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Aim Recently, textural parameters assessed in FDG-PET/CT as surrogate marker for tumor heterogeneity have been shown to provide prognostic power. Therefore, we investigated the use of such parameters in FDG-PET/CT examinations before the start of immunotherapy with vemurafenib or ipilimumab in patients with malignant melanoma. Methods In this retrospective analysis 26 patients with histologically proven advanced melanoma were included. FGD-PET/CT was performed before the start of treatment either with vemurafenib (n = 9) or ipilimumab (n = 17) and tumors were analyzed for textural parameters as well as conventional PET features. Lesions were classified as responding or not responding following PERCIST criteria. ROC analysis was performed to analyze the predictive power and cut-off values. In addition, the change of maximum SUV of the lesions between pretherapeutic PET/CT and another PET/CT performed about 12 weeks after start of treatment was evaluated and correlated with the pretreatment parameters. Results In both groups, six textural parameters showed statistically significant predictive power as well as the metabolic tumor volume. In the group treated with vemurafenib eight additional textural parameters as well as the maximum and mean SUV and the TLG showed significance. A statistically significant correlation between the change of maximum SUV in the course of treatment and the pretherapeutic parameters was found in both treatment groups for three textural features. Conclusion In patients with malignant melanoma textural parameters in pretherapeutic FDG-PET/CT examinations seem to have prognostic power for treatment response of immunotherapy with vemurafenib and ipilimumab. This can be an important step towards personalized tumor therapy.

Radium-223 dichloride (Xofigo®, Alpharadin) is approved for the treatment of metastatic castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastases. As a calcium mimetic, it is integrated into osteoplastic bone lesions and emits alpha particles with high energy which leads to local destruction of tumor cells. In the 2013 published ALSYMPCA trial, a significant advantage for overall survival and quality of life in comparison to placebo was found. Recent data suggest an increased potential in combination with next generation hormonal treatment.

In failure to respond to bacillus Calmette-Guérin (BCG) in patients with carcinoma in situ (CIS) of the urinary bladder, radical cystectomy remains the mainstay after BCG failure.The aim of this pilot study was to evaluate tolerability and safety of the α‑emitter radioimmunoconjugate instillation in patients after BCG failure.Nine patients were included. After emptying the bladder via a transurethral catheter, Bi-213-anti-EGFR-mAb was instilled. Treatment was terminated by emptying of the radioimmunoconjugate from the bladder 120 min after instillation. Efficacy was evaluated via endoscopy and histology 6 weeks after instillation.All patients showed excellent toleration of the treatment without any side effects. Treatment resulted in complete eradication of tumor cells in 3 patients and persistent tumor detection in the other 6 patients.Intravesical instillation of Bi-213-anti-EGFR-mAb is a promising therapeutic option for treatment of in situ bladder cancer after BCG failure for patients who wish to preserve the bladder.

Neuroendocrine tumours are frequently located in the upper abdomen and especially in the pancreas. Imaging of the abdomen with somatostatin analogs such as (68)Ga-DOTA-Phe(1)-Tyr(3)-octreotide (DOTATOC) is a standard approach for imaging neuroendocrine cancer, but is still challenging due to physiological and technical considerations in this area. Therefore, the aim of this study was to further investigate the origin of (68)Ga-DOTATOC findings in the pancreas.Forty-three consecutive patients with neuroendocrine tumours were examined by (68)Ga-DOTATOC positron emission tomography (PET)/CT for staging or restaging. As imaging of the upper abdomen is frequently affected by breathing artefacts, PET and CT data were analysed for misalignment and rearranged if necessary. Any noticeable uptake in the pancreas was described. Tracer uptake in the head of the pancreas and the liver was measured by means of maximum and average standard uptake value (SUV(max), SUV(av)). The reference standards (malignant versus benign) for correlation with PET findings were clinical and radiological follow-up (mean follow-up time 14 months) (n = 37) or histological confirmation (n = 6).In 23 of 43 studies (54%) misalignment between PET and CT data was found with a mean value of 1.4 cm. Visual assessment demonstrated that 20 of 43 scans (46.6%) showed no uptake in the head of the pancreas. Of 43 scans, 23 (53.4%) showed noticeable uptake with focal pattern in the head of the pancreas in 10 scans and irregular pattern in 13 scans. Follow-up indicated malignant pancreatic lesions in three patients. The pancreatic head to liver SUV(av) ratios in these patients ranged from 1.62 to 6.85, whereas in cases of uptake without known malignancy ratios ranged from 0.56 to 1.19. Considering SUV(max), the ratio ranged from 3.24 to 9.1 and from 0.84 to 1.47, respectively. No statistically significant difference was noted between uptake in the head of the pancreas and the liver in patients without malignant pancreatic tumours (p0.05).(68)Ga-DOTATOC uptake in the head of the pancreas is a common finding in patients undergoing (68)Ga-DOTATOC PET/CT. However, this finding most likely represents a physiological condition, especially if the uptake in the pancreatic head is similar to the uptake in the liver (uptake ratio head to liver SUV(av)1.4). Therefore, quantification is recommended to avoid false-positive diagnosis. Misalignment due to respiratory motion must always be taken into account.

