Real-World Data for Lenvatinib in Radioiodine-Refractory Differentiated Thyroid Cancer (RELEVANT): A Retrospective Multicentric Analysis of Clinical Practice in Austria

BACKGROUND

Lenvatinib has proven efficacy in progressive, radioiodine- (RAI-) refractory thyroid cancer (TC). Dose reductions are commonly performed due to decreased tolerability and adverse effects. This retrospective multicenter study analyzed overall survival (OS) and progression-free survival (PFS) and tolerability in the Austrian patient population treated with lenvatinib.

METHODS

Clinical data of 43 patients (25 males and 18 females) with a median age of 70 years (range: 39-91 years) and RAI-refractory TC with metastases to the lymph nodes (74%), lungs (86%), bone (35%), liver (16%), and brain (12%) were analyzed. The mean duration of treatment with lenvatinib was 26.6 ± 15.4 months with dosage reductions required in 39 patients (91%).

RESULTS

PFS after 24 months was 71% (95% CI: 56-87), and overall survival (OS) was 74% (95% CI: 60-88), respectively. OS was significantly shorter (p=0.048) in patients with a daily maintenance dosage ≤ 10 mg (63%) (95% CI: 39-86) as compared to patients on ≥ 14 mg lenvatinib (82%) (95% CI: 66-98) daily. Dose reduction was noted in 39 patients (91%). Grade ≥3 toxicities (hypertension, diarrhea, weight loss, and palmar-plantar erythrodysesthesia syndrome) were most common leading to discontinuation of lenvatinib in 7 patients (16%).

CONCLUSION

Lenvatinib showed sustained clinical efficacy in patients with metastatic RAI-refractory TC even with reduced maintenance dosages over years. The effects were comparable to the registration trial, although patients had a higher median age and, more commonly, dose reductions.

Attenuation correction for myocardial perfusion imaging

Aim: We investigated the impact of photon attenuation in myocardial perfusion imaging with SPECT and PET in patients with coronary artery disease. In fact, the regional tracer distribution can be quantitatively assessed by polar map analysis if the effects of photon attenuation are accounted for. PET imaging permits accurate measurement of and correction for photon attenuation, whereas results of attenuation correction in SPECT imaging have been inconsistent. Patients, methods: We compared photon attenuation in resting perfusion imaging studies with SPECT (99mTc-sestamibi) and PET (13N-ammonia) from 21 patients. Transaxial images were reconstructed with and without attenuation correction and reoriented into short axis images. Polar map analysis was utilized to generate regional tracer uptake in six anatomical segments. Results: Average segmental photon attenuation calculated as the ratio of counts in corrected and uncorrected images was 7.2 ± 1.4 in SPECT and 14.0 ± 3.1 in PET imaging (p <0.01). This attenuation factor was significantly related to body mass index for both methods (p <0.001). While attenuation correction for SPECT imaging did compensate for attenuation effects in the inferior wall (from –15% to +6% vs. PET), relative tracer uptake in the anterior wall in SPECT images was significantly reduced after attenuation correction (from –2% to –18% vs. PET, p <0.01). Conclusion: Differential effects of attenuation correction for myocardial SPECT perfusion imaging need to be considered when algorithms designed to compensate effects of photon attenuation in SPECT imaging are employed in clinical practice.

Uptake of 18F-FLT and 18F-FDG in primary head and neck cancer correlates with survival

The aim of the study was to determine the practicability of 18F-FLT in tumours of the head and neck area in terms of visualization, a possible correlation between FLT uptake and proliferation fraction as determined by Ki-67 immunostaining, and if tumoural FLT-uptake has a prognostic meaning, as determined by a correlation to patient survival time. Results were compared to 18F-FDG. Patients, methods: 20 patients with previously untreated lesions of the head and neck area, which were clinically highly suspicious to be malignant, underwent PET scans with 18F-FLT and 18F-FDG, a CT of the head and neck area, and a biopsy. Tumour tracer uptake was determined by standardized uptake value (SUV) normalized to body weight and /non-tumor ratios (T/N). 18F-FDG and 18F-FLT uptake were compared with histopathologic and immunohistochemical results. Results: 19 patients had malignant tumours; one patient had a benign cystadenoma (so called Warthin's tumour) of the parotid gland. One negative lesion turned out to be a malignant T1 stage squamous cell carcinoma in both PET scans, the Warthin's tumour was false positive with 18F-FDG but showed only faint uptake with 18F-FLT, resulting in a sensitivity of 95 % for both tracers. Of all lesions, maximum SUVs of 18F-FLT ranged from 1.53 to 11.70 (mean ± SD 5.81 ± 2.28) those of FDG from 2.63 to 16.50 (mean ± SD 8.91 ± 3.58), p < 0.001. 18F-FLT-T/N ranged from 0.94 to 5.85 (mean ± SD, 3.18 ± 1.21), 18F-FDG-T/N was from 0.92 to 7.50 (mean ± SD, 3.6 ± 1.74), n.s. The mean survival time was 18 months in a maximum follow up time of 36 months. A significant correlation between both PET tracers and survival was detected, but no correlation between the amount of Ki-67 positive cells and FLT. Conclusion: In head and neck cancer in the primary setting 18F-FLT does not provide additional visual information in comparison to 18F-FDG.18F-FLT uptake is inversely correlated with patient survival, as well as 18F-FDG.

