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M Zimny

Publications and source records attributed to M Zimny.

At least 37 records · Page 2Linked to original sources
PubMed2000

Benign versus malignant osseous lesions in the lumbar vertebrae: differentiation by means of bone SPET.

Bone scanning is a well-accepted and frequently performed diagnostic procedure with a high sensitivity, especially when single-photon emission tomography (SPET) acquisitions are added. However, the differentiation of benign from malignant osseous lesions often poses difficulty. The purpose of this study was to find out whether the particular localisation of an intraosseous lesion in a lumbar vertebra is an indicator of its aetiology. Bone scintigraphy including planar whole-body scans as well as SPET imaging of the lumbar spine was performed in 109 patients. The diagnoses of osseous lesions in the lumbar vertebrae were made strictly on the basis of the findings of magnetic resonance imaging, computed tomography or plain radiography. Sixteen patients had to be excluded from the study because they did not undergo adequate radiological examination. To determine the particular localisation of vertebral lesions in the bone scan, two experienced nuclear medicine physicians examined the studies independently while blinded to the radiological results. Four anatomical regions were differentiated within the vertebra: the vertebral body, the pedicle, the facet joints and the spinous process. Clopper-Pearson analysis, which takes into account the number of examinations, yielded the following probability intervals for the malignancy of intraosseous lesions in the lumbar spine: vertebral body 36.8%-57.3%, pedicle 87.7%-100%, facet joints 0.8%-21.4% and spinous process 18.7%-81.3%. It was concluded that lesions affecting the pedicle are a strong indicator for malignancy, whereas involvement of the facet joints is usually related to benign disease. Lesions affecting the vertebral body or the spinous process do not show a clear tendency towards either malignancy or benignity. In contrast to other studies, a significant probability of malignancy (35.6%) was observed in lesions affecting exclusively the vertebral body.

Adult↗
PubMed2000

Fluorodeoxyglucose positron emission tomography and the prognosis of pancreatic carcinoma.

BACKGROUND: Pancreatic carcinoma is associated with a poor prognosis. The aim of this study was to determine whether glucose metabolism in pancreatic cancer has prognostic significance for patients suffering from this disease. METHODS: The survival data of 52 patients with pancreatic carcinoma was correlated with the standardized uptake value (SUV) as a semiquantitative parameter of glucose metabolism, as determined with fluorodeoxyglucose positron emission tomography (FDG PET). A multivariate analysis, including SUV and accepted factors of prognosis, such as stage at presentation and tumor marker Ca 19-9, was performed to determine the prognostic value of FDG PET. RESULTS: The median survival in 26 patients with low SUV (< 6.1) was 9 months (95% confidence interval 6-12 months) vs. 5 months (95% confidence interval 4-6 months) in 26 patients with high SUV (> or = 6.1). Multivariate analysis revealed SUV and tumor marker Ca 19-9 as independent factors of prognosis in patients with pancreatic carcinoma. CONCLUSION: Glucose metabolism, as determined with FDG PET, provides additional prognostic information in patients with pancreatic carcinoma.

Adenocarcinoma↗
PubMed2000

One-year follow-up of neuropsychology, MRI, rCBF and glucose metabolism (rMRGlu) in cerebral microangiopathy.

BACKGROUND: MRI shows lacunar infarctions (LI), deep white matter lesions (DWML) and atrophy in cerebral microangiopathy, which is said to lead to vascular dementia. In a first trial series on 57 patients with confirmed pure cerebral microangiopathy (without concomitant macroangiopathy), neuropsychological impairment and (where present) brain atrophy correlated with decreased rCBF and rMRGlu. LI and DWML did not correlate with either neuropsychological impairment or decreased rCBF/rMRGlu. This study was done one year later to detect changes in any of the study parameters. METHODS: 26 patients were re-examined for rCBF, rMRGlu, LI, DWML, atrophy and neuropsychological performance (7 cognitive, 3 mnestic, 4 attentiveness tests). Using a special head holder for exact repositioning, rCBF (SPECT) and rMRGlu (PET) were measured and imaged slice by slice. White matter/cortex were quantified using MRI-defined ROIs. RESULTS: After one year the patients did not show significant decreases in rCBF or rMRGlu either in cortex or in white matter (p > 0.05), nor did any patient show LI, DWML or atrophy changes on MRI. There were no significant neuropsychological decreases (p > 0.05). CONCLUSIONS: Cerebral microangiopathy ought to show progressive neuropsychological, functional (rCBF, rMRGlu) and morphological deterioration over periods > 1 year. It is unlikely that direct cortical damage (e.g., incomplete infarction) is responsible for neuropsychological impairment since one-year follow-up of our patients revealed no progression of brain atrophy or any other cortical damage.