Neuroendokrine Neoplasien werden immer noch in ihrer Haufigkeit unterschatzt. Fruher teilweise als eher gutartige Tumoren angesehen, betrachtet man sie nun alle als potenziell maligne. Die Kenntnisse „typischer“ Symptome ist wichtig, denn werden diese erkannt, so konnen betroffene Patienten einer adaquaten Diagnostik zugefuhrt werden. Leider lassen selbst die als charakteristisch angesehenen Symptome viele, weitaus haufigere Differenzialdiagnosen zu und sind selten – und dann meist erst in spateren Krankheitsstadien – von vornherein wegweisend. Heute stehen in der Diagnostik hervorragende biochemische, endoskopische, radiologische und nuklearmedizinische Optionen zur Verfugung. Ihre sinnvolle Kombination erlaubt eine fruhe(re) Diagnosestellung, Risikostratifizierung, Festlegung des individuellen Therapiekonzepts und optimale Nachsorge.

The accuracy of functional SPECT imaging has been significantly improved by addition of CT. This is especially relevant for functional imaging of neuroendocrine tumors using highly specific radiopharmaceuticals. Parathyroid adenomas can be detected by 99m Tc-MIBI SPECT/CT with very high sensitivity and specificity, playing an important role especially when minimally invasive techniques are used for surgical resection. With SPECT/CT, extra-adrenal manifestations of pheochromocytomas and tumors of the adrenal cortex can be detected with high accuracy. Because of the availability of PET radiopharmaceuticals such as 68 Ga-DOTATOC, the clinical relevance of 111 In-Octreotide SPECT for detection of neuroendocrine cancers has been recently reduced. Because of the better availability, SPECT and SPECT/CT still represent standard tools for imaging neuroendocrine cancers. SPECT/CT represents the superior imaging modality for monitoring radiopeptide based therapies, which are now increasingly used for treatment of neuroendocrine cancers.

Persistent differentiated papillary thyroid cancer following radical locoregional surgery with metastases is an indication for limited reoperation or radioiodine therapy. Following injection of radioiodine, radio-guided surgery with application of an intraoperative gamma probe offers detection of metastases not seen by conventional imaging and control of completeness of resection. We demonstrate four patients with locoregional metastases, two of them with additional distant metastases of papillary thyroid cancer following radical neck surgery. Postoperative radioiodine scans demonstrated persistent ipsilateral or contralateral cervical and mediastinal lymph node and isolated rib metastases. Radio-guided surgery (RGS) leads to complete clearance of persistent lymph node metastases by limited recurrent neck surgery, resection of metastases not seen by conventional imaging and control of complete mediastinal lymph node dissection. Post-RGS scans allowed early diagnosis of occult diffuse or nodal pulmonary metastases in two patients. At last follow-up, 23 to 48 months following RGS and radioiodine therapy, there was no evidence of disease. Radio-guided surgery is an additive surgical technique with low morbidity in selected patients with persistent thyroid cancer individualizing tumor therapy options in multimode oncological therapy.

Reoperation for thyroid cancer needs to consider patient-, tumor- and therapy-related aspects as well as present diagnostic results. Reoperation because of thyroid remnants, persistence of the primary tumor and lymph node metastasis (completion surgery) has to be distinguished from reoperation due to locoregional recurrence (primary tumor, lymph nodes). The primary surgical strategy should avoid the need for reoperation. The extent of reoperation is related to the extent of primary surgery, stage, and distant metastasis. The timing and indication of reoperation for differentiated thyroid carcinoma in an interdisciplinary multimodal treatment setting depends on diagnostic radioiodine scans and radioiodine therapy. Long-term, recurrence-free survival is achieved by sufficiently radical surgery with acceptable morbidity, including all additive or adjuvant treatment options.

Scintigraphy continues to play an important diagnostic role in internal medicine. Many diagnostic questions can only be answered with scintigraphic methods. The application of specific radiopharmaceutical tracers offers the unique possibility to visualize ongoing functional changes, associated with diseases concerning internal medicine. The diagnostic potential of modern scintigraphic procedures such as PET for internal medicine is not yet sufficiently used and will continue to grow with hybrid systems, such as PET-CT and SPECT-CT.

Early detection of local and regional recurrence is the main goal during follow-up of patients with larynx and pharynx cancer. Hypothyroidism occurring in those patients stays frequently undiagnosed as screening for hypothyroidism is not part of the routine follow-up. This study was performed to assess the prevalence of hypothyroidism in these patients. We included 120 patients (106 male, 14 female) with larynx or pharynx cancer treated more than 2 months earlier (mean = 41 months) in the study. Cancer treatment consisted of either surgery (n = 44), radiotherapy (n = 15), or surgery combined with postoperative radiotherapy (n = 61). In all patients, thyroid function studies (thyrotropin [TSH], free triiodothyronine [FT3], and free thyroxine [FT4]) were performed. Twenty-six of all patients (22%) were hypothyroid; in two patients hypothyroidism was diagnosed postoperatively and these two patients were on replacement therapy with thyroid hormones. The highest rate of hypothyroidism (34%) was present in patients treated with surgery combined with radiotherapy, whereas among patients treated with surgery only 7% were hypothyroid (p0.001). There was no difference in the duration of follow-up between therapy and inclusion in the study between those two groups. Two of 15 patients treated only with radiotherapy were diagnosed hypothyroid, but in this group the latency was shorter (p0.05). The results indicate that thyroid function studies should be routinely performed in the follow-up of head and neck cancer patients, especially if radiotherapy was part of the treatment.