Quality of life aspects in the management of thyroid cancer

While there is agreement that quality of life (QoL) is a central aim of medical treatment, the methods of its evaluation as well as its role in the patient's overall treatment experience are under continuous scrutiny. Different perspectives on patients' QoL have emerged; from the treating physician, from the psychologist, and naturally from the patient him/herself. This article provides insights into each of these views within the context of thyroid cancer where, as a consequence of increasing incidence and decreasing mortality rates, QoL aspects deserve close attention. Physicians often find themselves in situations where they perform a balancing act between what they know is best from a somatic point of view and learning about what is best for the individual patient. For psychologists in the field of oncology, a main area of interest is the incorporation of the patient's perspective into research by using patient-reported outcomes (PROs) which include QoL assessment. PROs can also be used in clinical practice as a way to start a conversation about symptoms and QoL aspects that perhaps patients might not volunteer, and this allows physicians to address QoL issues more directly. Patients usually appreciate being asked about all aspects of QoL, and need sound information about how their QoL might be affected by the disease and its treatment. By examining and understanding the different perspectives on QoL, and how QoL differs in patients with thyroid cancer compared with other cancers, it is hoped that the QoL can be enhanced in this particular patient group.

[Treatment of patients with radioiodine refractory, differentiated thyroid carcinoma. A Consensus Statement]

There is no clear standard therapy for patients with radioactive iodine (131I)-refractory locally advanced or metastatic differentiated thyroid cancer. The therapeutic options for this indication have expanded with the recently approved multiple kinase inhibitor sorafenib. Recommendations for the definition and the management of iodine refractory patients were worked up by an interdisciplinary expert panel, consisting of endocrine surgeons, medical oncologists and nuclear medicine specialists.

Radiosynthesis and in vitro evaluation of the 5HT2 receptor ligand [N-11C-methyl]-1-[2,5-dimethoxy-4-iodophenyl]-2-methylaminopropane for PET

In vivo labelling of serotonergic receptors (5HT) could be a useful tool for understanding the physiological and pathophysiological role of neurodegenerative disorders. 1-[2,5-Dimethoxy-4-iodophenyl]-2-aminopropane (DOI), a well known agonist with high affinity to 5HT2 receptors, was labelled with C-11 for PET. Here we report the evaluation of the mono-methylated and dimethylated analogs of DOI for PET. The syntheses of [N-11C-methyl]-DOI ([11C]MDOI) and [N-11C-dimethyl]-DOI ([11C]DMDOI) were optimized resulting in radiochemical yields of up to 43%, allowing efficient production for clinical use. High affinities for the 5HT2A and 5HT2C receptors with a slight preference for 5HT2A were found for MDOI, similar to the highly potent hallucinogen DOI.

Uptake of (18)F-FLT and (18)F-FDG in primary head and neck cancer correlates with survival

The aim of the study was to determine the practicability of (18)F-FLT in tumours of the head and neck area in terms of visualization, a possible correlation between FLT uptake and proliferation fraction as determined by Ki-67 immunostaining, and if tumoural FLT-uptake has a prognostic meaning, as determined by a correlation to patient survival time. Results were compared to (18)F-FDG.

PATIENTS, METHODS

20 patients with previously untreated lesions of the head and neck area, which were clinically highly suspicious to be malignant, underwent PET scans with (18)F-FLT and (18)F-FDG, a CT of the head and neck area, and a biopsy. Tumour tracer uptake was determined by standardized uptake value (SUV) normalized to body weight and /non-tumor ratios (T/N). (18)F-FDG and (18)F-FLT uptake were compared with histopathologic and immunohistochemical results.

RESULTS

19 patients had malignant tumours; one patient had a benign cystadenoma (so called Warthin's tumour) of the parotid gland. One negative lesion turned out to be a malignant T1 stage squamous cell carcinoma in both PET scans, the Warthin's tumour was false positive with (18)F-FDG but showed only faint uptake with (18)F-FLT, resulting in a sensitivity of 95 % for both tracers. Of all lesions, maximum SUVs of (18)F-FLT ranged from 1.53 to 11.70 (mean +/- SD 5.81 +/- 2.28) those of FDG from 2.63 to 16.50 (mean +/- SD 8.91 +/- 3.58), p < 0.001. (18)F-FLT-T/N ranged from 0.94 to 5.85 (mean +/- SD, 3.18 +/- 1.21), (18)F-FDG-T/N was from 0.92 to 7.50 (mean +/- SD, 3.6 +/- 1.74), n.s. The mean survival time was 18 months in a maximum follow up time of 36 months. A significant correlation between both PET tracers and survival was detected, but no correlation between the amount of Ki-67 positive cells and FLT.

CONCLUSION

In head and neck cancer in the primary setting (18)F-FLT does not provide additional visual information in comparison to (18)F-FDG.(18)F-FLT uptake is inversely correlated with patient survival, as well as (18)F-FDG.

Occlusion of iatrogenic pseudoaneurysms with percutaneous ultrasound guided thrombin injection

BACKGROUND

Pseudoaneurysm is a common complication of cardiac catheterization and coronary intervention with an incidence of 2% even in experienced centers.

PATIENTS AND METHODS

In a feasibility study conducted between December 2004 and February 2006 we enrolled 76 patients consecutively to receive local thrombin injection (mean 329 IU; range 100-800 IU) into the aneurysma sac.

RESULTS

Ultrasound guided thrombotic occlusion of pseudoaneurysms was successful after one injection in 83% of the patients, 17% of the patients required more than one injection. The overall success rate of the procedure was 98,9%. No peripheral embolisation of thrombin was noted during any injection and we registered no other complication that needed any further intervention.

