[Scintigraphically "hot" thyroid nodules mainly go hand in hand with a normal TSH]

AIM

In recent years, various professional societies published guidelines for diagnostic evaluation of thyroid nodules, in which the indication for scintigraphy is restricted to patients with subnormal TSH values. It is seen controversial whether such recommendations should be transferred to Germany, partly because of lower iodine intake in this country and the consequent higher percentage of autonomous thyroid nodules, which are not accompanied by a measurable dysfunction. Since reliable data to this topic are scarce, we analyzed multicentrically the spectrum of scintigraphically "hot" and "warm" nodules under the current epidemiological conditions.

PATIENTS, METHODS

In 10 German nuclear medicine out-patient institutions we evaluated the diagnostic data from a total of 514 patients, in whom unequivocally hyperfunctional nodules (focal increased uptake in comparison to perinodular tissue with a sonographically nodular correlative ≥1 cm) could be detected by (99m)Tc-pertechnetate scintigraphy. To minimize selection bias, the surveys were not carried out in hospitals.The recorded parameters included the thyroid hormone levels, the global (99m)Tc-uptake (TcTU), the size of each nodule and the total autonomous nodular volume (V(aut)).

RESULTS

Only 20% of the patients with "hot" nodules had subnormal TSH levels (<0.1 to 0.33 mU / l), the remaining patients had TSH levels from 0.34 to 3.5 mU /l (in one third of the patients TSH levels even exceeded 1.0 mU/l). Moreover, we found no relevant correlation between TSH and TcTU or V(aut).

CONCLUSIONS

In Germany, in at far the largest proportion of patients with autonomous thyroid nodules objectified by means of scintigraphy, TSH levels are within the normal range. Since such nodules with maximum safety can be classified as benign, a corresponding scintigraphic finding has a high priority for the patient. These current data support that it is not reasonable to restrict scintigraphy to patients with subnormal TSH values in this country.

Basal and Stimulated Calcitonin and Procalcitonin by Various Assays in Patients with and without Medullary Thyroid Cancer

BACKGROUND

Calcitonin (CT) is a sensitive marker for evaluation of medullary thyroid cancer (MTC). However, CT measurement can vary with assay- and nonassay-dependent factors, and procalcitonin (PCT) measurement has been proposed for evaluating questionable increases in CT.

METHODS

We tested 2 fully automated CT assays (Immulite [IL] and Liaison [LIA]) and 1 nonautomated CT assay (IRMA, Medipan) and compared these results with PCT (Brahms Kryptor). We evaluated preanalytical conditions and PCT cross-reactivity in sera of 437 patients with clinical conditions associated with hypercalcitoninemia. Additionally, we determined the true “nil” CT concentration in 60 thyroidectomized patients and defined CT cutoff concentrations for pentagastrin stimulation testing in 13 chronic kidney disease (CKD) patients and 10 MTC patients.

RESULTS

Markedly decreased CT concentrations were found after storage of sera for &gt;2 h at room temperature and &gt;6 h at 4 °C. Cutoff concentrations for basal and stimulated CT were disease and assay dependent. Proton pump inhibitor therapy was the most frequent reason for increased CT. PCT concentrations were higher in patients with MTC than in patients with CKD without infections (P &lt; 0.001). Whereas IL and LIA demonstrated comparable analytical quality, the IRMA gave increased CT concentrations in nil sera and showed cross-reactivity with PCT in patients with concomitant bacterial infection.

CONCLUSIONS

IL, LIA, and IRMA detected increased CT concentrations in non-MTC patients and discriminated MTC from CKD patients in pentagastrin tests. PCT assessment may be helpful in the diagnostic work-up of increased CT concentrations in questionable clinical circumstances.

Somatostatin receptor scintigraphy in advanced renal cell carcinoma. Results of a phase II-trial of somatostatine analogue therapy in patients with advanced RCC

AIMS

Objective of this prospective study was to evaluate the role of somatostatin receptor scintigraphy (SRS) in advanced renal cell carcinoma (RCC) with respect to potential therapy with somatostatin analogue (SST-A) and to assess the response rate under therapy with SST-A.

