Jin Kyoung Oh

Prognostic Significance of 18F-FDG Uptake in Hepatocellular Carcinoma Treated with Transarterial Chemoembolization or Concurrent Chemoradiotherapy: A Multicenter Retrospective Cohort Study

This study aimed to assess the prognostic value of 18F-FDG uptake in hepatocellular carcinoma (HCC) patients who had transarterial chemoembolization (TACE) or concurrent intraarterial chemotherapy with external-beam radiotherapy (CCRT) and to compare the prognosis between patients treated with TACE and those with CCRT according to 18F-FDG uptake. Methods: Two hundred fourteen intermediate–to–advanced-stage HCC patients without extrahepatic metastasis who underwent staging 18F-FDG PET/CT before TACE (153 patients) or CCRT (61 patients) were recruited from 7 hospitals. Progression-free survival (PFS) and overall survival (OS) were compared using an optimal cutoff value for tumor-to-normal liver uptake ratio (TLR). Further, PFS and OS were compared according to treatment modalities (TACE vs. CCRT) using the same TLR cutoff value. Results: On multivariate analysis, age and TLR were independent prognostic factors for PFS (P < 0.050). For OS, Child–Pugh classification and TLR were independent prognostic factors (P < 0.050). When the TLR was greater than 2.0, patients treated with CCRT showed significantly better PFS and OS than those treated with TACE after adjusting for tumor size and number (P = 0.014, for all). In contrast, there was no significant difference in PFS and OS between patients treated with TACE or CCRT when the TLR was 2.0 or less. Conclusion: 18F-FDG uptake was an independent prognostic factor for PFS and OS in HCC patients treated with TACE or CCRT. Especially, in HCCs with high 18F-FDG uptake, patients treated with CCRT showed better survival than those treated with TACE. 18F-FDG PET/CT may help determine the treatment modality for intermediate–to–advanced-stage HCCs.

Effectiveness of Breast MRI and 18F-FDG PET/CT for the Preoperative Staging of Invasive Lobular Carcinoma versus Ductal Carcinoma

Purpose We evaluated the utility of magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for the preoperative staging of invasive lobular carcinoma (ILC) of the breast and compared the results with those of invasive ductal carcinoma (IDC). Methods The study included pathologically proven 32 ILCs and 73 IDCs. We compared clinical and histopathological characteristics and the diagnostic performances of MRI and 18F-FDG PET/CT for the primary mass, additional ipsilateral and/or contralateral lesion(s), and axillary lymph node metastasis between the ILC and IDC groups. Results Primary ILCs were greater in size, but demonstrated lower maximum standardized uptake values than IDCs. All primary masses were detected on MRI. The detection rate for ILCs (75.0%) was lower than that for IDCs (83.6%) on 18F-FDG PET/CT, but the difference was not significant. For additional ipsilateral lesion(s), the sensitivities and specificities of MRI were 87.5% and 58.3% for ILC and 100.0% and 66.7% for IDC, respectively; whereas the sensitivities and specificities of 18F-FDG PET/CT were 0% and 91.7% for ILC and 37.5% and 94.7% for IDC, respectively. The sensitivity of 18F-FDG PET/CT for ipsilateral lesion(s) was significantly lower in the ILC group than the IDC group. The sensitivity for ipsilateral lesion(s) was significantly higher with MRI; however, specificity was higher with 18F-FDG PET/CT in both tumor groups. There was no significant difference in the diagnostic performance for additional contralateral lesion(s) or axillary lymph node metastasis on MRI or 18F-FDG PET/CT for ILC versus IDC. Conclusion The MRI and 18F-FDG PET/CT detection rates for the primary cancer do not differ between the ILC and IDC groups. Although 18F-FDG PET/CT demonstrates lower sensitivity for primary and additional ipsilateral lesions, it shows higher specificity for additional ipsilateral lesions, and could play a complementary role in the staging of ILC as well as IDC.

