[Procedure guideline for sentinel lymph node diagnosis]. / Verfahrensanweisung für die nuklearmedizinische Wächter-Lymphknoten-Diagnostik.

The authors present a procedure guideline for scintigraphic detection of sentinel lymph nodes in malignant melanoma and other skin tumours, in breast cancer, in head and neck cancer, and in prostate and penile carcinoma. Important goals of sentinel lymph node scintigraphy comprise reduction of the extent of surgery, lower postoperative morbidity and optimization of histopathological examination focussing on relevant lymph nodes. Sentinel lymph node scintigraphy itself does not diagnose tumorous lymph node involvement and is not indicated when lymph node metastases have been definitely diagnosed before sentinel lymph node scintigraphy. Procedures are compiled with the aim to reliably localise sentinel lymph nodes with a high detection rate typically in early tumour stages. Radiation exposure is low so that pregnancy is not a contraindication for sentinel lymph node scintigraphy. Even with high volumes of scintigraphic sentinel lymph node procedures surgeons, theatre staff and pathologists receive a radiation exposure <1 mSv/year so that they do not require occupational radiation surveillance.

Lithium as an adjunct to radioiodine therapy in Graves' disease for prolonging the intrathyroidal effective half-life of radioiodine. Useful or not?

AIM: Evaluation of intrathyroidal kinetics of radioiodine with and without lithium as adjunct with respect to the increase in radiation dose delivered to the thyroid. PATIENTS, METHODS: 267 patients in three groups were included in the study. Group I with 227 patients served as control group, Group II with 21 patients and Group III with 19 patients were distinguished by an intrathyroidal half-life of radioiodine below 3.5 days in the diagnostic test. Patients in Group III received 885 mg lithium carbonate a day for 2 weeks as adjunct to radioiodine therapy. Both diagnostic and therapeutic radioiodine kinetics were followed up by at least 10 uptake measurements within a minimum of 48 h. Kinetics of radioiodine were defined mathematically as balance of the thyroidal iodine intake and excretion by a two-compartment model. RESULTS: Under therapy the maximum uptake of radioiodine was reduced by nearly 10% in all groups, in Group I, the effective half-life as well as the product of maximum uptake x effective half-life as an equivalent of radiation dose independent of thyroid volume was lowered in the same magnitude. In Group II, the energy-dose equivalent remained constant under therapy. With adjunct lithium in Group III, the effective half-life was prolonged significantly by factor 1.61 +/- 0.49 and the volume-independent energy-dose equivalent by factor 1.39 +/- 0.37. No severe side effects of lithium were observed. CONCLUSION: Using lithium as adjunct to radioiodine therapy increases the radiation dose delivered to the thyroid by 39% on average and nearly 30% of radioiodine activity can be saved in these patients. Lithium is recommended in patients with very short effective half-life in the diagnostic test in order to reduce the activity required and whole-body radiation dose.

[Results of a risk adapted and functional radioiodine therapy in Graves' disease]. / Ergebnisse einer risikoadaptierten und funktionsorientierten Radioiodtherapie bei Morbus Basedow.

UNLABELLED: Aim of this study was to find out, if results of a functional orientated radioiodine therapy in Graves' disease could be optimized using a risk adopted dose concept. PATIENTS, METHOD: 351 patients with Graves' disease were treated for the first time between 11/97 and 8/01. The basic dose was 125 Gy, which was increased up to 250 Gy in a cumulative manner depending on clinical parameters (initial thyroid metabolism, thyroid volume, immunoreactivity). Two different methods of dosimetry were used. Occasional thyreostasis was withdrawn two days before the radioiodine test was started. Follow up was done on average 8 +/- 2.4 (4-17.2) months. TSH > or = 0.27 microIU/mL confirmed as a measure of the success. RESULTS: With improved pretherapeutic dosimetry and a mean target dose of 178 +/- 31 Gy (n=72) therapeutic success occurred in 66.7%, in 51.4% euthyreosis was restalled and in 15.3% of patients hypothyroidism was seen (TSH > 4.20 microIU/mL). With simplified pretherapeutic dosimetry and a mean target dose of 172 +/- 29 Gy (n=279) results were moderately impaired (63.8%, 40.1% and 23.7%). With increasing target dose therapeutic failure increased, as insufficiently adopted risk factors for therapeutic failure turned out the initial thyroid metabolism, the TcTU(s) as the (h)TRAb titer. CONCLUSION: Functional orientated RIT can be optimized by including illness specific characteristics, principal limitations are a high initial thyroid metabolism, a large thyroid volume and a high (h)TRAb-titer.

