[Procedural guideline for Iodine-131 whole-body scintigraphy in differentiated thyroid carcinoma (version 5)]

Version 5 of the procedural guideline for Iodine-131 whole-body scintigraphy (WBS) in differentiated thyroid carcinoma is an update of the version 4, published by the "Deutsche Gesellschaft für Nuklearmedizin" (DGN). This procedural guideline advises on how to best perform I-131 whole body scintigraphy after I-131 therapy or after application of a diagnostic I-131 activity. A representative expert group has discussed and reached consensus on the procedural guideline; the development of this procedural guideline therefore fulfils the criteria for level S1 (first step) within the classification of the German Workgroup of Scientific Medical Societies ("Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften"; AWMF).

Thyroid stunning in radioiodine-131 therapy of benign thyroid diseases

PURPOSE

Existence and cause of thyroid stunning was controversially discussed for decades but the underlying mechanism remains unclear. Numerous studies describe thyroid stunning in radioiodine-131 therapy (RIT) of differentiated thyroid carcinoma. However, there are no studies evaluating thyroid stunning in benign thyroid diseases caused by the radioiodine uptake test (RIUT). Therefore, the influence of pre-therapeutic tracer radiation dose on therapeutic iodine-131 uptake was evaluated retrospectively.

METHODS

A total of 914 RIT patients were included. Exclusion criteria were anti-thyroid drugs, pre- and/or intra-therapeutic effective half-lives (EHL) beyond 8.04 days and externally performed RIUT or 24 h RIUT. All patients received RIUT 1 week before RIT. Thyroid volume was estimated via ultrasound. Tracer radiation dose to the thyroid was calculated retrospectively. The dependence of changes in the pre-therapeutic to the therapeutic extrapolated-maximum-¹³¹I-uptake (EMU) from the dose in RIUT was evaluated statistically.

RESULTS

EMU in RIUT ranged from 0.10 to 0.82 (median: 0.35) and EMU in RIT ranged from 0.10 to 0.74 (median: 0.33). Averaged over the whole cohort the therapeutic EMU decreased significantly (2.3% per Gray intra-thyroidal tracer radiation dose). A disease-specific evaluation showed dose-dependent thyroid stunning from 1.2% per Gray in solitary toxic nodules (n = 327) to 21% per Gray in goiters (n = 135) which was significant for the subgroups of disseminated autonomies (n = 114), multifocal autonomies (n = 178) and goiters (p < 0.05) but not for Graves' diseases (n = 160) and solitary toxic nodules (p > 0.05).

CONCLUSIONS

The presented data indicate for the first time a significant dependence of pre-therapeutic radiation dose on thyroid stunning in goiter and disseminated and multifocal autonomy. To achieve the desired intra-thyroidal radiation dose, RIT activity should be adapted depending on the dose in RIUT.

[Dopamine Transporter SPECT with I-123 labelled FP-CIT (DaTSCANTM)]

The aim of the S1 guideline is to assist in establishing the indication and in performing, interpreting and reporting SPECT investigations of the dopamine transporter (DAT) with DaTSCAN^TM. Compared to the preceding version dated from 2007 the current update considers relevant new publications, the guidelines of the European (EANM) and Society of Nuclear Medicine (SNM), and the current version of the S3 guideline of the German Society of Neurology on "Idiopathic Parkinsonsian Syndrome". In addition new technical developments are incorporated.

The value of different 18F-FDG PET/CT baseline parameters in risk stratification of stage I surgical NSCLC patients

OBJECTIVE

Administration of postoperative chemotherapy to patients with completely resected stage I NSCLC is still a matter of debate. The aim of the present study was to evaluate the value of different baseline ¹⁸F-FDG PET parameters in identifying surgical stage I NSCLC patients who are at high risk of recurrence, and thus are indicated for further postoperative treatment.

METHODS

This is a retrospective study, which included 49 patients (28 males, 21 females) with the median age of 69 years (range 28-84), who had pathologically proven stage I NSCLC. All patients underwent ¹⁸F-FDG PET/CT at baseline followed by complete surgical resection of the tumor (R0). Baseline SUV_max, MTV and TLG were measured. Patients' follow-up records were retrospectively reviewed, and DFS (disease-free survival) was assessed. For each parameter, the most accurate cut-off value for the prediction of recurrence was calculated using the ROC curve analysis and the Youden index. DFS was evaluated for patients above and below the calculated cut-off value using the Kaplan-Meier method and the difference in survival between the two groups was estimated using the log-rank test.