PATIENTS, METHODS

16 patients with documented progression of histologically confirmed advanced RCC were included. Planar whole-body SRS was performed 4, 24 and 48 h post i.v. injection of 175-200 MBq 111In-pentetreoide. 5 and 25 h p.i. SPECT of thorax and abdomen were performed. Documentation of somatostatin receptor expression via SRS in >50% of known tumour lesions was the criteria for treatment start with SST-A (Sandostatin LAR-Depot 30 mg i.m. every four weeks).

RESULTS

In 9/16 of the patients SRS showed at least one metastasis with moderate (n = 5) or intense (n = 4) tracer uptake. Lesion-based SRS evaluation showed only 12.1% (20/165) of all metastases. Most false-negative lesions were located in the lungs. In two patients, the majority of the known metastases was SRS positive and these patients received SST-A therapy. The first radiographic evaluation after a two-month interval showed progressive disease in both patients.

CONCLUSIONS

We conclude that SRS is of limited value in staging of advanced RCC. In our patients SST-A did not result in a growth control of RCC. Consequently, the use of SST-A in advanced RCC seems to be no relevant therapeutic option.

Economic image compression of output documentation of the most frequent examinations in nuclear medicine

RATIONALE AND OBJECTIVES

In recent years, picture archiving and communication systems and electronic transfer of radiologic images using the digital imaging and communications in medicine file standard has become more widely employed in diagnostic radiology. It seems to be likely that nuclear medicine will be integrated within such systems. On the other hand, many departments possess older nuclear medicine equipment without digital output facilities. There is an increasing tendency to display and archive evaluated images ("save-screens," printouts) on nondedicated, inexpensive systems using file formats capable of data compression. This was the reason for examining the value of the JPEG format in this pilot study.

MATERIALS AND METHODS

Fifty scanned planar bitmap images of the most frequent scintigraphic examinations (thyroid, bone, myocardium, lungs, and kidneys) were compared with JPEG format at different data compressions by two blinded observers. The visualization of details (eg, pathologic findings) is described for all these images as the visual appearance of the images and the storage capacity required.

RESULTS

Relevant loss of clinical information did not occur up to compression factors of 0.75. A major decrease of subjective image quality was seen at compression factors >0.90. Compared with bitmap files, the use of these factors reduced the storage capacity required by 98% at a (JPEG-related) compression factor of 0.50, and 99% at a compression factor of 0.90. Compared with the GIF format, a reduction by 4.0-5.7 could be achieved.

CONCLUSIONS

Use of the JPEG format can therefore be recommended to save costs of image transfer or archiving of standard planar scans for nuclear medical evaluation.

[Protective factors for anxiety and depression in thyroid cancer patients]

OBJECTIVES

Depression and anxiety are the most common mental symptoms in patients with thyroid cancer (DTC) and have an important influence on the quality of life. The aim of the current study was to identify protective factors of depression and anxiety in DTC patients.

METHODS

In a cross-sectional study 230 DTC patients were examined with Hospital Anxiety and Depression Scale (HADS-D), the Sense of Coherence Scale (SOC-13) and the Questionnaire of Social Support (F-SOZU).

RESULTS

Depression correlated highly significantly with anxiety (r = .633, p = 0,001). Social support and sense of coherence correlated highly significantly negative with depression as well as with anxiety (both p < or = 0,001). Although still significant, the correlation between age and anxiety was lower (r = -.19; p < or = 0,005). The TSH level as an indicator of hypothyreodism did not correlate with depression or with anxiety on a significant statistical level. Furthermore, variables such as education, religiosity and elapsed time interval since initial diagnosis were not correlated with depression and anxiety.

DISCUSSION

Our results support the thesis that low social support and low sense of coherence enhance vulnerability to depressive and anxiety symptoms.

124I-PET dosimetry in advanced differentiated thyroid cancer: therapeutic impact

PURPOSE

This study evaluated the impact of (124)I-positron emission tomography (PET) dosimetry on post-primary surgery therapy in radioiodine-naïve patients with advanced differentiated thyroid cancer (DTC).