The bone mineral density (BMD) of 14 children, adolescents, and adults with phenylketonuria (PKU) on dietary treatment (age 5-28 y; 6F, 8M) was investigated using peripheral quantitative computed tomography (pQCT) of the distal radius. BMD of total (TBMD) and spongy bone (SBMD) were compared to those of healthy gender-, age-, weight- and height-matched controls. We found a significant decrease of SBMD in patients with PKU while TBMD was only slightly decreased, reaching no statistical significance. These results indicate minor changes of BMD in patients with PKU under treatment, which are more accentuated in the trabecular bone compartment. One additional patient who was untreated until the pQCT investigation at the age of 10 y also showed markedly decreased SBMD and TBMD.

Variations of Hauri's penile revascularization have been in clinical use since 1983. The hemodynamics of the so-called three-vessel anastomosis remain uncertain despite successful, clinically reproducible results. The goal of this study was to depict the increased perfusion of the erectile system of the penis following revascularization by means of the inferior epigastric artery. Ten milliliters of heparinized peripheral venous blood was drawn from 10 patients prior to surgery. The radioactively tagged erythrocytes (1 mCi 99mTc) were reinjected via an additional incision in the donor vessel proximal to the anastomosis following completion of the three-vessel anastomosis and intracavernous injection of 20 micrograms PGE1. Once again, blood was drawn during the tumescence phase from both a peripheral vein and the corpora cavernosa within the normal circulatory duration and compared to the original specimen. Eight of ten patients displayed evidence of primary reperfusion of the corpora cavernosa via the inferior epigastric artery as the donor vessel. Using strict indications, revascularization of the penis is an effective mode of therapy for arterial erectile dysfunction.

The elevated rate of glycolysis in malignomas compared to normal tissues can be visualised by positron-emission-tomography (PET) using 2[18F]fluoro-deoxy-D-Glucose (FDG). Based on the case of a 38-year old woman with multifocal carcinoma of the right breast (pT1 c pN0 M0, G2) as a vehicle, we describe a FDG-PET procedure which is comparable to established methods of nuclear medicine (e.g. bone scan) with regard to patient's burden and time consumption and could be used on a routine basis. This technique allowed correct assessment of suspicious breast findings and visualised multifocal growth of a tumour which was judged to be a unifocal breast cancer by conventional methods of clinical examination, mammography and ultrasound.

Summary Infections represent a complication after transient or permanent implantation of medical devices (e. g. catheters or pacemaker systems), leading in many cases to therapeutic consequences such as the removal of the implanted system. Diagnosis of foreign body infections is difficult and mainly based on clinical findings rather than laboratory methods or modern morphological imaging tools. Two-dimensional echocardiography by transthoracic and transesophageal approach may be helpful in the detection of vegetations, but is not very sensitive for infections. Most methods in nuclear medicine, however, are based on function and not on form: some methods for the detection of an infection are unspecific like the use of labelled nanocolloids or Ga-67-citrate, or they need time-consuming and susceptible techniques for the labelling of autologous leukocytes. Monoclonal antibodies against epitopes on granulocytes, however, offer a fast and reliable in-vivo labelling technique. It has been demonstrated in a group of four patients that scintigraphic detection of pacemaker infections by immunoscintigraphy may represent a valuable diagnostic tool.

ZusammenfassungNachdem gezeigt wurde, daß die Applikationsform 87Y-NTA-EDTMP-Ca der bisher verwendeten Zitratform des Yttriums insbesondere hinsichtlich der Tumor/Leber- und Tumor/Femur-Verhältnisse überlegen ist, wurden die Zusammenhänge zwischen der Konzentration der Komponenten in dem 87Y-NTA-EDTMP-Ca-Gemisch und der Veränderung der 87Y-Biokinetik an tumortragenden Mäusen untersucht. Die Erhöhung der EDTMP- und Ca2+-Konzentrationen verursachten keine signifikanten Veränderungen der Tumorradioaktivität, aber eine deutliche Verringerung der Radioaktivität in Leber und Milz bzw. Knochen. Die Erhöhung der NTA-Konzentration führte auch zu einer Abnahme der Radioaktivität in allen untersuchten Organen und Geweben (im Tumor nach Applikation relativ hoher NTA-Mengen). Die Betrachtungen der Tumor/Untergrund-Verhältnisse in Abhängigkeit unterschiedlicher Zusammensetzungen des Injektionsgemisches zeigten, daß es möglich ist, die Bioverteilung des Radionuklids zu optimieren.

