Resection of ectopic mediastinal parathyroid glands with the da Vinci robotic system.

BACKGROUND: Mediastinal ectopic parathyroid adenoma is a frequent cause of persistent or recurrent hyperparathyroidism, traditionally treated by open surgery. Thoracoscopic access is associated with reduced morbidity in mediastinal surgery. The aim of this study was to evaluate the feasibility and effectiveness of robot-assisted dissection for mediastinal ectopic parathyroid glands. METHODS: Two patients with recurrent secondary hyperparathyroidism and three with complicated primary hyperparathyroidism were operated on between July 2004 and August 2008 for ectopic mediastinal parathyroid glands. Fusion of single-photon emission computed tomography and computed tomography led to an exact identification of the culprit glands. Surgery was performed thoracoscopically with the da Vinci robotic system using a three-trocar approach. RESULTS: All procedures were completed successfully with the robotic system. No perioperative morbidity or mortality was noted. Median operating time was 58 (range 42-125) min. Intraoperative parathyroid hormone reduction indicated complete resection. Median hospital stay was 3 (range 2-4) days. CONCLUSION: Robot-assisted dissection is a promising approach for resection of ectopic parathyroid glands in remote narrow anatomical locations such as the mediastinum.

[Imaging techniques in rheumatology: PET in rheumatology]. / Bildgebende Verfahren in der Rheumatologie : PET in der Rheumatologie.

Positron emission tomography (PET) using F-18-fluoro-deoxyglucose (FDG) is suitable for many indications in oncology and can also be used in rheumatology to search for inflammatory foci and benign lesions with increased glucose metabolism in, for example soft tissue and joints (arthritis, vasculitis etc.) and fever of unknown origin. Usually a whole-body scanning technique is used for data acquisition in the search for foci of unknown localization or for the characterization of glucose metabolism of one or more known lesions - also for observation of the effect of, for example pharmacotherapy. Patients are admitted under fasting conditions and acquisition starts 1 h after i.v. injection of FDG with an acquisition time of 30-60 min. The method is sensitive and can measure glucose metabolism in an objective manner, but is not specific for inflammatory diseases (FDG also accumulates in malignant diseases).

Allogeneic hematopoietic cell transplantation following conditioning with 90Y-ibritumomab-tiuxetan.

Radioimmunotherapy (RIT) of relapsed lymphoma is gaining increasing importance. Especially the commercially available anti-CD20 antibody 90Y-ibritumomab tiuxetan is currently under investigation in various trials including dose escalation and autologous hematopoietic progenitor cell support. It is not clear, however, whether the implementation of this radiolabeled antibody into another treatment option for relapsed or poor risk lymphoma patients-allogeneic hematopoietic cell transplantation-interferes with or delays successful engraftment. This study reports encouraging results with 2 relapsed lymphoma patients (1 transformed marginal zone lymphoma and 1 mantle cell lymphoma) who underwent allogeneic hematopoietic cell transplantation from HLA-matched donors. The conditioning regimen consisted of Rituximab 250 mg m(-2) on days -21 and -14, 0.4 mCi kg(-1) body weight 90Y-ibritumomab tiuxetan on day -14 and fludarabine (30 mg m(-2)) plus cyclophosphamide (500 mg m(-2)) on days -7 to -3. The data demonstrate that engraftment is fast and reliable with leukocytes >1 x 10(9) L(-1) on day 12 and platelets >50 x 10(9) L(-1) on day 10. Thus, the incorporation of radioimmunotherapy into allogeneic transplant protocols combines established modalities with proven anti-lymphoma activity and, hence, offers an attractive new therapeutic option for relapsed lymphoma patients.

[Radiation exposure in (90)Y-Zevalin therapy: results of a prospective multicentre trial]. / Strahlenexposition bei der (90)Y-Zevalin-Therapie: Ergebnisse einer prospektiven multizentrischen Studie.