PATIENTS, MATERIAL, METHODS

In each of 28 thyroidectomized patients with high-risk DTC (one or more of pT4, pN1 or pM1), we gave 23-50 MBq of (124)I as an oral capsule and performed PET dosimetry to calculate the individualized therapeutic (131)I activity that would, insofar as possible, achieve a radioiodine dose >or=100 Gy to all metastases without exceeding 2 Gy to the blood (a surrogate for bone marrow toxicity). We thus determined the absorbed lesion dose per GBq of administered 131I activity (LDpA) based on serial PET (4, 24, 48, 72 and 96 h after oral 124I intake) and PET/computed tomography (25 h after (124)I intake) and the critical blood activity (CBA) based on blood and whole-body radiation counting (2, 4, 24, 48, 72, 96 h after 124I intake). We compared the dosimetry-based interventions with our standard empirical protocol.

RESULTS

25 patients had a total of 126 iodine-positive metastases. 18 (72%) of the 25 had solely iodine-avid metastases, while seven (28%) had both iodine-avid and -non-avid metastases. In two patients (8%), none of the iodine-avid metastases could have been practically treated with a sufficient radiation dose. Relative to the empirical protocol, (124)I-PET dosimetry findings changed management in 7 (25%) patients, e.g. allowing application of activities >11 GBq (131)I. Further changes included implementation of hematological back-up in a patient found to be at risk of life-threatening marrow toxicity, and early multimodal therapy in 9 (32%) patients.

CONCLUSION

124I-PET dosimetry is a useful routine procedure in advanced DTC and may allow safer or more effective radioiodine activities and earlier multimodal interventions than do standard empirical protocols.

Optimizing preoperative imaging in primary hyperparathyroidism

BACKGROUND

Scintigraphy of the hyperfunctioning parathyroid glands using technetium 99m ((99m)Tc)-methoxyisobutylisonitrile ((99m)Tc-MIBI) is an established and highly sensitive preoperative localization tool whose importance has been further increased by advances in minimally invasive surgery . The goal of the present prospective study was to determine the benefit of optimized imaging in a consistent patient population.

METHODS

Eighty-four patients with first presentations of primary hyperparathyroidism were investigated with (99m)Tc-MIBI scintigraphy, thyroid scintigraphy, and cervical ultrasonography. The evaluation algorithm consisted of (a) evaluation of the planar images alone, (b) additional evaluation of single-photon emission computed tomography (SPECT), (c) additional evaluation of thyroid gland scintigraphy, and (d) additional evaluation of ultrasound. All patients subsequently underwent parathyroidectomy. The intraoperative and the histologic findings were correlated with the results of the scintigraphic imaging.

RESULTS

The sensitivity of planar parathyroid scintigraphy was 74% and could be increased to 91% by the additional investigations. The difference was statistically significant (p<0.05). At the same time, a small increase in specificity from 96% to 99% was seen.

CONCLUSIONS

Prior to minimally invasive treatment of hyperparathyroidism, we recommend combined localization studies consisting of sequential (99m)Tc-MIBI scintigraphy, additional SPECT plus thyroid gland scintigraphy, plus high-resolution cervical ultrasonography.

Relationship between cumulative radiation dose and salivary gland uptake associated with radioiodine therapy of thyroid cancer

AIM

To estimate the individual absorbed dose to the parotid and submandibular salivary glands in radioiodine therapy and its dependence from the previous cumulative therapy.

METHODS

Fifty-five patients with differentiated thyroid carcinoma after thyroidectomy received 1-21 GBq (131)I using single activities of 1-6 GBq. The patients were stratified according to the cumulative activities into low-activity (1-2 GBq), middle-activity (3-7 GBq), and high-activity groups (9-21 GBq). The time-activity curves over the respective salivary glands were derived from multiple static calibrated images measured for each patient up to 48 h after ingestion of the radioiodine therapy capsule with a gamma camera. Manually drawn regions of interests were used to determine the background activities and the activities arising from the salivary glands. The gland volumes were determined by ultrasonography using appropriate volume models.

RESULTS

The median absorbed dose per administered activity of each single parotid and submandibular gland was about 0.15 Gy.GBq (range, 0.1-0.3 Gy.GBq(-1)) and 0.48 Gy.GBq(-1) (range, 0.2-1.2 Gy.GBq(-1)), respectively. The maximum uptake of both gland types was significantly lower for the high-activity than for the low-activity groups and correlated with the mean cumulative administered activity of the activity groups.

