F-18-FDG-PET zur Primärdiagnostik und Dignitätsbeurteilung pleuraler Prozesse

Ziel: Zahlreiche Studien belegen die hohe Treffsicherheit der Positronen-Emissions-Tomographie (PET) mit 2-[F-18]-Fluoro-2-desoxy-D-Glukose (FDG) bei der Dignitätsbeurteilung nicht-verkalkter Lungenrundherde. Ziel dieser Untersuchung war die Evaluation der Wertigkeit der FDG-PET in der Primärdiagnostik und Dignitätsbeurteilung pleuraler Veränderungen. Patienten/Methode: Dreizehn Patienten mit computertomographisch bekannten pleuralen Raumforderungen, von denen drei zusätzlich einen Pleuraerguß aufwiesen, sowie drei Patienten mit ätiologisch unklarem Pleuraerguß wurden einer FDG-PET unterzogen. Die PET wurde 50 min nach i.v. Injektion von 400-670 MBq F-18-FDG in Standardtechnik (ohne Schwächungskorrektur) durchgeführt. Die Sicherung der endgültigen Diagnose erfolgte in allen Fällen histologisch. Ergebnisse: Histologisch hatten zwölf Patienten pleurale beziehunsgweise pulmonale Malignome (neun Pleuramesotheliome, drei Adenobronchialkarzinome mit Pleuritis carcinomatosa), vier Patienten wiesen benigne pleurale Veränderungen auf (ein Fibrom, ein tuberkulöse Pleuritis, ein Pleuraschwarte, ein Pleuraempyem). Mittels FDG-PET wurden alle pleuralen Prozesse richtig klassifiziert, wobei zwölf richtig positive und vier richtig negative Befunde erhoben wurden. Schlußfolgerung: Unsere Daten zeigen, daß FDG-PET mit hoher Sensitivität maligne pleurale Prozesse detektieren kann.

Skelettdiagnostik mittels 18F-Natriumfluorid-PET und -PET/CT

In nuclear medicine, bone scanning is based on the principle of scintigraphy using boneseeking radiopharmaceuticals which accumulate in sites of increased bone formation. From a historical point of view, 18F-fluoride was one of the first osteotropic tracers which was replaced by 99mTc-labelled polyphosphonates. With the development of modern PET equipment the superior diagnostic performance of 18F-fluoride PET for the detection and characterization of osseous lesions was proven in comparison to conventional bone scanning. Recently, its importance as a substitute of conventional skeletal scintigraphy increased in a time with limited availability of 99Mo/ 99mTc. To ensure health care during this period, 18F-fluoride PET currently became part of common outpatient care.

This guideline comprehends recommendations on indications, protocols, interpretation and reporting of 18F-fluoride PET and PET/CT.

Sentinel node biopsy in breast cancer

The international consensus conference from St. Gallen concerning the treatment of early breast cancer concluded in 2003, that sentinel node biopsy was now accepted as method allowing axillary staging in breast cancer. This procedure may avoid complete lymph node dissection in appropriate cases. Since numerous questions associated with the technique are still not defined and the procedure itself is not yet standardized, the German Society of Senology defined the conditions for the routine clinical use of sentinel node biopsy in an interdisciplinary consensus meeting.

[18F]FDG-PET in patients with Alzheimer's disease: marker of disease spread

BACKGROUND

It is not known yet whether temporoparietal glucose hypometabolism in patients with probable Alzheimer's disease (AD) reflects disease severity or different subtypes of patients.

METHODS

Twenty-five subjects with mild probable AD [NINCDS-ADRDA criteria; age 65.8 +/- 9.3 years (mean +/- SD); Mini-Mental State Examination (MMSE) 26.0 +/- 3.3] were investigated. [(18)F]FDG-PET data were analyzed visually with raters blinded to the diagnosis and with a quantitative analysis in the region of interest on individual anatomically normalized PET scans.

RESULTS

Thirteen of 25 patients showed temporoparietal hypometabolism on visual inspection (PET+; age 65.7 +/- 10.7), 12 patients had normal FDG-PET results (PET-; age 65.9 +/- 8.0; n.s.). The MMSE and immediate reproduction of the Wechsler Memory Scale (WMS-R-I) were 27.7 +/- 1.9 and 31.1 +/- 6.1 in the PET- vs. 24.5 +/- 3.6 (p = 0.012) and 22.0 +/- 7.4 (p = 0.006) in the PET+ group. Immediate and delayed recall in the California Verbal Learning Test and delayed reproduction in the Wechsler Memory Scale were alike. Regression analysis revealed a significant correlation of temporoparietal glucose metabolism with the block span (r = 0.60; p < 0.01) and the WMS-R-I (r = 0.68; p < 0.01) but not with measures of hippocampal function.