To evaluate the diagnostic value of positron-emission tomography/computed tomography (PET/CT) in stage I lung cancer patients treated with stereotactic body radiation therapy (SBRT), who have suspicious or unclear local recurrence findings in CT 1 year after treatment. A group of 29 patients with unclear or suspicious CT findings 1 year after SBRT were examined with PET/CT. The ability of standard uptake values (SUVmax, SUVmean and posttherapeutic reduction in SUV) to detect local failure and identify patients at a high risk of disease-specific death was evaluated using logrank statistics. Histology and clinical follow-up were the gold standards for local recurrence. SUVmean greater than 3.44 (p = 0.001); SUVmax greater than 5.48 (p = 0.009) or a relative reduction in SUVmean or SUVmax of less than 43 (p = 0.030) or 52 % (p = 0.025), respectively, was indicative of local recurrence. These parameters also correlated with an increased risk of disease-specific death: SUVmean greater than 2.81 (p = 0.023); SUVmax greater than 3.45 (p = 0.007) or a relative reduction in SUVmean or SUVmax of less than 32 (p = 0.015) or 52 % (p = 0.013), respectively, was indicative of an increased risk of disease-specific death. PET/CT performed 1 year after SBRT can reliably identify local recurrence and therefore help to clarify unclear CT findings. As posttherapeutic glucose metabolism also correlates with disease-specific survival, PET/CT may help to stratify lung cancer patients for additional treatment 1 year after SBRT.

ZusammenfassungDie Radiojodtherapie ist sowohl bei benignen als auch bei malignen Schilddrüsenerkrankungen etabliert. Während die hochdosierte Radiojodtherapie bei differenzierten Schilddrüsenkarzinomen in ablativer Zielsetzung fast ausnahmslos unter stationären Bedingungen in Abteilungen mit entsprechenden Einrichtungen zum Strahlenschutz erfolgt, kann die niedrig dosierte, u.U. fraktionierte Radiojodtherapie der Schilddrüse bei Hyperthyreosen, Autonomien und Strumen in vielen Ländern ambulant erfolgen. Hier gibt es von Land zu Land ganz unterschiedliche Grenzwerte. In Deutschland ist die ambulante Radiojodtherapie überhaupt nicht zulässig. Bei gleichzeitig hohem Therapiebedarf und begrenzter Bettenkapazität sind die Wartezeiten auf einen Therapieplatz zum Teil auf mehrere Monate angewachsen. Dies führt zunehmend zu einem regelrechten Medizintourismus in das benachbarte Ausland, wo die ambulante Therapie z.T. zulässig ist. Dies erscheint sowohl unter medizinischen als auch gesundheitsökologischen Aspekten äußerst bedenklich und unter den ökonomischen Aspekten des Gesundheitsstrukturgesetzes sehr fragwürdig. Die Zusammenstellung und Auswertung einer Umfrage unter den Landesdelegierten der EANM zeigt eine große Varianz in den europäischen Ländern und spiegelt den aktuellen Stand der großen Unterschiede in der politischen und strahlenschutz-rechtlichen Einschätzung der medizinisch unbestrittenen Radiojodtherapie wider.

Ultrasound, scintigraphy and sonographically guided fine-needle biopsy are the cornerstones in the diagnostic work-up multinodular goitre. Subsequent decisions for adequate treatments should be based on accurate tests to avoid unnecessary intervention. Especially in areas with endemic goitre a preselection of patients for the most effective procedure e.g. surgical or medical treatment is mandatory. Autoimmune hyperthyroidism (Graves' disease), solitary hyperfunctioning thyroid nodules and toxic multinodular goitre (Plummer's disease) constitute a clear indication for radioiodine treatment in many cases. Recently, there is an emerging role for I-131 in the treatment for so called subclinical hyperthyroidism caused by either of three first entities and for patients with non-toxic goitre, in whom surgery is not an option. These patients with large non toxic goitre encompass a group of patients who are euthyroid but may benefit from diminishment of thyroid volume. We review the spectrum of diagnostic tests and provide some recommendations regarding (nuclear medicine) therapy.