CONCLUSION

The iodine uptake of salivary glands is significantly reduced, whereas the absorbed dose per administered (131)I activity was not significantly decreased during the course of therapy. Comparing the well-known dose-effect relationships in external radiation therapy, the absorbed dose per administered (131)I activity is too low to induce comparable radiation damage, suggesting an inhomogeneous distribution of (131)I in human salivary glands.

Health-related Quality of Life, Depression and Anxiety in Thyroid Cancer Patients

OBJECTIVES

We examined the relationships among physical complaints, health-related quality of life (HRQL), anxiety and depression in differentiated thyroid cancer (DTC) patients under short-term hypothyroidism.

METHODS

We conducted a cross-sectional study in 136 patients hypothyroid on thyroid hormone withdrawal (THW) hospitalized for radioiodine administration. Patients were assessed using Short Form SF-36 (SF-36), Hospital Anxiety and Depression Scale (HADS), Profile of Mood States (POMS), Beck Depression Inventory (BDI), and physical complaints.

RESULTS

Compared to the German general population, hypothyroid patients had significantly impaired HRQL. Surprisingly, the prevalence of anxiety (62.5%), but not depression (17.9%) was much higher in hypothyroid DTC patients than in the general population. In multivariate analysis, depression and age were independently associated with the physical health score (R(2) = 0.21), but only psychological variables (depression, mood disturbance, and anxiety) were associated with the mental health score (R(2) = 0.43), on the SF-36 HRQL instrument.

CONCLUSIONS

HRQL is severely impaired in DTC patients under short-term hypothyroidism. As potential predictors of generic HRQL impairment, depression, anxiety, and mood disturbance could be used to preselect the patients most needing psychiatric care. The high frequency of anxiety should be considered in the aftercare of thyroid cancer patients.

The C allele of theGNB3 C825T polymorphism of the G protein β3-subunit is associated with an increased risk for the development of oncocytic thyroid tumours

Carriers of the C allele of the common C825T polymorphism in the GNB3 gene of the G protein have been associated with the development of follicular thyroid adenomas. Since the C allele of this polymorphism is related to a lower signalling capacity, it was speculated whether the C825T polymorphism may play a particular role in oncocytic thyroid tumours, which are recognized for their reduced ability to synthesize thyroid-specific proteins and hormones, although they possess an intact thyroid-stimulating hormone receptor-adenylyl cyclase system. Using pyrosequencing, both the genotype distribution and the allele frequency of the C825T polymorphism were investigated in a series of 104 patients with oncocytic thyroid tumours of follicular cell origin [58 adenomas, 41 follicular thyroid carcinomas (FTCs), and five papillary thyroid carcinomas (PTCs)]; the results were compared with those obtained from 321 age and gender-matched healthy blood donors and a series of 327 non-oncocytic thyroid tumours of follicular cell origin (119 adenomas, 80 FTCs, and 186 PTCs). Analysis of the genotype distribution (comparing oncocytic with non-oncocytic tumours of the present series) revealed a significantly increased odds ratio (OR) for CC versus TT (OR = 4.22; p = 0.011) and CC versus CT (OR = 1.62; p = 0.049) carriers to develop an oncocytic thyroid tumour; ORs to develop an oncocytic thyroid tumour were also increased comparing the genotype distribution between the group of oncocytic tumours and healthy controls for CC versus TT (OR = 3.73; p = 0.017) and CC versus all T carriers (OR = 1.56; p = 0.034). Oncocytic thyroid tumours as a group showed a statistically significant increase of the C-allele frequency when compared with all non-oncocytic tumours (p = 0.0039) as well as healthy blood donors (p = 0.017). The results strongly suggest that the C allele of the GNB3 C825T polymorphism of the G protein beta3-subunit is associated with an increased risk for the development of oncocytic thyroid tumours. This polymorphism may thus be considered a (co)factor favouring the development of oncocytic thyroid tumours, although the biological mechanism(s) underlying this association remain obscure.

[Evil radioactivity. Subjective perception of radioactivity in patients with thyroid disease prior to treatment with radioiodine]

AIM

We assess the perspective of patients with thyroid disease towards radiation and radioactivity by means of a cultural-anthropological approach based on qualitative measures and quantitative scores. From the interviews with the patients we evaluate as to how much radioactivity is accepted as an abstract term or as a benefit within the medical context.