CONCLUSIONS

Temporoparietal glucose metabolism in patients with very mild AD is a sign of disease spread beyond the temporal lobe. This may aid in establishing objective parameters for future therapeutic studies.

[ 18 F] 3-deoxy-3′-fluorothymidine positron emission tomography: alternative or diagnostic adjunct to 2-[ 18 f]-fluoro-2-deoxy- d -glucose positron emission tomography in the workup of suspicious central focal lesions?

BACKGROUND

2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography has been established as a standard diagnostic imaging method in the preoperative workup of suspicious pulmonary focal lesions, showing a sensitivity of more than 90% and a specificity of about 80%. Determination of malignant pulmonary lesions with FDG positron emission tomography depends on the assessment of glucose metabolism. However, false-positive findings can occur in inflammatory processes, such as sarcoidosis or pneumonia. The thymidine analogue 3-deoxy-3[(18)F]-fluorothymidine (FLT) is a new positron emission tomography tracer that more specifically targets proliferative activity of malignant lesions. The objective of this study was to determine whether FLT positron emission tomography, in comparison with FDG positron emission tomography, provides additional information in the preoperative workup of central pulmonary focal lesions.

METHODS

In this prospective study FLT and FDG positron emission tomography examinations were performed as a part of the preoperative workup in 20 patients with histologically confirmed bronchial carcinoma, 7 patients with benign lesions, and 1 patient with an atypical carcinoid. Results were compared with final pathologic findings.

RESULTS

For staging of the primary tumor, FLT positron emission tomography revealed a sensitivity of 86% and a specificity of 100% compared with a sensitivity of 95% and a specificity of 73% for FDG positron emission tomography. For N staging, the sensitivity of FLT positron emission tomography was 57% and the specificity was 100%, and for FDG positron emission tomography, the sensitivity was 86% and the specificity was 100%, respectively.

CONCLUSIONS

Our preliminary findings indicate specific FLT uptake in malignant lesions. The number of false-positive findings in FDG positron emission tomography might be reduced with FLT positron emission tomography. Therefore positron emission tomography imaging with FLT represents a useful supplement to FDG in assessing the malignancy of central pulmonary focal lesions.

Lymph Node Staging in Lung Cancer Using [18F]FDG-PET

BACKGROUND

Mediastinal lymph node staging is essential to determine treatment options in patients with NSCLC. Positron emission tomography (PET) detects increased glucose uptake in malignant tissue using the glucose analogue 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG).

PATIENTS AND METHODS

In the present study were evaluated 155 patients with focal pulmonary tumors who underwent both preoperative computed tomography (CT) and FDG-PET scanning (116 malignant and 39 benign lesions).

RESULTS

Findings in 155 patients included 116 malignant and 39 benign lesions. For N-staging, FDG-PET showed a sensitivity of 88%, a specificity of 91%, and an accuracy of 89%. Corresponding figures for CT were 77%, 76%, and 77%, respectively.

CONCLUSIONS

FDG-PET is an effective, noninvasive method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to operability, FDG-PET could differentiate reliable between patients with N1/N2 disease and those with unresectable N3 disease.

Sentinel-node biopsy for axillary staging in breast cancer: results from a large prospective German multi-institutional trial

PURPOSE

To analyse the reliability of sentinel-node biopsy (SNB) in a multicentre setting and define conditions for the routine use of the procedure.

MATERIAL AND METHODS

SNB with consecutive axillary clearing was performed in 1124 breast cancer patients. The detection rate of a sentinel lymph node and its dependence on the choice of lymphography technique, patient selection, and technical procedure were analysed. The diagnostic performance of the sentinel-node method was compared to clinical, ultrasound-guided and histological staging. In order to study training effects all learning periods were included.

RESULTS

Twenty-two institutions with a total of 89 surgeons participated in the trial. The detection rate (overall: 85.2%) was found to be related to the applied lymphography technique, the experience of the institution and various technical factors of the procedure itself. The false-negative rate (FNR, overall: 8.2%) was independent of patient selection and technical features. The FNR did not depend on experience in the application of the method, but seemed related to surgical accuracy to detect sentinel nodes. Compared to conventional staging procedures (palpation, ultrasound) SNB yielded highly reproducible results for the prediction of the axillary status even in a multicentre setting involving surgeons with different training status.