CONCLUSIONS

We conclude that ultrasound guided occlusion of pseudoaneurysms using thrombin injection with a success rate of the procedure of 98,9% is feasible and safe.

18F-Fluoro-deoxy-glucose positron emission tomography in lymphoma of mucosa-associated lymphoid tissue: histology makes the difference

BACKGROUND

The usefulness of 2-[fluorine-18]fluoro-2-deoxy-D-glucose Positron emission tomography (18F-FDG-PET) in lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is still a matter of debate, and conflicting results have been reported. We have evaluated whether the histological feature of plasmacytic differentiation (PD) might explain the heterogeneous behavior of MALT lymphoma regarding 18F-FDG uptake.

PATIENTS AND METHODS

A total of 35 patients with a diagnosis of MALT lymphoma referred to our PET unit were studied. Whole-body 18F-FDG-PET scans were carried out on a General Electrics advanced PET scanner 40 min after i.v. injection of 300-380 MBq 18F-FDG. Images were reconstructed iteratively. In areas with focally elevated FDG uptake, standard uptake values (SUVs) were calculated.

RESULTS

A total of 19 patients had MALT lymphoma with plasmacytic differentiation (pMALT), while MALT lymphoma without plasmacytic features was diagnosed in 16 patients. Sixteen of 19 patients with PD showed significant 18F-FDG uptake in involved sites (SUV: 3.5-11.7). By contrast, 13 of 16 patients with normal MALT lymphoma showed a false-negative 18F-FDG-PET result. Two of these patients disclosed no tracer uptake in the majority of involved sites apart from one single lesions, while three had a true-positive 18F-FDG-PET scan (SUV: 3.4-6.0).

CONCLUSIONS

18F-FDG-PET visualizes pMALT in a high proportion of patients, whereas FDG-PET results are significantly less reliable in typical MALT (P = 0.001). This finding may partly account for the heterogeneous results of 18F-FDG-PET-studies in MALT lymphoma.

18F-fluoro-deoxy-glucose positron emission tomography (18F-FDG-PET) visualizes follicular lymphoma irrespective of grading

BACKGROUND

18F-fluoro-deoxy-glucose positron emission tomography (18F-FDG-PET) has become a routine measure for staging and follow-up of patients with aggressive lymphoma. By contrast, its usefulness to visualize indolent lymphomas characterized by a lower cellular turnover has not clearly been defined. We have investigated accuracy and clinical usefulness of 18F-FDG-PET in patients with follicular lymphoma (FL).

PATIENTS AND METHODS

A total of 64 patients with FL WHO grade I - III (48, 5, and 11 patients) were imaged at our institution to assess the value of 18F-FDG-PET for imaging of FL of different gradings. A total of 115 scans (48 before therapy and 67 for response assessment after treatment) were performed, and findings were compared to conventional staging including CT-scan of thorax and abdomen, sonography of lymph nodes and bone marrow biopsy.

RESULTS

Overall, 18F-FDG-PET had a sensitivity of 98%, a specificity of 94%, a positive predictive value of 95% and a negative predictive value of 98%. These results were significantly more accurate (P = 0.023) than the conventional radiology studies. There was no significant difference (P = 0.093) in the accuracy between patients with indolent (WHO grade I and II) versus aggressive FL (WHO grade III).

CONCLUSION

18F-FDG-PET scan is a reliable method for staging and follow up of patients with nodal FL irrespective of tumor grading.

Attenuation correction for myocardial perfusion imaging. A comparison between SPECT and PET imaging by polar map analysis

AIM

We investigated the impact of photon attenuation in myocardial perfusion imaging with SPECT and PET in patients with coronary artery disease. In fact, the regional tracer distribution can be quantitatively assessed by polar map analysis if the effects of photon attenuation are accounted for. PET imaging permits accurate measurement of and correction for photon attenuation, whereas results of attenuation correction in SPECT imaging have been inconsistent.

PATIENTS, METHODS

We compared photon attenuation in resting perfusion imaging studies with SPECT ((99m)Tc-sestamibi) and PET ((13)N-ammonia) from 21 patients. Transaxial images were reconstructed with and without attenuation correction and reoriented into short axis images. Polar map analysis was utilized to generate regional tracer uptake in six anatomical segments.

RESULTS

Average segmental photon attenuation calculated as the ratio of counts in corrected and uncorrected images was 7.2 +/- 1.4 in SPECT and 14.0 +/- 3.1 in PET imaging (p < 0.01). This attenuation factor was significantly related to body mass index for both methods (p < 0.001). While attenuation correction for SPECT imaging did compensate for attenuation effects in the inferior wall (from -15% to +6% vs. PET), relative tracer uptake in the anterior wall in SPECT images was significantly reduced after attenuation correction (from -2% to -18% vs. PET, p < 0.01).

CONCLUSION

Differential effects of attenuation correction for myocardial SPECT perfusion imaging need to be considered when algorithms designed to compensate effects of photon attenuation in SPECT imaging are employed in clinical practice.

