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Biomedical subjects

C Menzel

Publications and source records attributed to C Menzel.

At least 37 records · Page 2Linked to original sources
PubMed2004

Limitations of dual time point FDG-PET imaging in the evaluation of focal abdominal lesions.

AIM: For the evaluation of the diagnostic potential of dual time point FDG positron emission tomography (PET) in patients with suspicious focal abdominal uptake, dual time point PET imaging was compared with clinical findings. PATIENTS, METHODS: In a prospective study, 56 patients exhibiting a solitary suspicious, intense abdominal FDG uptake, underwent dual time point PET imaging for staging or restaging of different malignant tumors, maximal standardized uptake value (SUVmax) measurements included. The first acquisition was started 64.8 +/- 19.5, the second 211.3 +/- 52.5 min after FDG injection. The final diagnosis based on CT or MRT imaging and a follow-up period of 12.6 +/- 2.8 months. Additionally, colonoscopy was done in 6 patients. In another 6 patients histopathology was obtained from CT guided biopsy. RESULTS: Malignant focal abdominal lesions with a SUVmax <2.5 (n = 4) showed an uptake increase of > or =30%. In the remaining malignant cases with an uptake of > or =2.5 (n = 11), uptake increased in 64% and decreased in 36%. Malignant lesions showing FDG uptake decrease (n = 4) had an initial SUVmax value > or =2.5 and remained with a SUVmax > or =2.5 in the second imaging. In benign lesions with an initial SUVmax > or =2.5 (n = 31), the uptake increased in 17 patients (55%) and decreased in 14 patients (45%). All lesions which changed configuration (33%) were confirmed as benign (n = 5). CONCLUSION: Using dual time point PET abdominal lesions show a very hetergenous uptake pattern regardless of their dignity. Malignancy can only be reliably excluded in lesions which change their configuration and in lesions with an initial SUVmax value <2.5 combined with an SUV decrease in the delayed imaging. Particularly abdominal lesions which show an initial SUVmax > or =2.5 combined with a SUV increase in the delayed imaging are suspicious for malignancy and need further clarification.

Abdominal Neoplasms↗
PubMed2004

Atypical thoracic and supraclavicular FDG-uptake in patients with Hodgkin's and non-Hodgkin's lymphoma.

AIM: In FDG-PET imaging abnormal supraclavicular and paravertebral FDG uptake is a frequent finding which recently could be demonstrated to partly represent brown fat tissue. This study was carried out to further investigate causes for this phenomenon. Patients variables such as age, gender, body mass index (BMI) and the value of sedation and delayed imaging were compared with the presence of atypical uptake in 2 distinct groups of diseases, Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). METHODS: PET images of 81 patients (53 HD and 28 NHL) were evaluated for atypical uptake. In 5 patients additional delayed images were acquired. Sedatives were used in anxious patients (n=45). RESULTS: Twelve out of 53 patients with HD and 2 out of 28 patients with NHL showed an atypical uptake. The BMI of patients with atypical uptake (median, 21 kg/m2 versus 24 kg/m2; p<0.05) and the age (median, 25 y versus 44 y; p<0.05) were significantly lower compared with patients without atypical uptake. In nearly 50% of all women with HD= or <30 y and 20% of all male patients with HD= or <30 y an atypical uptake was observed. Delayed images showed a SUVmax decrease in 4 patients and an increase in 1 patient. All patients with atypical uptake received sedatives which had an anxiolytic effect in all patients, but did not prevent atypical uptake. CONCLUSION: Abnormal supraclavicular and paravertebral FDG accumulation occurs particularly in younger patients and those with lower BMI values. The use of sedatives or delayed acquisition does not increase the diagnostic information in these cases.

Adolescent↗
PubMed2003

Monitoring the efficacy of iodine-131-MIBG therapy using fluorine-18-FDG-PET.