CONCLUSION

SNB is suited as standard of care procedure. Measures of quality control appear more important than learning periods to minimize the FNR.

[Sentinel node biopsy in breast cancer]

The international consensus conference from St. Gallen concerning the treatment of early breast cancer concluded in 2003, that sentinel node biopsy was now accepted as method allowing axillary staging in breast cancer. This procedure may avoid complete lymph node dissection in appropriate cases. Since numerous questions associated with the technique are still not defined and the procedure itself is not yet standardized, the German Society of Senology defined the conditions for the routine clinical use of sentinel node biopsy in an interdisciplinary consensus meeting.

Pre-operative staging of invasive breast cancer with MR mammography and/or PET: boon or bunk?

This study compared pre-operative staging with MR mammography (MRM) and positron emission tomography (PET) in patients with clinically suspected breast cancer according to the Breast Imaging Reporting and Data System, category 5. A total of 43 patients with breast cancer were examined. MRM included both T(2) weighted turbo spin echo sequences and T(1) weighted gradient echo sequences (three-dimensional fast low angle shot) before and after application of gadolinium-DPTA. All patients then underwent examination with a modern full-ring PET scanner following injection of fluorodeoxyglucose. We evaluated the efficacy of these methods in the diagnosis of primary tumour, contralateral carcinomas, bifocal, trifocal or multifocal disease, as well as non-invasive cancer portions and tumour size. Determination of patients' N-status was only attempted using PET. All findings were validated by histological examination. MRM was slightly superior to PET in several areas, such as in the respective methods' sensitivity and specificity. Sensitivities for MRM and PET were: 100% vs 93.0% in diagnosis of the primary tumour; 100% vs 100% in diagnosis of contralateral carcinomas; and 95.2% vs 92.5% in diagnosis of bifocal, trifocal or multifocal disease. Specificities for MRM and PET were: 100% vs 97.5% in diagnosis of contralateral carcinomas; and 96.8% vs 90.3% in diagnosis of bifocal, trifocal or multifocal disease. Non-invasive cancer portions and tumour sizes were equally well determined with both methods. The sensitivity of PET for detection of lymph node involvement was 80% and specificity 95%. MRM and PET were superior to conventional methods in nearly all areas studied; the findings of one or both of the methods impacted positively on patients' surgical treatment in 12.5-15% of cases. Pre-operative MRM and/or PET can have a positive influence on surgical treatment planning. Therefore, it appears useful to perform pre-operative staging with MRM or PET in these patients.

Initial results in the assessment of multiple myeloma using 18F-FDG PET

This prospective study was undertaken to investigate the appearance of multiple myeloma on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET). Furthermore, the accuracy of FDG-PET in detecting myeloma lesions and its influence on patient management were evaluated. Forty-three patients with known multiple myeloma (n=28) or solitary plasmacytoma (n=15) underwent FDG-PET. The results of routinely performed radiographs and of scans obtained using all available imaging modalities (MRI, CT), as well as the clinical course, were used for verification of detected lesions. Focally increased tracer uptake was observed in 38 of 41 known osteolytic bone lesions (sensitivity 92.7%) in 23 patients. In addition, 71 further bone lesions which were negative on radiographs were detected in 14 patients. Twenty-six (36.6%) of these lesions could be confirmed in ten patients. As a result of FDG-PET imaging, clinical management was influenced in five (14.0%) patients. The positive predictive value for active disease was 100% in patients with focal or mixed focal/diffuse skeletal FDG uptake and 75% in patients with diffuse bone marrow uptake. Depending on the interpretation of the PET scans in patients with diffuse bone marrow uptake, the sensitivity ranged from 83.8% to 91.9% and the specificity from 83.3% to 100%. FDG-PET thus proved highly accurate in detecting multiple myeloma, and revealed a greater extent of disease than routine radiographs in 14 of 23 (60.9%) patients who had osteolytic bone lesions. FDG-PET might contribute to the initial staging of solitary plasmacytoma.

