Abnormal Brain Glucose Metabolism in Papillary Thyroid Cancer Patients 4 Weeks After Withdrawal of Levothyroxine: A Cross-Sectional Study Using 18F-FDG PET/CT.

Background: There is no doubt that thyroid dysfunction is associated with psychiatric disorders. A large amount of thyroid carcinoma patients displayed mood disorders after the withdrawal of levothyroxine (LT4). However, it is unclear whether the disorders are related to the transient withdrawal of LT4, and if yes, what the possible underlying mechanism is. This study aims to investigate the abnormal regional cerebral glucose metabolism (rCMRglu) in a group of papillary thyroid cancer (PTC) patients without LT4 for 4 weeks and prove the relationship between the abnormal rCMRglu with depression and anxiety. Methods: Brain 18F-FDG PET/CT data of 38 consecutive PTC patients with high/intermediate-risk from June 2016 to December 2017 have been analyzed. Of the 38 patients, 23 are in the LT4 withdrawal group (WG) and 15 in the LT4 replacement group (RG). These patients were also evaluated for depressive and anxiety symptoms within 24 h after the scans based on the Hamilton Depression Rating Scale (17 items, HRDS-17) and the Hamilton Anxiety Rating Scale (HAMA) respectively. Results: Thirty-eight patients (12 men, 26 women; age range, 25-69 years; mean age, 45.8 years) were selected in the study. Compared with the RG, patients in WG showed depression and anxiety with higher total scores of HRDS-17 and HAMA (14.7 ± 5.8 vs 3.8 ± 5.5, t = -5.74, p = 0.00; 9.3 ± 4.3 vs 2.7 ± 4.1, t = -4.74, p = 0.00, respectively). In the brain glucose metabolism analysis, the WG patients showed lower rCMRglu in Occipital_Mid_R and Postcentral_L. On the other hand, data illustrated significant rCMRglu increases in the Frontal_Sup_Orb_L. Compared with the healthy group (HG), the rCMRglu of the Postcentral_L and Precuneus_L showed hypoactivity, but the Hippocampus_R and the Temporal_Inf_L showed hyperactivity. This analysis yielded a significant correlation between abnormal rCMRglu with the free thyroxine level, the serum thyroid-stimulating hormone level, HRDS-17, and HAMA scores. Conclusions: The findings showed that more PTC patients exhibited depression and anxiety after LT4 withdrawal for 4 weeks. More attention should be paid to these hypothyroid patients while they were in the hospital. Such a short-term LT4 withdrawal also likely induced abnormal rCMRglu. Our study attempts to explain the possible mechanism of mood disorders related to transient hypothyroidism.

Characterization of tubo-ovarian abscess mimicking adnexal masses: Comparison between contrast-enhanced CT, 18F-FDG PET/CT and MRI.

0BJECTIVE: We compared the diagnostic accuracy of contrast-enhanced computed tomography (CT), fluorine 18-labeled-fludeoxyglucose (18F-FDG) positron emission tomography (PET)/CT and conventional magnetic resonance imaging (MRI) without and with diffusion-weighted imaging (DWI) for characterization of tubo-ovarian abscesses (TOAs) that mimic adnexal tumors. MATERIALS AND METHODS: We evaluated (retrospectively) 43 patients who underwent contrast-enhanced CT, PET/CT, conventional MRI without and with DWI, and who were found to have TOAs and complex adnexal tumors. All images were evaluated independently by four radiologists using a two-point grading system. Results of contrast-enhanced CT, PET/CT, MRI without DWI, and MRI with DWI were compared for each patient using receiver operating characteristic curves. Sensitivity, specificity, and positive predictive value (PPV) were calculated and compared using the chi-square test. RESULTS: Sensitivity of MRI with DWI (95%) was significantly higher than that of contrast-enhanced CT (78.6%), PET/CT (86.7%) and MRI without DWI (87.5%). Specificities of these modalities were not significantly different. The PPV of MRI with DWI (100%) was significantly higher than that of the other three modalities (CT, 72.4%; PET/CT 78.5%; MRI without DWI, 81.5%). Overall accuracy of MRI with DWI was significantly higher than that of the other three modalities (CT, 74.4%; PET/CT, 81.4%; MRI without DWI, 83.7%). CONCLUSION: MRI with DWI shows high accuracy for characterization of complex ovarian lesions, and is the most useful method for differentiation of TOAs from ovarian tumors.

The study of influence factors on (131)I treatment of differentiated thyroid carcinoma with lymph node metastases.

