99mTc-besilesomab (Scintimun) in peripheral osteomyelitis: comparison with 99mTc-labelled white blood cells.

PURPOSE: The diagnosis of osteomyelitis is a challenge for diagnostic imaging. Nuclear medicine procedures including white blood cell imaging have been successfully used for the identification of bone infections. This multinational, phase III clinical study in 22 European centres was undertaken to compare anti-granulocyte imaging using the murine IgG antibody besilesomab (Scintimun) with (99m)Tc-labelled white blood cells in patients with peripheral osteomyelitis. METHODS: A total of 119 patients with suspected osteomyelitis of the peripheral skeleton received (99m)Tc-besilesomab and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO)-labelled white blood cells (WBCs) in random order 2-4 days apart. Planar images were acquired at 4 and 24 h after injection. All scintigraphic images were interpreted in an off-site blinded read by three experienced physicians specialized in nuclear medicine, followed by a fourth blinded reader for adjudication. In addition, clinical follow-up information was collected and a final diagnosis was provided by the investigators and an independent truth panel. Safety data including levels of human anti-mouse antibodies (HAMA) and vital signs were recorded. RESULTS: The agreement in diagnosis across all three readers between Scintimun and (99m)Tc-HMPAO-labelled WBCs was 0.83 (lower limit of the 95% confidence interval 0.8). Using the final diagnosis of the local investigator as a reference, Scintimun had higher sensitivity than (99m)Tc-HMPAO-labelled WBCs (74.8 vs 59.0%) at slightly lower specificity (71.8 vs 79.5%, respectively). All parameters related to patient safety (laboratory data, vital signs) did not provide evidence of an elevated risk associated with the use of Scintimun except for two cases of transient hypotension. HAMA were detected in 16 of 116 patients after scan (13.8%). CONCLUSION: Scintimun imaging is accurate, efficacious and safe in the diagnosis of peripheral bone infections and provides comparable information to (99m)Tc-HMPAO-labelled WBCs.

Low Malignancy Rates in Fine-Needle Aspiration Cytologies in a Primary Care Setting in Germany.

BACKGROUND: Reported results for thyroid nodule fine-needle aspiration (FNA) cytology mainly originate from tertiary centers. However, thyroid nodule FNA cytology is mainly performed in primary care settings for which the distribution of FNA Bethesda categories and their respective malignancy rates are largely unknown. Therefore, this study investigated FNA cytology malignancy rates of a large primary care setting to determine to what extent current evidence-based strategies for the malignancy risk stratification of thyroid nodules are applied and applicable in such primary care settings. METHODS: In a primary care setting, 9460 FNAs of thyroid nodules were retrospectively analyzed from 8380 patients evaluated by one cytologist (I.R.) during a period of two years. The 8380 FNA cytologies were performed by 64 physicians in different private practices throughout Germany in primary care settings. RESULTS: The cytopathologic results were classified according to the Bethesda System as non-diagnostic in 19%, cyst/cystic nodule in 21%, benign (including thyroiditis) in 48%, atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) in 6%, follicular neoplasms/suspicious for follicular neoplasm (FN/SFN) in 4%, suspicious for malignancy (SFM) in 1%, and malignant in 1%. The proportion of patients proceeding to surgery or with a follow-up of at least one year and the observed risks of malignancy were 22%/8% for AUS/FLUS, 69%/17% for FN/SFN, 78%/86% for SFM, and 71%/98% for malignant. For 112 cytologically suspicious and malignant FNAs, there were 102 true positives and 10 false positives, considering histology as gold standard. CONCLUSION: At variance with other data mostly originating from tertiary centers, these data demonstrate low percentages for malignant, SFM, FN/SFN, and AUS/FLUS, and high percentages for cysts/cystic nodules in this primary care setting in Germany. The risks of malignancy for malignant, SFM, AUS/FLUS, and FN/SFN FNA cytologies are according to Bethesda recommendations.

Evaluation of a Two-Year Routine Application of Molecular Testing of Thyroid Fine-Needle Aspirations Using a Seven-Gene Panel in a Primary Referral Setting in Germany.

BACKGROUND: Major differences with respect to the diagnostic performance of a "ruling in" approach in the presurgical diagnosis of indeterminate thyroid fine-needle aspirations (FNAs) have been reported. Therefore, the aim of this prospective multicenter study was to investigate the specific diagnostic impact of mutation testing using a seven-gene panel in a routine primary referral setting analyzing FNAs from endocrinology and nuclear medicine practices in Germany. METHODS: RNA and DNA was extracted from 564 routine air-dried FNA smears obtained from 64 physicians and cytologically graded by one experienced cytopathologist. PAX8/PPARG and RET/PTC rearrangements were detected by quantitative polymerase chain reaction, while BRAF and RAS mutations were detected by pyrosequencing. Molecular data were compared to histology and follow-up >1 year, which were available for 322/348 patients undergoing surgery and 33/74 patients having follow-up. Histology results were obtained from the local routine pathologists who were blinded to the molecular test results. RESULTS: BRAF and RET/PTC mutations were associated with carcinoma in 98% and 100% of samples, respectively. RAS and PAX8/PPARG mutations were associated with carcinoma in 31% and 0% of samples, respectively. Thirty-six percent of the carcinomas were identified by molecular testing in the atypia of undetermined significance/follicular lesion of undetermined significance and follicular neoplasm/suspicious for a follicular neoplasm categories, with malignancy rates of 15% and 17%, respectively. Due to a low percentage of RAS mutation-positive carcinomas in combination with a rather high percentage of RAS mutation-positive benign nodules, the positive predictive values of 41% and 36% in the atypia of undetermined significance/follicular lesion of undetermined significance and follicular neoplasm/suspicious for a follicular neoplasm categories offer only limited diagnostic potential. CONCLUSION: In conclusion, the data suggest that the application of the current seven-gene panel in a routine primary referral setting does not improve the presurgical diagnosis of thyroid FNAs. While the diagnostic relevance of RAS mutations in thyroid tumors needs further investigation, more comprehensive mutation panels with more cancer-specific mutations may improve the presurgical diagnosis of thyroid FNAs.

Multicenter comparison of calibration and cross calibration of PET scanners.

UNLABELLED: The purpose of this study was to compare the calibration of PET scanners and their cross calibration to peripheral devices in a multicenter study. METHODS: Twenty-three dedicated PET scanners were investigated, applying standardized protocols. To ensure exact determination of the activity used, dose calibrators were checked using (68)Ge standards. RESULTS: Nine of 19 and 11 of 20 scanners displayed an error of <5% in 3-dimensional and 2-dimensional acquisition modes, respectively. Four and 5 scanners displayed an error of 10% in 3-dimensional and 2-dimensional modes, respectively. All other scanners yielded errors of 5% to <10%. Because of hardware and software problems, the measurements performed on 1 scanner could not be adequately analyzed. CONCLUSION: An investigation of calibration is mandatory. Especially for quantitative analyses in clinical multicenter trials, identification of potentially miscalibrated scanners is necessary.