[Guideline for Radioiodine Therapy for Benign Thyroid Diseases (6/2022 - AWMF No. 031-003)]

This version of the guideline for radioiodine therapy of benign thyroid disorders is an update of the version, which was published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) in co-ordination with the German Society of Endocrinology (Deutsche Gesellschaft für Endokrinologie, DGE, Sektion Schilddrüse) and the German Society of General- and Visceral-Surgery (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie, DGAV) in 2015. This guideline was harmonized with the recommendations of the European Association of Nuclear Medicine (EANM). According to the German "Directive on Radiation Protection in Medicine" the physician specialised in nuclear medicine ("Fachkunde in der Therapie mit offenen radioaktiven Stoffen") is responsible for the justification to treat with radioiodine. Therefore, relevant medical indications for radioiodine therapy and alternative therapeutic options are discussed within the guideline. This procedure guideline is developed in the consensus of an expert group. This fulfils the level S1 (first step) within the German classification of Clinical Practice Guidelines.

Focus on radioiodine-131 biokinetics: the influence of methylprednisolone on intratherapeutic effective half-life of 131I during radioiodine therapy of Graves' disease

AIM

Radioiodine therapy (RIT) may trigger the development of Graves' ophthalmopathy (GO) or exacerbate pre-existing subclinical GO. Therefore, glucocorticoid administration is recommended for patients with pre-existing GO. Aim of this study was to analyze the influence of glucocorticoid therapy with methylprednisolone on intratherapeutic effective half-life (EHL) of radioiodine-131 in patients with Graves' disease (GD) as recent studies showed an effect for prednisolone.

METHODS

In a retrospective study, 264 patients with GD who underwent RIT without any additional antithyroid medication were evaluated. Intrathyroidal EHL was determined pre- and intratherapeutically. Patients with co-existing GO (n = 43) received methylprednisolone according to a fixed scheme starting 1 day prior to RIT, patients without GO (n = 221) did not receive any protective glucocorticoid medication. The ratios of EHL during RIT and during radioiodine uptake test (RIUT) were compared.

RESULTS

Patients receiving methylprednisolone showed a slight decrease of the mean EHL from 5.63 d (RIUT) to 5.39 d (RIT) (p > 0.05). A comparable result was obtained in patients without glucocorticoids (5.71 d (RIUT) to 5.47 d (RIT); p > 0.05). The ratios of the EHL between RIT and RIUT failed to show a significant difference between the two groups. EHL is therefore not significantly influenced by an additional protective treatment with methylprednisolone.

CONCLUSIONS

In the present study a decreased intrathyroidal EHL under glucocorticoid medication with methylprednisolone could not be detected. Therefore, co-medication with methylprednisolone in patients with GO may be preferred to avoid an intratherapeutic decrease of EHL by accompanying protective glucocorticoides.

Correction for hyperfunctioning radiation-induced stunning (CHRIS) in benign thyroid diseases

PURPOSE

Radioiodine-131 treatment has been a well-established therapy for benign thyroid diseases for more than 75 years. However, the physiological reasons of the so-called stunning phenomenon, defined as a reduced radioiodine uptake after previous diagnostic radioiodine administration, are still discussed controversially. In a recent study, a significant dependence of thyroid stunning on the pre-therapeutically administered radiation dose could be demonstrated in patients with goiter and multifocal autonomous nodules. A release of thyroid hormones to the blood due to radiation-induced destruction of thyroid follicles leading to a temporarily reduced cell metabolism was postulated as possible reason for this indication-specific stunning effect. Therefore, the aim of this study was to develop dose-dependent correction factors to account for stunning and thereby improve precision of radioiodine treatment in these indications.

METHODS

A retrospective analysis of 313 patients (135 with goiter and 178 with multifocal autonomous nodules), who underwent radioiodine uptake testing and radioiodine treatment, was performed. The previously determined indication-specific values for stunning of 8.2% per Gray in patients with multifocal autonomous nodules and 21% per Gray in patients with goiter were used to modify the Marinelli equation by the calculation of correction factors for hyperfunctioning radiation-induced stunning (CHRIS). Subsequently, the calculation of the required activity of radioiodine-131 to obtain an intra-therapeutic target dose of 150 Gy was re-evaluated in all patients. Furthermore, a calculation of the hypothetically received target dose by using the CHRIS-calculated values was performed and compared with the received target doses.

RESULTS

After integrating the previously obtained results for stunning, CHRIS-modified Marinelli equations could be developed for goiter and multifocal autonomous nodules. For patients with goiter, the mean value of administered doses calculated with CHRIS was 149 Gy and did not differ from the calculation with the conventional Marinelli equation of 152 Gy with statistical significance (p = 0.60). However, the statistical comparison revealed a highly significant improvement (p < 0.000001) of the fluctuation range of the results received with CHRIS. Similar results were obtained in the subgroup of patients with multifocal autonomous nodules. The mean value of the administered dose calculated with the conventional Marinelli equation was 131 Gy and therefore significantly below the CHRIS-calculated radiation dose of 150 Gy (p < 0.05). Again, the fluctuation range of the CHRIS-calculated radiation dose in the target volume was significantly improved compared with the conventional Marinelli equation (p < 0.000001).