Although predictive factors (PF) for conventional lymphoma therapy are established and frequently used in clinical practice and medical research, the PF for radioimmunotherapy (RIT) have not been fully defined until now. The aim of this multicenter evaluation is to prove the feasibility of the multicenter web-based data collection and to preliminary explore imaging findings and prediction of therapy response in patients with follicular lymphoma (FL) following radioimmunotherapy (RIT) with 90Y-ibritumomab tiuxetan.We retrospectively analyzed and correlated clinical and imaging data (CT and FDG-PET) before and after RIT as documented by the RIT-Network. Evaluation of treatment response was done on both patient and lesion basis. Every measurable lesion was analyzed in terms of standardized uptake value (SUV), volume (CT and PET) and response. PF were identified using a uni- and multivariate model. A web-based system was used for the documentation and evaluation of clinical and imaging data.16 patients with at least one PET before and after RIT were eligible for analysis. Concerning response three months postRIT, 5 patients achieved a CR, 6 patients a PR and 4 patients remained with NC. A total of 159 lesions were measured (mean 10±8). In the multivariate model the log lesion volume (p0.0001), the total (p = 0.03) and maximum lesion volume (p = 0.05) were predictors for response (CR + PR). Concerning the lesional CR initial small lesion volume (p = 0.009) and its high metabolic activity (p = 0.01) were identified as predictors. The web-based system showed no major disturbances allowing secure data transfer and central image interpretation in a reasonable time.The use of a web-based multicenter archiving system for clinical and imaging data is technically feasible in a multicenter setting and allows a central analysis. This preliminary analysis suggests that FDG-PET may predict the likelihood of response to RIT.

Neuroendocrine tumors (NET) are defined by biochemical characteristics and structures which can be specifically addressed by radioligands for diagnostic imaging as well as radionuclide therapy in nuclear medicine. Somatostatin receptor imaging has been shown to be an important part of the diagnostic process in the management of NET for a long time. In recent years a number of tracers enabling PET-based imaging of somatostatin receptors and amine precursor uptake have been developed. By combining the specific functional information of the PET signal with anatomical information by CT imaging using PET-CT hybrid scanners, primary tumors and metastases can be detected with high resolution and high sensitivity. Compared with conventional indium-111 octreotide scintigraphy PET-CT has a higher resolution and also a lower radiation exposure. In addition, quantification of the tracer uptake allows therapy monitoring. By labelling with therapeutic beta-emitters, such as lutetium-177 or yttrium-90, a systemic internal radiotherapy with somotostatin analogues (peptide radionuclide radiation therapy, PRRT) can be provided as a therapeutic option for patients with unresectable and metastasized neuroendocrine tumors.

Der Ostradiol-Rezeptorstatus (ER-Status) hat fur die Prognose und die hormonelle Therapieplanung beim Mammakarzinom Bedeutung. Im Rahmen einer Multizenterstudie (5 Zentren) wurde daher l6-alpha-l2,J-Jodostradiol-l7-s (123J-E2) zur rezeptorspezifischen (E2-)Szintigraphie (planar und SPECT) bei 62 Patientinnen mit Mammakarzinom oder Verdacht auf Mammakarzinom eingesetzt, um methodische Probleme zu klaren und die Methode zu validieren. Nach i.v. Gabe zeigte sich eine schnelle Elimination der Verbindung aus dem Blutpool und eine rasche Konzentration in der Leber mit nachfolgender Ausscheidung uber die Gallenwege in den Darm, was zwar fruhe Aufnahmen bei niedrigem Background im Thoraxbereich ermoglichte, die Beurteilung des Abdomens aber erschwerte. Bei 42 Patientinnen (30 Karzinome, 12 benigne Veranderungen) ergab sich in Abhangigkeit vom ER-Status (cut-off: 10 fmol/mg) eine Sensitivitat von 66%. Bei einigen Patientinnen mit Tumoren zeigten sich fokale oder diffuse Mehrbelegungen in den Lymphabflusbereichen parasternal und axillar ohne ein klinisches Korrelat, was Verlaufsbeobachtungen erfordert. Bei den bioptisch gesicherten Fallen wurde szintigra-phisch lediglich ein falsch-positiver Befund erhoben; somit erscheint auch eine nichtinvasive Bestimmung des Rezeptorstatus moglich. Aufgrund der geringen Tumoranreicherung ist die Sensitivitat der 123J-E2-Szintigra-phie beim Tumornachweis in der Primardiagnostik und der Lokalisation von Rezidiven und Metastasen im Vergleich z.B. zur Mammographie noch zu gering. Die 123J-Szintigraphie kann als Screeningmethode derzeit noch keine Rolle spielen. Eine sichere Differenzierung zwischen malignen und benignen Lasionen erscheint nicht ohne weiteres moglich, da auch benigne Veranderungen einen positiven Rezeptorstatus zeigen konnen, so z. B. Mastopathien. Die -Szintigraphie ist ein bildgebendes In-vivo-Verfahren zur Erkennung maligner Mam-matumoren unter Ausnutzung des positiven ER-Status und last Aussagen uber die Tumorlokalisation zu. Sie konnte eine spezifische Methode zur nichtinvasiven In-vivo-Diagnostik des ER-Status darstellen und bietet daneben neue Perspektiven in der Nachsorge des Mammakarzinoms. Als rezeptorspezifisches bildgebendes Verfahren hat die E2-Szintigraphie moglicherweise bei Fragestellungen nach der Tumor-Heterogenitat oder nach einem Wechsel des Rezeptorstatus unter Therapie eine Anwendungsberechtigung.

A 41-year-old male patient suffering from psoriasis arthropathica underwent a two-phase bone scan for activity of joint affections. Extensive diffuse skin contamination of the extremities in the delayed images was due to the use of the patient's own radioactive urine as an embrocation for psoriasis exanthema.