OBJECTIVE: Thyroid carcinoma is the most common malignant endocrine tumor, which comprises 1% in all human tumors. As for differentiated thyroid carcinoma (DTC), lymph nodes are the most common metastatic site for which the major treatment is (131)I therapy. This retrospective study aimed to investigate the therapeutic effect and analyze the influence factors on (131)I treatment of DTC with lymph node metastases. METHODS: Collecting clinical data of 66 DTC patients with lymph node metastases at the Department of Nuclear Medicine, Xin Hua Hospital from January 1996 to January 2006. Investigating the therapeutic effect firstly and then dividing 66 patients into an eliminated group and an uneliminated group according to the evaluation criteria of the therapeutic effect. Finally, observing the differences between the two groups. The significant differences in the following 10 influence factors were determined: gender, age, pathological type, the periods from the thyroidectomy to the first (131)I therapy, when the metastases were found, the history of resection of the lymph node metastases, the uptake of (18)F-FDG in the lymph node metastases, remnant thyroid, multiple metastases, and the cumulative dose of (131)I. This retrospective study was analyzed by Student t test, chi(2) test, and Fisher's exact test. RESULTS: Of all 66 patients with lymph node metastatic DTC treated by (131)I therapy, 31 patients (46.97%) had complete elimination. Twenty-seven patients were improved or controlled, and the overall effective rate reached 87.88%. The elimination rate of lymph node metastases in patients with resection was significantly higher than in those without resection (chi(2)=5.561, P=.018<0.05). The elimination rate of lymph node metastases in patients with (18)F-FDG uptake was significantly higher than in those without (18)F-FDG uptake (chi(2)=4.014, P=.045<.05). There was no significant difference in the elimination rate among the patients with various values in the other eight factors. CONCLUSIONS: (131)I Therapy is an effective treatment of lymph node metastatic DTC. The history of resection of the lymph node metastases and the uptake of (18)F-FDG in the lymph node metastases were the influence factors on the therapeutic effect, whereas the other eight factors were probably not.

Evaluation of radionuclide cerebrospinal fluid scintigraphy as a guide in the management of patients with hydrocephalus.

PURPOSE: Radionuclide cerebrospinal fluid scintigraphy (RCFS) has long been clinically applied in the diagnosis of hydrocephalus. This study aims to evaluate the clinical value of RCFS as a guide in the management of patients with hydrocephalus. METHODS: Thirteen patients with hydrocephalus were investigated. They underwent RCFS scanning and computed tomography/magnetic resonance imaging examination in our hospital. Follow-up treatment was performed, and prognosis was made. RESULTS: Four of seven patients diagnosed with obstructive hydrocephalus by RCFS underwent endoscopic third ventriculostomy, and five of six patients diagnosed with obstructive hydrocephalus underwent ventriculoperitoneal shunt. All patients who underwent operation had good prognosis on follow-up after at least 1 year. CONCLUSION: RCFS can definitely differentiate obstructive hydrocephalus from communicating hydrocephalus and had significance as a guide in the treatment of patients with hydrocephalus.

The role of single-photon emission computed tomography/computed tomography for precise localization of metastases in patients with differentiated thyroid cancer.

PURPOSE: It is very important in the management of patients with differentiated thyroid cancer (DTC) to precisely localize the foci of I-131 uptake, but it is difficult because of a lack of anatomic landmarks. The purpose of this study was to investigate the added value of I-131 single-photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging using a hybrid system in patients with DTC. METHODS: Ninety-four patients with DTC underwent I-131 SPECT/CT using a hybrid tomography consisting of a dual-head variable-angle gamma camera and a low-dose X-ray tube. Results were compared with I-131 whole-body scan (WBS). SPECT/CT was performed 5-7 days after administration of a therapeutic dose of I-131. Fusion images were constructed by combining the digital CT and SPECT images on a computer workstation. RESULTS: Compared with I-131 WBS, SPECT/CT imaging had improved the precise localization in 21% (20/94) of patients. In addition, SPECT/CT provided additional clinical data in 12 of the patients examined (12/94) and also caused physicians to reconsider the (131)I therapeutic approach in 22 patients. CONCLUSION: The results of the current study indicate that the addition of I-131 SPECT/CT to WBS can improve the localization of metastases in patients with DTC. It may also detect metastases missed by WBS and adjust the therapy plan.

Comparison of whole-body 18F-FDG SPECT and posttherapeutic 131I scintigraphy in the detection of metastatic thyroid cancer.

PURPOSE: The usefulness of fluorine 18 fluorodeoxyglucose ((18)F-FDG) imaging in differentiated thyroid cancer (DTC) has been demonstrated by investigators. The aim of this study is to compare the ability of fluorodeoxyglucose (FDG)-single photon emission computed tomography (SPECT) to detect metastatic DTC with posttherapeutic iodine131 ((131)I) scintigraphy. METHODS: 239 patients (78 men, 161 women; age range, 23-76 years, mean 45 years); All patients underwent FDG-SPECT and (131)I whole-body scan. RESULTS: The sensitivity of (18)F-FDG and (131)I imaging in the patients with high hTg levels is 48.7% (114/234) and 50.4% (118/234) respectively. However, the combined sensitivity of both protocols is 89.7% (210/234). In the patients with (131)I Imaging negative, the sensitivity of (18)F-FDG is 79.3%,but in the patients with (131)I imaging positive, the sensitivity of (18)F-FDG is only 18.6%. CONCLUSION: This study with (131)I and (18)F-FDG in FDG-SPECT further demonstrates the single study of (131)I whole body scan or (18)F-FDG imaging can not provide a high enough sensitivity for the detection of metastatic thyroid cancer. But, the combined protocols can get better results for the staging of thyroid carcinoma with the alternating uptake of (131)I and (18)F-FDG.