The Success Rate of Initial 131 I Ablation in Differentiated Thyroid Cancer: Comparison Between Less Strict and Very Strict Low Iodine Diets

PurposeTo decrease the risk of recurrence or metastasis in differentiated thyroid cancer (DTC), selected patients receive radioactive iodine ablation of remnant thyroid tissue or tumor. A low iodine diet can enhance uptake of radioactive iodine. We compared the success rates of radioactive iodine ablation therapy in patients who followed two different low iodine diets (LIDs).Materials and MethodsThe success rates of postsurgical radioactive iodine ablation in DTC patients receiving empiric doses of 150xa0mCi were retrospectively reviewed. First-time radioactive iodine ablation therapy was done in 71 patients following less strict LID and 90 patients following very strict LID. Less strict LID restricted seafood, iodized salt, egg yolk, dairy products, processed meat, instant prepared meals, and multi-vitamins. Very strict LID additionally restricted rice, freshwater fish, spinach, and soybean products. Radioactive iodine ablation therapy was considered successful when follow-up 123I whole body scan was negative and stimulated serum thyroglobulin level was less than 2.0xa0ng/mL.ResultsThe success rate of patients following less strict LID was 80.3% and for very strict LID 75.6%. There was no statistically significant difference in the success rates between the two LID groups (pu2009=u20090.48).ConclusionsVery strict LID may not contribute to improving the success rate of initial radioactive iodine ablation therapy at the cost of great inconvenience to the patient.

Value of F-18 FDG PET/CT in detection and prognostication of isolated extra-axillary lymph node recurrences in postoperative breast cancer

We assessed the role of F-18 FDG PET/CT in evaluating isolated extra-axillary lymph node recurrences in postoperative breast cancer patients and its prognostic value on clinical outcome. We reviewed PET/CT scans of postoperative breast cancer patients performed at our institution between July 2003 and February 2012. We recorded PET/CT findings, clinicopathologic variables and treatment modalities. We analyzed metabolic parameters from PET/CT and clinicopathologic variables with respect to progression free survival (PFS). A total of 3561 PET/CT scans were performed in 1906 postoperative breast cancer patients with a median interval of 43 month from curative surgery. Fifty seven patients (2.99%) demonstrated isolated extra-axillary nodal recurrences (n=85) on PET/CT (internal mammary node recurrences in 28, supraclavicular 24, infraclavicular 4, interpectoral 8, cervical 12, and mediastinal 9).The median SUVmax was 7.8 (range, 1.8~19.0), and the median node size was 15 mm (range, 6~38 mm). All recurrences were nonpalpable. Based on PET/CT findings, 53 out of 57 patients with extra-axillary node recurrences underwent subsequent chemotherapy/radiation therapy. The estimated 3-year PFS rate was 48.6%. Cutoff points of SUVmax 2.7 and size 14 mm were the best discriminative values for predicting clinical outcome. SUVmax and size of extra-axillary nodal recurrences were significantly correlated to PFS on univariate and multivariate analyses (p<0.001 and p=0.019, respectively).

18F-FDG PET/CT Can Predict Survival of Advanced Hepatocellular Carcinoma Patients: A Multicenter Retrospective Cohort Study

Barcelona Clinic Liver Cancer (BCLC) stage C hepatocellular carcinoma (HCC) consists of a heterogeneous group of patients with a wide range of survival times, requiring further prognostic stratification to facilitate treatment allocation. We evaluated the prognostic value of 18F-FDG uptake on PET/CT at the time of presentation in patients with BCLC stage C HCC. Methods: A total of 291 patients with BCLC stage C HCC who underwent 18F-FDG PET/CT between 2009 and 2010 for staging were retrospectively enrolled from 7 university hospitals. The patients were further divided into 2 groups according to the extent of disease, as intrahepatic or extrahepatic. Tumor-to-liver SUV ratio (TLR) of the primary tumor was measured on 18F-FDG PET/CT. Prognostic values of TLR and other clinical variables were analyzed to predict overall survival (OS) in univariate and multivariate analyses. Differences in the OS stratified by TLR were examined by the Kaplan–Meier method. Results: Higher TLR was associated with extrahepatic disease (P = 0.018). On multivariate analysis, Child–Pugh classification and TLR were independent prognostic factors in the intrahepatic disease group (all P < 0.05), whereas TLR was the only independent prognostic factor in the extrahepatic disease group (P < 0.05). Patients with high TLR showed a significantly worse OS than those with low TLR (P < 0.05) in both groups. Conclusion: In patients with BCLC stage C HCC, 18F-FDG uptake in the primary tumor was significantly higher in patients with extrahepatic disease than in those with intrahepatic disease. In addition, 18F-FDG uptake on pretreatment PET/CT had an incremental prognostic value for OS in both intrahepatic and extrahepatic disease groups.

