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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.

Aim: Zirconium-89 has gained great interest for PET, when imaging at late time points is required. Desferrioxamine B (DFO), is mostly used for this radionuclide as bifunctional chelator (BFC) and w ...

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.

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.

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.

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.

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].

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.

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 (

In connection with the prevention of osteoporosis, paediatrics is challenged with ensuring the optimal formation of the skeletal system with maximal bone strength during childhood and youth. Biomechanical use represents the most important stimulus for activating the skeletal system. The measurement of muscle strength (grip strength) in 97 females aged 3-62 years and 71 males aged 3-61 years showed an age-dependent course. On the whole, males have greater strength with a more pronounced increase after puberty, reaching a peak maximum at 25-30 years. Females show a more moderate increase after puberty. In a pilot study, bone strength (as bone strength index-BSI) was analysed at the distal radius using peripheral quantitative computerized tomography (pQCT). BSI was calculated on the basis of the geometric data of the polar moment of resistance in combination with the cortical bone density. BSI values increase with age and reach a peak maximum at 25-30 years. There was a highly significant correlation between BSI and grip strength (r = 0.87). These relationships are especially interesting for therapeutic concepts differentiating between direct and indirect (via the muscle system) influences on the skeletal system. The non-invasive bone strength analysis in combination with muscle strength offer new perspectives for the evaluation of the functional muscle-bone unit.

The differential diagnosis of tumours in the skull base is often difficult. With the experience that various intracranial tumours differ in their expression of somatostatin binding sites (SBS) somatostatin receptor scintigraphy (SRS) with the somatostatin analogue octreotide can give additional information of the tumour entity. Seventy patients with various tumours of the skull base were examined with 111Indium-labelled DTPA-octreotide injected i.v.. Planar and tomographic images were obtained with a gamma camera 4-6 and 24 hours after injection. All of the meningiomas (unifocal and multifocal tumours in various locations) showed a high density of SBS whereas in none of the examined neurinomas SR were found. Pituitary adenomas revealed in only 50% SR in different concentrations and independent of the endocrine activity. SRS can help in the differential diagnosis between meningiomas and other tumours, postoperative scar or radionecrosis at the skull base. A dural infiltration with meningioma tissue ("meningeal sign") may be discriminated from a reactive hypervascularisation in lesions with a diameter0.5 cm. We conclude that SRS can offer additional diagnostic aspects in the pre- and postoperative management of patients with skull base tumours.

The aim of this study was to investigate a technique that visualizes findings from PET images in a context useful for surgery.Simultaneously acquired PET emission and transmission scans were used. By applying a multipurpose imaging, registration and rendering tool (MPM), displays of orthogonal and volume-rendered views or any combination thereof were obtained. The PET emission and transmission scans were acquired under routine conditions. The final user-customized display (with a combination of orthogonal cuts and rendered views) was processed in 10 min or less on commercially available hardware. Distinct features of the body shape were clearly visible on the volume-rendered transmission views. Hot spots, e.g., in primary breast cancer, from the emission scans could be easily assessed in their localization relative to the body outline.Rendering of the main signatures in a single comprehensive display makes this method potentially valuable for simple presurgical workup and therapeutic management of breast cancer.

18Fluor-Deoxy-D-Glucose (FDG) reichert sich in Geweben mit hoher Hexokinaseaktivitat an. Plattenepithelkarzinome und deren Metastasen weisen eine hohe Hexokinaseaktivitat auf und konnen daher mit Hilfe der FDG-Positronenemissionstomographie (PET) lokalisiert werden. Den etablierten bildgebenden Verfahren steht damit ein stoffwechselbezogenes bildgebendes Verfahren gegenuber. Ziel unserer Studie war die Validisierung der FDG-PET bei Patienten mit Plattenepithelkarzinomen des Kopfes und des Halses im Vergleich zu Sonographie, Magnetresonanztomographie (MRT) und Computertomographie (CT).