V/Q-scanning/SPECT for the diagnosis of pulmonary embolism.

Pulmonary embolism (PE) is visualized indirectly by perfusion (Q) scanning as a parenchymal defect related to the embolized artery, and is confirmed by combined ventilation (V) scanning, showing a normal regional ventilation. Based on its principle of detection, V/Q scanning is able to show even small emboli and this ability is enhanced by SPECT. Compared to angiography, V/Q scanning seems to be burdened with low specificity, whereas its sensitivity is sufficiently high. Correlation of V/Q scanning with single-slice CT is comparable with that with angiography. The positive predictive value of V/Q scanning cannot be assessed by the reference standard angiography or by single-slice CT because both have turned out to be inadequate. Correlation of V/Q scanning with high-resolution CT is very promising, revealing high sensitivity as well as specificity of V/Q scanning, but this needs further evaluation in larger studies. Nevertheless, the use of V/Q scanning as a one-step diagnostic approach to PE is unrestricted in patients with normal chest radiograph, whereas V/Q scanning in combination with spiral CT is recommended in patients with abnormal chest radiograph. The negative predictive value of V/Q scanning for recurrent PE is unsurpassed high and by this, V/Q scanning tends to be used primarily to exclude rather than confirm PE.

[Nuclear medicine diagnosis of the lung]. / Nuklearmedizinische Diagnostik der Lunge.

Scintigraphic recording of regional ventilation and perfusion with 99mTc-Aerosol and 99mTc-MAA remain in the foreground of nuclear medicine pulmonary diagnostics. The most important indication for ventilation scintigraphy is the prediction of postoperative pulmonary function, which is still performed in many hospitals with perfusion scintigraphy, and with which, in turn, intrapulmonary right-left shunts can be simply and also semiquantitatively recorded. Combined ventilation/perfusion scintigraphy offers a very high degree of sensitivity in the proof of acute pulmonary embolism, is therefore exceptionally well suited for exclusion diagnostics, while specificity compared to pulmonary angiography and spiral CT still needs some clarification. The self-cleaning mechanism of the lung can be quantitatively examined using mucociliary and resorptive clearance. The clinical areas of application are limited for methodical reasons. Primary diagnostics of bronchial carcinoma and dignity differentiation of solitary pulmonary nodules, preferably with 18F-FDG PET are gaining steadily in importance.

[Detection of atypical site of "sentinel lymph nodes" by lymph drainage scintigraphy in patients with breast carcinoma]. / Nachweis atypisch lokalisierter "Wächterlymphknoten" durch Lymphabstromszintigraphie bei Patientinnen mit Mammakarzinom.

OBJECTIVE: Sentinel lymph node (SLN) localization in breast cancer allows biopsy of directly tumor drained lymph nodes. The objective was to study the association of tumor and SLN localization. PATIENTS AND METHODS: SLN was identified in 39 (81%) of 48 patients with histologically proven breast cancer, clinically and sonographically unsuspected axillary lymph nodes after peritumoral application of 40-50 Mbq 99mTc-Nanocolloid. Patients age, tumor size and localization, histology and localization of the SLN as well as removed axillary lymph nodes were analyzed. RESULTS: Axillary lymph node metastases were found in 11 (28%) of 39 patients. Involvement of the SLN was confirmed by intraoperative frozen sections (n = 9) and paraffin embedded histology (n = 1). One (9%) patient with a positive node revealed a false-negative SLN. In 24 patients with a tumor in the lateral hemisphere of the breast the SLN were identified in the ipsilateral axilla. In 6 (40%) of 15 patients with a central or medial localized tumor the SLN was observed infraclavicular (n = 3), parasternal (n = 2) or in the contralateral axilla (n = 1). In the latter one the SLN of the contralateral axilla showed metastases, whereas the simultaneous SLN and all removed lymph nodes of the ipsilateral axilla were not involved. More than one SLN were found in 12 (31%) of the 39 cases. CONCLUSION: A correlation between tumor localization and localization of the SLN is suggested, but the lymph drainage seems more variable in cases of medial tumor size. Using blue dye for map of extraaxillary SLN seems inappropriate. Currently the diagnostic and therapeutic impact of the detection of extraaxillary SLN is still unclear.