PATIENTS, METHODS

68 patients with autonomously functioning thyroid lesions (35 women, 33 men, 32-81 years) were included in this study. All patients were interviewed in an open dialogue with the principal investigator. Patients were asked to describe their attitude towards radioactivity in general and towards radioiodine therapy in particular. Patients were asked to use a scoring system (1 = positive, 5 = negative) to quantify their attitudes.

RESULTS

The responses of all patients towards radioactivity in general were heterogeneous with most responses reflecting a negative perception. Many patients expressed their associated fears about atomic energy, malignant diseases and radioactive contamination. The scoring system reflected a mostly negative opinion base. However, patients became more positive once they assumed an immediate benefit of radioactivity for the treatment of their own disease (p = 0.01).

CONCLUSIONS

Knowing about significant differences in patient's perception about radioactivity in general or in the clinical context may help to optimise and tailor the initial, pre-therapeutical interview towards the patient.

Different genotype distribution of theGNB3 C825T polymorphism of the G protein β3 subunit in adenomas and differentiated thyroid carcinomas of follicular cell origin

A C825T polymorphism has been demonstrated in the GNB3 gene that encodes the Gbeta3 subunit of heterotrimeric G proteins. Due to enhanced G protein activation, the GNB3 825T allele is associated with an increased signal transduction activity. To elucidate a possible role in the development and course of thyroid tumours of follicular cell origin, C825T polymorphism genotypes and allele frequencies were investigated in a series of adenomas and differentiated carcinomas. Genotypes and the allele frequency of the Gbeta3 polymorphism were investigated in samples from 361 patients (all white Caucasians) with differentiated thyroid tumours of follicular cell origin [80 adenomas and 95 follicular (FTCs) and 186 papillary carcinomas (PTCs)]. The results were compared with those of 1859 healthy controls. Both the genotype distribution (p = 0.029) and the allele frequency (p = 0.028) of the adenoma group were statistically significantly different from those of the control group. Thyroid adenomas also differed for both parameters significantly from FTCs (p = 0.042 and 0.033, respectively) and PTCs (0.0018 and 0.0081, respectively), whereas no statistical difference was noted between the FTC and PTC groups. Although the biological significance of these observations remains obscure, the results are suggestive of a putative role for the GNB3 polymorphism in thyroid tumour development and/or progression. Further research has to elucidate if, and to what extent, this common germ-line variation influences the TSH-triggered signalling pathways responsible for thyroid function and proliferation.

Health-related quality of life, anxiety and depression in thyroid cancer patients under short-term hypothyroidism and TSH-suppressive levothyroxine treatment

OBJECTIVE

Very few previous studies have compared the degree of health-related quality of life (HRQL), depression and anxiety of differentiated thyroid cancer patients (DTC) under short-term hypothyroid-ism and levothyroxine treatment.

METHODS

Using patient-completed instruments, we examined the frequency of physical complaints, HRQL, anxiety and depression in 130 DTC patients hospitalized for radioiodine therapy or whole-body diagnostics (age 52 years, female 71%) under short-term hypothyroidism (4 weeks of levothyroxine withdrawal; DTC-H) and in 100 DTC out-patients under TSH-suppressive doses of levothyroxine subsequent to radioiodine therapy (DTC-L; age 49 years, female 81%).

RESULTS

Compared with the German general population, DTC-H as well as DTC-L patients had significantly impaired HRQL. Notably, the decrease in HRQL was significantly higher in DTC-H than in DTC-L patients. Surprisingly, the prevalence of anxiety (44.6%) but not depression (17.7%) was much higher in the DTC-H patients than in the general population. In contrast to expectations, similar results for anxiety (44.0%) and depression (17.6%) were observed in the DTC-L patients.

CONCLUSIONS

This mounting evidence suggests that a consistent pattern of HRQL impairment is experienced by patients with DTC. The high frequency of anxiety and the significantly reduced HRQL should be considered in the aftercare of DTC patients.