CONCLUSIONS

With the presented CHRIS equation it is possible to calculate a required individual stunning-independent radioiodine activity for the first time by only using data from the radioiodine uptake testing. The results of this study deepen our understanding of thyroid stunning in benign thyroid diseases and improve precision of dosimetry in radioiodine-131 therapy of goiter and multifocal autonomous nodules.

Non-Surgical and Non-Radioiodine Techniques for Ablation of Benign Thyroid Nodules: Consensus Statement and Recommendation

Thyroid nodules and cysts are frequently diagnosed in Germany with a prevalence of about 20% in young adults reaching up to 70% in older adults. Surgery is the standard treatment of symptomatic nodules, nodules with suspicion of malignancy and thyroid cancer. Radioiodine treatment is applied for autonomously functioning nodules. During the last years new non-surgical and non-radioiodine techniques have been introduced to treat thyroid nodules. These techniques include ethanol/polidocanol treatment, radiofrequency, microwave, and laser ablation, and high frequency ultrasound ablation. A significant reduction in nodule size could be documented for these techniques in several studies, but long-term outcome data are missing. Until now, there is no general consensus regarding the appropriate indications for these methods. For this reason, the Thyroid Section (German Society for Endocrinology), the Thyroid Working Committee (German Society for Nuclear Medicine), and the German Association of Endocrine Surgeons (CAEK) for the German Society of General and Visceral Surgery (DGAV) reviewed the respective literature, discussed the pro and cons and developed a consensus statement and recommendation to help physicians and patients in their decision making.

Konversion eines postoperativen Hypoparathyreoidismus in einen Hyperparathyreoidismus bei ektopem Nebenschilddrüsenadenom

We present a patient with a history of thyroid cancer, presumably following radiochemotherapy of a childhood medulloblastoma, who developed a primary hyperparathyroidism 10 years after long-term postsurgical hypoparathyroidism. All established imaging modalities failed to detect the origin and only selective neck sampling could identify the suspected parathyroid adenoma causing hyperparathyroidism. This encourages the use of selective neck vein catheterization, particularly in patients with only slightly elevated parathyroid hormone-levels or suspected small ectopic adenoma.

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.

Guideline for in vivo- and in vitro procedures for thyroid diseases (version 2)

The version 2 of the guideline for diagnostic standards of thyroid disorders is an update of the guideline published in 1999 and describes standards of in vitro and in vivo procedures. The following statements are modified: In vitro procedures: When measurement of the TSH-receptor antibodies is indicated, the guideline recommends the use of a second generation assay (recombinant human TSH-receptor as antigen). The functional assay sensitivity for the measurement of thyroglobulin should reach a value ≤1 ng/ml. Moleculargenetic tests (RET proto-oncogen) are indicated in patients with a newly diagnosed medullary thyroid cancer and in the relatives of patients with hereditary medullary thyroid cancer. In vivo procedures: The sonographic examination should use a probe with a frequency of at least 7.5 MHz. Indications for the thyroid scintigraphy: nodule size ≥1 cm in diameter, autonomous goitre/nodule with clinical or subclinical hyperthyroidism, necessity of a differentiation between Graves’ disease and chronic lymphocytic thyroiditis, therapy control after a definitive treatment and – in individual cases – the follow-up of untreated autonomous nodules.

Residual kidney function after donor nephrectomy

Aim: We evaluated the long-term residual renal function after donor nephrectomy using 99mTc-mercaptoacetyltriglycin (MAG3)-clearance. Donors, methods: Altogether 49 kidney donors were examined using 99mTc-MAG3-clearance after nephrectomy for donation to a relative (m:f = 11:38; age 55±27 years). The donors were examined 16±8 years postoperatively (1.5-26 years). 42 donors (86%) showed normal creatinine values, whereas the other seven (14%) exhibited slightly elevated levels. 20 donors were examined pre- and postoperatively and compared intraindividually. The kidney function was compared to the age adapted normal values of healthy persons with two kidneys (67–133% of age related mean). Results: After nephrectomy all donors showed a normal perfusion, good secretion, merely physiological intrarenal transit and a normal elimination from the kidneys. The 99mTc-MAG3-clearance was 69 ±15% of the normal mean value of healthy carriers of two kidneys regardless of the gender. 20 donors with a preoperative examination showed a significantly reduced total renal function from 84 ± 15% of the mean normal value preoperatively to 60 ± 15% postoperatively (p <0.0005). 15 donors of this group exhibited a significant functional increase of the residual kidney from 40% initially to 60% after nephrectomy (p = 0.003). No correlation was found between the initial 99mTc-MAG3-clearance measured prior to nephrectomy and the clearance levels after nephrectomy. Also, no correlation between the preoperative 99mTc- MAG3-clearance and the postoperative serum creatinine values could be observed. Altogether, 22% of the donors (11/49) developed arterial hypertension 10 ± 8 years after donation (1-23 years). This corresponds to the normal age prevalence of hypertension in the carriers of two kidneys. Three donors suffered from arterial hypertension prior to the operation. Conclusion: Kidney donors with normal or slightly elevated creatinine values postoperatively show a 99mTc- MAG3-clearance value of 69% of the mean value of healthy carriers of two kidneys. This may serve as a reference value for healthy carriers of one kidney. In our study we demonstrated a good compensation of the contralateral kidney via renal scintigraphy by means of 99mTc-MAG3-clearance.

