Added value of pretreatment (18)F-FDG PET/CT for staging of advanced gastric cancer: Comparison with contrast-enhanced MDCT.

PURPOSE: To evaluate the added clinical value of pretreatment (18)F-FDG PET/CT compared with conventional contrast-enhanced multidetector-row CT (CECT) alone for staging of advanced gastric cancer MATERIALS AND METHODS: We studied 106 patients with locally advanced gastric cancer who underwent pretreatment CECT and (18)F-FDG PET/CT. Two experienced reviewers assessed the diagnostic performance of both CECT alone and the combination of CECT and (18)F-FDG PET/CT for the primary tumor, regional lymph node metastasis (N) and distant metastasis (M), rating their diagnostic confidence with a 5-point scoring system for each location. The two methods were compared using receiver operating characteristic (ROC) curve analysis for histopathologic findings, imaging, and clinical follow-up as the reference standards. RESULTS: Among the 106 patients, 96 primary tumors (90.6%) were detected by CECT, while 101 (95.3%) were clearly identified by (18)F-FDG PET/CT (p=0.074). Patient-based areas under the ROC curves for CECT alone versus the combination of CECT and (18)F-FDG PET/CT for diagnosis of N stage, peritoneal dissemination, liver metastasis, distant lymph node metastasis, bone metastasis, metastasis at other sites and overall M stage were 0.787 vs. 0.858 (p=0.13), 0.866 vs. 0.878 (p=0.31), 0.998 vs. 1.0 (p=0.36), 0.744 vs. 0.865 (p=0.049), 0.786 vs. 0.998 (p=0.034), 0.944 vs. 0.984 (p=0.34), and 0.889 vs. 0.912 (p=0.21), respectively. The diagnostic performance of primary tumor detection and NM staging was not influenced by the histologic subtype. CONCLUSION: Adding (18)F-FDG PET/CT to CECT provides better diagnostic accuracy for detection of distant lymph node metastasis and bone metastasis in patients with untreated advanced gastric cancer.

SUVmax on FDG-PET is a predictor of prognosis in patients with maxillary sinus cancer.

PURPOSE: Our aim was to determine whether the maximum standardized uptake value (SUVmax) of the primary lesion demonstrated by [(18)F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is associated with the prognosis of maxillary sinus cancer. MATERIALS AND METHODS: The relationships of clinicopathological factors including age, T stage, N stage, histologic type, treatment strategy, and primary tumor SUVmax with progression-free (PFS) and overall (OS) survival were evaluated using the log-rank test and Cox method in 31 patients with maxillary sinus cancer before combined superselective intra-arterial chemotherapy using high-dose cisplatin with concurrent radiotherapy, or radiotherapy alone. RESULTS: The median duration of follow-up was 55.4 (range 9.7-72.6) months. PFS and OS of patients exhibiting a high SUVmax (≥16 and ≥17, respectively) for the primary tumor were significantly lower than those of patients for whom the primary tumor SUVmax was low (p = 0.0010 and p = 0.033, respectively). Multivariate analyses showed that T stage (p = 0.0049) and primary tumor SUVmax (p = 0.026) were independently prognostic of poorer PFS and that only primary tumor SUVmax (p = 0.049) was independently prognostic of poorer OS. CONCLUSION: SUVmax of the primary tumor determined by FDG-PET/CT before treatment could be a good surrogate marker for prognostication of maxillary sinus cancer.

FDG-PET/CT as a post-treatment restaging tool in urothelial carcinoma: Comparison with contrast-enhanced CT.

PURPOSE: To assess the clinical usefulness of FDG-PET/CT in the diagnosis of recurrent and metastatic urothelial carcinoma in comparison with contrast-enhanced CT. MATERIALS AND METHODS: Eighty-three patients who had undergone treatment for histopathologically proven urothelial carcinoma underwent whole-body FDG-PET/CT and contrast-enhanced CT for suspected recurrence within a time interval of two weeks. Patient-based analysis and lesion sites besides the urinary tract, as interpreted by two experienced readers, were compared between the two modalities using McNemar test. Lesion status was determined on the basis of histopathology, radiological imaging and clinical follow-up for longer than 6 months. RESULT: Patient-based analysis showed that the sensitivity, specificity, and accuracy of FDG-PET/CT were 97.4%, 93.3% and 95.2%, respectively, whereas those of contrast-enhanced CT were 86.8%, 93.3% and 90.4%, respectively. The sensitivity and accuracy of FDG-PET/CT were higher than contrast-enhanced CT without significant difference (p=0.13). The sensitivity of FDG-PET/CT for diagnosis of bone metastasis was significantly higher than that of contrast-enhanced CT (93.8% vs. 25%, p=0.0026). CONCLUSION: FDG-PET/CT is a more accurate modality than CT for assessment of recurrence outside the urinary tract in patients with urothelial carcinoma, especially for bone lesion. Cystoscopy, urine cytology, and FDG-PET/CT are complementary procedures and may have a definite management role.

Diagnostic and prognostic value of (18)F-FDG PET/CT for axillary lymph node staging in patients with breast cancer.

PURPOSE: To investigate the diagnostic and prognostic value of (18)F-FDG-PET/CT for axillary lymph node (LN) staging in breast cancer patients, employing histologic evaluation as the reference. METHODS: Among 196 patients with biopsy-proven breast cancer who had undergone (18)F-FDG-PET/CT before mastectomy or breast-conserving surgery with sentinel LN biopsy and/or axillary LN dissection, 200 axillae were retrospectively analyzed by visual assessment and quantitatively using SUVmax. LN SUVmax as well as other clinicopathological features were assessed for their prognostic value using the log-rank test and Cox method. RESULTS: Metastasis was diagnosed histopathologically in 56 (28 %) axillae. The sensitivity, specificity, and accuracy of visual PET/CT for diagnosing node metastasis were 55.4, 95.8, and 84.5 %, respectively. When the optimal discriminative SUVmax cutoff was 1.5, these figures were 51.8, 97.2, and 84.5 %, respectively. Fourteen of 55 patients (25.5 %) with LN metastases suffered a recurrence during follow-up (median 39 months). Patients with a high nodal SUVmax (≥1.7) had a significantly lower progression-free survival rate than those with a low SUVmax (p = 0.0499). Axillary nodal and primary tumor SUVmax as well as estrogen receptor status were significantly associated with recurrence. CONCLUSION: Axillary nodal SUVmax may be a prognostic indicator of disease recurrence in patients with axillary LN metastases.