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Objective: The purpose of this study was to compare the predictive capabilities of diffusion-weighted MRI (DWI) and 18F-FDG PET/CT for tumor response to therapy and survival in patients with non-small cell lung cancer (NSCLC) receiving chemoradiotherapy., Subjects and Methods: The study included 64 patients with NSCLC diagnosed as stage III who underwent pretherapeutic DWI and FDG PET/CT and were treated with chemoradiotherapy. For quantitative prediction, apparent diffusion coefficient (ADC) for DWI and maximum standardized uptake value (SUVmax) for PET/CT were measured at all targeted lesions and averaged to obtain final values for each patient. To evaluate the predictive capability of either index for distinguishing partial response and nonresponse (stable or progressive disease) groups, receiver operating characteristic analysis was performed, and sensitivity, specificity, and accuracy of the two modalities were compared using the McNemar test. Finally, overall and progression-free survival curves divided by the corresponding threshold value were compared by means of the log-rank test., Results: The area under the curve (Az) for ADC (Az=0.84) was significantly larger than that for SUVmax (Az=0.64, p<0.05). The application of feasible threshold values resulted in specificity (44.4%) and accuracy (76.6%) of DWI becoming significantly higher than those of PET/CT (specificity, 11.1%; p<0.05 and accuracy, 67.2%, p<0.05). In addition, only overall survival and progression-free survival of the two groups divided by ADC at 2.1×10(-3) mm2/s and SUVmax at 10 showed a significant difference (p<0.05)., Conclusion: DWI may have better potential than FDG PET/CT for prediction of tumor response to therapy in NSCLC patients before chemoradiotherapy.

Purpose: To prospectively compare the diagnostic capability of short inversion time inversion-recovery (STIR) turbo spin-echo (SE) imaging, diffusion-weighted (DW) magnetic resonance (MR) imaging, and fluorodeoxyglucose (FDG) combined positron emission tomography (PET) and computed tomography (CT) in N stage assessment in patients with non-small cell lung cancer (NSCLC)., Materials and Methods: This prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. A total of 250 consecutive patients with NSCLC (136 men; mean age, 73 years; 114 women; mean age, 72 years) prospectively underwent pretherapeutic STIR turbo SE imaging, DW MR imaging, and FDG PET/CT, as well as surgical and pathologic examinations (N0 disease, n = 157; N1 disease, n = 72; N2 disease, n = 16; N3 disease, n = 5). Lymph node-to-saline ratio (LSR), lymph node-to-muscle ratio (LMR), apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV(max)), and visual scoring were assessed for 135 metastatic lymph nodes and 135 randomly selected nonmetastatic lymph nodes. Receiver operating characteristic curve analysis was used to determine feasible threshold values. Diagnostic capabilities for N stage assessment were compared with the McNemar test on a per-patient basis., Results: When feasible, threshold values were used for quantitative assessment; sensitivity and accuracy of LSR and LMR (sensitivity, 82.8%; accuracy, 86.8%) proved to be significantly higher than those of ADC (sensitivity: 74.2%, P = .01; accuracy: 84.4%, P = .04) and SUV(max) (sensitivity: 74.2%, P = .01). For qualitative assessment, sensitivity of STIR turbo SE imaging (77.4%) was significantly higher than that of DW MR imaging (71.0%, P = .03) and FDG PET/CT (69.9%, P = .02)., Conclusion: Quantitative and qualitative assessments of N stage disease in patients with NSCLC obtained with STIR turbo SE MR imaging are more sensitive and/or more accurate than those obtained with DW MR imaging and FDG PET/CT., Supplemental Material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11110281/-/DC1., (RSNA, 2011)