Guideline for radioiodine therapy for benign thyroid diseases (version 3)

The version 3 of the guideline for radioiodine therapy for benign thyroid diseases presents first of all a revision of the version 2. The chapter indication for radioiodine therapy, surgical treatment or antithyroid drugs bases on an interdisciplinary consensus. The manifold criteria for decision making consider the entity of thyroid disease (autonomy, Graves’ disease, goitre, goitre recurrence), the thyroid volume, suspicion of malignancy, cystic nodules, risk of surgery and co-morbidity, history of subtotal thyroidectomy, persistent or recurrent thyrotoxicosis caused by Graves’ disease including known risk factors for relapse, compression of the trachea caused by goitre, requirement of direct therapeutic effect as well as the patient’s preference. Because often some of these criteria are relevant, the guideline offers the necessary flexibility for individual decisions. Further topics are patients’ preparation, counseling, dosage concepts, procedural details, results, side effects and follow-up care. The prophylactic use of glucocorticoids during radioiodine therapy in patients without preexisting ophthalmopathy as well as dosage and duration of glucocorticoid medication in patients with preexisting ophthalmopathy need to be clarified in further studies. The pragmatic recommendations for the combined use of radioiodine and glucocorticoids remained unchanged in the 3rd version.

Increased FDG bone marrow uptake after intracoronary progenitor cell therapy

Patients with coronary artery disease who undergo FDG PET for therapy monitoring after intracoronary progenitor cell infusion (PCT) show an increased bone marrow up-take in some cases. Aim of the study was to evaluate the systemic bone marrow glucose metabolism in this patient group after PCT. Patients, methods: FDG bone marrow uptake (BMU), measured as standardized uptake value (SUVmax) in the thoracic spine, was retrospectively evaluated in 23 control patients who did not receive PCT and in 75 patients who received PCT 3 ± 2.2 days before PET scanning. Five out of them were pretreated with granulocyte colony-stimulating factor (G-CSF) 5 days prior to PCT and 10 ± 1.2 days before PET scanning. In 39 patients who received only PCT without G-CSF and underwent PET therapy monitoring 4 months later, baseline and follow up bone marrow uptake were measured. Leucocytes, C-reactive protein (CRP) levels and the influence of nicotine consumption were compared with the BMU. Results: In patients (n = 70) who received PCT without G-CSF, BMU median (1.3) was slightly, but significantly higher than in the controls (1.0) (p = 0.02) regardless nicotine consumption. BMU did not change significantly 4 months later (1.2) (p = 0.41, n.s.). After G-CSF pretreatment, patients showed a significantly higher bone marrow uptake (3.7) compared to patients only treated with PCT (1.3) (p = 0.023). Leucocyte blood levels were significantly higher in patients with a BMU ≥ 2.5 compared to patients with a bone marrow SUVmax < 2.5 (p <0.001). CRP values did not correlate with the BMU (rho -0.02, p = 0.38). Conclusion: Monitoring PCT patients, a slightly increased FDG BMU may be observed which remains unchanged for several months. Unspecific bone marrow reactions after PCT may be associated with increased leucocyte blood levels and play a role in the changed systemic glucose BMU.

18F-Deoxyglucose PET for the staging of oesophageal cancer

Aim: Evaluation of the influence of histopathologic sub-types and grading of primaries of oesophageal cancer, relative to their size and location, on the uptake of 18F-deoxyglucose (FDG) as measured by positron emission tomography (PET). Methods: 50 consecutive patients were evaluated. There were four drop-outs due to previous surgical and/or chemotherapeutical treatments and thus in 46 patients (28 squamous cell carcinomas and 18 adenocarcinomas) a pretherapeutic PET evalution of the primary including a standard uptake value (SUV) was obtained. In 42 cases data on tumour grading were available also. Results: Squamous cell carcinomas (SCC) were in 7/13/8 cases located in the proximal, medial and distal part of the oesophagus, respectively the grading was Gx in 3, G 2 in 12, G2-3 in 7, and G3 in 6 cases. The SUVmax showed a mean of 6.5 ± 2.8 (range 1.7-13.5). Adenocarcinomas (ACA) were located in the medial oesophagus in two cases and otherwise in its distal parts. Grading was Gx in one, G2 in 4, G2-3 in 3, G3 in 3, G3-4 in 3, and G4 in one case. The mean SUVmax was 5.2 ± 3.2 (range 1-13.6) and this was not significantly different from the SCC. Concerning the tumour grading there was a slight, statistically not relevant trend towards higher SUVmax in more dedifferentiated cancer. Discussion: SCC and ACA of the oesophagus show no relevant differences in the FDG-uptake. While there was a significant variability of tumour uptake in the overall study group, a correlation of SUV and tumour grading was not found.