Adult↗
PubMed1999

Dual-head gamma camera 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography in oncological patients: effects of non-uniform attenuation correction on lesion detection.

The purpose of this study was to evaluate a dual head coincidence gamma camera (DH-PET) equipped with single-photon transmission for 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients. Forty-five patients with known or suspected malignancies, scheduled for a positron emission tomography (PET) scan, were first studied with a dedicated ring PET and subsequently with DH-PET. All patients underwent measured attenuation correction using germanium-68 rod sources for ring PET and caesium-137 sources for DH-PET. Ring PET emission scan was started 64+/-17 min after intravenous administration of 235+/-42 MBq FDG. DH-PET emission followed 160+/-32 min after i.v. FDG. Attenuation-corrected and non-attenuation-corrected images were reconstructed for ring PET and DH-PET. The image sets were evaluated independently by three observers blinded to clinical data and to results of conventional imaging. Attenuation-corrected ring PET as the standard of reference depicted 118 lesions, non-attenuation-corrected ring PET 113 (96%) lesions, and attenuation-corrected DH-PET and non-attenuation-corrected DH-PET, 101 (86%) and 84 (71%) lesions, respectively (P<0.05). The lesion detection rate of attenuation-corrected and non-attenuation-corrected DH-PET was almost similar for lesions >20 mm, whereas attenuation correction increased the detection rate from 60% to 80% for lesions </=20 mm (P<0.01). A patient-based analysis revealed concordant results relative to attenuation-corrected ring PET for non-attenuation-corrected ring PET, attenuation-corrected DH-PET and non-attenuation-corrected DH-PET in 42 (93%), 36 (80%) and 31 (69%) patients, respectively. Differences might have influenced patient management in two (4%), six (13%) and ten (22%) patients, respectively. In conclusion, measured attenuation correction markedly improves the lesion detection capability of DH-PET. With measured attenuation correction the diagnostic performance of DH-PET is closer to that of dedicated ring PET.

Evaluation Studies as Topic↗
PubMed1999

"Ecstasy"-induced changes of cerebral glucose metabolism and their correlation to acute psychopathology. An 18-FDG PET study.

The aim of this study was to determine the acute effects of the "Ecstasy" analogue MDE (3,4-methylene dioxyethamphetamine) on cerebral glucose metabolism (rMRGlu) of healthy volunteers and to correlate neurometabolism with acute psychopathology. In a randomized double-blind trial, 15 healthy volunteers without a history of drug abuse were examined with fluorine-18-deoxyglucose (18FDG) positron emission tomography (PET) 110-120 min after oral administration of 2 mg/kg MDE (n = 7) or placebo (n = 8). Two minutes prior to radiotracer injection, constant cognitive stimulation was started and maintained for 32 min using a word repetition paradigm to ensure constant and comparable mental conditions during cerebral glucose uptake. Individual brain anatomy was represented using Tl-weighted 3D flash magnetic resonance imaging (MRI), followed by manual regionalization into 108 regions of interest and PET/MRI overlay. After absolute quantification of rMRGlu and normalization to global metabolism, normalized rMRGlu under MDE was compared to placebo using the Mann-Whitney U-test. Acute psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS) and rMRGlu was correlated to PANSS scores according to Spearman. MDE subjects showed significantly decreased rMRGlu in the bilateral frontal cortex: left frontal posterior (-7.1%, P < 0.05) and right prefrontal superior (-4.6%, P < 0.05). On the other hand, rMRGlu was significantly increased in the bilateral cerebellum (right: +10.1%, P < 0.05; left: +7.6%, P < 0.05) and in the right putamen (+6.2%, P < 0.05). There were positive correlations between rMRGlu in the middle right cingulate and grandiosity (r = 0.87, P < 0.05), both the right amygdala (r = 0.90, P < 0.01) and the left posterior cingulate (r = 0.90, P < 0.01) to difficulties in abstract thinking, and the right frontal inferior (r = 0.85, P < 0.05), right anterior cingulate (r = 0.93, P < 0.01), and left anterior cingulate (r = 0.85, P < 0.05) to attentional deficits. A negative correlation was found between the left frontal operculum (Broca's area) and attentional deficits (r = -0.85, P < 0.05). The present study revealed acute neurometabolic changes under the "Ecstasy" analogue MDE, indicating a frontostriatocerebellar imbalance paralleling other psychotropic substances or various psychiatric disorders.

