyzed. The echogenicity of the substantia nigra (SN) and the striatal binding of dopamine transporters (DAT) were evaluated by TCS and FP-CIT SPECT, respectively. Three patients were excluded due to an insufficient transtemporal bone window using TCS. Forty-six and 25 patients were clinically classified as PD and ET. SPECT revealed a reduced DAT binding in 42 of all 71 included patients. Thirty-six of the 42 patients with abnormal FP-CIT SPECT findings had a pathological SN hyperechogenicity, whereas TCS findings in the remaining 6 patients were normal. In 27 of 29 patients with normal SPECT findings the SN echogenicity was regular. Referring to FP-CIT SPECT, the sensitivity and specificity of TCS for detection of PD were 86 and 93%; the positive and negative predictive values were 95 and 82%, respectively. Sensitivity and specificity in detection of clinically diagnosed PD patients were 78 and 92% for TCS and 91 and 100% for FP-CIT SPECT, respectively. In patients with pathological FP-CIT SPECT and pathological TCS, the extent of SN hyperechogenicity did not correlate with the degree of reduction in dopamine transporter binding on the side opposite of the more affected limb. TCS allows a reliable differentiation of PD and ET. The TCS SN hyperechogenicity does not correlate with the extent of dopaminergic neuron degeneration.

• Occurrence of a spinal anaplastic pilocytic astrocytoma and a supratentorial PNET in an adolescent.

  Authors: Friederike Blankenburg, Frank K H van Landeghem, Michail Plotkin, Günter Henze, Andreas von Deimling, Pablo Hernáiz Driever

  Journal of pediatric hematology/oncology : official journal of the American Society of Pediatric Hematology/Oncology. 01/2008; 29(12):832-5.

  A 15-year-old girl was diagnosed with a spinal anaplastic pilocytic astrocytoma. The histologic features were similar to pilocytic astrocytoma WHO grade I, but with an increased mitotic rate, highA 15-year-old girl was diagnosed with a spinal anaplastic pilocytic astrocytoma. The histologic features were similar to pilocytic astrocytoma WHO grade I, but with an increased mitotic rate, high nuclear pleomorphism, microvascular proliferation, and necrosis. The tumor was subtotally resected and treated with chemotherapy and irradiation. Four years after diagnosis no local progression was seen. At the age of 17, the patient developed a supratentorial primitive neuroectodermal tumor. We report the first case of a primary anaplastic pilocytic astrocytoma and primary primitive neuroectodermal tumor occurring in the same patient.

• Positron emission tomography for staging of pediatric sarcoma patients: results of a prospective multicenter trial.

  Authors: Thomas Völker, Timm Denecke, Ingo Steffen, Daniel Misch, Stefan Schönberger, Michail Plotkin, Juri Ruf, Christian Furth, Brigitte Stöver, Hubertus Hautzel, Günter Henze, Holger Amthauer

  Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 01/2008; 25(34):5435-41.

  PURPOSE: The objective of this study was to evaluate the impact of positron emission tomography (PET) using fluorine-18-fluorodeoxyglucose (FDG) for initial staging and therapy planning in pediatricPURPOSE: The objective of this study was to evaluate the impact of positron emission tomography (PET) using fluorine-18-fluorodeoxyglucose (FDG) for initial staging and therapy planning in pediatric sarcoma patients. PATIENTS AND METHODS: In this prospective multicenter study, 46 pediatric patients (females, n = 22; males, n = 24; age range, 1 to 18 years) with histologically proven sarcoma (Ewing sarcoma family tumors, n = 23; osteosarcoma, n = 11; rhabdomyosarcoma, n = 12) were examined with conventional imaging modalities (CIMs), including ultrasound, computed tomography (CT), magnetic resonance imaging, and bone scintigraphy according to the standardized algorithms of the international therapy optimization trials, and whole-body FDG-PET. A lesion- and patient-based analysis of PET alone and CIMs alone and a side-by-side (SBS) analysis of FDG-PET and CIMs were performed. The standard of reference consisted of all imaging material, follow-up data (mean follow-up time, 24 +/- 12 months), and histopathology and was determined by an interdisciplinary tumor board. RESULTS: FDG-PET and CIMs were equally effective in the detection of primary tumors (accuracy, 100%). PET was superior to CIMs concerning the correct detection of lymph node involvement (sensitivity, 95% v 25%, respectively) and bone manifestations (sensitivity, 90% v 57%, respectively), whereas CT was more reliable than FDG-PET in depicting lung metastases (sensitivity, 100% v 25%, respectively). The patient-based analysis revealed the best results for SBS, with 91% correct therapy decisions. This was significantly superior to CIMs (59%; P < .001). CONCLUSION: In staging pediatric sarcoma, subsidiary FDG-PET scanning depicts important additional information and has a relevant impact on therapy planning when analyzed side-by-side with CIMs.