FDG uptake after intraarterial chemotherapy in head and neck cancer

Aim: The intraarterial chemotherapy (i.a. CHT) using high dose cisplatin combined with systemic neutralization in patients with head and neck cancer (HNSCC) is used to reduce the tumor volume preoperatively. Aim of the study is the evaluation of the influence of i.a. CHT on the metabolism of fluor-18-deoxyglucose (FDG) in the primary and lymph nodes (LN). The value of FDG positron emission tomography (PET) preoperative and as follow-up method after i.a. CHT is examined. Patients, methods: Altogether 16 patients with HNSCC underwent two preoperative FDG PET examinations: the baseline examination one week before and the follow-up three weeks after i.a. CHT. The SUVmax values of the primary and the LN and LN metastases were evaluated and compared with each other and the histopathology. Results: The SUVmax value of the primary decreased after i.a. CHT significantly from a median (25th percentile/ 75th percentile) of 6.4 (4.1/ 7.8) to 3.6 (2.4/ 6.7) (p = 0.01). In 11 out of 16 patients cervical LN metastases were detected. The cervical LN metastases showed a decrease of the SUVmax value from 3.6 (2.3/ 4.8) in the pretreatment examination to 2.3 (1.7/ 3.6) after i.a. CHT (p = 0.008). Only in one patient with LN metastases the SUVmax of the nodes increased. The histopathologically measured size of the LN metastases ranged from 2 to 30 mm. Non malignant LN did not reveal a significant SUVmax decrease after i.a. CHT (p = 0.13). Conclusions: As expected, primaries of HNSCC showed a significant reduction of SUV after i.a. CHT. Compared to the primary the SUVmax decrease in LN metastases was less, but also significant. Since cytotoxic levels of cisplatin do not occur systemic, postinflammatory reactions of the LN or a lymphatic drainage of the chemotherapeutic drug into the LN could be an explanation. PET for staging of HNSCC must thus be performed prior to i.a. CHT.

Therapy of hepatocellular carcinoma with iodine-131-lipiodol

Aim: To evaluate the efficacy and tolerance of iodine- 131-lipiodol (131I-lipiodol) for hepatocellular carcinoma (HCC) in German long term patients and comparison with medically treated controls. Patients, Methods: 38 courses of intra-arterial 131I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC (6 with portal vein thrombosis). Liver and tumour volume and lipiodol deposition were measured by computed tomography and 131I activity by scintigraphy. Therapeutic efficacy was determined by tumour volume change and matched-pairs analysis in comparison to medically (i.e. tamoxifen or medical support) treated patients. Results: Tumour volume decreased in 20/32 index nodules (63%) after the first course. Repeated therapy frequently resulted in further tumour reduction. Overall response to treatment was partial in 11 nodules, minor response in 4 nodules, and disease was stable in 12 and progressive in 5. Significant response was associated with pretherapeutic nodule volume up to 150 ml (diameter of 6.6 cm). Survival rate after 3, 6, 9, 12, 24 and 36 months was 78, 61, 50, 39, 17, and 6%. Matched-pairs analysis of survival revealed 131I-lipiodol to be superior to medical treatment. The most important side effect was a pancreatitis-like syndrome whereas overall tolerance was good. Conclusion: The long term results confirm that HCC therapy with 131I-lipiodol is effective and probably superior to medical treatment. Tumour nodules of up to 6 cm diameter are well suited for this therapy even in the presence of portal vein thrombosis.

Procedure guidelines for radioiodine therapy of differentiated thyroid cancer (version 2)

The procedure guidelines for radioiodine therapy (RIT) of differentiated thyroid cancer (version 2) are the counterpart to the procedure guidelines for 131I whole-body scintigraphy (version 2) and specify the interdisciplinary guidelines for thyroid cancer of the Deutsche Krebs-gesellschaft and the Deutsche Gesellschaft für Chirurgie concerning the nuclear medicine part. Compared with version 1 facultative options for RIT can be chosen in special cases: ablative RIT for papillary microcarcinoma ≤1 cm, ablative RIT for mixed forms of anaplastic and differentiated thyroid cancer, and RIT in patients with a measurable or increasing thyroglobulin concentration but without detectable metastases by imaging. The description of the pretherapeutic dosimetry now includes the isotopes 123I and 124I as well as a broader range of the activity of 131I. Activities of 2-5 GBq 131I are recommended for the first ablative RIT. If high accumulative activities of 131I are expected, men who have not yet finished their family planning should be advised to the option of sperm cryoconservation. An interdisciplinary consensus is necessary whether the new TNM-classification (UICC, 6th edition, 2002) will lead to modified recommendations for surgical or nuclear medicine therapy, especially for the surgical completeness and for the ablative RIT of pT1 papillary cancer.