RESULTS

Median observation time of the patients after surgery was 28.7 months (range 3.5-58.8 months). 9 patients developed recurrence. The calculated cut-off values for SUV_max, MTV and TLG were 6, 6.6 and 33.6, respectively. Using these cut-offs, the observed sensitivity for SUV_max, MTV and TLG for prediction of recurrence was 100%, 89% and 89%, respectively, while the observed specificity was 43%, 73% and 65%, respectively. The difference in survival between patients below and above the cut-off value was statistically significant in all three studied parameters. The highest AUC was observed for MTV (AUC = 0.825, p = 0.003), followed by TLG (AUC = 0.789, p = 0.007), and lastly SUV_max (AUC = 0.719, p = 0.041). ROC curve analysis showed that volumetric parameters had better predictive performance than SUV_max as regards recurrence.

CONCLUSION

PET-derived parameters at baseline were predictive of recurrence in stage I surgical NSCLC patients. Moreover, the metabolic volume of the tumor was the most significant parameter for this purpose among the studied indices.

Iod-131-Ganzkörperszintigraphie beim differenzierten Schilddrüsenkarzinom

Die Version 4 der Verfahrensanweisung für die Iod-131-Ganzkörperszintigraphie beim differenzierten Schilddrüsenkarzinom ist ein Update der Version 3, die im Jahr 2007 durch die Deutsche Gesellschaft für Nuklearmedizin (DGN) und die Deutsche Gesellschaft für Medizinische Physik (DGMP) publiziert wurde. Diese Verfahrensanweisung beschreibt mit primärer Zielsetzung die fachgerechte Durchführung der Ganzkörperszintigraphie nach Applikation einer diagnostischen bzw. therapeutischen I-131-Aktivität. Die aktualisierten Indikationen zur I-131-Ganzkörperszintigraphie werden in der Verfahrensanweisung aufgelistet. Neue Erkenntnisse bezüglich der Beziehung zwischen verabreichter Aktivität und Bildqualität wurden in der aktualisierten Verfahrungsanweisung berücksichtigt. Die Verfahrensanweisung wurde von einer repräsentativen Expertengruppe im Konsensverfahren verabschiedet. Sie entspricht damit einer Verfahrensanweisung der ersten Stufe (S1) nach den Kriterien der Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF). Zusätzlich wurden Indikationsstellung, Zeitpunkt und Aktivitätswahl für die diagnostische Ganzkörperszintigraphie im erweiterten Kollegenkreis am 30. November 2012, am 19. April 2013 und am 23. April 2015 bei Tagungen der Arbeitsgemeinschaft Schilddrüse der Deutschen Gesellschaft für Nuklearmedizin ausführlich diskutiert.

Comparison of Mono- and Bipolar Radiofrequency Ablation in Benign Thyroid Disease

PURPOSE

Radiofrequency ablation (RFA) is an approved minimal invasive method for the treatment of benign thyroid nodules. Several experimental, mainly ex vivo animal studies have compared the effectiveness of different RFA procedures in liver tissue. The aim of this retrospective clinical study was to evaluate the difference between monopolar and bipolar RFA in thyroid tissue considering thyroid volume reduction, patient discomfort and ultrasound evaluation.

METHODS

Eighteen patients with symptomatic complex benign thyroid nodules were treated in a single RFA session. Nine patients were treated with monopolar RFA, and nine other patients were treated with bipolar RFA. All patients underwent assessments before therapy and at 3-month follow-up (3MFU) including a complete hormone status (T3, T4, TSH, TG, TPOAb, TgAb, TRAb) and several ultrasound (US) evaluations using B-mode and color-coded Doppler imaging. The US evaluations contained measurement of volume, US Doppler, US echogenicity and US elastography. Additionally, applied energy (kJ), power output (W), number of shots (N) and total treatment time (s) were recorded in every case.

RESULTS

Monopolar RFA resulted in a significant (p < 0.05) average thyroid volume reduction of Ø 18 ± 77 ml (25.1 ± 103%) and a nodule volume reduction of Ø 10.6 ± 22 ml (60.3 ± 62%). Bipolar RFA resulted in a significant (p < 0.05) average thyroid volume reduction of Ø 21.2 ± 54 ml (43.2 ± 84%) and a nodule volume reduction of Ø 13.8 ± 33 ml (70.8 ± 46%). Both groups showed equal results concerning volume reduction (p > 0.05). Monopolar RFA did not lead to any significant changes concerning the US scores, whereas bipolar RFA led to a significant (p < 0.05) reduction in US Doppler and nodular blood flow. No significant difference between both groups could be found concerning applied energy, treatment time, power output and number of shots (p > 0.05).