3,4-Methylenedioxyamphetamine↗
PubMed1999

Does positron emission tomography using 18-fluoro-2-deoxyglucose improve clinical staging of testicular cancer?--Results of a study in 50 patients.

OBJECTIVES: To compare positron emission tomography (PET) using 18-fluoro-2-deoxyglucose (FDG) with conventional clinical staging in unselected patients with germ cell cancer. METHODS: Fifty patients underwent PET scans of the abdomen (n = 50) and chest (n = 41 ) after the initial diagnosis. PET images were evaluated qualitatively and quantitatively using standardized uptake values (SUVs). The results were compared with computed tomography (CT) results and tumor markers (human chorionic gonadotropin, alpha-fetoprotein, and lactate dehydrogenase). Retroperitoneal lymphadenectomy in 12 patients and clinical staging, including follow-up data in all patients, were taken as a reference standard. RESULTS: PET detected metastases in 13 (87%) of 15 patients and excluded metastases in 33 (94%) of 35 patients. A sensitivity of 73% and a specificity of 94% were obtained using CT. The respective values for tumor marker determination were 67% and 100%. Retroperitoneal metastases were detected in 2 patients by PET only and in 1 patient by CT only. In the latter patient, surgery of a residual mass after chemotherapy revealed a well-differentiated teratoma. False-negative findings with PET and CT occurred in 2 patients with retroperitoneal metastases approximately 10 mm in size. False-positive findings were due to sarcoidosis or to muscular activity of the neck. Quantitative FDG uptake was very heterogeneous, with an SUV ranging from 1.8 to 17.3. CONCLUSIONS: FDG PET has the potential to improve clinical staging of testicular cancer. However, PET, as well as CT, is limited in the detection of small retroperitoneal lymph node metastases.

Adult↗
PubMed1999

Radioiodine therapy in Graves' disease patients with large diffuse goiters treated with or without carbimazole at the time of radioiodine therapy.

We sought to ascertain how high the success rates of radioiodine therapy are for Graves' disease patients with large diffuse goiters when aiming for a constant absorbed dose of 250 Gy. Thirty-six patients with a thyroid volume of 50-110 mL were evaluated for changes in thyroid function and appearance 3, 6, and 12 months after radioiodine therapy. Success was defined as definitive elimination of hyperthyroidism following therapy (hypothyroidism corrected with thyroxine on diagnosis); failure as persistent/recurrent hyperthyroidism after 12 months. Overall success rate was 50%. However, a subgroup of 20 patients without simultaneous carbimazole (carbimazole-off) showed a highly significantly larger success rate (85%) than the 16 patients with simultaneous carbimazole (carbimazole-on) at the time of radioiodine therapy (6.3%, p < 0.000005). Successful cases showed a significantly higher volume reduction after radioiodine than failures (75.5% vs. 35.4%, p < 0.00005). Stepwise logistic regression showed that therapy failure was related to administration of carbimazole during radioiodine therapy (p < 0.0250 and absorbed dose (p < 0.05), but not thyroid function (free triiodothyronine [FT3] and free thyroxine [FT4]), initial thyroid volume or thyrotropin-receptor antibody (TRAb) value. However, a significant correlation of therapy success to absorbed dose (r = 0.69, p < 0.005) could be shown only for carbimazole-off patients, but not for the others. Finally, multivariate factor analysis consistently showed that therapy success was correlated only to absorbed dose and antithyroid drugs, not to initial thyroid volume, TRAb value, or thyroid function. Thyroid volume per se is not responsible for the lower success rate in Graves' disease patients with large goiters because even a comparable group of 32 Graves' disease patients with small thyroid glands (< or =20 mL) and without simultaneous carbimazole showed a success rate of 87.5%. The high failure rate in the carbimazole-on patients (absorbed dose comparable to carbimazole-off) is due to the simultaneous administration of carbimazole. Therefore, if clinically feasible, we recommend discontinuing carbimazole at least one day before beginning radioiodine therapy.