Measurement of renal function in patients with Fabry disease

Appropriate measurement of the glomerular filtration rate (GFR) is important for the assessment of renal function. This paper reviews the methods used to assess GFR in clinical trials of enzyme replacement therapy (ERT) in patients with Fabry disease, which include inulin clearance, 24-hour creatinine clearance, chromium ethylene diamine tetraacetate (51Cr-EDTA) clearance and cystatin C concentrations. GFR has also been estimated using calculations based on creatinine clearance (the Cockcroft-Gault formula) and the Modification of Diet in Renal Disease (MDRD) equation. Analysis of the results of these studies shows that there are striking discrepancies between estimated and measured GFR. For example, the MDRD equation overestimates GFR in patients with Fabry disease who have normal renal function. In addition, cystatin C has been shown to be of limited use for measuring renal function during ERT, because it is influenced by other factors such as age, gender and weight.

CONCLUSION

The use of exact methods, such as inulin clearance, 124I-iothalamate, 99mTc-DTPA, 51Cr-EDTA and iohexol, appears to be mandatory for a robust evaluation of the effects of ERT on GFR in patients with Fabry disease.

Value of combined XCT/SPECT technology for avoiding false positive planar (123)I-MIBG scintigraphy

AIM

The clinical value of combined XCT/SPECT technology in a single device in patients undergoing (123)I-MIBG scintigraphy was analyzed.

METHODS

31 patients (19 men, 12 women; mean age 55 years, range: 31-79 years) demonstrating focal accumulation in planar (123)I-MIBG scan were further investigated with a double headed gamma camera with an X-ray tomograph mounted on the same gantry (GE Medical Systems, Millennium VG with Hawkeye, Milwaukee, USA) for anatomical definition of the focal (123)I-MIBG uptake. The patients were referred to (123)I-MIBG scintigraphy because of biochemically (81%) and/or clinically (19%) suspected pheochromocytoma.

RESULTS

In 23 out of 31 patients (74%) the fused images demonstrated physiological accumulation (i. e. intestinal, renal) of (123)I-MIBG. In two patients (6%) suspected adrenal MIBG-accumulation was caused by inhomogeneous liver uptake. In two patients (6%) focal abdominal accumulation was correctly localised in the adrenal glands. Furthermore, the differentiation of bone metastasis from a local recurrence for phaeochromocytoma was accurately possible for two patients (6%). Adrenal lesions mimicking liver foci were correctly localised in the remaining two patients (6%).

CONCLUSION

Our study demonstrates the clinical value of XCT/SPECT in a single device in patients demonstrating focal (123)I-MIBG uptake in planar scintigraphy. The combined XCT/SPECT technology provides a higher diagnostic accuracy.

Prognostic value of FDG-PET in malignant lymphoma

Lymphomas have represented an indication for nuclear medicine investigations for 30 years. Gallium-67 scintigraphy has been shown to be a valuable complementary method in Hodgkin's disease and non-Hodgkin lymphoma for detecting viable residual lesions after chemotherapy and for diagnosis of a relapse. Thallium-201 is of interest in differentiating cerebral lymphomas from infectious lesions in AIDS patients but less useful in extra-cerebral lymphomas. PET with fluorine-18-FDG is more accurate than 67Ga in lymphoma. In patients with a positive PET scan after chemotherapy an early relapse occurs in up to 100%, while more than 80% of patients with a negative PET will have a long-term remission. Most studies show that FDG-PET is significantly correlated with patient outcome whereas there is much weaker or even no correlation for CT. The main reason is that PET is not bound to morphological criteria like lymph node size while CT is often not able to differentiate between residual tumour and post-therapeutic fibrosis. Therefore, based on a considerable number of clinical studies, FDG-PET gains increasing significance for staging, restaging and therapy monitoring in malignant lymphomas.

Positron emission tomography with [18F]2-fluoro-D-2-deoxyglucose (FDG-PET) predicts relapse of malignant lymphoma after high-dose therapy with stem cell transplantation

We have determined the predictive value of [18F]2-fluoro-2-deoxy-glucose (FDG-PET) in patients with Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL) scheduled for high-dose therapy with stem cell transplantation (HDT/SCT). Inclusion criteria were the presence of an FDG-PET scan after chemotherapy (ChT) within 8 weeks prior to HDT/SCT and available follow-up data. Sixteen patients (10 NHL and six HD) were observed during a follow-up period of 4 to 28 months (median 13 months). Before SCT, five patients had a negative PET, three were weakly positive, two moderately positive, and six strongly positive. None of the five patients with a negative PET before HDT/SCT relapsed and two of three patients with a weakly positive scan are still in remission after HDT/SCT. Of eight patients with a moderate or high positive PET before HDT/SCT, seven relapsed and one died of early HDT/SCT related complications (P< 0.01). Three of eight relapsing patients died of lymphoma 5 to 10 months after SCT and in one additional patient not responding to HDT/SCT, the main cause of death was chronic toxicity 4 months after transplantation. After 12 months, in PET-negative patients the overall and relapse-free survival was 100%, in PET-positive patients 55% and 18%, respectively. In NHL, two patients with negative PET, but with an age-adjusted international prognostic index (AaIPI) of 2 and one with AaIPI = 1 are still in remission. In the seven PET-positive subjects, one patient with AaIPI = 0, three with AaIPI = 1, and two with AaIPI = 2 relapsed. We conclude that FDG-PET is accurate in the prediction of relapse prior to HDT/SCT in patients with lymphoma. It provides additional information when compared with the AaIPI.

Predictive impact of 2-18fluoro-2-deoxy-D-glucose positron emission tomography for residual postchemotherapy masses in patients with bulky seminoma

PURPOSE

To establish the predictive potential of 2-18fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) for detecting viable tumor tissue in residual postchemotherapy masses of seminoma patients.