CONCLUSION

Bipolar RFA did not show any disadvantages in comparison with monopolar RFA in the treatment of benign thyroid nodules. It shows better performance in terms of volume reduction and is superior when it comes to feasibility and patient discomfort. The recent study confirms the good ex vivo results for bipolar RFA.

[Influence of glucocorticoid therapy on intratherapeutic biodistribution of 131I radioiodine therapy in Graves' disease]

AIM

Radioiodine therapy (RIT) is an important therapeutic method in the definitive treatment of Graves' disease (GD). However, RIT may trigger development of Graves' ophthalmopathy (GO) or exacerbate a pre-existing GO. Therefore, the procedure recommendation of the DGN (German Society of Nuclear Medicine) for RIT of benign thyroid diseases recommends an additional glucocorticoid therapy for patients with pre-existing GO. Aim of this study was to analyze the influence of a protective glucocorticoid therapy on ¹³¹I biokinetics during RIT of patients with GD.

MATERIAL AND METHODS

In this retrospective analysis 211 patients with GD who underwent RIT without additional thyreostatic medication were examined. To analyze ¹³¹I biokinetics the extrapolated maximum uptake (EMU) and the effective half-life of ¹³¹I in the thyroid were determined. Patients suffering from GO received glucocorticoids according to a fixed scheme starting one day prior to RIT, patients without GO did not receive glucocorticoids. Subsequently the ratios of values measured during RIT and those measured during radioactive iodine uptake test were compared among the groups. To take into account other factors, the groups were also compared regarding age, weight, TSH, TRAb, TgAb and TPOAb.

RESULTS

In patients with additional glucocorticoid therapy, a reduction of the median EMU from 44 % in radioiodine uptake test to 35 % during RIT was observed. The pretherapeutic (47 %) and intratherapeutic (46 %) EMU of the control group without glucocorticoids remained constant. Comparison of the change in the EMU showed a statistically significant difference between both groups (p < 0.001). Comparison of all other parameters including the effective half-life of ¹³¹I (p = 0.79) did not show any statistically significant difference.

CONCLUSION

The present study suggests that glucocorticoids affect the biokinetics of ¹³¹I by reducing its thyroidal uptake. As a result of this study, for patients without antithyroid medication undergoing glucocorticoid therapy, an adjustment of therapeutic ¹³¹I activity determined in radioiodine uptake test could be considered.

Vergleich von 201T1 und 99mTc-MIBI in der Nachsorge des differenzierten Schilddrüsenkarzinoms

12 patients with suspected recurrence of differentiated thyroid carcinoma following thyroidectomy, radioiodine therapy and, in some cases, external radiation therapy had 201T1 and 99mTc-MIBI scintigraphy. Except in one case, the findings concerning tumor localization and extension were identical. In all cases, locoregional lymph node metastases as well as osseous metastases were imaged by 201T1 and 99mTc-MIBI scintigraphy. MRI images obtained in all patients with suspected lymph node metastases revealed inoperable situations in 2 cases, whereas there was no correlation in patient with positive 201T1 and 99mTc-MIBI scintigraphy. In contrast, the sensitivity of the two methods was relatively low in the detection of pulmonary metastases which were imaged in 1 out of 3 patients only. Discrepancies between 201T1 and 99mTc-MIBI were observed in a case of axillary lymph node metastasis. Although tumor-/background ratios were slightly higher for 201T1, 99mTc-MIBI SPECT showed a higher imaging quality compared to 201T1 SPECT, especially in deeply situated tumor lesions. In conclusion, 99mTc-MIBI seems to be a promising alternative imaging agent in the follow-up of differentiated thyroid carcinomas.

HMPAO-SPECT bei zerebralen Anfällen

ln nine patients with suspected psychogenic seizures and in three patients with proven epileptic seizures HMPAO-SPECT was performed prior to and during seizure. In the patients with lateron-proven psychogenic seizures no, or only slight, changes of regional cerebral blood flow were found. Patients with proven epilepsy revealed partly normal findings interictally but during seizure a markedly increased circumscript blood flow was found in all patients. Even though PET is superior to SPECT with respect to spatial resolution, in the diagnosis of seizures HMPAO-SPECT has the advantage of enabling injection of the tracer during the seizure and the performance of the SPECT study subsequently.