Development and clinical impact of thyroglobulin antibodies in patients with differentiated thyroid carcinoma during the first 3 years after thyroidectomy

OBJECTIVE AND DESIGN

Cross-sectional studies have reported an increased prevalence of circulating thyroglobulin autoantibodies (TgAbs) in patients with differentiated thyroid carcinoma (DTC). With the advent of more sensitive assays, a longitudinal study monitoring the development of TgAb levels after ablative therapy was warranted.

METHODS

One hundred and twelve consecutive patients with follicular cell-derived thyroid cancer were followed for 3 years. All patients had been thyroidectomized and received, on average, two radioiodine therapies. Residual tissue was quantified scintigraphically by 131I 24-h uptake. TgAb and thyroglobulin (Tg) serum levels were determined with a sensitive direct radioligand assay and an IRMA respectively.

RESULTS

The prevalence of TgAbs at the initial examination was 29% (median 130 U/ml). During follow-up, TgAb levels rose transiently in one-tenth of the patients, but the prevalence of demonstrable TgAbs decreased to < 10% after 3 years. The median serum half-life of TgAbs in treated DTC patients was 10 weeks. At initial examination (when all patients still had residual thyroid tissue and 17 had metastases), rising TgAb levels were correlated with the inability to detect Tg in 4, 30 and 73% of the patients, when initial TgAbs were < 6, 6-50 or > 50 U/ml respectively. While the Tg recovery test was valid for all patients, an in vitro dilution assay with TgAb serum reduced Tg values by up to 32%.

CONCLUSIONS

The development and course of TgAbs in DTC patients cannot be predicted by initial or residual tumour volume, TgAb or Tg levels. The presence of TgAbs, even in low concentrations, may cause Tg underestimation despite valid recovery tests in DTC patients.

Impact of disease activity on thyroid diseases in patients with acromegaly: basal evaluation and follow-up

In patients with acromegaly, the exact incidence of thyroid disorders is still controversial and less is known about the impact of disease activity and successful treatment. To address this issue, we investigated 73 acromegalic patients (age 55 +/- 13 yr; mean +/- SD) by ultrasonography in comparison to an age-matched control group (54 +/- 1 yr) in the same moderate iodine deficient area (retrospective study). These non-acromegalic volunteers (n = 199) were examined in the same clinic during a thyroid screening test. At the time of examination, 52 (71.2 %) of the acromegalic patients were active, 17 (23.3 %) were cured, and 4 (5.5 %) were controlled with somatostatin analogues. The prevalence of goiter (normal range < 18 ml female, < 25 ml male) was significantly higher (82.2 %) in the mixed group of acromegalics (active, well controlled, cured; n = 73) and in the active group (90.4 %) than in the control group (n = 199, 18.1 %, p < 0.001). Thyroid nodules were found in 63.0 % of the mixed group of acromegalics and in 71.2 % of patients with active disease (33.1 % in controls, p < 0.001). (99 m)Tc scintigraphy revealed thyroid autonomy in 9/73 (12.3 %) and cold nodules in 19/73 (26.0 %) patients. Thyroid cancer was diagnosed in 4 (5.5 %) of acromegalic patients (3 papillary and 1 follicular carcinoma). We found a weak correlation between the disease duration and the initial thyroid volume (r = 0.54, p < 0.0056). Thirty-seven newly diagnosed acromegalics were followed over a period of 7.3 +/- 4.1 years. 5 (13.5 %) of these patients remained active, 8 (21.6 %) were controlled with somatostatin analogues, and 24 (64.9 %) were cured. The mean age, sex distribution, disease duration, prevalence of TSH-deficiency, and initial thyroid volume (46 +/- 11 ml in active, 42 +/- 7 ml in controlled, and 45 +/- 5 ml in cured patients) did not differ statistically between the three groups. In patients with active acromegaly, thyroid volume increased by 19.5 +/- 8.1 %. In contrast, thyroid volume decreased in the group of medically controlled and cured acromegalics (- 21.5 +/- 7.1 %; p < 0.005 and - 24.2 +/- 5.7 %; p < 0.002, respectively). No correlation was found between thyroid volume and TSH levels, levothyroxine and/or iodide administration neither in TSH sufficient nor in TSH insufficient patients. In conclusion, successful treatment of patients with active acromegaly decreases thyroid volume. Cold nodules and thyroid cancer frequently occur in acromegalic patients.

