The value of ultrasound-guided biopsy of fluorodeoxy-glucose positron emission tomography (FDG-PET)-positive supraclavicular lymph nodes in patients with suspected lung cancer.

BACKGROUND: Accurate lymph node staging is essential for adequate prognostication and therapy planning in patients with non-small cell lung cancer (NSCLC). FDG-PET/CT is a sensitive tool for the detection of metastases, including non-palpable supraclavicular lymph node (SCLN) metastases. Histological proof of metastatic spread and mutation analysis is crucial for optimal staging and therapy. The aim of this study was to investigate the value of ultrasound-guided fine needle aspiration cytology (FNAC) and core biopsy (CB) of FDG active, non-palpable SCLN's in patients with suspicion for lung cancer. METHODS: Twelve consecutive patients with suspected lung cancer and FDG-positive SCLN underwent FNAC (n = 11) and/or CB (n = 10) and were included and evaluated retrospectively in this study. Cytologic and/or histologic evaluation was performed to confirm initially suspected diagnosis (lung cancer), to confirm N3 stage, and to screen for driver mutations in lung adenocarcinoma. RESULTS: FNAC alone showed diagnostic success in 11/11 cases (100%), CB alone in 9/10 patients (90%), and the combination of both procedures was successful in 12/12 cases (100%). Lymph node metastases from NSCLC (7 adenocarcinoma, 2 squamous cell carcinoma) could be confirmed in 9 patients. Other diagnoses were small cell lung cancer (SCLC), breast cancer and sarcoidosis. There was enough material for immunhistochemistry in all patients. For molecular testing, material from this lymph node biopsies and lung biopsy was used. In two patients with adenocarcinoma of the lung driver mutations were detected (EGFR Exon 19 deletion and ALK rearrangement) out of the lymph node metastasis. CONCLUSIONS: US-guided combined FNAC and CB of FDG positive supraclavicular lymph nodes in patients with suspected lung cancer is a safe and effective procedure to confirm N3-stage and to obtain representative material for molecular testing.

Feasibility and preliminary results of SPECT/CT arthrography of the wrist in comparison with MR arthrography in patients with suspected ulnocarpal impaction.

PURPOSE: To evaluate the feasibility and performance of SPECT/CT arthrography of the wrist in comparison with MR arthrography in patients with suspected ulnocarpal impaction. METHODS: This prospective study included 28 wrists of 27 patients evaluated with SPECT/CT arthrography and MR arthrography. Iodine contrast medium and gadolinium were injected into the distal radioulnar and midcarpal joints. Late-phase SPECT/CT was performed 3.5 h after intravenous injection of approximately 650 MBq (99m)Tc-DPD. MR and SPECT/CT images were separately reviewed in relation to bone marrow oedema, radionuclide uptake, and tears in the scapholunate (SL) and lunotriquetral (LT) ligaments and triangular fibrocartilage complex (TFCC), and an overall diagnosis of ulnar impaction. MR, CT and SPECT/CT imaging findings were compared with each other, with the surgical findings in 12 patients and with clinical follow-up. RESULTS: The quality of MR arthrography and SPECT/CT arthrography images was fully diagnostic in 23 of 28 wrists (82%) and 25 of 28 wrists (89%), respectively. SPECT/CT arthrography was not diagnostic for ligament lesions due to insufficient intraarticular contrast in one wrist. MR and SPECT/CT images showed concordant findings regarding TFCC lesions in 22 of 27 wrists (81%), SL ligament in 22 of 27 wrists (81%) and LT ligament in 23 of 27 wrists (85%). Bone marrow oedema on MR images and scintigraphic uptake were concordant in 21 of 28 wrists (75%). MR images showed partial TFCC defects in four patients with normal SPECT/CT images. MR images showed bone marrow oedema in 4 of 28 wrists (14%) without scintigraphic uptake, and scintigraphic uptake was present without MR bone marrow oedema in three wrists (11%). Regarding diagnosis of ulnar impaction the concordance rate between CT and SPECT/CT was 100% and reached 96% (27 of 28) between MR and SPECT/CT arthrography. The sensitivity and specificity of MR, CT and SPECT/CT arthrography were 93%, 100% and 100%, and 93%, 93% and 93%, respectively. CONCLUSION: SPECT/CT arthrography of the wrist is feasible. Regarding diagnosis of ulnar impaction we found a high concordance with MR arthrography. SPECT/CT arthrography of the wrist is an alternative to MR arthrography in patients with contraindications to MR imaging.