Adult↗
PubMed1999

Success rate of radioiodine therapy in Graves' disease: the influence of thyrostatic medication.

There is controversy whether simultaneous thyrostatic medication influences the outcome of radioiodine (131I) therapy in Graves' disease by reducing the absorbed energy dose of 131I when delivering a standard dose. We therefore sought to ascertain whether the outcome of ablative 131I therapy is in any way affected by simultaneous thyrostasis (carbimazole) by aiming for a constant absorbed dose of 200-250 Gy. We prospectively studied 207 patients with Graves' disease (106 with and 101 without simultaneous carbimazole at the time of 131I therapy). All patients were reexamined 3, 6, and 12 months after 131I therapy. The 101 nonthyrostatic patients showed a highly significantly greater success rate (93%) than the 106 thyrostatic patients (49%). Stepwise logistic regression demonstrated that failure was related to the administration of carbimazole during 131I therapy (P < 0.00005) and the absorbed dose (P < 0.025), but was not related to free T3, free T4, TSH receptor antibodies, or thyroid volume. The success rate was 100% in 93 nonthyrostatic patients with absorbed doses of 200 Gy or more, but was only 12.5% (1 of 8) for absorbed doses less than 200 Gy. Correlation between success and absorbed dose was significantly higher for nonthyrostatic than for thyrostatic patients (r = 0.93 vs. r = 0.24). Sixteen patients who discontinued thyrostasis 1-3 days before 131I therapy showed 94% successes. Simultaneous thyrostasis is the decisive factor against a successful 131I therapy even if the significantly reduced 131I uptake/half-life values under thyrostasis are compensated with a higher delivered dose to ensure a comparable absorbed dose, possibly due to the additionally effective radioprotective properties of carbimazole. Therefore, if clinically feasible, we recommend discontinuing thyrostasis at least 1 day before beginning 131I therapy, because even in hyperthyroid nonthyrostatic patients the success rate was 100%.

Adult↗
PubMed1999

F-18-FDG positron imaging in oncological patients: gamma camera coincidence detection versus dedicated PET.

AIM: Of the present study was to investigate the feasibility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients with a dual head gamma camera modified for coincidence detection (MCD). METHODS: Phantom studies were done to determine lesion detection at various lesion-to-background ratios, system sensitivity and spatial resolution. Thirty-two patients with suspected or known malignant disease were first studied with a dedicated full-ring PET system (DPET) applying measured attenuation correction and subsequently with an MCD system without attenuation correction. MCD images were first interpreted without knowledge of the DPET findings. In a second reading, MCD and DPET were evaluated simultaneously. RESULTS: The phantom studies revealed a comparable spatial resolution for DPET and MCD (5.9 x 6.3 x 4.2 mm vs. 5.9 x 6.5 x 6.0 mm). System sensitivity of MCD was less compared to DPET (91 cps/Bq/ml/cmFOV vs. 231 cps/Bq/ml/cmFOV). At a lesion-to-background ratio of 4:1, DPET depicted a minimal phantom lesion of 1.0 cm in diameter, MCD a minimal lesion of 1.6 cm. With DPET, a total of 91 lesions in 27 patients were classified as malignant. MCD without knowledge of DPET results revealed increased FDG uptake in all patients with positive DPET findings. MCD detected 72 out of 91 DPET lesions (79.1%). With knowledge of the DPET findings, 11 additional lesions were detected (+12%). MCD missed lesions in six patients with relevance for staging in two patients. All lesions with a diameter above 18 mm were detected. CONCLUSION: MCD FDG imaging yielded results comparable to dedicated PET in most patients. However, a considerable number of small lesions clearly detectable with DPET were not detected by MCD alone. Therefore, MCD cannot yet replace dedicated PET in all oncological FDG studies. Further technical refinement of this new method is needed to improve image quality (e.g. attenuation correction).