Alteration patterns of brain glucose metabolism: comparisons of healthy controls, subjective memory impairment and mild cognitive impairment

Background Some groups have focused on the detection and management of subjective memory impairment (SMI) as the stage that precedes mild cognitive impairment (MCI). However, there have been few clinical studies that have examined biomarkers of SMI to date. Purpose To investigate the differences in glucose metabolism as a prodromal marker of dementia in patients with SMI, MCI, and healthy controls using brain F-18 fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Material and Methods Sixty-eight consecutive patients with SMI, 47 patients with MCI, and 42 age-matched healthy subjects were recruited. All subjects underwent FDG-PET and detailed neuropsychological testing. FDG-PET images were analyzed using the statistical parametric mapping (SPM) program. Results FDG-PET analysis showed glucose hypometabolism in the periventricular regions of patients with SMI and in the parietal, precentral frontal, and periventricular regions of patients with MCI compared with healthy controls. Interestingly, hypometabolism on FDG-PET was noted in the parietal and precentral frontal regions in MCI patients compared to SMI patients. Conclusion The results suggest that hypometabolism in the periventricular regions as seen on FDG-PET may play a role as a predictive biomarker of pre-dementia, and the extension of reduced glucose metabolism into parietal regions likely reflects progression of cognitive deterioration.

Herpes Zoster Mimicking Breast Cancer With Axillary Lymph Node Metastasis on PET/CT.

Herpes zoster is a reactivated varicella-zoster virus infection and demonstrates typical dermatomal distribution. We herein describe a case of a 41-year-old woman with a history of ovarian cancer. Intense hot uptake in the left breast and enlarged ipsilateral axillary lymph nodes were noted on ¹⁸F-FDG PET/CT for adjuvant chemotherapy response evaluation. Blinded to the patients clinical information, these lesions were interpreted as incidental breast cancer with axillary nodal metastasis. However, clinically she presented with vesicles along the T4 dermatome and palpable enlarged nodes in the left axilla. On 3-month follow-up PET/CT after antiviral treatment, these intense hot uptake areas were no longer visualized.

Osteonecrosis Mimicking Bone Metastasis in Femoral Head on 18F-FDG PET/CT: A Case Report

A 77-year-old woman underwent chemotherapy, radiotherapy, and brachytherapy for cervical cancer 9 years ago. On a follow-up 18F-fluorodeoxyglucose (FDG) PET/CT image, focal FDG uptake was noted in a focal osteolytic lesion in the right femoral head. During magnetic resonance imaging, this lesion showed subchondral dark-signal-intensity rim on T1-weighted image and double line sign on T2-weighted image, suggestive of osteonecrosis. The lesion was pathologically confirmed as osteonecrosis after surgery. This case demonstrates that osteonecrosis of the femoral head may demonstrate focal FDG uptake mimicking bone metastasis.

