Yuko Suenaga

Value of fusion of PET and MRI for staging of endometrial cancer: Comparison with 18F-FDG contrast-enhanced PET/CT and dynamic contrast-enhanced pelvic MRI

PURPOSE To investigate the diagnostic value of retrospective fusion of pelvic MRI and (18)F-fluorodeoxyglucose ((18)F-FDG) PET images for assessment of locoregional extension and nodal staging of endometrial cancer. MATERIALS AND METHODS Thirty patients with biopsy-proven endometrial cancer underwent preoperative contrast-enhanced PET/CT (PET/ceCT) and pelvic dynamic contrast-enhanced MRI for initial staging. Diagnostic performance of PET/ceCT, contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) for assessing the extent of the primary tumor (T stage) and metastasis to regional LNs (N stage) was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis. RESULTS Fused PET/MRI and MRI detected 96.7% of the primary tumors, whereas PET/ceCT detected 93.3%. Accuracy for T status was 80.0% for fused PET/MRI, and MRI proved significantly more accurate than PET/ceCT, which had an accuracy of 60.0% (p=0.041). Patient-based sensitivity, specificity and accuracy for detecting pelvic nodal metastasis were 100%, 96.3% and 96.7% for both fused PET/MRI and PET/ceCT, and 66.7%, 100% and 96.7% for MRI, respectively. These three parameters were not statistically significant (p=1). CONCLUSION Fused PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for assessment of the primary tumor and nodal staging in patients with endometrial cancer.

Value of retrospective image fusion of 18F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

PURPOSE To assess the clinical value of retrospective image fusion of neck MRI and (18)F-fluorodeoxyglucose ((18)F-FDG) PET for locoregional extension and nodal staging of neck cancer. MATERIALS AND METHODS Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated. RESULTS Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p=0.041 and p=0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p=0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p=0.0026) and accuracy (p=0.041) were significant. CONCLUSION Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer.

Fusion of PET and MRI for staging of uterine cervical cancer: comparison with contrast-enhanced (18)F-FDG PET/CT and pelvic MRI.

PURPOSE To investigate the fusion of pelvic magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (PET) for assessment of locoregional extension and nodal staging of cervical cancer. METHODS PET/computed tomography (CT), MRI, and non-fused and fusion of PET and MRI for assessing the extent of the primary tumor and metastasis to nodes were evaluated. RESULTS Accuracy for T-status was 83.3% for fused and non-fused PET/MRI and MRI proved significantly more accurate than PET/CT (53.3%) (P=.0077). Sensitivity, specificity, and accuracy for nodal metastasis were 92.3%, 88.2%, and 90.0% for fused PET/MRI and PET/contrast-enhanced CT; 84.6%, 94.1%, and 90.0% for non-fused PET/MRI; and 69.2%, 100%, and 86.7% for MRI. CONCLUSION Fused PET/MRI combines the individual advantages of MRI and PET.

Prognostic Value of FDG PET Imaging in Patients with Laryngeal Cancer

Background and Purpose To investigate the prognostic value of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with laryngeal cancer. Materials and Methods The study included 51 patients of whom 30 underwent definitive radiotherapy with or without chemotherapy and 21 underwent radical surgery with or without adjuvant chemoradiation therapy. FDG uptake by both the primary lesion and the neck node was measured using the maximum standardized uptake value (SUVmax). The effects of clinicopathological factors including primary tumor SUVmax and nodal SUVmax on progression-free survival, local control, nodal progression-free survival, and distant metastasis-free survival were evaluated using the log-rank test and Cox method. Results The median duration of follow-up was 48.6 months (range 8 to 82.1 months). Univariate analysis showed that nodal SUVmax, N status, and tumor TNM stage were significantly associated with recurrence, whereas primary tumor SUVmax, age, treatment strategy and T status were not. Multivariate analysis demonstrated that only the nodal SUVmax was a significantly unfavorable factor for progression-free survival (p = 0.029, hazard ratio 0.54, 95% CI 0.38-0.87) and nodal progression-free survival (p = 0.023, hazard ratio 0.51, 95% CI 0.34-0.81). ROC curve analysis and log-rank test showed that patients with a high nodal SUVmax (≧4) had a significantly lower progression-free survival rate than those with a low SUVmax (<4; p<0.0001). Conclusions The pretreatment SUVmax of nodal disease in patients with laryngeal cancer is prognostic for recurrence.

Respiratory-gated 18F-FDG PET/CT for the diagnosis of liver metastasis

PURPOSE To ascertain the role of respiratory-gated PET/CT with (18)F-fluorodeoxyglucose ((18)F-FDG) for accurate diagnosis of liver metastasis. MATERIALS AND METHODS Forty patients with suspected liver metastasis underwent conventional whole-body PET/CT scan initially, followed by respiratory-gated PET/CT scan covering the liver. Visual detectability (using a 5-point confidence scale), maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of hepatic metastatic lesions were assessed for three data sets including ordinary whole-body (WB) scan, and non-respiratory-gated (nRG) and respiratory-gated (RG) scans. Results of enhanced CT and/or MRI, or clinical and radiological follow-up were used for reference. RESULTS Sixteen of the patients were found to have 53 metastatic lesions in the liver. Patient-based accuracy of WB, nRG, and RG was 92.5%, 95.0%, and 97.5%, respectively, with a lesion-based detection rate of 67.9%, 73.6%, and 73.6%, respectively. The average SUVmax of 34 liver metastatic lesions for WB, nRG, and RG was 6.60 ± 2.34, 7.19 ± 2.66, and 8.08 ± 3.24, respectively. SUVmax for RG was significantly higher than that for WB (p=0.0069). The average MTV of these 40 lesions for the three protocols was 5.32 ± 4.78 cm(3), 5.07 ± 4.73 cm(3), and 4.73 ± 4.67 cm(3), respectively. Among the three protocols, RG showed the best visual and quantitative evaluation for diagnosis of liver metastasis. CONCLUSION Respiratory-gated PET/CT allows more accurate identification of liver metastases than non-respiratory-gated PET/CT.