[Results of TcTUs-optimized radioiodine therapy in multifocal and disseminated autonomy]. / Ergebnisse der TcTUs-optimierten Radioiodtherapie bei multifokaler und disseminierter Autonomie.

AIM: The presented study prospectively evaluates the efficacy of optimized radioiodine therapy in patients (pts) with multifocal (MFA) and disseminated (DISA) autonomy. The target dose was related to the total thyroid volume and was increased in moderate and nonlinear increments from 150 to 300 Gy dependent on the pretherapeutic Tc-99m pertechnetate thyroid uptake under suppression (TcTUs). Patients with focal autonomy were treated with a target dose independent of TcTUs and were used as control group. METHODS: The data of 641 pts (518 women, 123 men) were evaluated, 466 pts with MFA or DISA and 175 pts with focal autonomy. In pts with MFA and DISA the target dose was increased in four steps: TcTUs < 3%: 150 Gy, > 3-6%: 200 Gy, > 6-12%: 250 Gy and > 12%: 300 Gy. In pts with focal autonomy a fixed target dose of 300 or 400 Gy was applied. The radioactivity to be administered was calculated using a modified Marinelli formula. The follow-up examination was performed at the earliest after four, on average after eight months. Normalization of TSH was the only criterion for successful therapy. RESULTS: The success rate in pts with latent or manifest hyperthyroidism in focal autonomy was 91.5%, therapy was not successful in 5.1% and hypothyroidism occurred in 3.4%. The average success rate in pts with MFA and DISA was 91.5%, therapy failed in 7.5% and a very low rate of 1% with hypothyroidism was seen. CONCLUSION: The presented optimized therapy concept with calculated, nonlinear increase of the target dose according to the TcTUs-level guaranteed even in MFA and DISA a high success rate comparable to that in focal autonomy along with a very low rate of hypothyroidism.

[Paradoxical effect of radioiodine therapy in functional thyroid autonomy and mild immunothyropathy]. / Paradoxe Effekte der Radiojodtherapie bei funktioneller Schilddrusenautonomie und milder Immunthyreopathie.

AIM: To examine all cases with Graves' disease after radioiodine therapy of autonomously functioning thyroid tissue (AFFT) in order to find the cause. METHODS: We retrospectively studied 1428 pts who were treated between 11/93 and 3/97 with radioiodine for AFTT and who underwent at least one control examination. RESULTS: 15 (1.1%) of all pts developed Graves' disease 8.4 (4-13) months after radioiodine therapy. There was no direct suggestion of Graves' disease (TRAK negative, no endocrine ophthalmopathy) in any pt at the time of radioiodine therapy. More detailed analysis of anamnestic data, however, revealed evidence that immunothyropathy predated radioiodine therapy in 11 of the 15 pts. Paradoxical effects of radioiodine therapy manifested as an increase in immunothyropathy in 14 pts, a deterioration in metabolism in 11 pts and a first occurrence of endocrine ophthalmopathy in 5 pts. CONCLUSION: Exacerbation of preexisting, functional primarily insignificant immunothyropathia is held responsible in most cases for the observed paradoxical effects after radioiodine therapy, resulting in radiation-induced manifest Graves' disease; however no therapeutical consequences are recommended.

Combined thallium 201/technetium 99m-labeled pyrophosphate tomography for identification of the "culprit" vessel in acute myocardial infarction.