Guideline for radioimmunotherapy of rituximab relapsed or refractory CD20+ follicular B-cell nonHodgkin´s lymphoma

This guideline is a prerequisite for the quality management in the treatment of non-Hodgkin-lymphomas using radioimmunotherapy. It is based on an interdisciplinary consensus and contains background information and definitions as well as specified indications and detailed contraindications of treatment. Essential topics are the requirements for institutions performing the therapy. For instance, presence of an expert for medical physics, intense cooperation with all colleagues committed to treatment of lymphomas, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how the treatment has to be carried out technically. Here, quality control and documentation of labelling are of greatest importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with those colleagues (haematology-oncology) who propose, in general, radioimmunotherapy under consideration of the development of the disease.

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

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

Thyroid sonomorphology, thyroid peroxidase antibodies and thyroid function

Aim: Employees of Sanofi-Aventis Deutschland GmbH underwent thyroid screening in 2006 to assess new data about the prevalence of irregular sonomorphological pattern, elevated thyroid peroxidase antibodies (TPO AB) and thyroid function in an unselected adult German population. Participants, methods: The examination included 700 unselected employees. Blood samples were analyzed for serum TSH and TPO AB, and ultrasound of the thyroid was performed. Results: In 40.7% of the participants (n = 285) an irregular sonomorphological pattern was detected: goiter in 13.7%, nodules in 35.6%, nodular goiter in 8.6% and a hypoechogenic pattern of the thyroid gland in 20.4%. Serum TSH was increased in 3.9% and decreased in 0.6%. Elevated TPO AB values were observed in 13%. Only 1.4% (n= 10) showed elevated TPO AB combined with a TSH increase. Sonomorphological abnormalities were associated with increased TPO AB in 7.1%. Elevated TPO AB was observed significantly more often in combination with sonomorphological pathology (54.9%) than without (45.1%) (p = 0.003). Conclusions: Sonomorphological disorders are still very common in Germany and our results are comparable with previous screening examinations. Elevated TPO AB correlated significantly with the sonomorphological pattern of nodules and goiter. This may reflect an improved iodine supply or a hypertrophic stage of autoimmune thyroiditis in some cases.

Percutaneous thermal microwave ablation of thyroid nodules

Microwave ablation (MWA) is a new minimal invasive method for thermal ablation of benign thyroid nodules. In contrast to well-established radiofrequency ablation (RFA), MWA offers several advantages with similarly successful results. There has not been any use of functional imaging with 99mTc-per- technetate and 99mTc-MIBI-scans as a mere qualitative analysis of this imaging in the field of MWA in Europe until now. The aim of this study has been to demonstrate the feasibility of MWA as well as the applicability of functional imaging to verify effectiveness with a centerspecific score. Patients, methods: 11 patients (5 women, 6 men, average age 62.3 years) with 18 benign thyroid nodules were treated. MWA was operated under local anesthesia with a system working in a wavelength field of 902 to 928 MHz (Avecure MWG881, MedWaves, Inc. San Diego, CA). Pre- and postablative scans were controlled by two specialists in nuclear medicine with longtime work experience. Results: A center specific functional imaging score (CSFIS) was defined, a decrease of 1.4 points at an average was noticeable (range 1-3 points). In 66.7% (n = 12) of all nodules the score decreased by 1 point, 27.8% (n = 5) by 2 points and 5.6% (n = 1) by 3 points. The treatment was well tolerated and no severe complications were observed. Conclusion: The preliminary data suggests that MWA is an effective method to treat benign thyroid nodules. Functional imaging is a promising technique for early verification of effectiveness of thermal ablation.

Is radioiodine therapy conducted too late in patients suffering from thyroid autonomy?

Aim: The effectiveness of radioiodine therapy (RIT) is proven. The aim of this study was to determine, how much time passes between diagnosis of thyroid autonomy or occurrence of functional and/or local symptoms on one hand and RIT on the other hand. Patients, methods: This retrospective study comprises 196 patients, who were treated with radioiodine for thyroid autonomy between 2002 and 2005. Evaluated parameters are begin of functional and/ or local symptoms, first scintigraphy with relevant Tc-Uptake as time point of primary diagnosis of thyroid autonomy and time point of implementation of RIT. Results: Between first scintigraphy with relevant Tc-Uptake and implementation of RIT 0–72 months passed (median: 3 months). 160 patients (81.6%) had a prior diagnosis of goitre by their general practitioner and 163 patients (83.3%) had a prior diagnosis of TSH suppression. The time period between first recommendation of RIT and implementation of RIT was 0–89 months (median: 2 months). In 142 patients (71.4%) functional and/or local symptoms were present over 73 months (median; range: 0–180 months) before the first scintigraphy with therapy relevant Tc-Uptake was conducted. Conclusion: Despite clear recommendations in corresponding guidelines too much time passes between first symptoms (median: 73 months), primary diagnosis of therapy relevant thyroid autonomy (median: 2 months) and implementation of RIT. Patients with functional and/or local symptoms should be examined for thyroid autonomy early. If thyroid autonomy is proven, RIT should be planned immediately, especially in high-risk patients.