BACKGROUND: The purpose of this study was to assess the potential of fluorine-18 fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG-PET) for monitoring the efficacy of iodine-131 metaiodobenzylguanidine (131I-MIBG) therapy in neuroendocrine tumours. METHODS: A total of seven 131I-MIBG therapies with 3.7 to 10.2 GBq were carried out in three patients suffering respectively from a phaeochromocytoma, a paraganglioma and a metastatic neuroendocrine tumour of an unknown primary. The post-therapeutic whole-body scintigrams were compared with the results of six 18F-FDG-PET studies performed at the time of the therapies. One patient received three PET scans prior to each one of the MIBG therapies, and one patient was studied twice. RESULTS: 18F-FDG uptake in tumour sites seemed to correlate well with tumour differentiation, showing no uptake in one patient with a highly differentiated neuroendocrine tumour, and moderate-to-intense uptake in the two other patients with metastatic disease. Those tumour sites that had a simultaneous positive uptake in both the MIBG scintigram and the PET scan showed response to therapy as a continuous reduction in MIBG uptake over time. They also showed a qualitative decrease in FDG accumulation during the follow-up. This was associated with a decrease in the mean and maximum standard uptake values of more than 50 % in some metastases, while the X-ray computed tomography showed no decrease in tumour volume. Two patients revealed additional metastases that were unknown on the basis of prior diagnostic or therapeutic PET scans and radiological follow-up. CONCLUSIONS: It may be concluded from these cases that 18F-FDG-PET is a valuable tool for an initial metabolic staging of neuroendocrine tumours prior to 131I-MIBG therapy, as it can reveal tumour sites beyond the reach of radioisotope therapy. It may also be of importance in assessing therapeutic potential in those tumour sites that do show positive MIBG uptake.

3-Iodobenzylguanidine↗
PubMed2003

Sentinel lymph node biopsy alone without axillary lymph node dissection--follow up of sentinel lymph node negative breast cancer patients.

AIMS: To evaluate the rate of axillary recurrences in sentinel lymph node (SLN) negative breast cancer patients after sentinel lymph node biopsy (SLNB) alone without further axillary lymph node dissection (ALND). METHODS: Between May 1999 and February 2001 all patients who had primary invasive breast cancer and were SLN negative were eligible for this prospective study. SLNB was performed by using the combined method with radioactive tracer and blue dye. SLNs were examined by frozen section, standard H/E staining and immunohistochemistry staining. SLN negative patients did not receive further ALND. Follow-up was done three-monthly with clinical controls, blood samples and ultrasound of the breast and axilla. An annual mammogram was performed. RESULTS: 116 patients with T1 or T2 invasive breast cancer were included in this trial. All 116 patients had negative SLNs in frozen sections, in H/E staining and in immunohistochemistry staining. The mean number of removed SLNs was 2.03+/-1.22. Mean tumor size was 17.15+/-7.62 mm. Postmenopausal patients totalled 79.3 and 20.7% of patients were premenopausal. No local or axillary recurrences occurred at a mean duration of follow-up of 22.12+/-6.38 months. CONCLUSION: The absence of axillary recurrences after SLNB without ALND in SLN negative breast cancer patients supports the hypothesis that SLNB is accurate and safe while providing less surgical morbidity. Short term results are very promising. SLNB without ALND in SLN negative patients is an excellent procedure for axillary staging in a cohort of breast cancer patients with small tumors.

Adult↗
PubMed2003

[Sentinel lymph node biopsy in breast cancer patients--results and experience after 500 sentinel lymph node biopsies].