PATIENTS AND METHODS

In this prospective multicenter trial, results of FDG PET studies in seminoma patients with postchemotherapy masses > or = 1 cm were correlated with either the histology of the resected lesion or the clinical outcome on follow-up without resection. Negative PET scans of residual lesions that were devoid of viable tumor tissue on resection or disappeared, shrunk, or remained stable in size for at least 2 years were rated as true-negative (TN). Positive scans without histologic or clinical evidence of tumor tissue were classified as false-positive. In patients with histologically positive or progressive lesions, positive PET scans were defined as true-positive (TP) and negative scans, false-negative (FN).

RESULTS

Thirty-seven PET scans of 33 patients were assessable at a median follow-up time of 23 months (range, 2 to 46 months). Histologic data were available from nine patients who had undergone resection. Twenty-eight patients were followed-up clinically and radiologically. Twenty-eight scans were TN, eight were TP, and one was FN. All 14 residual lesions more than 3 cm and 22 (96%) of the 23 < or = 3 cm were correctly predicted by FDG PET. The specificity (100%; 95% confidence interval [CI], 87.7% to 100%), sensitivity (89%; 95% CI, 51.7% to 99.7%), positive predictive value (100%), and the negative predictive value (97%) of FDG PET were superior to data obtained by assessing residual tumor size (< or = or > 3 cm).

CONCLUSION

FDG PET is a clinically useful predictor of viable tumor in postchemotherapy residuals of pure seminoma, especially those greater than 3 cm.

FDG-PET in adrenocortical carcinoma

Adrenal cortical carcinoma (ACC) is a rare malignant neoplasm with a poor prognosis. Radical surgery of the primary tumor and of local as well as of distant recurrence is the only effective treatment, and requires accurate and early localization of recurrent tumors. In this regard, we prospectively scanned 10 patients with ACC, 8 during follow-up and 2 at primary work-up. In all patients PET scans from the neck to the upper thighs were obtained 45 minutes after injection of 370 MBq [18F]FDG. Reading was done visually, with the investigator blinded to the results of other diagnostic modalities. All known sites of ACC lesions showed markedly increased FDG uptake. In 3 patients, previously unknown lesions were identified by PET in the lung (one lesion), the abdomen (3 lesions), and the skeleton (multiple), respectively. One false positive liver focus was shown by PET aside from the true positive lung metastases in the same patient. The sensitivity/specificity of PET based on different organs was 100/97%, that based on the number of PET-detected lesions (N = 23) was 100/95%. PET altered or influenced the tumor stage in 3/10 patients, modifying the subsequent therapeutic management in 2/10 patients. We conclude that FDG-PET is highly useful in ACC and should be included in the work-up for initial staging as well as for follow-up.

FDG positron emission tomographic, radioiodine, and MIBI imaging in a patient with poorly differentiated insular thyroid carcinoma

Poorly differentiated insular thyroid carcinoma is now classified as a separate entity among other tumors of the thyroid gland. Its histologic pattern and its clinical course are regarded as intermediate between well differentiated and anaplastic thyroid cancer. Insular carcinoma accumulates I-131, but no data exist regarding its fluorodeoxyglucose (FDG) positron emission tomographic (PET) uptake. The authors report F-18 FDG PET, Tc-99m MIBI, and radioiodine imaging features in a 63-year-old patient with metastatic insular thyroid carcinoma. After total thyroidectomy (for poorly differentiated insular carcinoma pT3a), the patient was referred for radioiodine ablation. No signs of recurrence were present until 16 months later, when thyroglobulin levels increased. An I-131 scan showed a single lesion in the right lung, and further radioiodine treatment was administered (cumulative dose [530 mCi], 19,610 MBq I-131). Three years after the initial diagnosis, FDG-PET and Tc-99m MIBI scans were performed within 5 days during thyroxine treatment. After that, thyroxine substitution was withdrawn; 6 weeks later, an I-131 whole-body scan was performed. Both radioiodine and MIBI images showed increased tracer uptake in the known lung lesion. However, FDG PET showed a normal tracer distribution. Magnetic resonance and computed tomographic imaging confirmed a 12-mm lesion in the right upper lobe. These findings support the concept of the "flip-flop phenomenon" in insular thyroid carcinoma, an alternating pattern of metastases with either I-131 or FDG-uptake. Despite poorly differentiated histologic findings, glucose metabolism was not increased in this patient with an insular tumor.

18F-fluorodeoxyglucose (FDG)-PET features of focal nodular hyperplasia (FNH) of the liver

AIM

The aim of this paper is to describe the imaging pattern of focal nodular hyperplasia (FNH) by l8F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET).

METHODS

Eight consecutive asymptomatic patients with histologic proof of FNH underwent 18F-FDG PET imaging. The lesions were found incidentally. The 18F-FDG PET imaging was performed with a dedicated PET tomograph after intravenous injection of 300-370 MBq 18F-FDG. The 18F-FDG accumulation in the lesions was (semi)quantified by calculating the standardized uptake value (SUV) and SUV has been corrected for the lean body mass (LBM). Eight patients with liver metastases spread from melanoma (n=2) and colorectal carcinoma (n=6) served as controls. The size of the FNH lesions and of the control group ranged from 2.0 to 8.5 cm (mean 4.83 cm +/- 2.37) and from 1.5 to 6 cm (mean 3.28 +/- 1.52), respectively.