Adult↗
PubMed1999

18FDG-positron emission tomography in pancreatic cancer.

UNLABELLED: POSITRON EMISSION TOMOGRAPHY: Malignant cells present an increased glucose consumption compared to normal pancreatic tissue. Positron emission tomography with 18F fluoro-D-deoxyglucose is a new imaging tool to in vivo assess the amount of glucose metabolism. This method provides metabolic information on tumors rather than morphological information. METHODS: In most PET centers a static emission scan of the upper abdomen is performed 45-60 minutes after intravenous administration of the radiotracer. To obtain quantitative parameter an additional transmission scan is necessary to correct for attenuation. Today, both visual analysis and semiquantitative parameters of glucose consumption as the Standardized Uptake Value (SUV) are used for image interpretation. To allow coregistration of the metabolic PET images and morphological imaging tools as CT or MRI external markers may be used. Following exact reorientation both the metabolic information (PET) and the morphologic information (MRI/CT) can be merged in one 3D data set (image fusion). RESULTS: In our series of patients the sensitivity for PET to detect pancreatic cancer was 85%, the specificity 84%. False negative results were obtained in patients with hyperglycemia, false positive results in patients with chronic active pancreatitis. Excluding hyperglycemic patients the sensitivity for PET increased to 98%. In a sample statistics of 305 euglycemic patients sensitivity, specificity and accuracy were 92%, 79%, and 87%, respectively. Image fusion of metabolic (PET) and morphologic data (MRI/CT) can help to better localize the focus of increased glucose consumption demonstrated with PET and to differentiate multifocal cancer from lymph node metastases. CONCLUSION: 18FDG PET is a feasible diagnostic modality to differentiate benign and malignant pancreatic masses when morphological imaging is equivocal. Image fusion of PET and CT or MRI can combine the advantages of both modalities in one image-detailed anatomic information combined with accurate metabolic data.

Fluorodeoxyglucose F18↗
PubMed1999

[Various dynamics of Tc-99m-tetrofosmin and Tc-99m-MIBI in a parathyroid adenoma].

Case report of a patient with hypercalcemia and suspected parathyroid adenoma. Because of a previous strumectomy a precise preoperative localization of the suspected parathyroid adenoma was demanded. Tc-99m-tetrofosmin scintigraphy in double phase technique failed to detect a parathyroid adenoma by failing to show a region of increased focal uptake with delayed washout in relation to the thyroid gland. Only comparison of the Tc-99m-tetrofosmin images with a Tc-99m-pertechnetate scan revealed a right caudal parathyroid adenoma. A double phase Tc-99m-MIBI study of the same patient was able to localize this parathyroid adenoma without the need of a corresponding Tc-99m-pertechnetate scintigraphy due to a differential washout with persistent focal uptake in the parathyroid adenoma and a progressively decreasing uptake in the thyroid tissue. This case indicates that Tc-99m-tetrofosmin is a suitable agent for parathyroid imaging only if used together with Tc-99m-pertechnetate but it seems to lack the differential washout characteritics of Tc-99m-MIBI according parathyroid gland and thyroid gland.

Adenoma↗
PubMed1999

[Quantification of repositioning errors in PET studies through superimposition of emission and transmission scans. Comparison between acquisition with and without repositioning].