INTRODUCTION: Sentinel lymph node biopsy (SLNB) is a widely used technique for axillary staging in breast cancer patients. The principle to evaluate the axillary status of a breast cancer patient with a less invasive surgery than axillary lymph node dissection (ALND) meets the new minimally invasive concept in breast cancer surgery. Some breast cancer centers proceed to SLNB without ALND in SLN-negative patients. PATIENTS AND METHODS: Between March 1998 and March 2002, 500 SLNBs were performed. After a learning period with SLNB and ALND in 75 patients with a sensitivity of 96.2% and a false-negative rate of 3.8%, SLNB alone without further ALND was performed in a group of patients. In addition, the feasibility of SLNBin patients with locally advanced breast cancer, in patients after neoadjuvant chemotherapy and in patients with multicentricity was evaluated. The combined method with blue dye and technetium-99m-labeled human albumin for identification of SLNs was applied. RESULTS: 500 SLNBs were performed. The identification rate was 86.2%. After exclusion of patients with neoadjuvant chemotherapy and patients with multicentricity, the identification rate was 94.5%. SLNs were positive in 41.3% of patients and negative in 58.7% of patients. DISCUSSION: SLNB is an excellent method for axillary stag-ing and an alternative for ALND in a certain group of breast cancer patients.

Axilla↗
PubMed2003

Paraneoplastic syndromes: detection of malignant tumors using [(18)F]FDG-PET.

AIM: Paraneoplastic syndromes (PS) comprise a variety of clinical symptoms and diseases associated with underlying malignancy. Differentiation towards benign autoimmune diseases is necessary due to different therapeutic options. This diagnostic challenge includes cost- and time-consuming methods and is not successful in many cases. The aim of this study was the evaluation of [(18)F]fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) for detecting or ruling out malignancy in these patients. METHODS: In this retrospective work-up a total of 30 patients with suspected PS (m:f = 17:13, mean age 55, range 22-76 years) were examined with [(18)F]FDG-PET between 1996 and 2001. Diagnoses were erythrodermia, cerebellar degeneration, dermatomyositis, polyneuropathia and others. PET scans were compared to histopathological (n=14), radiological and follow up data (mean follow up 3.6 years, range 1-6 years). RESULTS: In 7 out of 30 patients (23%) an underlying malignancy was detected. Six out of 7 malignant neoplasms showed a distinctly increased glucose consumption. One benign neoplasm caused increased tracer uptake, another PET positive patient refused biopsy and showed no growth of a malignant tumour during clinical follow up of 28 months. The remaining 21 patients without suspicious glucose consumption did not demonstrate a malignancy in other diagnostic modalities or during subsequent clinical follow-up. CONCLUSION: [(18)F]FDG-PET seems to be a useful tool in the diagnostic work-up of patients with suspected paraneoplastic syndrome.

Adult↗
PubMed2003

[Positron-emission tomography in oncology].

This review analyses clinical results, new trends and recommendations of the leading medical centers concerning application of positron-emission tomography (PET) with F-18 fluorodeoxyglucose (F18 FDG) in cancer patients. This method of radionuclide visualization has been widely introduced for the last decade in diagnosis of cancer of unknown primary location, or CUP-syndrome, bronchogenic cancer of the lungs, cancer of the head and neck, malignant lymphoma and melanoma, colorectal and neuroendocrine cancer. Efficacy of this procedure, physiological grounds, performance are considered. Potentialities of F18 FDG PET are demonstrated in tumor screening, detection of metastases, recurrences after surgical, radiation or drug antitumor treatment or monitoring. In combination with CT, MRT, USI and other techniques, F18 FDG PET raises accuracy of the diagnosis of pathological changes at any stage of cancer with resulting improvement in further therapeutic and follow-up efficacy.

Colorectal Neoplasms↗
PubMed2003

Subclinical hyperthyroidism in dementia and correlation of the metabolic index in FDG-PET.