Somatostatin receptors (SR) have been identified in vitro in normal brain tissue, neuroendocrine tumors, and cerebral gliomas of WHO grades 1 and 2 by autoradiography and with somatostatin-gold conjugates [1, 2, 4]. In vivo SR detection has become possible by scintigraphy with the somatostatin analogue octreotide radiolabeled with 111In [2, 4, 5]. It was thought that the expression of SR in cerebral gliomas correlates with low malignancy and in vivo somatostatin receptor scintigraphy (SRS) might offer an alternative grading system for cerebral gliomas [3]. The aim of this study was to evaluate whether SRS can improve the preoperative determination of tumor nature or the postoperative management of patients with cerebral gliomas.

Bei steigender Inzidenz und gleichbleibender Morbiditat gilt der Fruherfassung des Mammakarzinoms grosses Interesse. Fur Therapie und Prognose ist das Tumorstadium sowie der axillare Lymphknotenstatus zum Zeitpunkt der Erstdiagnose ein bedeutender Faktor. Therapieentscheidungen werden weiterhin vom Ostrogenrezeptorstatus (ERStatus) dieses hormonsensitiven Tumors abhangig gemacht. Im Tumorzytosol von Primartumoren findet sich bis zu 60% ein positiver ER-Status. Bisher war eine quantitative oder qualitative Aussage nur an Hand von Biopsiematerial des Primartumors und nur in seltenen Fallen an Hand von Biopsaten aus Metastasen moglich. Wir berichten uber eine Pilotstudie bei der 16 Patientinnen mit primaren Mammalasionen und eine Patientin mit einem metastasierten Mammakarzinom hinsichtlich der diagnostischen Aussagefahigkeit der Rezeptorszintographie untersucht wurden.

Somatostatin receptors have been demonstrated on various tumors of neuroendocrine and other origin. They have been detected in vitro by biochemical techniques as well as by autoradiography. The development of long-acting somatostatin analogs and the recent availability of radiolabeled octreotide have made the in vivo detection of somatostatin receptors possible. This preliminary study embraced 45 patients with meningiomas, brain tumors or pituitary tumors, which were imaged by planar and tomographic scintigraphy after intravenous injection of 111Indium-labeled octreotide. In all of the meningiomas studied (unifocal and multifocal tumors in various locations), a high density of somatostatin receptors was detected by scintigraphy. Pituitary tumors were slightly positive in 50% of cases only, independent of the endocrine activity. Gliomas with an intact blood-brain barrier showed no enhanced tracer uptake in vivo, while gliomas with disturbed blood-brain barrier had a high activity uptake. We conclude that in vivo somatostatin receptor scintigraphy, although not tumor-specific, may aid in the preoperative diagnosis and staging of intracranial tumors, especially skull base tumors.

Der Ostrogenrezeptor (ER)-Status von Mamma- und Endometriumkarzinom ist wichtig fur die Prognose und Therapie (1). Die Notwendigkeit zur Entnahme von Biopsien zur ER-Bestimmung limitiert die Zahl von Tumorlokalisationen, die simultan untersucht werden konnen, und sequentielle Bestimmungen bei Metastasierung und Rezidiv. Heterogenitat von Primartumor und Metastasen und mogliche Anderungen des ER-Phanotyps wahrend der Therapie werden daher unzureichend erfast. Durch Tumorexzision und Aufarbeitung des Gewebes konnen Artefakte auftreten, so das der vom Labor ermittelte ER-Status eventuell nicht mehr mit der Situation in-vivo entspricht. Das Verstandnis der Rezeptorbiologie und die Behandlung der Patienten wurden von Techniken profitieren, welche die Bestimmung des ER-Status in vivo gestattet. Wir testeten, ob ein Gamma-emittierender, hochaffiner ER-Ligand (16α-[123J]Jod-Ostradiol-17β, [123J]E, spez. Aktivitat > 10.000 Ci/mmol) (2) in ER-reichen Geweben fur eine szintigraphische Darstellung in-vivo hinreichen spezifisch konzentriert wird.

Metastasiertes follikulares Schilddrusenkarzinom mit intrakranieller lod-131 -Anreicherung in einem Hirnodem bei frontalem Meningeom