SPECT bei reversibler Symptomatik zerebrovaskulärer Erkrankungen

ln 16 patients with reversible symptoms of cerebrovascular disease a HMPAO- and/or IMP-SPECT was performed. 12 of these patients were suffering from TIA, 4 from PRIND. Using HMPAO-SPECT in 8 out of 9 patients with TIA and in 1 of 2 with PRIND a hypoperfusion could be demonstrated; IMP-SPECT showed a pathological pattern in 3 of 5 patients with TIA and in none of 2 patients with PRIND. A semiquantitative evaluation showed a tracer accumulation reduced by 13 ± 12% (HMPAO) and 8 ± 7% (IMP), respectively, in the clinically involved hemisphere, compared to the contralateral side. In circumscript SPECT lesions a reduction by 21 ± 8% (HMPAO) or 17 ± 7% (IMP) was observed. The interhemispheric ratio from the HMPAO-SPECT showed a significant correlation to that of the 133Xe-rCBF measurement (r = 0.86; p <0.001). SPECT was positive in a higher percentage than TCT, Doppler sonography, radioangiography and 133Xe-rCBF measurement. This does not imply a higher specificity or sensitivity, because a slight inhomogenic SPECT pattern may occasionally be observed even in normal persons.

Erhöhte Sensitivität der Ganzkörperszintigraphie mit 131J für den Nachweis jodspeichernder Metastasen durch spätere Aufnahme-Zeitpunkte

In the follow-up of thyroid cancer patients we sometimes observed discrepancies between elevated thyroglobulin levels and negative results of post- therapeutic or diagnostic scans 48 h and 72 h after oral application of131I routinely. Consequently, delayed 131I scans (96 h and later) were performed in addition. In all cases, delayed 131I scans either showed a higher imaging quality or additional metastatic lesions. Thus, posttherapeutic (and diagnostic) scans should include late images (4 d and later).

Evaluation of Cerebral Vasoreactivity by SPECT and Transcranial Doppler Sonography using the Acetazolamide Test

Bei 29 Patienten (3 Kontrollpersonen, 26 Patienten mit zerebrovaskulärer Erkrankung) wurde prospektiv die Hirn-SPECT mit 99mTC-HMPAO und bei 20 Patienten (3 Kontrollpersonen, 17 Patienten mit ZVK) die transkranielle Dopplersonographie (TCD) vor und nach i. v. Gabe von Azetazolamid durchgeführt. Die Sensitivität der Hirn-SPECT erhöhte sich mit Azetazolamid von 62% auf 77%. Bei Patienten mit reversiblem neurologischem Defizit wurde eine Verbesserung von 50% auf 71 %, bei Patienten mit persistierendem Defizit von 75% auf 83% beobachtet. Die Ergebnisse der Hirn-SPECT und der TCD stimmten in der Beurteilung der zerebro-vaskulären Reservekapazität in 91% der Hemisphären überein. Die Korrelation zwischen den beiden Methoden war statistisch signifikant.

Functional Imaging of Hodgkin’s Disease with FDG-PET and Gallium-67

We report a case of Hodgkin’s lymphoma (Stage I B) which was studied using Ga-67-scintigraphy as well as whole body FDG-PET. Ga-67-scintigraphy detected a slightly increased uptake in the paraaortic and pelvic lymph nodes. However, FDG-PET was able to localize a much larger number of affected foci with a high glucose utilization rate in the right and left paraaortal regions, in the middle of the epigastrium, in the right and left parailiacal regions and one focus in the left upper mediastinum. Our experiences give rise to the assumption that FDG-PET ist significantly superior to gallium scintigraphy in Hodgkin’s disease. Whole body FDG-PET can result in an upstaging of the patient and has therefore a major impact on the therapeutic management.

HMPAO-SPECT bei Demenz vom Alzheimer-Typ und Major Depression mit mnestischen Störungen

Ziel der vorliegenden Untersuchung war es, zu prüfen, ob die HMPAO-SPECT zur Differenzierung zwischen der Demenz vom Alzheimer-Typ (DAT) und der Major Depression (MD) beitragen kann. Es wurden ECT-Befunde von 77 Patienten mit Gedächtnisstörungen beurteilt, davon hatten 48 eine DAT und 29 eine MD. Zunächst wurden die Defekte in der SPECT einer Hirn-Region zugeordnet und der Grad der Ausprägung (-1/-2/-3) bewertet. Anschließend wurden die einzelnen Befunde in eine von 7 Befundkategorien eingeordnet. In einigen dieser 7 Gruppen ergaben sich deutliche Häufungen der Fälle mit DAT bzw. MD. 35% aller DAT-Patienten wiesen bilaterale Defekte mit deutlicher (>-1) parietaler/parietotemporaler Minderperfusion auf, dagegen zeigte kein Patient mit MD dieses Muster. Unilaterale Defekte wiesen 62% der MD-, aber nur 31% der DAT-Patienten auf. Die Untersuchung zeigt, daß nur 35% der Patienten mit DAT das bislang als »pathognomonisch« bezeichnete Befundmuster aufwiesen. Dieses Perfusionsmuster kann aber - wenn es vorliegt - als sicheres Kriterium zur Abgrenzung gegen eine MD gewertet werden. Darüber hinaus lassen sich keine eindeutigen (»krankheitstypischen«) Perfusionsmuster erkennen, wenngleich unilaterale Defekte mehr auf eine MD hindeuten.