Preoperative prediction of microvascular invasion of hepatocellular carcinoma using 18F-FDG PET/CT: a multicenter retrospective cohort study

PurposeThe aim of this study was to assess the potential of tumor 18F-fluorodeoxyglucose (FDG) avidity as a preoperative imaging biomarker for the prediction of microvascular invasion (MVI) of hepatocellular carcinoma (HCC).MethodsOne hundred and fifty-eight patients diagnosed with Barcelona Clinic Liver Cancer stages 0 or A HCC (median age, 57xa0years; interquartile range, 50–64xa0years) who underwent 18F-FDG positron emission tomography with computed tomography (PET/CT) before curative surgery at seven university hospitals were included. Tumor FDG avidity was measured by tumor-to-normal liver standardized uptake value ratio (TLR) of the primary tumor on FDG PET/CT imaging. Logistic regression analysis was performed to identify significant parameters associated with MVI. The predictive performance of TLR and other clinical variables was assessed using receiver operating characteristic (ROC) curve analysis.ResultsMVI was present in 76 of 158 patients with HCCs (48.1%). Multivariable logistic regression analysis revealed that TLR, serum alpha-fetoprotein (AFP) level, and tumor size were significantly associated with the presence of MVI (Pu2009<u20090.001). Multinodularity was not significantly associated with MVI (Pu2009=u20090.563). The area under the ROC curve (AUC) for predicting the presence of MVI was best with TLR (AUCu2009=u20090.704), followed by tumor size (AUCu2009=u20090.685) and AFP (AUCu2009=u20090.670). We were able to build an improved prediction model combining TLR, tumor size, and AFP by using multivariable logistic regression modeling (AUCu2009=u20090.756).ConclusionsTumor FDG avidity measured by TLR on FDG PET/CT is a preoperative imaging biomarker for the prediction of MVI in patients with HCC.

Significance of Incidental Nasopharyngeal Uptake on 18F-FDG PET/CT: Patterns of Benign/Physiologic Uptake and Differentiation from Malignancy

PurposeThe purpose of this study was to assess the significance of incidental nasopharyngeal uptake on 18F-FDG PET/CT and to identify image patterns useful in the differentiation between benign or physiologic activity and nasopharyngeal carcinoma.MethodsWe retrospectively reviewed medical records of patients with nasopharyngeal uptakes on 18F-FDG PET/CT scans taken between January 2010 and July 2011. Patients with head and neck cancer, other metastatic head and neck lesions, or lymphoma were excluded. Total 177 patients were enrolled (Group A). PET images were reviewed for patterns of nasopharyngeal FDG uptake, presence/absence of cervical lymph node uptake and pattern of cervical node uptake. Diagnostic confirmation was made by pathology or clinical and radiological follow-up for 1 year or longer. Furthermore, initial PET/CT images of 48 patients with nasopharyngeal carcinoma (Group B) were reviewed for comparison with PET/CT images of Group A patients.ResultsAll nasopharyngeal uptakes in Group A were confirmed to be benign. Group B showed significantly more intense FDG uptake (SUVmax of Group A 3.9 ± 1.4 vs. Group B 10.4 ± 4.6, p<0.001). and asymmetric nasopharyngeal uptake (asymmetric uptake of Group A 67.8% vs. Group B 89.6%). When SUVmax of 6.0 was used as cut off for detection of malignant nasopharyngeal uptake, the area under the ROC curve was 0.93 (95% confidence interval, 0.88-0.98), with a sensitivity of 88.1% and a specificity of 91.7%. Metastatic nodes in Group B showed higher SUVmax (Group A 2.3 ± 0.6 vs. Group B 7.1 ± 4.0, p<0.001) and larger size (short axis of Group A 5.3 ± 2.0 mm vs. Group B 13.1 ± 4.7 mm, p<0.001) than benign nodes of Group A. The majority of Group B cases demonstrated retropharyngeal lymph node uptake (70.8%), compared to only 2 cases in Group A.ConclusionsIn patients without a history of underlying malignancy involving head and neck, incidental nasopharyngeal uptake on PET/CT does not indicate malignancy. However, if the nasopharyngeal uptake is intense (SUVmax≥6.0) or concomitant retropharyngeal lymph node uptake is present, the possibility of a malignant condition should be considered.