RESULTS

While in malignant liver lesions the accumulation of 18F-FDG was significantly increased, all FNH lesions showed normal or even decreased accumulation of 18F-FDG. In FNH lesions, SUV ranged between 1.5 and 2.6 (mean 2.12 +/- 0.38), whereas all liver metastases showed an increased SUV ranging between 6.20 and 16.00 (mean 10.07 +/- 3.79). The SUV corrected for LMB (SUVLBM) was similar to the SUV and ranged between 0.9 and 2.2 (mean 1.81 +/- 0.41) for FNH and between 5.9 and 16.3 (mean 9.15 +/- 4.03), respectively.

CONCLUSION

In contrast to liver metastases, there is no increased glucose metabolism in FNH in vivo. The imaging feature of FNH by 18F-FDG-PET imaging is not specific for FNH; however, it may be helpful to differentiate FNH from liver metastases in cancer patients if radiological methods are not diagnostic.

Chronic granulomatous meningitis with multiple cranial nerve lesions hydrocephalus, stroke, sinus thrombosis, and epilepsy

Most frequently, chronic granulomatous meningitis (CGM) is caused by infectious agents. However, in some cases the cause of CGM remains undetermined. It is unclear whether antimicrobial agents, including antituberculous drugs, are helpful in such cases. We describe a 61-year-old man who had multiple cranial nerve lesions, epilepsy, sinus thrombosis, stroke, and hydrocephalus attributable to CGM. Repeated extensive search for a causative agent in the cerebrospinal fluid (CSF) and the meninges remained negative. Only a single culture of the sputum revealed growth of Mycobacterium tuberculosis, which prompted antituberculous therapy with isoniazid, rifampicin, and ethambutol. After 6 months of therapy, neurologic abnormalities were slightly improved. We conclude that antimicrobial/ antituberculous agents have only a minor short-term effect in long-lasting CGM of undetermined cause.

Positron emission tomography with fluorine-18-2-fluoro-2-deoxy-D-glucose (F18-FDG) does not visualize extranodal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)-type

BACKGROUND

On the basis of promising data on the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (F18-FDG) whole body positron emission tomography (WB-FDG-PET) in the staging of patients with lymphoma, we initiated a pilot series to evaluate the role of WB-FDG-PET in the staging of extranodal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type.

PATIENTS AND METHODS

We examined ten consecutive patients with histologically-verified MALT-type lymphomas of various origin before initiation of therapy. Nine patients had low-grade lymphomas (five cases of gastric lymphoma, two patients with lymphoma arising in the lung, one parotid and one lacrimal gland lymphoma), while one patient had a high-grade gastric lymphoma arising from a low-grade background. Two patients had stage EI, seven had stage EII disease, and one presented with stage EIII. WB-FDG-PET scans were performed 40 min following the injection of 300-380 MBq of F18-FDG. The PET scans were correlated with extensive conventional staging including ophthalmologic investigation, otolaryngologic examination, gastroscopy, endosonography, enteroclysis, colonoscopy, CT of thorax and abdomen, and bone marrow biopsy.

RESULTS

WB-FDG-PET documented no lymphoma in any of the 10 patients studied, as no focal tracer uptake was demonstrated in either gastric or extragastric lesions or in involved lymph nodes, irrespective of histologic grading. In three patients the scan showed a false negative result with respect to the MALT lesions but showed focal tracer uptake indicating tumor spread, which, however, was ruled out by further follow-up and biopsy, respectively, and was thus rated false positive. Due to these results, the study was discontinued prematurely after the first ten patients.

CONCLUSIONS

These discouraging results indicated that WB-FDG-PET is not useful for staging and follow-up of MALT-type lymphoma, and should therefore not be included in the clinical decision making process.

[Malignant tumors of the mouth cavity and oropharynx. Stage classification]

Staging of malignant tumours of the oral cavity and the oropharynx not only requires far more than a basic knowledge of anatomy and the usual pathways of spread, but also a broad understanding of the diagnostic benefits of current imaging modalities. As radiology should never try to replace histology, the main aim should be precise prediction of tumour margins and differentiation of tumour from edema and posttherapeutic changes. Only then will imaging studies have a significant clinical impact.

[FDG-PET in oncology. Methodological principles and clinical applications]

Clinical PET is now primarily used in oncological indications. Fluorine-18-fluorodeoxyglucose (FDG) shows a high uptake in a variety of malignancies and accounts for approximately 95% of the oncological PET studies. The first part of this review deals with theoretical and methodological aspects of FDG-PET. Possible sources of errors for the method are discussed briefly. Oncological indications for FDG-PET are highlighted according to the results of consensus meetings of experts from nuclear medicine and oncology, organized by the German Society of Nuclear Medicine. FDG-PET is mainly used in staging and restaging, demonstrating of tumour recurrence and therapy control. Main benefits of the method are functional imaging, better spatial resolution than conventional scintigraphy and the possibility to perform whole-body imaging easily. A brief outlook on future prospects for the application of PET in oncology is given.