Disturbed neural circuits in a subtype of chronic catatonic schizophrenia demonstrated by F-18-FDG-PET and F-18-DOPA-PET

Permanent verbal, visual scenic and coenaestetic hallucinations are the most prominent psychopathological symptoms aside from psychomotor disorders in speech-sluggish catatonia, a subtype of chronic catatonic schizophrenia according to Karl Leonhard. These continuous hallucinations serve as an excellent paradigm for the investigation of the assumed functional disturbances of cortical circuits in schizophrenia. Data from positron emission tomography (F-18-FDG-PET and F-18-DOPA-PET) from three patients with this rare phenotype were available (two cases of simple speech-sluggish catatonia, one case of a combined speech-prompt/speech-sluggish subtype) and were compared with a control collective. During their permanent hallucinations, all catatonic patients showed a clear bitemporal hypometabolism in the F-18-FDG-PET. Both patients with the simple speech-sluggish catatonia showed an additional bilateral thalamic hypermetabolism and an additional bilateral hypometabolism of the frontal cortex, especially on the left side. In contrast, the patient with the combined speech-prompt/speech-sluggish catatonia showed a bilateral thalamic hypometabolism combined with a bifrontal cortical hypermetabolism. However, the left/right ratio of the frontal cortex also showed a lateralisation effect with a clear relative hypometabolism of the left frontal cortex. The F-18-DOPA-PET of both schizophrenic patients with simple speech-sluggish catatonia showed a normal F-18-DOPA storage in the striatum, whereas in the right putamen of the patient with the combined form a higher right/left ratio in F-DOPA storage was discernible, indicating an additional lateralized influence of the dopaminergic system in this subtype of chronic catatonic schizophrenia. Most likely, the prominent bitemporal F-18-FDG- hypometabolism in these chronic schizophrenic patients with speech-sluggish catatonia suffering from permanent continuous hallucinations, reflects a deficit in sensoric gating following prenatal cortical neurodevelopmental disturbances. However, the functional disturbances underlying hallucinations in "the schizophrenias" seem to be more complex; in different subtypes of the schizophrenic spectrum disorder hallucinations seem to be based on alterations in additional cortical and subcortical brain regions.

Prospective evaluation of the clinical value of planar bone scans, SPECT, and (18)F-labeled NaF PET in newly diagnosed lung cancer

Previous studies have shown that vertebral bone metastases (BM) not seen on planar bone scintigraphy (BS) might be present on (18)F-fluoride PET scans or at MRI. Therefore, we evaluated the effect of SPECT or (18)F-labeled NaF PET ((18)F PET) imaging on the management of patients with newly diagnosed lung cancer.

METHODS

Fifty-three patients with small cell lung cancer or locally advanced non-small cell lung cancer were prospectively examined with planar BS, SPECT of the vertebral column, and (18)F PET. MRI and all available imaging methods, as well as the clinical course, were used as reference methods. BS with and without SPECT and (18)F PET were compared using a 5-point scale for receiver operating characteristic (ROC) curve analysis.

RESULTS

Twelve patients had BM. BS produced 6 false-negatives, SPECT produced 1 false-negative, and (18)F PET produced no false-negatives. The area under the ROC curve was 0.779 for BS, 0.944 for SPECT, and 0.993 for (18)F PET. The areas under the ROC curve of (18)F PET and BS complemented by SPECT were not significantly different, and both tomographic methods were significantly more accurate than planar BS. As a result of SPECT or (18)F PET imaging, clinical management was changed in 5 patients (9%) or 6 patients (11%), respectively.

CONCLUSION

As indicated by the area under the ROC curve analysis, (18)F PET is the most accurate whole-body imaging modality for screening for BM. Routinely performed SPECT imaging is practicable, is cost-effective, and improves the accuracy of BS.

Anatomical distribution and sclerotic activity of bone metastases from thyroid cancer assessed with F-18 sodium fluoride positron emission tomography