AIM: The purpose of this study was to quantify positioning discrepancies between emission (E) and transmission (T) scan using image fusion. A direct comparison of one-step and two-step acquisitions was performed where all studies were analyzed in respect to artifacts caused by inaccurate positioning. In addition, phantom measurements were conducted to estimate the consequences of repositioning errors on standardized uptake value calculations (SUV). METHODS: 40 patients were examined by two-step whole-body scans using PET and 15 patients were subject to one-step examinations in the head/neck area. Repositioning between the scans was achieved by a laser matrix positioning system in combination with external body markings. After reconstruction and image fusion of the scans, the positioning discrepancies were measured as the distances between the outer boundaries of E and T in four different body regions. Additional evaluations of the SUV by increasing E-T dislocation were performed using a Jaszczak phantom containing hollow spheres. RESULTS: For the two-step acquisitions, the mean spatial deviations along the three orthogonal axes x, y, and z were between 8.9 mm and 13.8 mm, whereas for the one-step examinations mean values between 3.5 mm and 4.3 mm were determined (level of significance in each direction p < 0.0001). Artifacts were found in 47.5% of the whole body scans, but in none of the head/neck studies. The development of image artifacts was simulated by phantom studies. In contrast, the deviations of the computed SUV caused by increasing positioning discrepancies were minimal because of the minimal differences between the attenuation coefficients of the media involved. CONCLUSION: The presented data show that an artifactfree reconstruction of attenuation-corrected studies requires a precise positioning of the patient. One-step examination protocols without repositioning are advantageous due to the significantly lower positioning discrepancies. The additional reconstruction of nonattenuation-corrected studies has proven to be useful in discovering image artifacts and is therefore recommended.

Artifacts↗
PubMed1999

Diagnostic evaluation of malignant head and neck cancer by F-18-FDG PET compared to CT/MRI.

AIM: Evaluation of F-18-FDG PET in comparison to CT/MRI as diagnostic tool in primary and recurrent head and neck cancer. METHODS: 78 F-18-FDG PET studies were performed in 71 patients with known or suspected primary (n = 48) or recurrent (n = 30) head and neck cancer and compared to CT (n = 75) or MRI investigations (n = 3) concerning detection of the primary or recurrent tumor and detection of regional lymph node metastases in the ipsilateral and contralateral neck sides. Glucose uptake (SUV) of PET findings was correlated to tumor location, grading and dignity of the lesion. RESULTS: Sensitivity and specificity for PET in detection of primary tumors were 87%* and 67%, respectively (CT/MRI 67%* and 44%) (*p < 0.05), in detection of local recurrence 86% and 75%, respectively (CT/MRI 57% and 92%), in detection of necks affected by lymph node metastases 80% and 92%, respectively (CT/MRI 80% and 84%). Laryngeal, buccal (cheek) and salivary gland tumors had significant lower glucose uptake (SUV) when compared to tumors of the hypopharynx (p < 0.05). G1-tumors (mean SUV 4.26) had significant (p < 0.05) lower glucose uptake when compared to G2- and G3-tumors (mean SUV 7.73 and 8.19, respectively). Mean SUV of malignant PET findings (7.88) was significant (p < 0.05) higher than mean SUV of benign PET findings (5.70). However, a SUV threshold to improve diagnostic accuracy could not be defined. CONCLUSIONS: F-18-FDG PET is significantly more accurate than CT/MRI for detection of head and neck cancer. Both methods are valuable for detection of cervical lymph node metastases. Glucose uptake shows correlation to histological grading. A quantitative SUV analysis does not improve diagnostic accuracy.

Female↗
PubMed1999

[Clinical value of FDG PET for therapy monitoring of malignant lymphoma--results of a retrospective study in 72 patients].

AIM: Of the present retrospective study was to validate the clinical value of FDG-PET for therapy control of malignant lymphoma. METHOD: 72 patients (41 non-Hodgkin lymphomas, 29 Hodgkin's disease, 2 unclassified) received static FDG-PET scans of initially involved regions (n = 53) or of the entire neck and trunk (n = 19) after therapy. CT imaging (n = 70) and serum LDH measurement (n = 64) were also performed. Results were validated either by biopsy (n = 7) or by clinical follow-up (n = 65). The predictive value of PET was analysed in relation to different prognostic factors (stage, recurrence status, number of prior therapy regimen). RESULTS: PET obtained a sensitivity of 88%, a specificity of 83% and an overall accuracy of 85% for detection of residual disease. The values for CT were 84%, 31% resp. 54%, and for serum LDH 50%, 92% and 73%. The predictive value of PET was related to the prevalence of residual disease. PET predicted complete remission in more than 90% of patients with moderate risk (stage I-III, no relapse, no more than two different therapy regimens). In high risk patients, however, the negative predictive value of PET was 50-67%. CONCLUSION: FDG-PET is more accurate than CT imaging and LDH measurement for therapy monitoring of malignant lymphoma. Therapy success can be reliably predicted in patients with moderate risk.