Purpose: The purpose of this study was to compare the capability of integrated FDG-PET/CT for assessment of postoperative intra- and extrathoracic recurrence in non-small cell lung cancer (NSCLC) patients with that of standard radiological examinations., Materials and Methods: A total of 121 consecutive pathologically diagnosed NSCLC patients (80 males, 41 females; mean age, 71 years) underwent pathologically and surgically confirmed complete resection, followed by prospective integrated FDG-PET/CT and standard radiological examinations. Final diagnosis of recurrence was based on the results of more than 12 months of follow-up and/or pathological examinations. The probability of recurrence was assessed with either method for each patient by using 5-point visual scoring system, and final diagnosis was made by consensus between two readers. ROC analysis was used to compare the capability of the two methods for assessment of postoperative recurrence on a per-patient basis. The ROC-based positive test was used to determine optimal cut-off value for FDG uptake measurement at a site suspected on the basis of qualitatively assessed PET/CT. Finally, sensitivities, specificities and accuracies of all methods were compared by means of McNemar's test., Results: Areas under the curve of qualitatively assessed PET/CT and standard radiological examinations showed no significant differences (p>0.05). At an optimal cut-off value of 2.5, specificity and accuracy of quantitatively and qualitatively assessed PET/CT were significantly higher than those of qualitatively assessed PET/CT and standard radiological examinations (p<0.05)., Conclusion: Accuracy of assessment of postoperative intra- and extrathoracic recurrence in NSCLC patients by qualitative and/or quantitative FDG-PET/CT is equivalent to or higher than that by standard radiological examinations., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Objective: To determine whether contrast-enhanced PET/CT is more accurate than either non-enhanced PET/CT or enhanced CT alone for nodal staging of uterine cancer., Methods: Forty patients with endometrial cancer and cervical cancer underwent conventional PET/CT scan with low-dose CT (ldCT), followed by full-dose CT with IV contrast (ceCT) before radical hysterectomy with pelvic and, when applicable, para-aortic lymphadenectomy. Three data sets of PET/ldCT, PET/ceCT, and enhanced CT images were interpreted separately by two readers. For region-specific comparisons, para-aortic and pelvic lymph nodes were divided into the bilateral para-aortic, common iliac, external iliac, internal iliac, and obturator areas. Based on histopathological findings as the gold standard, we compared the diagnostic accuracy between the three methods using McNemar test with Bonferroni's adjustment., Results: Of the 40 patients, 21 underwent pelvic lymphadenectomy only. Region-based analysis showed that the sensitivity, specificity, and accuracy of PET/ceCT were 61.4% (27/44), 98.1% (308/314), and 93.6% (335/358), respectively, whereas those of PET/ldCT were 52.3% (23/44), 96.8% (304/314), and 91.3% (327/358), respectively, and those of enhanced CT were 40.9% (18/44), 97.8% (307/314), and 90.8% (325/358), respectively. Although PET/ceCT had the best sensitivity among the three imaging modalities, a significant difference was observed only between PET/ceCT and enhanced CT (p = 0.0027). Although PET/ceCT had better sensitivity and accuracy than PET/ldCT, the differences between the two imaging methods did not reach statistical significance (p = 0.046 and p = 0.047, respectively)., Conclusion: PET/ceCT is slightly but not significantly superior to PET/ldCT for nodal staging of uterine cancer. Nodal metastasis cannot be excluded even if PET/ceCT gives negative findings.

Objective: The purpose of this study was to assess retrospectively the characteristics of FDG uptake in elastofibroma dorsi using integrated PET/CT., Methods: From 10,261 oncology FDG-PET/CT scans performed over a 2-year period, findings suggestive of elastofiboma dorsi were observed in 46 FDG-PET/CT scans of 34 patients. As 20 patients had bilateral lesions and 14 had unilateral lesions, a total of 75 elastofibroma dorsi lesions on images were identified in this study. For visual analysis of intensity of FDG uptake , a four-point grading system was used: grade 0 for no uptake, grade 1 for less uptake than the liver, grade 2 for uptake comparable to the liver, and grade 3 for intense uptake greater than the liver. For quantitative analysis, the standardized uptake value (SUV) was calculated. The relationships between SUV and age, blood glucose level, lesion size, and related symptoms were also assessed., Results: Among the 75 lesions, 4 had an uptake grade of 0, 41 had grade 1, 25 had grade 2, and 5 had grade 3. The mean SUV (±SD) of the 75 lesions was 2.0 ± 0.63 (range 0-5.1). The Pearson correlation coefficient test indicated a weak positive correlation between SUV and lesion size and no correlation between SUV and either age or blood glucose level. The SUVs of patients with symptoms due to the disease and patients without symptoms were almost the same., Conclusion: Mild and moderate uptake of FDG is frequently observed in elastofibroma dorsi, which should not be misinterpreted as abnormal accumulation observed in malignant lesions.

Background and Aim: To evaluate the diagnostic value of integrated 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) to discriminate malignant from benign ovarian tumors., Methods: One hundred and eight women suspected of having ovarian cancer underwent preoperative FDG-PET/CT scans. FDG uptake was quantified by calculating the maximum standardized uptake value (SUV max) of each tumor. The receiver operating characteristic curve was drawn to determine the optimal cut-off values of SUV max that would best discriminate between benign and malignant tumors. Histopathologic results served as the reference standard. We assessed the association between SUV max and with International Federation of Gynecology and Obstetrics stage in borderline and malignant tumors, using one-factor analysis of variance and an unpaired t test with Bonferoni correction., Results: The SUV max of benign (n=26), borderline (n=12) and malignant (n=73) lesions was 2.00 ± 1.02, 2.72 ± 1.04, and 7.55 ± 4.29, respectively. Although there were significant differences between benign and malignant, and borderline and malignant lesions (P<0.0001), there was no significant difference between benign and borderline lesions. Using an SUV max cutoff of 2.55, the sensitivity, specificity and accuracy of FDG-PET/CT scanning to detect malignant or borderline tumors were 82.4, 76.9, and 81.1%, respectively. The SUV max of stage I (n=35), stage II (n=8), stage III (n=34) and stage IV (n=8) was 3.59 ± 2.32, 5.18 ± 1.34, 8.72 ± 2.69, and 15.05 ± 3.77, respectively, and significant differences were observed between SUV max values and the various International Federation of Gynecology and Obstetrics stage (P<0.0001)., Conclusion: FDG-PET/CT scanning has a high diagnostic value in differentiating between malignant and benign tumors, and a low diagnostic value in differentiating between borderline and benign tumors.