ZusammenfassungBei einem 41jährigen Patienten mit Psoriasisarthropathie fiel in der Skelettszintigraphie in den Aufnahmen der Mineralisationsphase eine flächige Aktivitätsbelegung der Beine auf. Als Ursache stellte sich das zwischenzeitliche Einreiben der Extremitäten durch den Patienten mit dem radioaktiven Eigenurin wegen eines Exanthems heraus.

Scintigraphy continues to play an important diagnostic role in internal medicine. Many diagnostic questions can only be answered with scintigraphic methods. The application of specific radiopharmaceutical tracers offers the unique possibility to visualize ongoing functional changes, associated with diseases concerning internal medicine. The diagnostic potential of modern scintigraphic procedures such as PET for internal medicine is not yet sufficiently used and will continue to grow with hybrid systems, such as PET-CT and SPECT-CT.

Reoperation for thyroid cancer needs to consider patient-, tumor- and therapy-related aspects as well as present diagnostic results. Reoperation because of thyroid remnants, persistence of the primary tumor and lymph node metastasis (completion surgery) has to be distinguished from reoperation due to locoregional recurrence (primary tumor, lymph nodes). The primary surgical strategy should avoid the need for reoperation. The extent of reoperation is related to the extent of primary surgery, stage, and distant metastasis. The timing and indication of reoperation for differentiated thyroid carcinoma in an interdisciplinary multimodal treatment setting depends on diagnostic radioiodine scans and radioiodine therapy. Long-term, recurrence-free survival is achieved by sufficiently radical surgery with acceptable morbidity, including all additive or adjuvant treatment options.

Mammography is the primary imaging modality for screening of breast cancer and evaluation of breast lesions (T staging). Ultrasonography is an adjunctive tool for mammographically suspicious lesions, in patients with mastopathy and as guidance for reliable histological diagnosis with percutaneous biopsy. Dynamic enhanced magnetic resonance mammography (MRM) has a high sensitivity for the detection of breast cancer, but also a high false positive diagnosis rate. In the literature, MRM is reported to have a sensitivity of 86–96%, a specificity of 64–91%, an accuracy of 79–93%, a positive predictive value (PPV) of 77–92% and a negative predictive value (NPV) of 75–94%. In unclarified cases, metabolic imaging using fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) can be performed. In the literature, FDG PET is reported to have a sensitivity of 64–96%, a specificity of 73–100%, an accuracy of 70–97%, a PPV of 81–100% and an NPV of 52–89%. Furthermore, PET or PET/CT using FDG has an important role in the assessment of N and M staging of breast cancer, the prediction of tumour response in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy, and the differentiation of scar and cancer recurrence. Other functional radionuclide-based diagnostic tools, such as scintimammography with sestamibi, peptide scintigraphy or immunoscintigraphy, have a lower accuracy than FDG PET and, therefore, are appropriate only for exceptional indications.

Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients.Therapy and body weight related data of 100 consecutive RITh-patients were retrospectively analysed from the time before up to three years after RITh. All patients suffered from hyperthyroidism (Graves' disease or autonomy), but were adjusted to euthyroid levels after RITh. Patients' data were compared to a control group of 48 euthyroid patients out of the same ambulance and during the same time scale.All patients (RITh and controls) gained weight over the time. There was no statistically significant difference in BMI development over three years between RITh-patients and controls (5.5% resp. 4.9% increase). In the first year after RITh, weight gain of the RITh patients was higher indeed, but lower in the follow up, resulting in the same range of weight gain after three years as the controls. Besides that women showed a slightly higher increase of BMI than men, and so did younger patients compared to elder as well as patients with overweight already before RITh.An initially distinct increase of body weight after RITh of hyperthyroidism is mainly a compensation of pretherapeutic weight loss due to hyperthyroidism. Presupposing adequate euthyroid adjustment of thyroid metabolism after therapy, RITh is not responsible for later weight gain and adipositas.

The neck lymph nodes are a common site of metastases from carcinoma of unknown primary (CUP syndrome). 2[(18) F]-fluoro-2-deoxy-D-glucose positron emission tomography (18-FDG-PET) has been shown to be a sensitive tool for detecting primary malignant lesions as well as metastatic spread. We have prospectively investigated the sensitivity of 18-FDG-PET in detecting occult primary carcinomas with manifestation in the head and neck lymph nodes.From May 1994 to July 1998, in 723 patients a cancer of the head and neck was diagnosed at the University of Cologne ENT outpatient clinic. The routinely performed staging procedures were chest radiography; full blood count; cervical and liver ultrasound; endoscopy of the nasopharynx, oropharynx, hypopharynx, larynx, and esophagus; and laboratory analyses. After the staging workup, in 27 of 723 patients (3.7%) CUP syndrome had to be presumed because the primary cancer could not be detected. In these patients 18-FDG-PET was performed, and images were reconstructed with a transmission-emission fusion technique.In 7 of 27 patients (26%) 18-FDG-PET revealed an unknown primary: in 2 a bronchial carcinoma, in 2 a nasopharyngeal carcinoma, in 1 a squamous cell carcinoma of the parotid gland, in 1 a squamous cell carcinoma of the hypopharynx, and in 1 a carcinoma of the tonsil. In 4 of 7 patients the occult primary tumor was removed surgically. In 8 of 27 patients therapeutic strategy was changed as a result of the 18-FDG-PET findings.18-FDG-PET should be performed in all patients with CUP syndrome after conventional diagnostic workup fails to identify the primary.