Currently, bone scintigraphy (BS) is considered to lack sensitivity in detecting bone metastases (BM) from thyroid cancer. We evaluated the anatomical distribution and metabolic behavior of BM as well as the accuracy of BS with and without combination of whole-body iodine scintigraphy (WBI) in detecting metastatic bone disease in thyroid carcinoma. F-18 positron emission tomography (PET), x-ray, BS, and WBI were performed in 35 patients with known or suspected bone metastases from papillary (9 patients) or follicular (26 patients) thyroid carcinoma. Twenty-two metastases were previously known in 14 patients. The indication was staging in 21 patients with high risk for BM, elevated thyroglobulin (Tg)-levels or evaluation of exact extent of BM (14 patients). In addition, results of WBI (35 patients), X-ray (35 patients) F-18 PET (35 patients), MRI of the spine (13 patients), and FDG-PET (15 patients) as well as the clinical course (1.5-4 years) were correlated. BM were detected in 18 patients. Solitary, bifocal, or multiple lesions were present in 9, 2, and 7 patients, respectively. The anatomical distribution of BM (n = 43) was as follows: spine, 42%; skull, 2%; thorax, 16%; femur, 9%; pelvis, 26%; humerus and clavicle, 5%. Sensitivity of BS in interpreting patients as positive or negative for having BM was 64%-85% (specificity, 95%-81%). The combination of BS and WBI was 100% sensitive in detecting metastatic bone disease. One patient had a single BM that was positive at BS but negative on WBI. All metastases were osteolytic on x-ray and two-thirds presented a missing or very limited osteosclerotic bone reaction on F-18 PET. Our data confirm the limited sensitivity of planar BS in detecting BM from thyroid cancer. The combination of BS and WBI, however, was highly accurate. Compared to other malignancies, the distribution pattern of BM presented a lower percentage of vertebral metastases and more patients with single metastases. Those findings in combination with a missing or only slight osteosclerotic bone reaction explain the limited sensitivity of planar BS alone.

2-(fluorine-18)fluoro-2-deoxy-D-glucose positron emission tomography in the detection and staging of malignant lymphoma. A bicenter trial

BACKGROUND

The authors undertook a prospective evaluation of the clinical value of 2-fluoro [18-]-2-deoxyglucose positron emission tomography (FDG-PET) in the detection and staging of malignant lymphoma compared with computed tomography (CT) and bone marrow biopsy (BMB).

METHODS

Fifty-two consecutive patients with untreated malignant lymphoma were evaluated prospectively in a bicenter study. FDG-PET, CT, and BMB were performed for investigating lymph node/extranodal manifestations and bone marrow infiltration. Thirty-three percnt of the discrepant results were verified by biopsy, magnetic resonance imaging, or clinical follow-up (range, 4-24 month).

RESULTS

Altogether, 1297 anatomic regions (lymph nodes, organs, and bone marrow) were evaluated. FDG-PET and CT scans were compared by receiver operating characteristic (ROC) curve analysis. The area under the ROC curve were as follows: lymph nodes, 0.996 (PET) and 0.916 (CT); extranodal, 0.999 (PET) and 0.916 (CT); supradiaphragmatic, 0.996 (PET) and 0.905 (CT); and infradiaphragmatic, 0.999 (PET) and 0.952 (CT). In these analyses, FDG-PET was significantly superior to CT (P < 0.05), except in infradiaphragmatic regions, in which the two methods produced equivalent results. In detecting bone marrow infiltration, FDG-PET was superior to CT and was equivalent to BMB. In 4 of 52 patients (8%), FDG-PET led to an upstaging and a change of therapy.

CONCLUSIONS

Noninvasive FDG-PET is very accurate in the staging of malignant lymphoma. Compared with standard staging modalities (CT and BMB), PET was significantly superior and led to changes in the therapy regimen for 8% of patients.

Fluorine-18 2-deoxy-2-fluoro-D-glucose PET in the preoperative staging of breast cancer: comparison with the standard staging procedures

The present study compared the diagnostic accuracy of fluorine-18 2-deoxy-2-fluoro-D-glucose positron emission tomography (FDG-PET) with conventional staging techniques. The differentiation between malignant and benign lesions and the detection of multifocal disease, axillary and internal lymph node involvement, and distant metastases were evaluated. One hundred and seventeen female patients were prospectively examined using FDG-PET and conventional staging methods such as chest X-ray, ultrasonography of the breast and liver, mammography and bone scintigraphy. All patients were examined on a modern full-ring PET scanner. Histopathological analysis of resected specimens was employed as the reference method. The readers of FDG-PET were blinded to the results of the other imaging methods and to the site of the breast tumour. The sensitivity and specificity of FDG-PET in detecting malignant breast lesions were 93% and 75% respectively. FDG-PET was twofold more sensitive (sensitivity 63%, specificity 95%) in detecting multifocal lesions than the combination of mammography and ultrasonography (sensitivity 32%, specificity 93%). Sensitivity and specificity of FDG-PET in detecting axillary lymph node metastases were 79% and 92% (41% and 96% for clinical evaluation). FDG-PET correctly indicated distant metastases in seven patients. False-positive or false-negative findings were not encountered with FDG-PET. Chest X-ray was false-negative in three of five patients with lung metastases. Bone scintigraphy was false-positive in four patients. Three patients were upstaged since FDG-PET detected distant metastases missed with the standard staging procedure. It is concluded that, compared with the imaging methods currently employed for initial staging, FDG-PET is as accurate in interpreting the primary tumour and more accurate in screening for lymph node metastases and distant metastases. Due to a false-negative rate of 20% in detecting axillary lymph node metastases, FDG-PET cannot replace histological evaluation of axillary status.