Prognostic value of c-erbB-2 expression in papillary thyroid carcinoma

AIMS

c-erbB-2 overexpression has been shown to be a potential marker of aggressive biological behaviour in a varity of tumours, whereas its role played in thyroid papillary thyroid carcinoma (PTC) remains unclear. Objective of the study is to determine whether c-erbB-2 overexpression correlates with the clinical course.

METHODS

We have studied 32 PTC by a two-step immunocytochemical staining procedure for paraffin-embedded specimens (DAKO Hercep-Test). Semiquantitative evaluations were performed, based on the intensity of immunostaining and the percentage of tumor cells.

RESULTS

34% (11/32) of the PTC showed a membranous overexpression of the HER2/neu oncoprotein. Correlating the pathological and clinical data revealed that 81% (9/11) c-erbB-2 positive patients and only 33% (7/21) c-erbB-2 negative patients developed a tumor recurrence or a progression (p = 0.02 in Fisher's exact test). 3/11 c-erbB-2 positive patients died from PTC whereas all (21/21) c-erbB-2 negative patients are still alive (p = 0.03).

CONCLUSIONS

Our results strongly suggest that c-erbB-2 oncoprotein overexpression is related to the clinical course of PTC.

Value of 124I-PET/CT in staging of patients with differentiated thyroid cancer

The aim of this study is to evaluate the clinical significance of (124)I positron emission tomography (PET) using a combined PET/CT tomograph in patients with differentiated thyroid carcinoma and to compare the PET/CT results with (131)I whole-body scintigraphy (WBS), dedicated PET and CT alone. Twelve thyroid cancer patients were referred for diagnostic workup and entered complete clinical evaluation, including histology, cytology, thyroglobulin level, ultrasonography, fluorine-18 fluorodeoxyglucose (FDG)-PET, FDG-PET/CT and CT. Lesion-based evaluation showed a lesion delectability of 56, 87 and 100% for CT, (124)I-PET, and combined (124)I-PET/CT imaging, respectively. Lesion delectability of (131)I-WBS was 83%. We conclude that (124)I-PET/CT imaging is a promising technique to improve treatment planning in thyroid cancer. It is particularly valuable in patients suffering from advanced differentiated thyroid cancer prior to radio-iodine therapy and in patients with suspected recurrence and potential metastatic disease.

FDG-PET/CT in re-staging of patients with lymphoma

The aim of this study was to evaluate the clinical significance of combined fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) in patients with lymphoma, and to compare the FDG-PET/CT staging results with those of FDG-PET and CT alone. Twenty-seven patients were studied. Each patient had clinical follow-up for >12 months and entered complete follow-up evaluation. Patient-based evaluation showed a sensitivity of 78% for CT alone, 86% for FDG-PET alone, 93% for CT and FDG-PET read side by side, and 93% for combined FDG-PET/CT imaging. Region-based evaluation showed a sensitivity for regional lymph node involvement of 61%, 78%, 91% and 96% respectively. FDG-PET/CT imaging is superior to CT alone ( P=0.02) and has additional benefit over FDG-PET alone due to exact anatomical localisation. We conclude that FDG-PET/CT imaging is accurate in re-staging lymphoma and offers advantages over separate FDG-PET and CT imaging.

[Thyroid tumors]

The vast majority of thyroid tumours are epithelial. In contrast to thyroid adenoma, which is a common tumour, thyroid carcinomas make up only 1% of all human malignancies. Routine pathology is regularly confronted with a differential diagnosis involving thyroid adenoma and carcinoma, as well as particular variants of these tumours. This paper deals with the standardised gross and histological examination, as well as the impact of immunohistochemistry and intraoperative frozen sections on thyroid pathology.

[Hyperplasia of the thyroid gland]

Hyperplasia of the follicular epithelium (goitre) is the most common morphological change in the thyroid seen by the pathologist. The present paper deals with the aetiology, epidemiology and clinical features of thyroid hyperplasia and its differential diagnosis from thyroid adenoma. Neoplastic hyperplasia of the calcitonin-producing thyroid C cells gives rise to familial medullary carcinoma. The second part of the paper deals with the definition of neoplastic C cell hyperplasia and its discrimination from physiological C cell hyperplasia.