The management of metastases of unknown primary origin presents considerable challenges to the treating physician, because therapy decisions are often determined by the nature of the primary tumor. Metastases originating from an unknown source are known as “CUP tumors” (carcinoma of unknown primary). Incidence of CUP tumors ranges from 0.5 to 10% of all newly diagnosed tumors [2, 8, 11, 15, 19, 26]; they are more prevalent in males and the mean age of diagnosis is about 60 years. Frequent first sittings for the metastatic lesions are lymph nodes (37%); of these, 31% are located in the head and neck region, which is the most common site for metastases of unknown origin [14].

Additional or expensive diagnostic imaging had to prove prospectively their diagnostic efficacy, their therapeutic efficacy, or their patient-outcome efficacy. The adherence to methodologic standards in the cost-effectiveness literature is required. Based on the bone scintigraphy in oncologic patients with a low prevalence of bone metastases, the cost-effectiveness is questionable. The economic role of 99m-Tc MIBI mammoscintigraphy and of the imaging for carcinomas of unknown origin is discussed controversially. Based on the reimbursement of the positron emission tomography (PET) in the USA and in Switzerland, cost-effectiveness literature and decision trees for cost-utility analyses are reviewed. PET imaging was cost-effective in non-small-cell lung cancer, in solitary pulmonary nodules, in recurrent colorectal cancer, in metastatic melanoma and in recurrent head and neck cancer with reduced costs of management. The German health insurance calls for PET-data based on the national reimbursement.

Vor der Behandlung einer Splenomegalie, die sich im Rahmen einer primaren oder sekundaren Osteomyelofibrose entwickelt hat, mus bekannt sein, ob eine signifikante Blutbildung auserhalb der Milz stattfindet. Im Gegensatz zur Ferrokinetik mit 59Fe, die keine bildliche Darstellung erlaubt, ermoglicht die Immunszintigraphie mit dem monoklonalen Antikorper Bw 250/183 eine spezifische szintigra-phische Darstellung des blutbildenden Knochenmarks. Anhand eines Fallbeispiels wird die klinische Relevanz dieser Methode als Erganzung zur Ferrokinetik illustriert und diskutiert.

The radiocytotoxic effects in estrogen receptor (ER) containing MCF-7 cells of a mamma carcinoma were investigated following incubation with [125I]E ranging from 1 h to 24 h.The receptor status of the cells was confirmed by immunohistochemical staining. The accumulation of [125I]E in MCF-7 cells was tested in the presence and absence of radioinert E and [127I]E and in ER-negative cells in comparison to ER-positive cells. The subcellular distribution was investigated in 0.25 M Saccharose by ultra centrifugation. The radiocytotoxicity was assessed in ER-positive and negative cells by a standard colony forming assay after incubating with [125I]E (1.85 kBq/ml-55.5 kBq/ml) for 1, 2, 4, 8, 12, and 24 h.A significant cytotoxicity was observed only when ER-rich MCF-7-cells were incubated with [125I]E alone. The maximal cytotoxic effect was a reduction of survival fraction to 20-25%. This was achieved at radioactivity concentrations37 kBq/ml. Maximal effect was seen after 8 h incubation, extension of incubation time did not further increase toxicity.The results suggest that the radioactivity was bound to ER. Through their nuclear localization radioestrogens tagged with radionuclides emitting very low energy electrons (Auger electrons) bear potential for therapy by ER-mediated deposition of lethal doses of ionizing radiation to single cells without affecting neighbouring cells. But, instead of 125I the shorter-living 123I shall be used for labelling because the deciding radiation effectes occur within the first 8 h.

Radio-labeled estrogen receptor ligands are tracers that can be used for functional receptor diagnosis. Their specificity towards receptors, together with the fact that only 50-70% of mammary carcinomas are receptor positive, renders them unsuitable for detection of primary tumors or metastases, and this means that estrogen receptor scintigraphy can be used neither for tumor screening nor for staging. However, both 18F-labeled and 123I-labeled estradiol derivatives are suitable for in vivo imaging of estrogen receptors. Their high specificity, established in animal experiments and in vitro studies has been reproduced in in vivo applications in humans. Tracers with positron radiation emitters are, however, hardly suitable for broad application owing to the short half-life of 18F, which would mean that users would need to be situated close to a cyclotron and a correspondingly equipped radiochemical laboratory. The number of available PET scanners, on the other hand, has increased over the last few years, especially in Germany, so that this, at least, does not present a limiting factor. All the same, 123I-labeled estradiol derivatives will find more widespread application, since the number of gamma-cameras incorporating modern multi-head systems is several times greater. The results of studies with 123I-E2-scintigraphy published to date are very promising, even given the initial technical problems mentioned above. As a method of examination, it could be optimised by using improved tracers with a higher tumor contrast and less disturbance from overlapping in diagnostically relevant locations, for instance, by selecting tracers with higher activities whose excretion is more renal than hepatobiliary. The use of modern multi-head camera systems can also be expected to improve the photon yield.