Positron emission tomography for detection and staging of malignant lymphoma

FDG-Positron emission tomography (FDG-PET) is an imaging modality using the physiological tracer glucose [modified as 18-fluorine-2-fluorodeoxyglucose (FDG)], whose uptake and metabolism is increased in malignant cells. While exact tumor staging in lymphomatous diseases is the basis for choosing the appropriate treatment strategy, the detection of nodal and extranodal manifestations are a key prerequisite. This study demonstrates that FDG-PET is an efficient, non-invasive method for the staging of primary untreated Hodgkin's lymphoma (HD) and non-Hodgkin's lymphoma (NHL). Clinical PET scanning is very useful in staging lymphoma patients and is more accurate than computed tomography (CT) in detecting lesions.

Is (18)F-fluorodeoxyglucose positron emission tomography in recurrent colorectal cancer a contribution to surgical decision making?

BACKGROUND

Accuracy of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and contribution to surgical decision making in recurrent or metastatic colorectal cancer were evaluated.

METHODS

One hundred whole-body PET tests in colorectal cancer patients (1994 to 1998) were compared with computed tomography (CT), liver ultrasonography, and carcinoembryonic antigen (CEA) test. Mean follow-up was 12 months.

RESULTS

Sensitivity, specificity, and accuracy of FDG-PET for malignant findings were, respectively, 98%, 90% and 95%; for 87 CT scans, 91%, 72%, and 82%; for 98 CEA tests, 76%, 90%, and 82%; for detection of liver metastases with PET, 100%, 99%, and 99%; and for 68 ultrasound tests, 87%, 96%, and 93%. PET accuracy for local recurrence was 96%. Additional information was provided by PET in 86% of cases (abdomen, thorax, liver). PET influenced surgical decisions in 61% of cases.

CONCLUSION

FDG-PET adds relevant accuracy to the conventional staging of patients with colorectal cancer and may cost-effectively help to select the appropriate treatment.

[F-18-FDG PET for primary diagnosis differential diagnosis of pleural processes]

PURPOSE

Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) has been shown to be accurate for differentiating benign from malignant pulmonary lesions. Therefore, we evaluated the capability of FDG-PET in the characterisation of pleural lesions.

PATIENTS AND METHODS

PET was performed in thirteen patients with pleural or intrapulmonal tumors (three with additional pleural effusion) and in three patients with aetiologically unclear pleural effusion demonstrated by CT. In all cases the diagnosis was confirmed histologically. The PET-imaging was carried out in fasted patients 50 minutes after injection of 400-670 MBq F-18-FDG without attenuation correction.

RESULTS

Twelve patients were found to have pleural or pulmonal malignomas (9 pleural mesotheliomas, 3 bronchogenic adenocarcinoma with carcinomatous pleurisy). Four patients had benign pleural changes (1 fibroma, 1 tuberculous pleurisy, 1 pleural fibrosis, 1 empyema). With FDG-PET, all 12 pleural or intrapulmonal malignomas had high FDG-uptake and were classified correctly. Due to very low or virtually deficient FDG-uptake, four histologically benign lesions were correctly interpreted as nonmalignant.

CONCLUSION

These preliminary results suggest that FDG-PET is accurate in detecting malignant pleural tumors.

Pericystic metabolic activity in alveolar echinococcosis: assessment and follow-up by positron emission tomography

Information on parasite viability in alveolar echinococcosis (AE) cannot be obtained by conventional imaging techniques. We evaluated the glucose metabolism of AE lesions by use of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) in 12 inoperable patients. Eight patients showed either perilesional or focal enhancement ("hot spots"), whereas 4 patients had nonenhancing (metabolically inactive) lesions. With PET, necrotic parasitic lesions and areas of enhanced metabolic activity could be clearly discriminated. Most notably, 3 of 8 patients with metabolically active lesions who were reexamined after chemotherapy treatment clearly showed improvement: the initial surrounding hot spots had disappeared in 2 of them, and had significantly decreased in 1. PET may prove valuable in assessing the efficacy of chemotherapy by showing the disappearance of metabolic activity and may also be useful for timely detection of relapses and metastases. Although costly and not readily available, FDG-PET is a promising tool toward improved management of AE and may thus help lower costs of long-term chemotherapy.