UNLABELLED: AIM of this study was the assessment of the radiation exposure from preparation and application of (90)Y-Zevalin, the measurement of the dose rate at the patient, the exposure of family members as well as the determination of the activity concentration in urine of patients. METHODS: Overall data from 31 therapeutic administrations carried out in four institutions were evaluated. During preparation and application of (90)Y-Zevalin the finger exposures of radiochemists, technicians, and physicians were measured. The dose rate of the patient was measured immediately after radioimmunotherapy. In patients treated in a nuclear medicine therapy unit, urine was collected over a two day period and the corresponding activity was determined. Family members of outpatients were asked to wear a dosimeter over a seven day period. RESULTS: During the preparation we found a maximum skin dose of 6 mSv at the average, and during application of 3 mSv, respectively. After administration of (90)Y the dose rate was 0.4 +/- 0.1 microSv/h at 2 m distance. Urine measurements yielded a cumulated 24 h excretion of 3.9 +/- 1.4% and 4.4 +/- 1.4% within 48 h, respectively, that is equivalent to 43 +/- 18 and 50 +/- 20 MBq of (90)Y, respectively. Family members received a radiation exposure of 40 +/- 14 microSv over seven days. CONCLUSION: During preparation and application of (90)Y-Zevalin appropriate radiation shielding is necessary. For family members as well as nursing staff no additional special radiation protection measures beyond those being common for other nuclear medicine procedures are necessary.

Reduced acute thrombus formation results in decreased neointimal proliferation after coronary angioplasty.

OBJECTIVES: We tested the hypothesis that reduced acute platelet deposition after angioplasty results in reduced late neointimal proliferation. BACKGROUND: Platelet-mediated mechanisms contribute to smooth muscle cell proliferation and migration. METHODS: Indium-111-labeled platelets were injected 16 h before coronary stent angioplasty in 10 Göttinger minipigs: group 1 (n = 5) = heparin (100-U/kg bolus) before angioplasty; group 2 (n = 5) = recombinant hirudin (CGP 39393, 1.0-mg/kg body weight bolus intravenously), followed by subcutaneous doses of 6 to 10 mg/kg every 8 h. Furthermore, stent angioplasty was performed in coronary arteries of 16 minipigs: group 3 (n = 5, nine stents) = 100 U/kg heparin only; group 4 (n = 5, 10 stents) = 1-mg/kg bolus hirudin before and 45 min after angioplasty; group 5 (n = 6, 11 stents) = hirudin (1-mg/kg intravenous bolus) before and 45 min after angioplasty, followed by 6 to 10 mg/kg subcutaneously every 8 h. RESULTS: In segments with deep arterial injury, the number of platelets/angioplasty segment in group 2 after 72 h (mean 21, range 9.7 to 39.7 x 10(6)) was significantly less than that in group 1 (mean 375, range 72 to 787 x 10(6)). Morphometric analysis after 4 weeks showed no difference between groups in degree of vessel wall injury. Mean (+/- SD) neointimal thickness was 0.70 +/- 0.06 mm in group 3 and was significantly reduced in both group 4 (0.46 +/- 0.11 mm) and group 5 (0.48 +/- 0.21 mm). CONCLUSIONS: The direct thrombin inhibitor hirudin significantly reduces platelet deposition up to 72 h after coronary stent angioplasty. A hirudin bolus alone as well as continued subcutaneous administration for 14 days substantially reduced neointimal proliferation compared with heparin 4 weeks after coronary stent angioplasty in minipigs.

Immunoscintigraphy using technetium-99m-labeled anti-NCA-95 antigranulocyte antibodies as an adjunct to echocardiography in subacute infective endocarditis.