Purpose: To prospectively compare the capability of quantitative first-pass perfusion 320-detector row computed tomography (CT) (ie, area-detector CT) with that of combined positron emission tomography and CT (PET/CT) for differentiation between malignant and benign pulmonary nodules., Materials and Methods: This prospective study was approved by the institutional review board, and written informed consent was obtained from 50 consecutive patients with 76 pulmonary nodules. All patients underwent dynamic area-detector CT, PET/CT, and microbacterial and/or histopathologic examinations. All pulmonary nodules were divided into three groups: malignant nodules (n = 43), benign nodules with low biologic activity (n = 6), and benign nodules with high biologic activity (n = 27). For each dynamic area-detector CT data set, the perfusion derived by using the maximum slope model (PF(MS)), extraction fraction derived by using the Patlak plot model (EF(PP)), and blood volume derived by using the Patlak plot model (BV(PP)) were calculated. These parameters were statistically compared among the three nodule groups. Receiver operating characteristic (ROC) analyses were used to compare the diagnostic capability of the CT and PET/CT indexes. Finally, the sensitivity, specificity, and accuracy of each index were compared by using the McNemar test., Results: All indexes in the malignant nodule group were significantly different from those in the low-biologic-activity benign nodule group (P < .05). Areas under the ROC curve for PF(MS) and EF(PP) were significantly larger than those for BV(PP) (P < .05) and maximal standard uptake value (SUV(max)) (P < .05). The specificity and accuracy of PF(MS) and EF(PP) were significantly higher than those of BV(PP) and SUV(max) (P < .05)., Conclusion: Dynamic first-pass area-detector perfusion CT has the potential to be more specific and accurate than PET/CT for differentiating malignant from benign pulmonary nodules., Supplemental Material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100245/-/DC1., (© RSNA, 2011)

Purpose: To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated (18)F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer., Methods: A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months., Results: Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT., Conclusion: PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations.

Purpose: The purpose of this study was to prospectively and directly compare diagnostic capabilities of whole-body integrated FDG-PET/CT and standard radiologic examination for assessment of recurrence in postoperative non-small cell lung cancer (NSCLC) patients., Materials and Methods: A total of 92 consecutive pathologically diagnosed NSCLC patients (65 males, 27 females; mean age, 71 years) underwent pathologically and surgically proven complete resection, followed by prospective whole-body FDG-PET/CT and standard radiological examinations. Final diagnosis of recurrence was based on the results of more than 1 year of follow-up and/or pathological examinations. On both methods, the probability of recurrence was assessed in each patient by using a five-point visual scoring system, and the each final diagnosis was made by consensus between two readers. Kappa analyses were performed to determine inter-observer agreement for both methods, and ROC analyses were used to compare capability of the two methods for assessment of postoperative recurrence on a per-patient basis. Sensitivity, specificity and accuracy were also compared between PET/CT and standard radiological examination by means of McNemar's test., Results: All inter-observer agreements were almost perfect (integrated PET/CT: kappa=0.89; standard radiological examination: kappa=0.81). There were no statistically significant differences in area under the curve, sensitivity, specificity and accuracy between integrated FDG-PET/CT and standard radiologic examinations (p>0.05)., Conclusion: Integrated FDG-PET/CT can be used for assessment of postoperative recurrence in NSCLC patients with accuracy as good as that of standard radiological examinations., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