AIM: Thyroid hormone status and thyroid antibodies were evaluated in patients suffering from dementia for further study of an association of hyperthyroidism with AD and vascular dementia (VD), respectively. PATIENTS: In 77 patients with dementia, and 42 controls, thyrotropin (TSH) and thyroid antibodies were correlated with the different types of dementia and the metabolic index (MI) based on imaging with F-18-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). RESULTS: Twenty-two of all patients with dementia (29%) had borderline (TSH 0.3-0.5 mU/l) or decreased TSH levels (TSH < 0.3 mU/L). TSH values were significantly lower in patients suffering from AD (median: 1.1 mU/l) and VD (0.5 mU/l) than in the control group (1.5 mU/l) (p < 0.01). Decreased or borderline TSH levels were present in 52% of the patients with VD, but in only 10% of the controls, and in 23% of the patients with AD. Antibodies to thyroid peroxidase were positive in 16% of all patients with dementia. The MI in patients suffering from AD with borderline TSH levels was 0.81 (0.70, 0.94). In contrast, patients suffering from AD with normal TSH values showed a slightly higher MI of 0.84 (0.76, 0.89) (p = n.s.). CONCLUSION: Decreased or borderline TSH values are associated with an increased probability of having dementia, especially VD.

Aged↗
PubMed2002

[Positron emission tomography for the preoperative staging of esophageal carcinoma].

BACKGROUND AND OBJECTIVE: Exact preoperative staging is a prerequisite for the indication as well as the choice of the appropriate operative technique for patients with esophageal carcinoma. In this prospective study we assessed whether positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) increases the accuracy of staging compared to standard computer tomography (CT) and leads to a different therapeutic approach. PATIENTS AND METHODS: 30 patients (25 men, 5 women, median age 63 years) with histologically identified carcinoma of the esophagus (n =29) and the cardia (n = 1), respectively, were studied. All patients underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity and accuracy were calculated for FDG-PET and CT to evaluate the detection of histologically identified lymph node metastases and distant metastatic disease. RESULTS: FDG-PET showed higher specificity whereas the accuracy of the CT proved to be higher not only for the detection of abdominal lymph node metastases (67 % vs. 46 %), but also for lymph node metastases of the thorax (71 % vs. 50 %). Furthermore, the accuracy of the CT for the detection of blood-bone and lymphatic distant metastases was also higher than that of FDG-PET (72 % vs. 68 %). FDG-PET was more specific (100 % vs. 71 %) albeit less sensitive than CT-imaging (27 % vs. 73 %). CONCLUSION: In our study, FDG-PET did not increase the accuracy of standard staging (CT) in patients with carcinoma of the esophagus. Therefore, no new consequences resulted for the operative indication as well as therapeutic procedure. Due to the high costs involved with PET investigation, this form of staging is momentarily indicated mainly for use in clinical studies, and in cases where CT does not offer unequivocal results. Increase in sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals as well as optimized apparatus resolution could lead to new indications for this staging procedure.

Carcinoma↗
PubMed2002

Time-efficient T2 relaxometry of the entire hippocampus is feasible in temporal lobe epilepsy.

OBJECTIVE: To test the clinical usefulness and reliability of a new dual-echo turbo-spin-echo (TSE) sequence for rapid and regional hippocampal T2 relaxometry. METHODS: Hippocampal T2 relaxation time (HRT) was determined by a TSE sequence on three to four consecutive coronal images in 16 control subjects and 12 patients with mesial temporal lobe epilepsy. HRT was related to neuropathology findings in hippocampal specimens including neuronal cell density (ND), results of visual analysis of MR images, clinical outcome after epilepsy surgery, and hippocampal volumetry. RESULTS: Rapid HRT differentiated patients from control subjects; all cases of hippocampal sclerosis (HS; n = 10) were correctly diagnosed. HRT showed a strong correlation with ND in CA1 (p < 0.02) and CA3 (p < 0.05). Diagnoses based on rapid relaxometry concurred fully with results of visual inspection. Mean HRT was prolonged ipsilaterally in all patients with excellent postoperative seizure outcome and bilaterally prolonged or normal in patients with poorer outcome. Rapid HRT was concordant with hippocampal volumetry in 10 of 12 patients. Regional HRT of control subjects revealed significantly higher values in the anterior than posterior hippocampus. In patients with unilateral HS, this gradient was absent. The gradient was also absent contralaterally to HS, although surgical outcome was excellent. CONCLUSIONS: Hippocampal dual-echo TSE-relaxometry can be regarded a reliable technique to detect and quantify HS. With a scan time of 3.31 minutes and immediate off-line analysis lasting a few minutes only, TSE-T2 relaxometry is easy to integrate in the routine diagnostic assessment of hippocampal morphology in large numbers of patients.