Guideline for radioiodine therapy for benign thyroid diseases (version 4)

Version 4 of the guideline for radioiodine therapy for benign thyroid diseases includes an interdisciplinary consensus on decision making for antithyroid drugs, surgical treatment and radioiodine therapy. The quantitative description of a specific goiter volume for radioiodine therapy or operation was cancelled. For patients with nodular goiter with or without autonomy, manifold circumstances are in favor of surgery (suspicion on malignancy, large cystic nodules, mediastinal goiter, severe compression of the trachea) or in favor of radioiodine therapy (treatment of autonomy, age of patient, co-morbidity, history of prior subtotal thyroidectomy, profession like teacher, speaker or singer). For patients with Graves' disease, radioiodine therapy or surgery are recommended in the constellation of high risk of relapse (first-line therapy), persistence of hyperthyroidism or relapse of hyperthyroidism. After counseling, the patient gives informed consent to the preferred therapy. The period after radioiodine therapy of benign disorders until conception of at least four months was adapted to the European recommendation.

Procedure guideline for iodine-131 whole-body scintigraphy for differentiated thyroid cancer (version 3)

Version 3 of the procedure guideline for 131I whole-body scintigraphy (WBS) is the counterpart to the procedure guideline for radioiodine therapy (version 3) and specify the interdisciplinary guideline for thyroid cancer of the Deutsche Krebsgesellschaft concerning the nuclear medicine part. 131I WBS 3–6 months after 131I ablation remains a standard procedure in an endemic area for thyroid nodules and the high frequency of subtotal surgical procedures. Follow-up without 131I WBS is only justified if the following preconditions are fulfilled: low-risk group pT1–2, pN0 M0 with histopathologically confirmed pN0, 131I uptake <2%, 131I WBS during ablation without any suspicious lesion, stimulated thyroglobulin (Tg)-level 3–6 months after ablation <2 ng/mL, and absence of anti-thyroglobulin- antibodies with normal recovery-testing. If patients from the low-risk group show normal 131I WBS 3–6 months after ablation and stimulated Tg is of <2 ng/mL, there will be no need for additional routine 131I WBS. If patients from the high-risk group show normal 131I WBS and stimulated Tg-level of <2 ng/mL 3–6 months after ablation, the follow- up care should include repeated stimulated Tgmeasurements. If the Tg-level remains below 2 ng/mL, an additional 131I WBS will be not necessary. The recommended intervals for stimulated Tg-testing are adapted to the prior intervals for 131I WBS-testing in the high-risk group. Increased anti-thyroglobulin-antibodies or incomplete recovery-testing make an individual strategy of follow- up care necessary, which include 131I WBS.

Procedure guidelines for radioiodine therapy of differentiated thyroid cancer (version 3)

The procedure guideline for radioiodine therapy (RIT) of differentiated thyroid cancer (version 3) is the counterpart to the procedure guideline for 131I whole-body scintigraphy (version 3) and specify the interdisciplinary guideline for thyroid cancer of the Deutsche Krebsgesellschaft concerning the nuclear medicine part. Recommendation for ablative 131I therapy is given for all differentiated thyroid carcinoma (DTC) >1 cm. Regarding DTC ≤1 cm 131I ablation may be helpful in an individual constellation. Preparation for 131I ablation requires low iodine diet for two weeks and TSHstimulation by withdrawal of thyroid hormone medication or by use of recombinant human TSH (rhTSH). The advantages of rhTSH (no symptoms of hypothyroidism, lower blood activity) and the advantages of endogenous TSHstimulation (necessary for 131I-therapy in patients with metastases, higher sensitivity of 131I whole-body scan) are discussed. In most centers standard activities are used for 131I ablation. If pretherapeutic dosimetry is planned, the diagnostic administration of 131I should not exceed 1–10 MBq, alternative tracers are 123I or 124I. The recommendations for contraception and family planning are harmonized with the recommendation of ATA and ETA. Regarding the best possible protection of salivary glands the evidence is insufficient to recommend a specific setting. To minimize the risk of dental caries due to xerostomia patients should use preventive strategies for dental hygiene.

Combination of ultrasound guided percutaneous microwave ablation and radioiodine therapy in benign thyroid diseases

Aim: Goiters and thyroid nodules are an ongoing problem in healthcare. There has not been any treatment of goiters and thyroid nodules based on the combined therapy of microwave ablation (MWA) and radioiodine therapy (RIT) until now. In this study the potential benefit of a combined therapy versus single RIT is evaluated in order to achieve improvements concerning 131I-dose and hospitalization time. Patients, material, methods: Ten patients with goiter and benign thyroid nodules or Graves' disease were included. Pre-ablation assessments included sonographical imaging, functional imaging with 99mTc and FNAB to collect data of nodules and total thyroid volume and to exclude malignancy. Prior to treatment, radioiodine uptake test was performed. MWA was operated under local anesthesia with a system working in a wavelength field 902–928 MHz. Post-MWA, thyroid volume was recalculated ultrasonically. Due to reduced vital volume, changes of 131I-dose and hospitalization time could be monitored. Results: Mean absolute thyroid volume reduction by MWA before applying RIT was 22 ± 11 ml, meaning a relative reduction of 24 ± 6% (p < 0.05). Thereby, administered activity could be reduced by 393 ± 188 MBq using the combined therapy, reflecting a relative reduction of 24 ± 6% (p < 0.05). Additionally, mean hospitalization time was decreased by 2.1 ± 0.8 days using MWA prior to RIT, implying a relative reduction of 28 ± 6% (p < 0.05). Conclusion: Depending on ablated volume by MWA, RITmonotherapy requires on average 31.2% more 131I-activity than the combined therapy. The combined therapy remarkably decreases 131I-dose and hospitalization time. The combined MWA and RIT therapy is a considerable, effective and safer alternative to surgery for the treatment of very large benign nodular goiters.