Adolescent↗
PubMed1999

[Radioiodine therapy in veterinary medicine: treatment of hyperthyroidism in a cat].

A nine-year-old cat with symptoms of a distinct hyperthyroidism was presented at the University Hospital of the RWTH Aachen. The clinical symptoms as well as the diagnostic procedures performed at the hospital confirmed the diagnosis. After five weeks of thyreostatic medication a regular metabolism of the thyroid gland was established, followed by a radioiodine therapy with 70.3 MBq 131-iodine. Subsequently, the cat was hospitalized for two days before it could be released in good condition. Six weeks after treatment the former drastically reduced weight of the cat recovered to near normal. Even though the chemical analysis detected a discrete hyperthyroidism, clinical symptoms were no longer prominent. Three months after treatment, the final examination showed a regular metabolism of the thyroid gland without a specific thyroidal medication. The presented case illustrates that radioiodine therapy is a safe and efficient treatment of thyroidal dysfunctions in veterinary medicine.

Animals↗
PubMed1998

Positron emission tomography with 18F-FDG to detect residual disease after therapy for malignant lymphoma.

We retrospectively evaluated the use of 18F-FDG PET for assessment of residual disease in 27 patients after therapy for malignant lymphoma. The images were evaluated qualitatively and quantitatively using standardized uptake values (SUV). All findings were validated either by biopsy or by clinical follow-up and compared with corresponding CT findings. The impact of blood glucose concentration, body weight, body surface area, lesion diameter and the time between injection and imaging on the SUVs were analysed. All 15 patients with biopsy-proven residual disease or relapse during follow-up and 11 of 12 patients who remained relapse-free were correctly identified by qualitative interpretation of the PET images. A case of pneumonitis after radiotherapy/chemotherapy accounted for the only false-positive finding. Compared with CT imaging, PET had a significantly higher specificity (P < 0.01), accuracy (P < 0.05) and positive predictive value (P < 0.05). The mean and maximum SUV of the tumour lesions were positively correlated to lesion diameter (P < 0.01) and imaging time post-injection (P < 0.01). Standardized uptake values corrected for the partial volume effect and normalized to a standardized imaging time (SUVBPT) were significantly higher (P < 0.05) in high-grade than in low-grade non-Hodgkin's lymphoma. In conclusion, 18F-FDG PET may help in the identification of patients who need additional treatment after the completion of conventional therapy. Qualitative image interpretation appears sufficient for this purpose.

Adolescent↗
PubMed1998

Is prostate-specific antigen a reliable marker of bone metastasis in patients with newly diagnosed cancer of the prostate?

OBJECTIVE: Staging in patients with newly diagnosed cancer of the prostate has significant ramifications in the management of the disease. At present, measurement of serum prostate-specific antigen (PSA) concentration and radionuclide bone scintigraphy are two important procedures in the metastatic work-up of these patients. We evaluated the efficacy of PSA as a staging marker to discriminate prostate cancer patients with and without bone metastases. METHODS: In a retrospective study, 359 prostate cancer patients with (n = 40) and without (n = 319) bone metastases were analyzed. In all patients the initial PSA measurement as well as the radionuclide bone scan were evaluated. RESULTS: Patients without bone metastases demonstrated a median serum PSA concentration of 12 ng/ml, whereas those with bone metastases revealed a median serum PSA concentration of 59 ng/ml, with 7 patients demonstrating a serum PSA concentration of < 10 ng/ml. This resulted in a negative predictive value of 96%. In addition, only 40% of these patients with bone metastases demonstrated a serum PSA concentration of > 100 ng/ml, which resulted in a positive predictive value of 50%. CONCLUSION: The serum PSA concentration seems only to provide limited information with regard to the presence of bone metastasis in patients with newly diagnosed cancer of the prostate. We therefore question whether a staging radionuclide bone scan may be omitted in patients with a serum PSA value of < 10 ng/ml.

Adenocarcinoma↗