Adolescent↗
PubMed2002

Discrimination between Alzheimer dementia and controls by automated analysis of multicenter FDG PET.

A new diagnostic indicator of FDG PET scan abnormality, based on age-adjusted t statistics and an automated voxel-based procedure, is presented and validated in a large data set comprising 110 normal controls and 395 patients with probable Alzheimer's disease (AD) that were studied in eight participating centers. The effect of differences in spatial resolution of PET scanners was minimized effectively by filtering and masking. In controls FDG uptake declined significantly with age in anterior cingulate and frontolateral perisylvian cortex. In patients with probable AD decline of FDG uptake in posterior cingulate, temporoparietal, and prefrontal association cortex was related to dementia severity. These effects were clearly distinct from age effects in controls, suggesting that the disease process of AD is not related to normal aging. Women with probable AD had significantly more frontal metabolic impairment than men. The new indicator of metabolic abnormality in AD-related regions provided 93% sensitivity and specificity for distinction of mild to moderate probable AD from normals, and 84% sensitivity at 93% specificity for detection of very mild probable AD (defined by Mini Mental Score 24 or better). All regions related to AD severity were already affected in very mild AD, suggesting that all vulnerable areas are affected to a similar degree already at disease onset. Ventromedial frontal cortex was also abnormal. In conclusion, automated analysis of multicenter FDG PET is feasible, provides insights into AD pathophysiology, and can be used potentially as a sensitive biomarker for early AD diagnosis.

Aged↗
PubMed2002

Intraoperative radiotherapy given as a boost after breast-conserving surgery in breast cancer patients.

Conventional radiotherapy after breast-conserving therapy is confined to 50-55 Gy external beam radiation therapy (EBRT) to the whole breast and 10-16 Gy external boost radiation to the tumour bed or brachytherapy to the tumour bed. Local recurrence rate after breast-conserving surgery varies between 5 and 18%. External boost radiation can partially miss the tumour bed and therefore can result in local failure. Intra-operative radiotherapy (IORT) as a high precision boost can prevent a 'geographical miss'. From October 1998 to December 2000, 156 patients with stage I and stage II breast cancer were operated upon in a dedicated IORT facility. After local excision of the tumour, the tumour bed was temporarily approximated by sutures to bring the tissue in the radiation planning target volume. A single dose of 9 Gy was applied to the 90% reference isodose with energies ranging from 4 to 15 MeV, using round applicator tubes 4-8 cm in diameter. After wound healing, the patients received additional 51-56 Gy EBRT to the whole breast. No acute complications associated with IORT were observed. In 5 patients, a secondary mastectomy had to be performed because of tumour multicentricity in the final pathological report or excessive intraductal component. 2 patients developed rib necroses. In 7 patients, wound healing problems occurred. After a mean follow-up of 18 months, no local recurrences were observed. Cosmesis of the breast was very good and comparable to patients without IORT. Preliminary data suggest that IORT given as a boost after breast-conserving surgery could be a reliable alternative to conventional postoperative fractionated boost radiation by accurate dose delivery and avoiding geographical misses, by enabling smaller treatment volumes and complete skin-sparing and by reducing postoperative radiation time by 7-14 days.

Adult↗
PubMed2002

A cryptic deletion of 2q35 including part of the PAX3 gene detected by breakpoint mapping in a child with autism and a de novo 2;8 translocation.