99mTc-MAA-Anreicherung in der Leber bei cavo-portalem Shunt über eine rekanalisierte Vena umbilicalis

Bei der Lungenperfusionsszintigraphie einer Patientin mit Vena-cava-superior-Verschluß fand sich eine deutliche MAA-Anreicherung in Teilen der Leber. Als Ursache konnte ein Kollateralkreislauf über Venen der Abdominalwand und eine rekanalisierte Vena umbilicalis ermittelt werden. Unter externer Bestrahlung von Lymphomen des oberen Mediastinums kam es zu einem raschen Rückgang des cavo-portalen Shunt-Volumens.

Myocardial Uptake of Technetium-99m-Furifosmin (Q12) Versus Technetiiim-99m-Sestamibi (MIBI)

Aim: This study was performed to compare the myocardial uptake of Tc-99m-furifosmin (Q12) versus Tc-99m-sestamibi (MIBI) in correlation to the whole-body uptake under resting conditions. Methods: 21 patients with coronary artery disease and no rest ischemia were examined. A whole-body scan was performed 60 min. p.i. under resting conditions. A quantification of the uptake (whole-body, heart and right lung) was done by ROI technique. Results: The heart-to-lung ratio of Q12 (1.56 ± 0.191) was significantly lower as compared to MIBI (1.94 ± 0.197; p <0.01). In contrast, the heart-to-whole-body ratios (Q12 versus MIBI: 0.027 ± 0.012 versus 0.026 ± 0.004; p <0.76) did not differ. The lung-to-whole-body ratio (Q12 versus MIBI: 0.018 ± 0.009 versus 0.013 ± 0.002; p <0.17) were different, but did not reach significance. Conclusion: These data show that under resting conditions the total myocardial uptake of Q12 does not differ significantly from that of MIBI. However, the pulmonary uptake of Q12 is slightly higher, resulting in a significant lower heart-to-lung ratio. These findings imply a lower image quality of Q12 compared to MIBI.

Rolle der Positronen-Emissions-Tomographie (PET) und Single-Photon-Emissions-Tomographie (SPECT) bei der sogenannten »Multiple Chemical Sensitivity« (MCS)

Die funktionell bildgebenden Verfahren SPECT und PET werden zunehmend genutzt, um die Existenz eines Syndroms der erworbenen Chemikalienüberempfindlichkeit »Multiple Chemical Sensitivity« (MCS) nachzuweisen. In der Folge spielen SPECT und PET-Befunde auch im Rahmen von Gutachten bei Berufskrankheiten-Anzeigen als Beweismittel eine große Rolle. In der vorliegenden Arbeit wird die zu diesem Thema existierende Literatur einer kritischen Betrachtung unterzogen. Die Autoren kommen zu dem Schluß, daß die gegenwärtig verfügbaren Daten nicht ausreichen, um die Existenz eines solchen Syndroms nachzuweisen. Die niedrige Spezifität der beschriebenen Veränderungen macht es sehr schwierig, einen kausalen Zusammenhang zu der toxischen Exposition herzustellen, und schränkt den Wert von PET und vor allem SPECT bei gutachterlichen Fragestellungen in diesem Zusammenhang ein.

Clinical applications of single photon emission tomography in neuromedicine

This article gives in his second part a critical review of the clinical applications of SPECT with perfusion markers and receptor ligands in dementing disorders and psychosis. In addition this review discusses clinical applications of SPECT investigations with perfusion markers in inflammatory diseases of the central nervous system and in brain trauma.

Clinical applications of single photon emission tomography in neuromedicine

Single photon emission tomography is, because of its availability and the relatively low costs, the functional imaging modality currently most widely used for clinical applications in the brain. Beside the application of radiopharmaceuticals for the assessment of regional cerebral blood flow there is an increasing clinical use of more selective SPECT-radiopharmaceuticals, like amino acid analogs or receptor ligands. This article gives in his first part a critical review of the clinical applications of SPECT in neuro-oncology, epilepsy, basal ganglia disorders and cerebrovascular disease.

Verfahrensanweisung für die nuklear medizinische 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.