The bone mineral density (BMD) of 14 children, adolescents, and adults with phenylketonuria (PKU) on dietary treatment (age 5-28 y; 6F, 8M) was investigated using peripheral quantitative computed tomography (pQCT) of the distal radius. BMD of total (TBMD) and spongy bone (SBMD) were compared to those of healthy gender-, age-, weight- and height-matched controls. We found a significant decrease of SBMD in patients with PKU while TBMD was only slightly decreased, reaching no statistical significance. These results indicate minor changes of BMD in patients with PKU under treatment, which are more accentuated in the trabecular bone compartment. One additional patient who was untreated until the pQCT investigation at the age of 10 y also showed markedly decreased SBMD and TBMD.

Summary Aim: FDG-PET and MIBI-scintigraphy with SPECT were compared to [131I]-whole-body scintigraphy (WBS) and morphologic imaging in the follow-up of differentiated thyroid cancer. Their influence on therapy-planning was analysed. Methods: In 50 consecutive patients (papillary/ follicular/variants of a follicular carcinoma: 33/13/4; primary status: pTI/2/3/4: 3/16/9/22) FDG-PET of neck/chest and MIBI-whole-body scan including SPECT were performed during hypothyreosis and before WBS. Morphologic imaging was done by MRI in all and by CT of the lung without contrast media in 21 patients. Results: The complete extent of metastases was detected by FDG-PET in 11 and by MIBI-scintigraphy also in 11 of 22 patients with evidence of disease. The combined evaluation of WBS and FDG-PET as well as of WBS and MIBI-scintigraphy held true in 18 of 22 patients. Limiting FDG-PET or MIBI-scintigraphy to patients with elevated thyroglobulin (Tg)-levels and negative WBS only, would not, therefore, alter the sensitivity of this algorithm. The diagnostic benefit of FDG-PET and MIBI-scintigraphy was confined to lymph node metastases. The 1 cm limit for lymph node size in morphologically based imaging did not apply to FDG-PET and MIBI-scintigraphy. None of the 6 patients with small (

A prospective study was performed to compare the sensitivity and accuracy of ultrasound (US), computed tomography (CT), and single photon emission computed tomography (SPECT) as a bone scan to detect subclinical invasion of the mandible by squamous cell carcinoma of the oral cavity and floor of mouth.The present study reports data on 35 patients with squamous cell carcinoma of the oral cavity. SPECT, mandibular orthopantomography (OPG), US, CT and magnetic resonance imaging (MRI) were performed as well as histologic examination of resected mandibles. Transverse slices of 12 mm thickness were reconstructed for SPECT and semi-quantitative assessment of radionuclide uptake was performed with a scoring system based on comparisons of tracer uptake in the mandible to that in an unaffected part of the mandible. Lesion to non-lesion count ratios in the mandible in 3 h SPECT images were calculated. OPG, US and CT were evaluated for comparison.In 12/35 patients, histologic examination showed carcinoma infiltrating mandibular bone. SPECT correctly predicted mandibular invasion in 11/12 cases, with no false-positive results. CT detected correctly 3/12 lesions, while OPG and ultrasound each demonstrated 2/12 tumors.Bone SPECT was found to provide an accurate means for assessing tumor invasion to the mandible by intraoral squamous cell carcinoma. As a complementary study to one of the other imaging modalities it was shown to have a high specificity, indicating that it should be performed routinely in patients with suspect mandibular bone involvement by causes.

Possibilities to exercise an influence on the biodistribution of a tumor-affine 153Sm-preparation, samarium-153-nitrilotriacetate (NTA), were tested.Animals experiments on tumor-bearing mice after additional application of EDTMP (ethylenediamine tetramethylene phosphonate) for the reduction of extratumorale liver-radioactivity and yttrium chloride for the reduction of unwanted underground radioactivity in bone were carried out. Furthermore, the combination of both measurements was tested.The biodistribution of 153Sm-NTA showed a rather low tumor-radioactivity of app. 0.72%/g. The additional EDTMP-application caused a dose-dependent decrease of the underground-radioactivity in liver especially if given 2 h in advance or simultaneously. The additional application of the stable yttrium salt reduced the bone radioactivity on simultaneous increase of liver- and spleen-radioactivity and practically unchanged tumor-radioactivity. The combined use of EDTMP together with the bone-affine metal salt led to a reduction of liver radioactivity on simultaneous reduction of bone radioactivity.The background radioactivity can be reduced on unchanged tumor-radioactivity by combined Na-EDTMP/YCl3-application. The present results do not allow a therapeutic exploitation because of the low tumor accumulation.