We report a de novo, apparently balanced (2;8)(q35;q21.2) translocation in a boy with developmental delay and autism. Cross species (colour) paint (Rx) and SKY FISH, forward and reverse chromosome painting, and FISH with subtelomeric probes were used to examine the patient's karyotype, but further rearrangements were not detected. FISH with region specific clones mapping near 2q35 and 8q21.2 breakpoints and STS mapping performed on the isolated derivative chromosomes were used to refine the location of the breakpoints further. A cryptic deletion of between 4.23 and 4.41 Mb in extent and involving at least 13 complete genes or transcription units was found at the breakpoint on 2q35. The deletion includes the promoter and 5' untranslated region of the paired box 3 (PAX3) gene. The child has very mild dystopia canthorum which may be associated with the PAX3 haploinsufficiency. The 8q21.2 breakpoint is within MMP16 which encodes matrix metalloproteinase 16. We postulate that the cryptic deletion and rearrangement are responsible for the patient's phenotype and that a gene (or genes) responsible for autism lies at 2q35 or 8q21.2. The results present a step towards identifying genes predisposing to autism.

Autistic Disorder↗
PubMed2001

A translocation breakpoint cluster disrupts the newly defined 3' end of the SNURF-SNRPN transcription unit on chromosome 15.

Balanced translocations affecting the paternal copy of 15q11--q13 are a rare cause of Prader-Willi syndrome (PWS) or PWS-like features. Here we report on the cytogenetic and molecular characterization of a de novo balanced reciprocal translocation t(X;15)(q28;q12) in a female patient with atypical PWS. The translocation breakpoints in this patient and two previously reported patients map 70-80 kb distal to the SNURF-SNRPN gene and define a breakpoint cluster region. The breakpoints disrupt one of several hitherto unknown 3' exons of this gene. Using RT--PCR we demonstrate that sequences distal to the breakpoint, including the recently identified C/D box small nucleolar RNA (snoRNA) gene cluster HBII-85 as well as IPW and PAR1, are not expressed in the patient. Our data suggest that lack of expression of these sequences contributes to the PWS phenotype.

Adult↗
PubMed2001

Radiation exposure and radiation protection of the physician in iodine-131 Lipiodol therapy of liver tumours.

Intra-arterial iodine-131 labelled Lipiodol therapy for liver cancer has been investigated for safety and efficacy over a number of years, but data on radiation exposure of personnel have remained unavailable to date. The aim of this study was to assess the radiation exposure of the physician during intra-arterial 131I-Lipiodol therapy for liver malignancies and to develop appropriate radiation protection measures and equipment. During 20 intra-arterial administrations of 131I-Lipiodol (1110-1924 MBq), radiation dose equivalents (RDE) to the whole body, fingers and eyes of the physician were determined for (a) conventional manual administration through a shielded syringe, (b) administration with an automatic injector and (c) administration with a lead container developed in-house. Administration by syringe resulted in a finger RDE of 19.5 mSv, an eye RDE of 130-140 microSv, and a whole-body RDE of 108-119 microSv. The injector reduced the finger RDE to 5 mSv. With both technique (a) and technique (b), contamination of angiography materials was observed. The container allowed safe transport and administration of the radiopharmaceutical from 4 m distance and reduced the finger RDE to <3 microSv and the eye RDE to <1 microSv during injection. During femoral artery compression, radiation exposure to the fingers reached 170 microSv, but the whole-body dose could be reduced from a mean RDE of 114 microSv to 14 microSv. No more contamination occurred. In conclusion, radiation exposure was high when 131I-Lipiodol was administered by syringe or injector, but was significantly reduced with the lead container.

Humans↗
PubMed2001

Painful multifocal arthritis: therapy with rhenium 186 hydroxyethylidenediphosphonate ((186)Re HEDP) after failed treatment with medication--initial results of a prospective study.

Eight patients (77 joints) with polyarthritis were treated systemically with 570 MBq (15.4 mCi) of rhenium 186 ((186)Re) hydroxyethylidenediphosphonate (HEDP). Pain and disease activity were assessed monthly. In six (75%) of eight patients, a single injection of (186)Re HEDP led to an improvement in disease activity. Systemic low-dose treatment with (186)Re HEDP can reduce pain and disease activity in patients with polyarthritis.

Arthritis, Rheumatoid↗