OBJECTIVES: This study was performed to assess the clinical value of immunoscintigraphy in subacute infective endocarditis. BACKGROUND: Radiolabeled granulocytes can reveal inflammatory lesions. METHODS: Using technetium-99m-labeled anti-NCA-95 anti-granulocyte antibodies, planar scintigraphy and single-photon emission computed tomography of the thorax were performed in 72 consecutive patients with suspected endocarditis. Each patient also underwent transthoracic and, if findings were negative, transesophageal echocardiography. RESULTS: Thirty-three patients were found to have endocarditis on the basis of clinical criteria (surgical confirmation in 17 patients), and the remaining 39 served as control subjects. Initial scintigraphy was true positive in 26 patients (sensitivity 79%) and false positive in 7 (specificity 82%). Echocardiography was true positive in 29 patients (sensitivity 88%) and false positive in 1 (specificity 97%). Scintigraphy was positive in the four patients with false negative echocardiography, and echocardiography was positive in the seven patients with false negative scintigraphy. Thus, the combination of scintigraphy and echocardiography yielded a sensitivity of 100% and a specificity of 82%. In 10 of the 11 patients with two to three follow-up studies, scintigraphy became negative parallel to clinical improvement, indicating decreasing floridity of the inflammatory process. CONCLUSIONS: Immunoscintigraphy in patients with subacute infective endocarditis provides valuable diagnostic information in equivocal echocardiographic findings and may be used to monitor antibiotic therapy.

Platelet and fibrin deposition on coronary stents in minipigs: effect of hirudin versus heparin.

OBJECTIVES: The present study was designed to test the hypothesis that the direct thrombin hirudin is more efficient than heparin in reducing thrombus formation after coronary stenting. BACKGROUND: Despite aggressive anticoagulation, subacute thrombosis of coronary stents is a major complication associated with these new devices. METHODS: In 19 minipigs indium-111-labeled thrombocytes and iodine-125-labeled fibrinogen were injected 14 to 19 h before coronary implantation of tantalum balloon-expandable stents. In group 1 (n = 6, seven stents), a bolus of heparin (100 U/kg body weight) was given before stenting. Group 2 (n = 6, 11 stents) received both dextran (500 ml) and heparin (a 100-U/kg bolus followed by a continuous infusion of 50 U/kg per h). In group 3 (n = 7, 13 stents), hirudin (recombinant desulphatohirudin HV 1 [CGP 39393] [1 mg/kg]) was given before stent implantation, followed by an infusion of 1 mg/kg per h. All animals were pretreated with aspirin (250 mg intravenously). RESULTS: Activated partial thromboplastin time was prolonged to > 1.8 times control values in groups 2 and 3. Histologic examination after perfusion fixation 12 h after stenting showed a variable extent of thrombus on all stents. Medial tear was observed in three stents in group 1, six stents in group 2 and six stents in group 3. The number of platelets on all stents averaged 116.2 (range 22 to 522) x 10(6) in group 1, 64.3 (range 11 to 169) x 10(6) in group 2 and 19.7 (range 9 to 38) x 10(6) in group 3 (p < 0.05 vs. group 1 and vs. group 2). The increase in platelet deposition, associated with medial tear in all groups, was lowest in the hirudin group. Similarly, fibrin deposition was lowest on stents in hirudin-treated animals. CONCLUSIONS: Recombinant hirudin significantly reduces platelet and fibrin deposition on coronary stents compared with the reduction achieved with combined heparin, dextran and aspirin.

Scintigraphic results in patients with lung transplants: a prospective comparative study.

AIM: We addressed the feasibility of scintigraphy in the postoperative monitoring of lung transplants. METHOD: 37 patients (22 women, 15 men, 37 +/- 15 years) in good clinical condition were examined after lung transplantation. Scintigraphic procedures for assessing ventilation (133Xe), perfusion (99mTc microspheres) and aerosol-inhalation (99mTc aerosol) were performed for all patients. The findings were compared with those of established diagnostic modalities. RESULTS: All lung transplants showed homogeneous ventilation but with a non-physiologic difference of over 20% between both pulmonary lobes in one-third of the cases. There was a difference between the impairement of perfusion and ventilation in the presence of an impaired Euler-Liljestrand reflex in 14/37 (38%) patients. Furthermore, bronchoscopy and aerosol-inhalation scans often did not correlate, e. g. a bronchoscopically evident stenosis was not necessarily associated with an increased activity, and vice versa. Although peripheral mucociliary clearance was preserved after transplantation, stasis in central airways resulted in significantly impaired global clearance. CONCLUSION: Ventilation and perfusion scintigraphy reveal in a significant number of lung recipients pathologic findings and therefore can be recommended for postoperative monitoring. From a clinical point of view aerosol-inhalation scintigraphy (clearance) is not of any additional value.