Objective: Positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D -glucose (FDG) has a limitation in detecting cerebral metastases; however, the feasibility of detection by inline PET/computed tomography (CT) system remains unknown. We evaluated the accuracy of FDG-PET/CT of body imaging protocol for the detection of cerebral metastases when compared with PET alone and CT alone., Methods: Fifty patients underwent whole-body FDG-PET/CT scanning including the brain and contrast enhanced brain MR (magnetic resonance) scan. PET-only, CT-only, and the fused images were interpreted, and the confidence of presence of cerebral metastases was recorded using a five-point grading scale. Area under the receiver-operating characteristic (ROC) curve (Az) was calculated. Differences among the three modalities were tested with the Cochran-Q test, followed by multiple comparisons using the McNemar test with Bonferroni adjustment., Results: Magnetic resonance imaging revealed 70 cerebral metastatic lesions in 20 patients. Patient-based analysis showed that the sensitivity, specificity, accuracy, and Az of PET-alone interpretation were 45%, 80%, 66%, and 0.6025, respectively, those of CT-alone interpretation were 50%, 97%, 78%, and 0.7158, respectively, and those of fused-image interpretation were 50%, 93%, 76%, and 0.7242, respectively. ROC analysis revealed significant differences among the three interpretation methods (P = 0.0238) and between PET and PET/CT (P = 0.0129). The sensitivity of PET, CT, and fused-image interpretation for detecting 70 lesions was 13%, 20%, and 20%, respectively., Conclusions: Even with an integrated PET/CT scanner of body imaging protocol, the sensitivity of cerebral metastases remained unsatisfactory. To assess intracranial lesions, MR scanning should still be considered.

Purpose: To prospectively and directly compare the capability of whole-body diffusion-weighted (DW) imaging, whole-body magnetic resonance (MR) imaging with and that without DW imaging, and integrated fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for M-stage assessment in non-small cell lung cancer (NSCLC) patients., Materials and Methods: The institutional review board approved this study; informed consent was obtained from patients. A total of 203 NSCLC patients (109 men, 94 women; mean age, 72 years) prospectively underwent whole-body DW imaging, whole-body MR imaging, and FDG PET/CT. Final diagnosis of the M-stage in each patient was determined on the basis of results of all radiologic and follow-up examinations. Two chest radiologists and two nuclear medicine physicians independently assessed all examination results and used a five-point visual scoring system to evaluate the probability of metastases. Final diagnosis based on each of the methods was made by consensus of two readers. Receiver operating characteristic (ROC) analysis was used to compare the capability for M-stage assessment among whole-body DW imaging, whole-body MR imaging with and that without DW imaging, and PET/CT on a per-patient basis. Sensitivity, specificity, and accuracy were compared with the McNemar test., Results: Area under ROC curve (A(z)) values of whole-body MR imaging with DW imaging (A(z) = 0.87, P = .04) and integrated FDG PET/CT (A(z) = 0.89, P = .02) were significantly larger than that of whole-body DW imaging (A(z) = 0.79). Specificity and accuracy of whole-body MR imaging with (specificity, P = .02; accuracy, P < .01) and that without DW imaging (specificity, P = .02; accuracy, P = .01) and integrated FDG PET/CT (specificity, P < .01; accuracy, P < .01) were significantly higher than those of whole-body DW imaging., Conclusion: Whole-body MR imaging with DW imaging can be used for M-stage assessment in NSCLC patients with accuracy as good as that of PET/CT.

Objective: The aim of this study was to assess the physiological uptake of 18F-fluoro-2-deoxyglucose (FDG) by an apparently normal testis with combined positron emission tomography-computed tomography (PET/CT) and its correlation with age, blood glucose level, and testicular volume., Methods: The testicular uptake of 18F-FDG, expressed as the standardized uptake value (SUV), was measured on PET/CT images in 203 men. The correlation between SUV and age, blood glucose level, and testicular volume was assessed., Results: The SUV in the total of 406 testes was 2.44 +/- 0.45 (range 1.23-3.85). The SUV was 2.81 +/- 0.43 (2.28-3.85) for 30-39 years (n = 12), 2.63 +/- 0.45 (1.77-3.75) for 40-49 years (n = 64), 2.46 +/- 0.35 (1.44-3.15) for 50-59 years (n = 82), 2.51 +/- 0.41 (1.50-3.46) for 60-69 years (n = 86), 2.43 +/- 0.47 (1.42-3.29) for 70-79 years (n = 86), and 2.18 +/- 0.45 (1.23-3.03) for 80-89 years (n = 76). When we calculated the mean SUV of bilateral testes in each patient, there were significant statistical differences between those in the age group of 30-39 years and 80-89 years, 40-49 years and 80-89 years, and 50-60 years and 80-89 years, when using an unpaired test with Bonferroni correction. The laterality index (|L - R|/(L + R) x 2) in 203 men was 0.066 +/- 0.067 (0-0.522). There was a mild correlation between the mean SUV and age (r = -0.284, P < 0.001) as well as between the mean SUV and mean volume (r = +0.368, P < 0.001). There was no correlation between the mean SUV and glucose blood level (r = -0.065, P = 0.358)., Conclusions: Some uptake of FDG is observed in the normal testis and declines slightly with age. Physiological FDG uptake in the testis should not be confused with pathological accumulation.