Percutaneous microwave ablation of benign thyroid nodules

Aim: Thyroid nodules represent a common clinical issue. Amongst other minimally invasive procedures, percutaneous microwave ablation (MWA) poses a promising new approach. The goal of this retrospective study is to find out if there is a correlation between volume reduction after 3 months and 99mTcuptake reduction of treated thyroid nodules. Patients, methods: 14 patients with 18 nodules were treated with MWA. Pre-ablative assessment included sonographical and functional imaging of the thyroid with 99mTcpertechnetate and 99mTc-MIBI. Additionally, patients underwent thyroid scintigraphy 24 hours after ablation in order to evaluate the impact of the treatment on a functional level and to ensure sufficient ablation of the targeted area. At a 3-month follow-up, ultrasound examination was performed to assess nodular volume reduction. Results: Mean relative nodular volume reduction after three months was 55.4 ± 17.9% (p < 0.05). 99mTcuptake 24 hours after treatment was 45.2 ± 31.9% (99mTc-MIBI) and 35.7 ± 20.3% (99mTcpertechnetate) lower than prior to ablation (p < 0.05). Correlating reduction of volume and 99mTc-uptake, Pearson's r was 0.41 (p < 0.05) for nodules imaged with 99mTc-MIBI and –0.98 (p < 0.05) for 99mTc-pertechnetate. According to scintigraphy 99.6 ± 22.6% of the determined target area could be successfully ablated. Conclusions: MWA can be considered as an efficient, low-risk and convenient new approach to the treatment of benign thyroid nodules. Furthermore, scintigraphy seems to serve as a potential prognostic tool for the later morphological outcome, allowing rapid evaluation of the targeted area in post-ablative examination.

Guideline Compliance in Surgery for Thyroid Nodules - A Retrospective Study

Diagnostic guidelines for thyroid nodules focus on malignancy risk assessment to avoid unnecessary diagnostic operations. These guidelines recommend a combination of tests in form of a diagnostic algorithm. The present study analyzed the recommended algorithm and its implementation by different medical professionals. Preoperative diagnostic procedures, laboratory tests and histopathological findings of patients who underwent thyroid surgery between 2006 and 2013 were analyzed. The results were stratified by the assignation by specialized endocrinologists (ENP), general practitioners (GP) or Goethe-University Hospital Frankfurt (UKF). 677 patients were enrolled, of these 62% were assigned by UKF, 18.5% by an ENP and 19.5% by a GP. Ultrasonography rate was significantly higher in UKF (97.6%) compared to patients assigned by GP (90.9%, p<0.0001). Rates for fine-needle aspiration cytology ranged between 47.6% in UKF and 23.2% in ENP (p<0.0001). In over 93% of the patients an analysis of thyroid-stimulating hormone and triiodothyronine/thyroxin was realized. The overall malignancy rate was 11.82%. The malignancy rate was significantly higher if a FNA biopsy was performed (16.35 vs. 8.94%; p=0.0048). A higher malignancy rate could only be seen if the preoperative diagnostic workup included FNA. Besides this, the grade of algorithm adherence showed no effect on the malignancy rate.

Bipolar Radiofrequency Ablation of Benign Symptomatic Thyroid Nodules: Initial Experience

PURPOSE

To determine the safety and efficacy of bipolar radiofrequency ablation (RFA) in benign thyroid nodules.

METHODS

23 patients with 24 symptomatic benign thyroid nodules (21 regressive, 3 adenomas) ranging in volume from 0.5 to 112 ml (mean ± sd: 18 ± 24.4 ml) underwent bipolar RFA. Pain during the procedure was measured on a 10-point scale. Side-effects revealed by ultrasound or patients' complaints were documented. Periablative efficacy was measured 24 hours after RFA as change (Δ) in serum thyreoglobulin (Tg) and sonographic criteria (echogenity, Doppler blood flow and elasticity) categorized on a 3-point scale (echogenity, Doppler blood flow) or 4-point scale (elasticity). Efficacy in the 3 autonomous adenomas was measured as normalization of (99 m)Tc-pertechnate scintigraphy.