Role of diffusion weighted imaging and contrast-enhanced MRI in the evaluation of intrapelvic recurrence of gynecological malignant tumor.

Background and Purpose To investigate the diagnostic performance of diffusion-weighted imaging (DWI) and contrast-enhanced imaging in combination with T2-weighted imaging (T2WI) for magnetic resonance imaging (MRI) evaluation of intrapelvic recurrence of gynecological malignancies. Materials and Methods Sixty-two patients with suspected intrapelvic recurrence of gynecological malignancies underwent pelvic MRI including T2WI DWI, and contrast-enhanced imaging. Diagnostic performance for detection of local recurrence, pelvic lymph node and bone metastases, and peritoneal lesions was evaluated by consensus reading of two experienced radiologists using a 5-point scoring system, and compared among T2WI with unenhanced T1-weighted imaging (T1WI) (protocol A), a combination of protocol A and DWI (protocol B), and a combination of protocol B and contrast-enhanced imaging (protocol C). Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. Receiver operating characteristic (ROC) analysis and McNemar test were employed for statistical analysis. Results Locally recurrent disease, lymph node recurrence, peritoneal dissemination and bone metastases were present in 48.4%, 29.0%, 16.1%, and 6.5% of the patients, respectively. The patient-based sensitivity, specificity, accuracy, and area under the ROC curve (AUC) for detection of intrapelvic recurrence were 55.0, 81.8, 64.5% and 0.753 for protocol A, 80.0, 77.3, 79.0% and 0.838 for protocol B, and 80.0, 90.9, 83.9% and 0.862 for protocol C, respectively. The sensitivity, accuracy, and AUC were significantly better for protocols B and C than for protocol A (p<0.001). There was no significant difference between protocols B and C. Conclusion MRI using a combination of DWI and T2WI gives comparatively acceptable results for assessment of intrapelvic recurrence of gynecological malignancies.

18F-FDG-PET/CT findings of retroperitoneal tumors: a pictorial essay

A variety of different tumors can arise from any of the tissues present in the retroperitoneum, and they exhibit a wide range of pathologic types. Although computed tomography (CT) and magnetic resonance imaging (MRI) can demonstrate important characteristics of these tumors, diagnosis is often challenging for radiologists. The purpose of this pictorial essay is to review 18F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) features of different kinds of benign and malignant retroperitoneal tumors in comparison with CT or MRI findings alone and to become familiar with the wide variety of imaging characteristics.

Evaluation of interobserver variability and diagnostic performance of developed MRI-based radiological scoring system for invasive placenta previa.

To evaluate the interobserver variability and diagnostic performance of a developed magnetic resonance imaging (MRI)‐based scoring system for invasive placenta previa.

Present and future role of FDG-PET/CT imaging in the management of head and neck carcinoma.

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[18F]fluoro-2-deoxy-d-glucose (FDG) is a useful technique for acquisition of both glucose metabolic and anatomic imaging data using a single device in a single diagnostic session, and has opened a new field in clinical oncologic imaging. FDG-PET/CT has been used successfully for the initial staging, restaging, monitoring of the response to therapy, and prognostication of head and neck carcinoma. The present review discusses the current role of FDG-PET/CT in the management of head and neck carcinoma, focusing on its usefulness and limitations for imaging in these patients.

[18F]Fluorodeoxyglucose uptake by positron emission tomography predicts outcomes for oropharyngeal and hypopharyngeal cancer treated with definitive radiotherapy

ABSTRACT This study evaluated the prognostic significance of the maximum standardized uptake value of the primary site (pSUVmax) in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans of patients with oropharyngeal or hypopharyngeal cancer who were treated using definitive radiotherapy. The study included 86 patients who were primarily treated with radiotherapy for oropharyngeal or hypopharyngeal cancer. Sixty-nine patients underwent concurrent chemotherapy. The associations between pre-treatment pSUVmax and treatment outcomes were evaluated. The most appropriate pSUVmax cut-off value for predicting disease-free survival (DFS) and local control (LC) was selected using receiver operating characteristic (ROC) curves. The median follow-up time for surviving patients was 60 months, while the median survival time in the entire patient cohort was 55 months. A pSUVmax cut-off value of 9.0 showed the best discriminative performance. Five-year OS and DFS rates were 65.9% and 60.0%, respectively. In univariate analyses, pSUVmax (p = 0.009), T-stage (p = 0.001), N-stage (p = 0.039), and clinical stage (p = 0.017) were identified as significant prognostic predictors for DFS. The multivariate analysis did not identify any statistically significant factors, but the association between pSUVmax and DFS was borderline significant (p = 0.055). Interestingly, pSUVmax was predictive of local controllability in T1–T2 disease (p = 0.024), but there was no significant association for T3–T4 disease (p = 0.735). In this study, pSUVmax was predictive of DFS and LC in patients with oropharyngeal or hypopharyngeal cancer that was treated with definitive radiotherapy. pSUVmax was strongly associated with LC in T1–T2 disease.