[Continously increasing sensitivity in thyroid cancer aftercare in the course of three generations of thyroglobulin IMAs]

Aim of our study was to evaluate the increasing sensitivity within three generations of thyroglobulin (Tg) assays, which were available during the past decade, and its clinical impact for patients with differentiated thyroid carcinoma.

METHODS

Determination of Tg using the IRMA introduced in 1989 (Dynotest Tg, Henning Berlin, Berlin; assay A) and 1994 (Selco Tg, Medipan Diagnostica, Selchow; assay B), as well as the IEMA available recently (Medizym Tg Rem, Medipan Diagnostica, Selchow; assay C).

RESULTS

We found a close correlation between the measurable Tg values of assay A and B (r=0.985; p<0.001) as well as assay B and C (r=0.978; p<0.001). Assay B (lowest detection limit: 0.3 ng/ml) was more than twice as sensitive as assay A and did not show quite as many disturbances of recovery (in 0.5% versus 4% of our patients). Due to its strict calibration to the European reference preparation CRM 457, Tg values determined by assay C were in the mean 1.9-fold higher than by assay B. Thus, with its functional sensitivity of 0.03 ng/ml assay C is nearly 20-fold more sensitive than assay B. Whereas the proportion of measurable Tg values was only 22% in a selected group of patients (criterion of inclusion: Tg in assay B< or =1 ng/ml with TSH-suppressive conditions; n=317 serum samples from 103 patients), it was 68% in assay C, with good intraindividual reproducibility of these values in the course.

CONCLUSION

The ultrasensitive assay C is especially suitable for the follow-up of treated thyroid cancer patients being considered as cured, and may shorten the time interval until the detection of a recurrence markedly: the gain of time calculated from the Tg courses in patients with a gradually progressive tumor relapse ranged from 5 to 15 months.

Diagnosis of labia metastasis by F-18 FDG PET and CT fusion imaging in sarcoma follow-up

ABSTRACT A 32-year-old woman with a history of pelvic sarcoma underwent whole-body fluorine-18 fluorodeoxyglucose positron emission tomography (PET) and computed tomographic (CT) fusion imaging for restaging after primary surgery and adjuvant combined radiation and chemotherapy. Interpreting the PET images alone showed an area of focal tracer accumulation in the pelvic floor and was interpreted as being secondary to urine contamination. Image fusion with fully coregistered CT scans showed a localized site of increased uptake from a metastasis to the labia, which was confirmed by biopsy. The presented case illustrates the usefulness of combined PET/CT fusion imaging to overcome some pitfalls of PET imaging alone (eg, differentiating malignant tumor from pooling of tracer in the genitourinary tract or contamination).

Sensitive calcitonin measurement by two-site immunometric assays: implications for calcitonin screening in nodular thyroid disease

The aim of this study was to investigate the impact of analytical aspects on the clinical usefulness of calcitonin (CT) measurement. In a retrospective analysis, CT levels measured by a polyclonal immunometric assay (Scantibodies Laboratory, CA, USA) were evaluated in various clinical situations. CT in newly diagnosed medullary thyroid cancer (MTC) (n = 20) ranged from 15.5-87130 pg/ml (median 661 pg/ml). Levels >10 pg/ml were seen in 7.3% of 314 patients with benign nodules, 48.9% of 45 patients with impaired kidney function, 97.7% of 87 patients on hemodialysis, 30.2% of 43 patients after renal transplantation, and in 71.0% of 31 patients with critical illnesses. Subgroups of patients were reevaluated by two monoclonal immunometric assays specific for mature CT. CT levels measured by the monoclonal immunometric assays were highly correlated to the polyclonal assay results in MTC patients, but were significantly different with a lower incidence of elevated levels in patients with renal disease and critical illnesses. In conclusion, highly sensitive assays with cut-off values of 10 pg/ml or below are mandatory for CT screening in nodular thyroid disease. The specificity of CT measurement in patients with renal disease and critical illnesses is higher with monoclonal assays specific for monomeric CT. These methodological aspects have to be regarded if CT measurement is used for decision making in nodular thyroid disease.