RESULTS

Bipolar RFA was well tolerated by all patients with a median pain score of 3 ± 1.5 (range: 1 - 7). Side-effects were hematomas in 4 of 23 patients (17 %). Bipolar RFA resulted in a significant (p < 0.01) decrease in echogenity, blood flow, elasticity (Δ = 1 ± 0.28, 1 ± 0.46 and 1 ± 0.85 points, respectively), a median increase in Tg of 403 ± 2568 ng/ml as well as in a normalization of scintigraphy.

CONCLUSION

Bipolar RFA is a safe and effective treatment option for symptomatic benign thyroid nodules.

KEY POINTS

• Bipolar RFA is a safe and effective treatment for benign thyroid nodules.• Ultrasound imaging allows guidance during bipolar radiofrequency ablation.• (99 m)Tc-pertechnetate is able to detect the ablation area of autonomous adenomas. Citation Format: • Korkusuz Y, Erbelding C, Kohlhase K et al. Bipolar Radiofrequency Ablation of Benign Symptomatic Thyroid Nodules: Initial experience with Bipolar Radiofrequency. Fortschr Röntgenstr 2016; 188: 671 - 675.

Age and body composition influence TSH concentrations after administration of rhTSH

AIM

Previous studies listed body surface area (BSA), lean body mass (LBM), and age as modifying factors on the TSH concentrations after administration of recombinant human thyrotropin (rhTSH). The purpose of this study was to identify the main modifying factors on serum TSH levels and to compare the stimulation via single rhTSH injection after a short thyroid hormone withdrawal (THW) with that of the standard stimulating protocol.

PATIENTS, METHODS

106 patients with differentiated thyroid cancer (DTC) undergoing radioiodine therapy (RIT) after rhTSH administration were obtained through chart review. Two groups were evaluated: Group I was treated with a single rhTSH administration after two weeks of T3 therapy followed by one week of THW. Group II was stimulated according to the international standard protocol via rhTSH injections for two consecutive days. Serum TSH concentrations were documented prior to rhTSH administration (day 1 TSH), one day after (day 3 TSH) and 3-6 days after (mean 4.2 days, day 6 TSH) the last rhTSH injection. The following data was collected: age, gender, weight, height, BMI, LBM, BSA, residual thyroid tissue, CRP, creatinine, GFR, liver enzymes, alkaline phosphatase, cholesterol, and triglycerides.

RESULTS

Group I: Age combined with anthropometric factors like BMI (TSH increase and day 6 TSH), BSA (TSH decrease), and gender (day 6 TSH) are the main modifying factors on serum TSH concentrations after rhTSH administration. Group II: Age and lean body mass (LBM) showed a significant impact on day 3 TSH, TSH increase (day 3-day 1), and TSH decrease (day 6-day 3). Day 6 TSH was found to be influenced by GFR (group II).

CONCLUSION

Age and anthropometric parameters have significant independent influence on TSH concentrations after rhTSH injection in both groups. Anthropometric parameters (BSA, LBM) and demographic parameters (female gender) show strong influence on TSH concentrations. Further research should be conducted to examine the influence of body compartments on TSH levels through measuring total body water.

Can peptide receptor radionuclide therapy be safely applied in florid bone metastases? A pilot analysis of late stage osseous involvement

AIM

Highly advanced metastatic bone disease with extensive osseous infiltration of neuroendocrine tumours (NET) may preclude patients from treatment with peptide receptor radionuclide therapy (PRRT) in concern about haematotoxicity. This study aims to assess the safety and efficacy of PRRT with 177Lu-octreotate in a patient cohort with this condition.

PATIENTS, METHODS

41 PRRT courses were performed in 11 patients with gastroenteropancreatic neuroendocrine tumours (GEP-NET) and florid bone metastases (severely advanced widespread metastatic bone disease). A mean activity of 6.95 GBq 177Lu-octreotate was administered per treatment cycle, aimed at four courses with standard intervals of 3 months. Haematological parameters were determined prior to each treatment course, in 2-4 weeks intervals between the courses, 8-12 weeks after the last course of PRRT and in 3 monthly intervals thereafter. Toxicity was recorded using Common Terminology Criteria for Adverse Events v3.0. Restaging was performed 3 months after termination of PRRT with CT/MRI and functional imaging (modified MDA criteria).

RESULTS

Significant (grade III-IV), reversible haematotoxicity occurred in 4 (35%) patients and after 10 (24%) administrations. It either resolved spontaneously (1 patient) or was controlled by supportive measures (3 patients), such as blood transfusions (3 patients) or deferral of the subsequent therapy cycle (1 patient). Patients returned to baseline blood values within up to 23 months after termination of PRRT. The observed treatment response of bone metastases consisted of a partial response in 2, a minor response in 1, stable disease in 7, and progressive disease in 1 patient. Of the 4 patients with metastatic bone pain, 1 experienced complete and 3 partial resolution of symptoms within 3-10 weeks after commencement of PRRT.

CONCLUSION

These preliminary data indicate that PRRT with 177Lu-octreotate can be safely applied even in florid bone metastases with extensive, severely advanced osseous replacement. The higher myelosuppression rate was not associated with serious complications and should not preclude patients from being treated and potentially experiencing remarkable treatment efficacy despite the very advanced stage.