Sensitivity in detecting osseous lesions depends on anatomic localization: planar bone scintigraphy versus 18F PET

Radionuclide bone scanning (RNB) is considered to be the most practical screening technique for assessing the entire skeleton for skeletal metastases. However, RNB has been shown to be of lower sensitivity than MRI and CT in detecting osteolytic metastases. A prospective study was designed to evaluate the accuracy of planar RNB versus tomographic bone imaging with 18F-labeled NaF and PET (18F PET) in detecting osteolytic and osteoblastic metastases and its dependency on their anatomic localization.

METHODS

Forty-four patients with known prostate, lung or thyroid carcinoma were examined with both planar RNB and 18F PET. A panel of reference methods including MRI of the spine, 1311 scintigraphy, conventional radiography and spiral CT was used as the gold standard. RNB and 18F PET were compared by a lesion-by-lesion analysis using a five-point score for receiver operating characteristic (ROC) curve analysis.

RESULTS

18F PET showed 96 metastases (67 of prostate carcinoma and 29 of lung or thyroid cancer), whereas RNB revealed 46 metastases (33 of prostate carcinoma and 13 of lung or thyroid cancer). All lesions found with RNB were also detected with 18F PET. Compared with 18F PET and the reference methods, RNB had a sensitivity of 82.8% in detecting malignant and benign osseous lesions in the skull, thorax and extremities and a sensitivity of 40% in the spine and pelvis. The area under the ROC curve was 0.99 for 18F PET and 0.64 for RNB.

CONCLUSION

18F PET is more sensitive than RNB in detecting osseous lesions. With RNB, sensitivity in detecting osseous metastases is highly dependent on anatomic localization of these lesions, whereas detection rates of osteoblastic and osteolytic metastases are similar. Higher detection rates and more accurate differentiation between benign and malignant lesions with 18F PET suggest the use of 18F PET when possible.

Early detection and accurate description of extent of metastatic bone disease in breast cancer with fluoride ion and positron emission tomography

PURPOSE

Previous studies have shown that bone metastases are revealed by magnetic resonance imaging (MRI) or bone marrow scintigraphy several months before they are visible by conventional bone scintigraphy (BS). We present a new approach for detecting bone metastases in patients with breast cancer. We compared findings obtained with fluoride ion (F-18) and positron emission tomography (PET) with those obtained with conventional BS.

PATIENTS AND METHODS

Thirty-four breast cancer patients were prospectively examined using F-18-PET and conventional BS. F-18-PET and BS were performed within 3 weeks of each other. Metastatic bone disease was previously known to be present in six patients and was suspected (bone pain or increasing levels of tumor markers, Ca(2+), alkaline phosphatase) in 28 patients. Both imaging modalities were compared by patient-by-patient analysis and lesion-by-lesion analysis, using a five-point scale for receiver operating characteristic (ROC) curve analysis. A panel of reference methods was used, including MRI (28 patients), planar x-ray (17 patients), and spiral computed tomography (four patients).

RESULTS

With F-18-PET, 64 bone metastases were detected in 17 patients. Only 29 metastases were detected in 11 patients with BS. As a result of F-18-PET imaging, clinical management was changed in four patients (11.7%). For F-18-PET, the area under the ROC curve was 0.99 on a lesion basis (for BS, it was 0.74; P <.05) and 1.00 on a patient basis (for BS, it was 0.82; P <.05).

CONCLUSION

F-18-PET demonstrates a very early bone reaction when small bone marrow metastases are present, allowing accurate detection of breast cancer bone metastases. This accurate detection has a significant effect on clinical management, compared with the effect on management brought about by detection with conventional BS.

[Positron-emission tomography of the skeletal system using 18FNa: the incidence, pattern of the findings and distribution of benign changes]

PURPOSE

We evaluated the frequency, distribution and appearance of benign lesions in 18F-PET scans.

METHODS

Between March 1996 and May 1997, 18F-PET scans were performed in 59 patients in addition to conventional planar bone scintigraphy. Eleven patients were subjected to additional SPECT imaging. The main indication was searching for bone metastases (58 pat.). The diagnosis was confirmed radiologically.

