[Guideline for therapy of malignant thyroid tumours: pleading for an actualization]. / Leitlinie zur Therapie maligner Schilddrüsentumoren: Plädoyer für eine Aktualisierung.

Total (or near total) thyroidectomy (TE) followed by radioiodine ((131)I) ablation (RIA) of residual thyroid tissue is considered to be the ideal treatment for differentiated thyroid carcinoma. However, the actual guideline of the DGN (German Society of Nuclear Medicine) recommends for the so-called papillary micro-carcinoma of the thyroid (PMC) no further therapeutic strategy (no complete TE, no (131)I-ablation of the remaining lobe). PMC has been defined as papillary carcinoma measuring 1 cm (T1) in maximal diameter according to the World Health Organization classification system for thyroid tumours (1988). The new WHO-classification (starting in 2003) defines the T1-tumour measuring 2 cm in maximal diameter. The authors demand a new, modern guideline, following the new WHO classification. This includes, that despite the overall excellent prognosis for patients with PMC, the treatment of patients with T1-tumours of the new WHO-classification (including the "old" PMC) should be no different from the treatment of patients with conventional papillary thyroid carcinoma, i.e. complete surgery (TE and central lymph node dissection) followed by RIA of residual thyroid tissue. The authors argue that it is not appropriate to consider the tumour size as the single most important key factor for therapy and prognosis. Even small tumours may have poor prognostic factors, such as lymph node metastasis, multifocality or molecular characteristics (expression of oncogenes).

[18Fluoro-FDG SPECT for the demonstration of hibernating myocardium: an interim account]. / 18Fluor-FDG-SPECT zum Nachweis von hibernierendem Myokard: eine Zwischenbilanz.

AIM: The present investigation demonstrates an intraindividual comparison of FDG-PET and FDG-SPECT. MATERIAL AND METHODS: Thirty patients with CHD and planed revascularisation underwent both modalities. Myocardial perfusion was evaluated by 99mTc-MIBI SPECT. The myocardium was divided into 25 segments and the results were compared by two experienced observers. RESULTS: Segmental concordance of FDG-PET and -SPECT was 94.1%. PET indicated a higher percentage of hibernating myocardium (8.9% vs. 5.7%) and a lower rate of matched defects (11.5% vs. 16.0%). In 22 cases the need for revascularisation was assessed identically. In the remaining 8 patients FDG-PET and FDG-SPECT required an intervention in 6 and 2 cases, respectively. CONCLUSION: The results of FDG-PET and FDG-SPECT showed a high segmental concordance, but the individual assessment of hibernation worthwhile for revascularisation demonstrated important differences in patient management.

[Palliative treatment for pain in osseous metastasized prostatic carcinoma with osteotropic rhenium-186 hydroxyethylidene diphosphonate (HEDP)]. / Palliative Schmerztherapie beim ossär metastasierten Prostatakarzinom mit dem osteotropen beta-Strahler 186Rhenium-Hydroxyethylidendiphosphonat (HEDP).

Systemic administration of strontium-89 is an important option for pain relief in advanced prostate carcinoma with multiple osseous metastases. Recently, rhenium-186-HEDP was introduced as a new substance which has important advantages (shorter physical half-life, scintigraphic imaging, dose distribution). The myelosuppressive effect can be estimated more accurately in advance, so that adverse effects can be reduced and the treatment can be repeated after a shorter period of time and more often. Our study comprises 15 treatments with rhenium-186-HEDP in advanced prostate cancer patients using the 1.4- to 2-fold standard dose. The response rate, estimated as reduction in pain and increase in patient mobility, was 87% with no major myelosuppressive effects. The mean duration of pain relief was 4-6 weeks. All four patients with repeated therapy were also responding to the second treatment. Radionuclide therapy for painful osseous metastases with rhenium-186-HEDP appears to be an effective and, even at higher doses, safe procedure.

Investigations of breast tumors with fluorine-18-fluorodeoxyglucose and SPECT.