Ultrastructural histology correlates with results of thallium-201/technetium-99m parathyroid subtraction scintigraphy.

Specimens from 15 scintigraphically true-positive adenomas (golden standard: histology), 15 false-negative adenomas, 15 true-positive hyperplasias, 15 false-negative hyperplasias, 15 true-negative normal glands from patients with hyperparathyroidism, and 15 normal glands from patients without hyperparathyroidism, all selected randomly, were studied. After fixation, sectioning and H and E staining, in all 90 tissues the number of oxyphil, chief, and clear cells was counted in five randomly selected squares (103 x 103 microns). In 30 tissues, the number of mitochondria per cell was counted in five randomly selected cells from each lesion in transmission electron photomicrographs. Total cell counts in each group and number of chief cells showed no correlation with lesion detectability by scintigraphy. However, true-positive lesions had a significantly higher number of oxyphil cells than false-negative or normal glands. Twenty-one of 30 true-positive lesions had a oxyphil-to-clear cell ratio > 1; in contrast to only two of 30 false-negative lesions and 0 of 30 normal glands (p < 0.0005). The number of mitochondria per cell was higher in oxyphil cells in true-positive lesions (adenomas: 155 +/- 58, hyperplasias: 55 +/- 18) than in chief or clear cells in false-negative or normal lesions (30 +/- 15, p < 0.001). Our data suggest that the detectability of abnormal parathyroid glands by 201TI/99mTc subtraction scintigraphy is in part dependent upon the presence of mitochondria-rich oxyphil cells.

Indium-111-antimyosin Fab imaging to demonstrate myocardial involvement in systemic lupus erythematosus.

Indium-111-antimyosin Fab imaging has been used to indicate myocardial injury. This report describes antimyosin accumulation in two patients with myocardial involvement in systemic lupus erythematosus. Both patients complained of chest pain, and significant stenoses of extramural coronary arteries were ruled out by angiography. The first patient, a 64-yr-old woman, had immunopathologic findings suggestive of systemic lupus. Indium-111-antimyosin Fab imaging showed myocardial tracer uptake. This prompted endomyocardial biopsy providing evidence of systemic lupus. The patient improved under immunosuppressive therapy. The second patient, a 47-yr-old man, had systemic lupus diagnosed by immunopathologic findings and skin biopsy. He had evidence of pericarditis on electrocardiography and echocardiography. Indium-111-antimyosin Fab imaging demonstrated additional myocardial involvement, which supported the initiation of immunosuppressive therapy. Our results suggest that 111In-antimyosin Fab imaging may provide valuable diagnostic information and influence patient management in systemic lupus erythematosus with suspected myocardial involvement.

Scintigraphic localization of lymphatic leakage site after oral administration of iodine-123-IPPA.

UNLABELLED: Chylothorax can occur secondary to traumatic lesions of the thoracic duct caused by chest injuries, surgical procedures involving the pleural space, neoplasms or malformations of the lymphatics. METHODS: Lymphatic leakage sites were localized by scintigraphy after oral administration of the 123I-labeled long-chain fatty acid derivative iodophenyl pentadecanoic acid (IPPA). We report on three patients with different lymphatic leakage sites and on one normal control subject. RESULTS: IPPA scintigraphy localized the lymphatic leakage site correctly in all three patients. In two of them, the method even guided the successful surgical treatment of the leakage. CONCLUSION: This approach is suitable for detecting lymphatic leakages of intestinal origin.

Somatostatin receptor scintigraphy in the staging of lymphomas.