RESULTS

With 18F-PET in 39 patients (66.1%) 152 benign lesions, mostly located in the spine were detected. 99mTc bone scans revealed 45 lesions in 10 patients. Osteoarthritis of the intervertebral articulations (69%) or of the acromioclavicular joint (15%) were the most common reasons for degenerative lesions detected with 18F-PET. Osteophytes appeared as hot lesions located at two adjacent vertebral endplates. Osteoarthritis of the intervertebral articulations showed an enhanced tracer uptake at these localizations, whereas endplate fractures of the vertebral bodies appeared very typical; solitary fractures of the ribs could not be differentiated from metastases. Rare benign lesions were not studied.

CONCLUSION

Most of the degenerative lesions (84%) detected with 18F-PET had a very typical appearance and could be detected with the improved spatial resolution and advantages of a tomographic technique. 18F-PET had an increased accuracy in detecting degenerative bone lesions.

[Imaging of the normal skeletal system with 18F Na-PET compared with conventional skeletal scintigraphy using Tc99m-MDP]

PURPOSE

We evaluated the feasibility of 18 Fluoride Positron Emission Tomography (18F-PET), investigated the characteristics appearance of bony structures, and compared the quality of 18F-PET images with conventional bone scans (BS).

METHOD

18F-PET scans were performed in 59 patients additional to conventional bone scintigraphy.

RESULTS

Even very small details in the spine like the spinous and transverse processes were clearly visible with 18F-PET. Only half of these structures were visualised with BS. When visualising the vertebral bodies of the first rib from the clavicles and the twelfth rib from the kidneys, we arrived at similar results. Hot spots in the skull or at the manubriosternal joint were observed in 29% of the patients without any evidence of trauma, degeneration or metastasis.

CONCLUSION

18F-PET shows more details of the skeleton compared to BS. Some hot spots not occurring with BS must be regarded as physiological.

[Positron-emission tomography in the diagnosis of abdominal tumors]

PET is recognized as a powerful imaging research tool. Its clinical application has been increasing significantly in recent years. Based on pathophysiological and biochemical principles, functional PET imaging makes it possible to assess parameters of tumor biology not easily accessible to conventional imaging, such as metabolic activity, proliferation, adrenergic transmitter uptake or accumulation of cytostatics in individual tumor manifestations. For clinical application, PET imaging with 2-[F-18]fluorodeoxyglucose (FDG) is of paramount importance. This article reviews recent developments in the use of PET in the diagnosis of abdominal malignant tumors. Diagnosis of pancreatic carcinoma and related liver metastases, locoregional and distant recurrence, as well as therapy control of colorectal cancer, nodal and extranodal staging and therapy monitoring of malignant lymphoma, can be reliably performed with PET. Several appropriately labeled adrenergic transmitters are currently being developed for specific imaging of neuroendocrine tumors. Radiolabeled cytostatics such as F-18 5-FU will shortly be available for clinical use as probes for primary or secondary cytostatic resistance. Encouraging clinical results and attractive new imaging concepts promise increasing use and importance for PET for imaging of abdominal malignancies.

[Collagen disease with pure red cell anemia and perimembraneous glomerulonephritis (author's transl)]

Record on a case of collagen disease with pure red cell anemia and perimembraneous glomerulonephritis. The direct antiglobulin tests with anti-IgG and anti-kappaserum were positive as were the tests on antinuclear serum-antibodies. During therapy with fluocortolon and azathioprin the anemia remitted completely even when therapy was stopped. The antiglobulin tests became negative, the glomerulitis remained active, there was no deterioration of renal function.

Untersuchungen über den Leukozytenumsatz mit radioaktivem Diisopropylfluorophosphat (DF32P) unter besonderer Berücksichtigung der myeloproliferativen Erkrankungen

Bei insgesamt 16 Patienten, darunter 5 Patienten mit chronischer Myelose, akuter Myelose und Osteomyelosklerose, wurde die Kinetik des Granulozytenumsatzes mit Hilfe der DF32P-Markierung untersucht. Die Markierungssubstanz wurde parenteral verabreicht und die Leukozytenradioaktivität nach Isolierung der Zellen verfolgt. Es ergaben sich charakteristische Kurvenbilder, die auf Grund der heute gültigen Modellvorstellung der Leukopoese diskutiert wurden. Bei Leukosen fand sich eine sehr viel langsamere Abnahme der Leukozytenradioaktivität als bei Normalen, was darauf hinweist, daß eine verlängerte Verweildauer der Leukozyten in der Peripherie mit für die Vermehrung der Leukozyten im peripheren Blut verantwortlich ist.