METHODS: We designed a prospective study to investigate the feasibility of combined FDG-SPECT and whole-body acquisition in the diagnostic work-up of breast tumors applying visual analysis. We studied 50 patients with breast tumors of unknown histology. RESULTS: All malignant diseases were accurately detected in tumors > 2.3 cm, while the smallest FDG-positive lesion was 1.4 cm. In a subgroup of these patients, quantitative evaluation (tumor-to-back-group ratios) was added, which improved the sensitivity. Lymph node metastases were accurately indicated in 9 of 13 patients, while the detection of distant metastases depended on the location and size. False-positive FDG scans were observed in inflamed tissue, in a rapidly growing phylloides tumor and in supposedly healthy breasts. CONCLUSION: These results are comparable with prior investigations of other groups using PET. Therefore, FDG-SPECT and whole-body acquisition may be an adequate and less expensive technique to meet the increasing demand of FDG examinations.

Radioimmunoscintigraphy of ovarian tumours with technetium-99m labelled monoclonal antibody-170: first clinical experiences.

The recently developed technetium-99m-labelled monoclonal antibody-170 (MAb-170) was designed for diagnostic use in patients suffering from gynaecological adenocarcinoma. Following in vitro studies which showed immunoreactivity of this antibody to more than 90% of human adenocarcinomas, the present investigation was initiated to verify its usefulness for radioimmunoscintigraphy of ovarian tumours. Most of the 30 patients participating in this study underwent immunoscintigraphy prior to first-look surgery. Biokinetic evaluation in two patients showed a plasma half-time of 18.9 h (mean value, n = 2, r = 0.98) and a biexponential total body curve with values of 7.7 h and 17 days (r = 0.98). The mean 24-h urinary excretion was 12% of the injected dose. Radioimmunoscintigraphy using the MAb-170 recognised 12 of 13 cases of adenocarcinoma of the ovaries, corresponding to an overall sensitivity of 92.3%. Specificity was 94.1% (16/17). The calculation of accuracy yielded a figure of 93.3% (28/30). Of 33 known lesions, 26 were visualised successfully; thus the locoregional sensitivity was 78.8%. Of 29 benign tumour sites, 28 showed no evidence of tracer accumulation, corresponding to a locoregional specificity of 96.6%. The smallest lesion visualised was an adenocarcinoma of the corpus uteri with a diameter of 1.5 cm. Technetium-99m labelled MAb-170 is a promising new radiopharmaceutical for immunoscintigraphy of ovarian adenocarcinoma.

[18FDG in the primary staging of lung tumors. Results with a gamma camera and a 511 keV collimator]. / 18FDG beim primären Staging von Lungentumoren. Ergebnisse an einer Gammakamera mit einem 511 keV Kollimator.

The diagnosis of primary lung tumors requires a precise staging according to the TNM classification. In contrast to established imaging methods 18FDG describes the functional metabolic processes in the tumor tissue due to increased glycolysis. This paper describes the use of 18FDG in the primary staging of lung tumors and metastases. 44 patients were studied with a gamma camera and a 511 keV collimator. In comparison to pulmonary tumors and metastases detected by other imaging methods (107) the accumulation of 18FDG has a sensitivity of 85%, in lesions verified by histology (50) of 89%, in primary tumors (35) of 100% and in metastases (63) of 76%. As an alternative to FDG PET studies, primary staging of lung tumors is possible with a gamma camera, suitable for ECT and fitted with a 511 keV collimator.

[Nuclear medicine diagnosis of focal liver lesions]. / Nuklearmedizinische Diagnostik fokaler Leberläsionen.

Confirmation and exclusion of benign focal liver lesions are the main object of liver studies in nuclear medicine. Hepatobiliary sequence scintigraphy (focal nodular hyperplasia, adenoma), blood pool scintigraphy (hemangioma) and, in some cases, colloid scintigraphy are the methods most frequently employed. Receptor scintigraphy with octreopeptides, immunoscintigraphy with monoclonal antibodies, PET and gamma camera scintigraphy with 18FDG, are used to solve special diagnostic problems, particularly in oncology. A stepwise diagnostic approach needs to be used for a successful classification of focal liver lesions and an extensive knowledge of indications for additional supplementary diagnostic procedures is required.

[A clinical evaluation of MAb BW 835/6 in breast and ovarian cancer]. / Klinische Prüfung mit MAk BW 835/6 bei Mamma- und Ovarialkarzinomen.

Studies with the 99mTc-labeled murine monoclonal antibody BW 835/6 in patients suspected of breast (n = 7) or ovarian cancer (n = 8) showed insufficient depiction of primary tumors and metastases of breast cancer, but promising results in the detection of primary tumors in ovarian cancer without metastases. The small number of patients does not allow statistical analysis.