BRCA1-related breast cancer in Austrian breast and ovarian cancer families: specific BRCA1 mutations and pathological characteristics

We identified 17 BRCA1 mutations in 86 Austrian breast and ovarian cancer families (20%) that were screened for mutations by denaturing high-performance liquid chromatography (DHPLC) and the protein truncation test (PTT). Eleven distinct mutations were detected, 4 of them (962del4, 2795del4, 3135del4 and L3376stop) not previously reported in families of non-Austrian origin. In addition, 6 rare missense mutations (allele frequency < 1%) with unknown biological effects were identified. Four mutations occurred more than once in the Austrian population: 2795del4 (3 times), Cys61Gly (3 times) 5382insC (2 times) and Q1806stop (2 times). Haplotype analysis of the 4 recurrent mutations suggested a common ancestor for each of these. Thirty-four breast cancer cases from 17 families with BRCA1 mutations were further analyzed. We observed a low median age of onset (39.5 years). Sixty-eight percent of all BRCA1 breast cancer cases had negative axillary lymph nodes. This group showed a significant prevalence of a negative estrogen and progesterone receptor status and stage I tumors compared with an age-related, node-negative control group. The prevalence of grade III tumors was marginally significant. Survival analysis either with a control group matched for age (within 5 years), grade, histologic subtype and estrogen receptor status, or with an age-related, node-negative comparison group, showed no statistical difference.

Kinetics of circulating selectin levels during bone marrow aplasia

We have studied the kinetics of plasma levels of circulating (c)selectins in 8 patients undergoing bone marrow or stem cell transplantation to gain estimates for the distribution and half-life of (c)selectins and to potentially identify an endothelial source of cP-selectin in patients who are deprived of platelets and megakaryocytes. Blood was sampled just before conditioning treatment and immediately after, at 2 occasions under bone marrow aplasia (1 and 2 wk after BMT), on 2 separate days (3-8 d apart) before and at 60 min after platelet transfusion, and 30-72 d after BMT. All (c)selectins showed a strikingly parallel decrease during bone marrow aplasia: cP-selectin decreased by a median of 70% (range: 59-95%), cE-selectin by 63% (range: 27-78%), and cL-selectin by 75% (range: 66-90%) compared to baseline (p=0.012 for all comparisons). Estimates for plasma half-lives of all (c)selectins were obtained from individual time vs. concentration profiles of the maximal decreases and ranged from 2 to 4 d. cP-selectin increased by 23% (p=0.003), cE-selectin by 5% (p=0.041) and cL-selectin by 19% (p=0.009) 1 h after the platelet transfusions. Based on these results the calculated volume of distribution (Vd) of transfused (c)selectins was 2.5-fold higher than the plasma volume, which supports the concept of the in-vivo expression of binding sites, i.e. ligands, for cE-selectin and cL-selectin. In summary, while our study cannot provide any evidence for endothelial cells as a source of cP-selectin, we have found for the first time evidence for the existence of ligands for soluble cE-selectin and cL-selectin in humans.

Bile duct adenocarcinoma mimicking veno-occlusive disease after autologous bone marrow transplantation for acute leukaemia

A 52-year-old female underwent autologous BMT because of acute myeloid leukaemia FAB M4 in second remission. Since the patient had no HLA-identical sibling she received a purged autologous BM transplant. On day +5 she developed signs of a sepsis syndrome with fluid retention and was treated with broad-spectrum antibiotic therapy. However, her body weight remained high, ascites and an increase of total serum bilirubin and alkaline phosphatase developed. The icterus worsened to a total bilirubin level of 25 mg/100 ml. Sonographic and endoscopic imaging showed a dilated gall bladder but disclosed a post-hepatic cause for the icterus. A transjugular liver biopsy on day +71 revealed severe cholestasis and siderosis. The patient remained aplastic with constantly increased bilirubin levels. On day +73 septic shock syndrome occurred and the patient died of multiorgan failure 3 days later. At autopsy, a highly differentiated bile duct adenocarcinoma at the porta hepatis, so-called Klatskin tumour, was found, explaining the fatal course with intractable cholestasis.

The diagnostic value of planar and SPET scintimammography in different age groups

Planar scintimammography (SMM) with 99Tcm-sestamibi (99Tcm-MIBI) has proved to be a useful method in the evaluation of breast lesions. The aim of our study was to determine the diagnostic value of planar and single photon emission tomograpic (SPET) SMM in different age group. We investigated women with breast lesions for which the surgeon recommended biopsy or careful follow-up. Seventy consecutive patients underwent supine planar SMM, while supine SPET was performed in 68 of the patients. Twenty-seven carcinomas in 23 patients and 35 benign lesions in 31 patients were confirmed histologically. In the remaining 16 patients, the findings were classified as benign at follow-up. The carcinomas and benign lesions had a mean (+/- S.D.) diameter of 25 +/- 17 and 17 +/- 11 mm respectively (P < 0.05). A sensitivity/specificity of 67/96% and 88/91% was obtained with the planar and SPET techniques respectively. The accuracy of both techniques was 90%. In patients aged 40 years or less, SPET increased the sensitivity from 50 to 100% (P < 0.01), whereas it decreased the specificity and accuracy from 94 to 81% and 91 to 81% respectively (N.S.). In patients aged 41-50 years, the sensitivity increased from 63 to 100% (P < 0.01), whereas there was a small decrease in specificity and an increase in accuracy (from 91 to 89% and 86 to 91% respectively, N.S.) We conclude that, in younger patients, a negative SPET SMM study indicates the need for careful follow-up rather than biopsy. However, the addition of SPET in supine scintimammography does-not change the overall accuracy significantly.