Comparison of (18)F-FDG PET/CT and (68)Ga-DOTATATE PET/CT imaging in metastasized Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is a rare but very aggressive neuroendocrine tumor of the skin in elderly patients with higher mortality compared with melanoma. No evidence-based standardized chemotherapy exists for metastasized patients.We report the case of an 87-year-old patient with the history of resection of a large MCC of the parietal scalp planned for radiotherapy and staged with FDG PET/CT showing disseminated distant metastases. Ga-DOTATATE PET/CT revealed more extensive tumor load compared with FDG, and due to the intensive expression of somatostatin receptors the patient qualified for Y DOTATOC therapy.

Comparative effectiveness of 18F-FDG PET/CT versus whole-body MRI for detection of malignant peripheral nerve sheath tumors in neurofibromatosis type 1.

PURPOSE: The aim of this study was to compare the diagnostic performance of ¹8F-fluorodeoxyglucose (FDG) PET/CT and whole-body MRI for the detection of malignant peripheral nerve sheath tumors (MPNSTs) in patients with neurofibromatosis type 1, and to evaluate a panel of imaging-based criteria serving that purpose. PATIENTS AND METHODS: Thirty-one patients were examined by whole-body MRI and ¹8F-FDG PET/CT. A panel of imaging-based criteria including tumor region, size, shape, margin definition, contrast enhancement, heterogeneity before and after contrast, intratumoral lobulation, target sign, and mean and maximum standardized uptake values (SUVs) were evaluated. A SUVmax cut-off value of 3.5 was used for lesion analysis. Histopathologic evaluation and/or clinical follow-up served as the reference standard. RESULTS: ¹8F-FDG PET/CT had a sensitivity of 100%, whereas MRI had a sensitivity of 66.7%. On PET/CT, tumor size (P<0.005), SUVmax (P<0.0001), SUVmean (P<0.0001), and tracer uptake heterogeneity (P=0.002) were significantly associated with MPNSTs. On MRI, intratumoral lobulation (P<0.02), ill-defined margins (P=0.007), and irregular enhancement on T1-weighted imaging (P<0.001) were significantly associated with MPNSTs. CONCLUSIONS: Both PET/CT and whole-body MRI may distinguish benign and malignant PNSTs, but PET/CT has higher sensitivity for that purpose. Imaging-based criteria for identification of MPNSTs on both modalities were identified. False-positive results, requiring biopsy or clinical follow-up, may be reduced by using a combination of MRI and PET derived markers, but only at the price of reduced sensitivity.

Simulated low-dose computed tomography in oncological patients: a feasibility study.

OBJECTIVE: Image quality of chest and abdominal computed tomographic (CT) scans was evaluated at different doses to assess the lowest value of x-ray dose at which the image quality was not being affected. MATERIALS AND METHODS: Using multislice CT (MSCT), 29 patients who submitted to follow-up examinations were examined using a combined MSCT protocol of the chest and the abdomen on 4-raw MSCT (Siemens, Erlangen, Germany). For each examination, approximately 120 mL of contrast agent (Bracco-Altana, Konstanz, Germany) was applied intravenously. The raw data were transferred to an external personal computer equipped with an image reconstruction software (CardioRecon 6; Siemens, Forchheim, Germany) to simulate 5 different dose levels. To simulate them correctly, a milliampere second-dependent noise was added to every image, so that the changes in a current-time product could be imitated. The images were compared in consensus by 2 radiologists who were not informed about the technical scanning parameters, that is, dose parameters, and were graded in 4 different subcategories on a 1-to-5-point scale. For statistical analysis, the Friedman test was used. Additional evaluations for lesions smaller than 1.0 cm were performed and analyzed separately. RESULTS: For image noise, there was a significant change between 40 and 60 mA s. For lesion detection, there was no significant change. The contour of the small objects did not differ between 90, 60, and 40 mA s. However, a dose reduction to 30 mA s had a significant effect. The contrast did not differ between 90, 60, 40, and even down to 30 mA s. Only a maximal dose reduction to 20 mA s had a significant effect on the contrast. The level of noise was most sensitive to the current. Whereas a dose reduction to 60 mA s did not yet have a significant effect, there was a significant increase of noise at 40 mA s. CONCLUSIONS: The MSCT can be applied with a lower dose than that usually selected in examinations at present to follow-up and stage the oncological patients adequately.