BACKGROUND: Many previous investigations have used the presence of transient ischemic 201Tl perfusion defect to localize coronary artery stenosis. This study reports the results of 201Tl tomography alone and combined 201Tl/99mTc-labeled pyrophosphate (99mTc PYP) tomography employed to identify the infarct-related vessel in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: All short-axis images were evaluated by dividing each left ventricular slice into eight equal sectors. In addition, for combined 201Tl/99mTc PYP tomography, two sectors were added to evaluate involvement of the right ventricle. In a preevaluation phase of the study, the sectors were assigned to the supplying coronary arteries in 75 patients with single chronic myocardial infarction related to the left anterior descending coronary artery (LAD), left circumflex artery (LCX), or right coronary artery (RCA). In this pilot phase, 201Tl tomograms were reviewed in conjunction with the angiographic data. This assignment was then tested prospectively in 117 patients with AMI. As confirmed by angiography, the AMI was related to the LAC, LCX, and RCA in 54, 17, and 46 patients, respectively. Sensitivity and specificity for 99mTc PYP accumulation on combined 201Tl/99mTc PYP tomography were 98% a nd 100% for the LAD, 88% and 99% for the LCX, and 98% and 96% for the RCA, respectively. For 201Tl tomography, sensitivity and specificity for identification of the culprit vessel were 94% and 89% for the LAD, 82% and 91% for the LCX, and 72% and 96% for the RCA, respectively. CONCLUSION: This prospective study demonstrates that combined 201Tl/99mTc PYP tomography is highly accurate for identification of the infarct-related artery in AMI, even in patients with multivessel disease. Positive contrast visualization of myocardial necrosis in both the left and right ventricle allows for reliable differentiation between AMI related to the LCX or RCA territory. In comparison, for 201Tl tomography the sensitivity to detect the culprit vessel, particularly the LCX and RCA, appears to be lower than for 201Tl 99mTc PYP imaging, particularly in patients with prior infarction or right dominant coronary artery.

Assessment of acute myocardial necrosis after cardiopulmonary resuscitation and cardioversion by means of combined thallium-201/technetium-99m pyrophosphate tomography.

Diagnosis of acute myocardial necrosis by means of conventional electrocardiographic criteria or the release of cardiac enzymes is often difficult or even impossible in patients with out-of-hospital cardiac arrest due to ventricular fibrillation with subsequent cardiopulmonary resuscitation including several DC countershocks. Simultaneous thallium-201/technetium-99m pyrophosphate (PYP) tomography was prospectively applied to 57 patients without typical clinical or electrocardiographic signs of acute myocardial infarction within 48 h after successful resuscitation from out-of-hospital cardiac arrest. Scintigraphic evidence of acute necrosis was present in 23/57 patients (40%). Increased 99mTc-PYP uptake in the pericardial tissue was found in 24 patients (42%). Maximal creatine kinase (CK) concentration was increased in 50/57 patients (88%). CK-MB activity averaged 68+/-52 U/l in patients with positive and 17+/-13 U/l in patients with negative tomograms (P<0.0005), demonstrating the validity of 201Tl/99mTc-PYP tomography. It may be concluded that simultaneous 201Tl/99mTc-PYP tomography is a valuable tool for evaluation of myocardial necrosis after cardiopulmonary resuscitation including DC countershock. Acute myocardial necrosis, as indicated by scintigraphy, represents a potential trigger for the occurrence of ventricular fibrillation. Therefore, 201Tl/99mTc-PYP tomography can be recommended in order to guide further diagnostic and therapeutic interventions in patients after cardiopulmonary resuscitation in whom the underlying cause of the occurrence of ventricular fibrillation is obscure.

Improved dose concept for radioiodine therapy of multifocal and disseminated functional thyroid autonomy.

The present study analyzes the improvement of the outcome of radioidine therapy in non-immunogenic hyperthyroidism by adapting the target dose to the 99mTc-pertechnetate thyroid uptake under suppression (TcTUs) prior to radioiodine therapy. The TcTUs is a substitute for the non-suppressible iodine turnover. The 89 patients presented with a basal thyrotropin level of < 0.1 mU/l, normal values for free triiodothyronine and thyroxine and with multifocal or disseminated thyroid autonomy. These terms describe the scintigraphic distribution pattern of autonomous iodine turnover. Thirty-two patients had a TcTUs between 1.6 and 3.2% (group A) and 57 had a TcTUs > 3.2% (group B). Fifty-five patients (three of group A and 52 of group B) were treated previously for overt hyperthyroidism with antithyroid drugs. Target doses of 150 and 200 Gy were used in both groups and 300 Gy in group B only. Six months after radioiodine therapy, a basal TSH level of > or = 0.5 mU/l as criterion of therapy success was observed in 94% of group A and in 54% of group B. Further differentiation of group B shows an increasing success rate with the target dose used: 45% after 150 Gy, 50% after 200 Gy and 90% after 300 Gy. In patients with a basal TSH level of < 0.5 mU/l after radioiodine therapy, the TcTUs was evaluated again.(ABSTRACT TRUNCATED AT 250 WORDS)

