Performance of orthopantomography, planar scintigraphy, CT alone and SPECT/CT in patients with suspected osteomyelitis of the jaw.

PURPOSE: The aim of this study was to evaluate the performance of a novel flat-panel single photon emission computed tomography (SPECT)/CT in patients with suspicion of osteomyelitis (OM) of the jaw in comparison with conventional orthopantomography (OPT), planar bone scintigraphy (PS) and CT alone. METHODS: Forty-two patients (21 female, 21 male, mean age 52, range 10-84 years) with suspected OM (n = 38) or exacerbation of a known OM (n = 4) were investigated with OPT, CT alone, PS and combined SPECT/CT. Images were separately reviewed by a nuclear physician/radiologist and jaw surgeon regarding presence of OM. Additionally, the different methods were rated regarding their usefulness for diagnosis (5-point scale: from 1 = diagnostic to 5 = useless). Biopsy served as the standard of reference in 30 patients and clinical/imaging follow-up of at least 6 months in 12 patients. RESULTS: In 35 of 42 patients the final diagnosis of OM was established according to the reference standard. Sensitivity, specificity and accuracy for OPT was 59, 100 and 66 %, for CT alone 77, 86 and 79 %, for PS 100, 71 and 95 % and for SPECT/CT 100, 86 and 98 %. SPECT/CT was significantly more accurate compared with CT alone (p = 0.0078) and OPT (p = 0.001). SPECT/CT was rated as the most useful imaging modality (mean value 1.2) compared with PS (2.2), CT (2.5) and OPT (3.2). CONCLUSION: SPECT/CT is an accurate method to assess the presence of OM of the jaw and superior to CT alone and OPT. SPECT/CT slightly improved the specificity of PS. However, SPECT/CT in this study was not significantly more accurate compared with PS and whether the advantages to the patient of a one-stop study as opposed to doing separate CT and PS justifies its routine use in terms of cost requires further study.

S-100B and FDG-PET/CT in therapy response assessment of melanoma patients.

OBJECTIVE: To compare the value of the tumor marker S-100B protein and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in patients treated for melanoma metastases. METHODS: In 41 patients with proven melanoma metastases, S-100B measurements and FDG-PET/CT were performed before and after therapy. The change of S-100B levels (DeltaS-100B) was assessed. In all patients, therapy response was assessed with PET/CT using visual criteria and change of maximal standard uptake value (DeltaSUV(max.)) or total lesion glycolysis (DeltaTLG). RESULTS: In 15 of 41 patients (37%), S-100B values were not suitable because they were normal before and after therapy. In 26 patients, S-100B was suitable for therapy response assessment. PET/CT was suitable for response assessment in all patients. Correlations between DeltaS-100B and DeltaTLG (r = 0.850, p < 0.001) and between DeltaS-100B and DeltaSUV(max.) (r = 0.818, p < 0.001) were both excellent. A complete agreement between S-100B and PET/CT response assessment was achieved in 22 of 26 patients. In 4 patients, therapy response differed between the S-100B and PET/CT findings, but subsequent S-100B measurements realigned the S-100B results with the later PET/CT findings. CONCLUSION: In a third of our patients with metastases, the S-100B tumor marker was not suitable for therapy assessment. In these patients, imaging techniques remain necessary, and FDG-PET/CT can be used for response assessment.

High-risk melanoma: accuracy of FDG PET/CT with added CT morphologic information for detection of metastases.

PURPOSE: To prospectively determine the accuracy of positron emission tomography (PET)/computed tomography (CT) with added CT morphologic information for depiction of metastases in patients with high-risk melanoma and negative findings for metastases at PET, by using histologic findings or additional imaging and/or follow-up findings as reference standard. MATERIALS AND METHODS: Institutional review board approval was obtained. Informed consent was obtained from patients. One hundred twenty-four consecutive high-risk melanoma patients (65 female, 59 male; mean age, 54.4 years; range, 15-82 years) were included. Fluorine 18 fluorodeoxyglucose (FDG) PET/CT was performed. First, PET/CT scans were evaluated for presence of metastases with increased FDG uptake; CT anatomic location was determined. Lesions were considered metastases if there was focal uptake higher than that of background tissue. Second, coregistered CT images of combined PET/CT scans were evaluated for presence of lesions without FDG uptake. Findings were compared with reference standard findings to determine the accuracy of each evaluation. McNemar test was used to assess statistical differences in accuracy. RESULTS: In 53 of 124 patients, metastases were found. In 46 of 53 patients with metastases, lesions had increased FDG uptake. In seven patients with metastatic disease, metastases did not have increased FDG uptake (maximum standard uptake value [SUV], <1.5; n = 5) or had faint FDG uptake (maximum SUV, 2.5 and 2.9; n = 2)-findings that were inconclusive with PET alone. These lesions were interpreted as metastases only with coregistered CT images. Lesions missed with PET were located in the lungs, iliac lymph nodes, subcutis, and psoas muscle. Sensitivity, specificity, and accuracy, respectively, of PET/CT for depiction of metastases were 85%, 96%, and 91%, and those of PET/CT with dedicated CT interpretation were 98%, 94%, and 96% (P = .016). CONCLUSION: Dedicated analysis of coregistered CT images significantly improves the accuracy of integrated PET/CT for depiction of metastases in patients with high-risk melanoma.