In this prospective study we evaluated the somatostatin receptor scintigraphy in the initial staging of 19 patients suffering from Hodgkin's (HD) and non-Hodgkin's lymphomas (NHL) and in the restaging of 16 patients. Scintigraphy was compared to the results of the methods applied for adequate staging of lymphoma patients in the large multicentre trials. Planar imaging and SPECT was performed after intravenous injection of 110 or 220 MBq of 111In-pentetreotide. The patient-based analysis yielded an overall sensitivity of 88%, contrasting lesion-based sensitivities of 57%, 35%, and 43% in HD, low-grade NHL and high-grade NHL, respectively. The best results were obtained in the head-and-neck region and the worst in the abdomen (sensitivities of 61% and 24%, respectively). Bone marrow infiltration was visible in 1/12 cases only. There was no significant difference between the outcomes of patients in the initial staging and restaging and no influence of the amount of injected radiopharmaceutical on the results. In terms of the Ann-Arbor classification, 10/35 patients were concordant whereas 22 were understaged and 3 overstaged scintigraphically. In conclusion, somatostatin receptor scintigraphy is not useful in the initial staging or restaging of malignant lymphomas, especially NHL, due to low lesion detection rates most probably because of low receptor densities. In addition, intraindividual heterogeneity of somatostatin receptor expression has to be considered.

[Radioiodine therapy of funcitonal autonomy using the functional autonomous volume]. / Radiojodtherapie der funktionellen Autonomie unter Verwendung des funktionellen autonomen Volumens.

In order to determine the effective radiation dose to be delivered by 131I in functional autonomy we have used the functional autonomous volume calculated from the global 99mTc thyroid uptake under exogenous or endogenous suppression before and 3 to 7 months after treatment. The radiation dose to the autonomous volume was calculated retrospectively in 131 patients with unifocal, multifocal and disseminated autonomy (75 hyperthyroid, 56 euthyroid) who received 131I treatment of 200-300 Gy to the total volume of the gland. It could be shown that at least 350 Gy to the autonomous volume are required to reach the desired effect of treatment which was dependent only on the radiation dose delivered to the functional autonomous volume.

Falsely negative 99mTc-antigranulocyte immunoscintigraphy and positive 99mTc-HMPAO-labelled leukocyte scan in active Crohn's disease. Possible effects of immunosuppressive therapy?

A 19-year-old woman with active Crohn's disease under immunosuppressive therapy underwent scintigraphy with 99mTc-anti-NCA-95 antigranulocyte antibodies in order to determine the extent of inflammation. It turned out to be falsely negative whereas a 99mTc-HMPAO-labelled leukocyte scan revealed a marked terminal ileitis and pancolitis. It is assumed that immunosuppressive therapy was the main reason for the falsely negative antibody scan, possibly affecting the red bone marrow where most of the antibodies bind to granulocytes. Peripheral leukocytes labelled in vitro do not seem to be subject to these hypothetical effects on red bone marrow.

Immunoscintigraphy for the detection of brain abscesses.

The aim of this prospective study was to assess the diagnostic usefulness of a 99Tcm-anti-granulocyte antibody in the early differentiation of the aetiology of a ring-enhancing structure on computed tomography (CT) scans following neurosurgical intervention. In 26 patients (15 males, 11 females) aged 20-82 years with suspected intracranial infection, 29 SPET scans of the head were obtained 4-6 h following the intravenous injection of 555 MBq 99Tcm-anti-granulocyte antibody. The patients had antibiotic, antimycotic or corticosteroid therapy. The diagnosis was confirmed by surgery (19 cases) or subsequent CT/MRI (magnetic resonance imaging) scans and clinical follow-up (10 cases). The immunoscan was true-positive (abscess) in 6 (sensitivity = 100%), true-negative in 19 and false-positive in 4 (specificity 83%) cases. There was no obvious detrimental effect on the results due to the antibiotic, antimycotic or corticosteroid therapy. In conclusion, despite false-positive results, the 99Tcm-anti-granulocyte antibody is a useful tool in the early detection and exclusion of intracranial abscess after neurosurgical interventions.