[Assessment of basal and stimulated TSH in overt and subclinical hyperthyroidism]. / Wertigkeit des basalen und stimulierten TSH bei manifester und subklinischer Hyperthyreose.

A TRH test was performed in 171 consecutive patients with a TSHbasal below the reference range. TSHbasal, TSHstimulated and delta TSH were determined and compared, using assays of the second and third generation. Free thyroid hormones were elevated in 48 and normal in 123 patients. The sensitivity of all evaluated parameters to assess overt hyperthyroidism was between 94 and 98% with both assays, using a defined TSH threshold (mean of patients with overt hyperthyroidism +2 standard deviations). However, specificity was much lower, only 34 and 23%, respectively, for the TSHbasal. Significant improvement followed TRH-testing: specificity rose to 63 and 57%. The superior reproducibility of TSH values in the lower range, using the third generation assays, was of little value in the differentiation between subclinical and overt hyperthyroidism.

[Thyrotoxic crisis after exposure to iodine. A case with fatal outcome]. / Thyreotoxische Krise nach Jodexposition. Ein Fall mit letalem Ausgang.

A 78-year-old woman is presented with a multinodular toxic goiter and euthyroidism under continuous low-dose treatment with antithyroid drugs. A period of hyperthyroidism had been documented 3 years previously. In the preoperative management, prior to resection of a benign ovarian tumour, an intravenous urogram was performed. Perchlorate was given for thyroid protection. One day after surgery the clinical signs of thyroid storm were observed. Immediately, high-dose antithyroid drug therapy was started. Nevertheless, the patient died of acute cardiovascular failure 3 days later. This case report focuses on the risk of thyroid storm following iodine excess in the presence of relevant functional thyroid autonomy without adequate thyroid protection.

Comparison in acute myocardial infarction of anisoylated plasminogen streptokinase activator complex versus heparin evaluated by simultaneous thallium-201/technetium-99m pyrophosphate tomography.

In a subgroup of 45 patients with acute myocardial infarction (AMI) from the German multicenter trial of anisoylated plasminogen streptokinase activator complex (APSAC) (n = 20) versus heparin (n = 25), simultaneous thallium (TI)-201 technetium (Tc)-99m pyrophosphate (PYP) tomography was initiated to elucidate a possible benefit of APSAC over heparin. Findings in the 2 treatment groups were similar with respect to TI-201 defect score, relative scintigraphic infarct size, and in keeping with the main group coronary artery patency, global ejection fraction and maximal creatine kinase level. However, 2 different TI-201/Tc-99m PYP accumulation patterns within the area of infarction (homogeneous, group A; inhomogeneous, group B) were identified. Both treatment groups were similar with regard to the frequency of the homogeneous and inhomogeneous pattern. In comparing the 2 accumulation patterns, creatine kinase peaked earlier in group A than in group B, and global left ventricular ejection fraction was significantly higher in group A than in group B. In Group A, 30 of 31 patients and in group B 7 of 11 patients had a patent infarct-related vessel (p < 0.025). TI-201 defect score was lower in group A than in group B. Likewise, relative size of the infarction as determined from Tc-99m PYP images was significantly lower in group A than in group B. Fifteen patients experienced cardiogenic shock or severe heart failure. Patients in group B had a higher incidence of these in-hospital complications than patients in group A (92 vs 12%, p < 0.0005). Scintigraphic infarct size and TI-201 defect score were greater in patients with the aforementioned clinical events.(ABSTRACT TRUNCATED AT 250 WORDS)