Comparison and histopathological correlation of three parathyroid imaging methods in a population with a high prevalence of concomitant thyroid diseases

The aim of this prospective study was to evaluate the diagnostic utility of a technetium-99m sestamibi dual-phase protocol enhanced by single-photon emission tomography (SPET) and semiquantitative analysis in comparison to established preoperative staging procedures in patients with primary hyperparathyroidism. Twenty-eight (50%) out of 56 patients had superimposed thyroid disease, and 12 patients had previously undergone neck surgery. Visual and semiquantitative analysis of planar 99mTc-sestamibi dual-phase imaging, SPET of the delayed phase, ultrasonography, and thallium-201 chloride-technetium-99m pertechnetate subtraction scintigraphy was further correlated with the histopathological examination of the surgical specimens. 99mTc-sestamibi dual-phase imaging achieved the highest sensitivity for side localization and precise localization compared with 201Tl-99mTc subtraction scintigraphy and ultrasonography, but the differences reached statistical significance only in comparison to ultrasonsography. Semiquantitative analysis did not enhance sensitivity. Adenoma detection by 99mTc-sestamibi dual-phase imaging was only correlated to serum calcium levels and osteocalcin, not to cell density or oxyphil cell count (SPET yielded additional information for the exact topographical localization of the parathyroid tumour in 22 (39%) patients with superimposed thyroid disease or previous neck surgery but did not enhance the overall detection rate.

Differentiation of benign and malignant breast lesions: MR imaging versus Tc-99m sestamibi scintimammography

PURPOSE

To compare the accuracies of magnetic resonance (MR) imaging and scintimammography in differentiating benign from malignant breast lesions.

MATERIALS AND METHODS

MR imaging was performed in 66 women with 75 lesions during intravenous administration of gadopentetate dimeglumine. Planar and single photon emission computed tomographic (SPECT) scintimammography were performed (with 740 MBq technetium-99m sestamibi administered intravenously) in all 66 patients with 75 lesions and in 64 patients with 73 lesions, respectively. MR imaging and scintimammographic studies were independently evaluated by using signal intensity measurements versus time or focal tracer uptake to differentiate benign from malignant lesions. Histopathologic proof was obtained in 63 lesions. Twelve lesions were monitored with follow-up.

RESULTS

MR imaging was false-negative in one and false-positive in nine lesions. Planar scintimammography was false-negative in 10 and false-positive in six lesions. SPECT scintimammography was false-negative in four and false-positive in 10 lesions. Sensitivities and specificities for malignancy were, respectively, 96% and 82% for MR imaging, 62% and 88% for planar scintimammography, and 83% and 80% for SPECT scintimammography.

CONCLUSION

Both MR imaging and scintimammography are useful in the evaluation of breast cancer. MR imaging is more sensitive and as specific as scintimammography.

Comparison of iodine-123-vasoactive intestinal peptide receptor scintigraphy and indium-111-CYT-103 immunoscintigraphy

Recently, we have shown that the expression of receptors for vasoactive intestinal peptide (VIP) on intestinal adenocarcinomas can be used for in vivo targeting of primary or metastatic tumor sites using 123I-labeled VIP. Several other receptors and antigens including the TAG-72 protein have also been implemented for in vivo localization purposes. In this study, we have compared the in vitro and in vivo binding of 123I-VIP and of the 111In-labeled monoclonal antibody (MAb) directed against TAG-72 (OncoScint; 111In-CR-103) in patients with intestinal adenocarcinomas in a single-blinded, prospectively randomized trial.

METHODS

Twenty patients were administered either 123I-VIP (150-200 MBq; 1 microgram) or 111In-CYT-103 (150 MBq; 1 mg) for one imaging study. After interim analysis demonstrated superior imaging with 123I-VIP, the next 10 patients (accounting for a total of 50 patients) enrolled in this trial underwent both studies in random order to allow for a direct comparison.

RESULTS

In total, 123I-VIP scans were true-positive in 28 of 30 patients (93%) versus 17 of 30 patients administered 111In-CYT-103 (56%). In the subgroup of 10 patients enrolled in the second part of the study, primary intestinal adenocarcinomas were imaged in five of five patients with 123I-VIP and in only two of these patients with 111In-CYT-103. Liver metastases were visualized in five of six patients by 123I-VIP receptor scanning and in four of these patients with 111In-CYT-103. The in vitro results indicated significant binding of 123I-VIP to primary colorectal tumors as well as to HT29 and COLO320 adenocarcinoma cells. In vitro, adenocarcinoma cells also expressed abundant numbers of the TAG-72 antigen.

CONCLUSION

Intestinal adenocarcinomas co-express VIP receptors and the IAG-72 antigen. Despite significant in vitro binding of both agents, however, the VIP receptor scan is more sensitive in localizing intestinal adenocarcinomas and metastatic spread.

[Supratentorial glioma: analysis of clinical and temporal parameters in 163 cases]

163 cases of supratentorial astrocytomas and glioblastomas were evaluated retrospectively after close-meshed observation and treatment. We attached the greatest importance to the reevaluation of already known prognostic parameters and to the temporal analysis of the course of gliomas. We could confirm the influence of the histologic grade on the survival time. Histologic grading by means of immunohistochemistry proved to be more precise than grading only by means of HE staining. Furthermore, the patient's age was one of the most important prognostic variables for survival time after operation. Other factors were the first preoperative Karnofsky rating, the preoperative diameter of the tumour, the duration of preoperative symptoms and the interval between operation and diagnosis of tumour recurrence as well as between tumour recurrence and reoperation. Epileptic seizures as preoperative symptoms were found to be far less prognostic for survival time. Localisation of the tumour, other preoperative symptoms, Karnofsky rating before reoperation and the extent of tumour resection proved to be of no importance for survival time.