18F-FDG PET/CT imaging in pulmonary sarcomatoid carcinoma

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare highly aggressive and poorly differentiated non-small cell carcinoma, and little is known about the information on the usefulness of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). We investigated the clinical and 18F-FDG PET/CT features of PSC.

Methods

We retrospectively analyzed 25 consecutive PSC patients who had undergone 18F-FDG PET/CT. Demographic data, PET/CT findings before treatment, pathological features, and prognosis in these patients were investigated to define correlates between maximal standard uptake value (SUVmax) and clinicopathological parameters.

Results

From March 2017 to January 2023, twenty-five eligible patients with PSC were identified. There were 23 (92%) men, aged 68.5 ± 8.5 (range 56-90) years. Eighteen (72%) patients had a frequent smoking history. The mean size of PSCs was 59.3 ± 18.6 (range 29-97) mm, and 23 (92%) PSCs were Stage IV tumors. 20 (80%) lesions were located in the upper lung and 19 (76%) cases belonged to the peripheral type. Necrotic foci appeared in 21(84%) tumors. 11 (44%) PSCs invaded the pleura. All PSCs were FDG avid, and the mean of SUVmax was 11.8 ± 5.3 (range 4.8-25.5). Metastases were found on PET/CT in 24(96%) patients. The SUVmax of the lesions ≥ 5cm was higher than that of the lesions < 5cm (p=0.004), and the SUVmax of lesions with TTF-1 expression was higher than those of lesions without TTF-1 expression (p=0.009). All of the 25 primary lesions were considered malignant and confirmative, probable, and possible diagnosis of PSC was made in 2 (8%), 4 (16%), and 5(20%) patients, respectively on PET/CT. PSC was not considered in 14 (56%) patients, in PET/CT. The survival of patients with surgery didn't demonstrate a significantly good prognosis as compared with those without surgery (p=0.675).

Conclusion

All PSCs had obvious FDG avidity. Although imaging diagnosis is still difficult, combined clinical and imaging features more than 40% of primary lesions were considered for the possibility of PSC in our group. Early histopathological diagnosis is necessary to help develop a reasonable regimen.

Pre-procedure 18F-FDG PET/CT imaging improves the performance of CT-guided transthoracic biopsy

PURPOSE

To compare computed tomography (CT)-guided transthoracic lung biopsies (CTLB) with and without pre-procedure 18F-fluorodeoxgyglucose positron emission tomography (18F-FDG PET)/CT images in the diagnosis of pulmonary nodules/masses.

METHODS

This is a case-control study in a single center. The data of patients with a transthoracic lung biopsy guided by CT and pre-procedure 18F-FDG PET/CT (group 2, here called the "PETCTLB" group), including demographics, clinical characteristics, and biopsy-related parameters, were collected. The PET/CT scan was performed within 15 days before the biopsy. The data from patients with CTLB were used as controls (group 1). Biopsies for all patients were performed by the same physician between January 2019 and December 2021. The final diagnosis was based on surgical outcomes, or imaging findings, and the results of at least one 6-month follow-up. The demographics and clinical characteristics of patients, lesions and biopsy-related variables, diagnostic yields, and incidence of complications were compared between the two groups. Two-tailed t-tests were used to compare the mean values in the two independent groups, while categorical variables were compared using the Pearson chi-squared test, and P values < 0.05 were considered to be significant.

RESULTS

A total of 84 patients were included, and 84 biopsies of 84 lung nodules/masses were analyzed. The demographics and clinical characteristics of group 2 (n = 39; 21 men; mean age, 63.2 ± 9.29 years) and group 1 (n = 45; 30 men; mean age, 61.2 ± 12.3 years) had no significant difference (P = 0.230 and 0.397, respectively). The procedure duration (11.1 ± 3.0 vs. 12.9 ± 3.3 minutes, P = 0.008), the number of samples (2.6 ± 0.5 vs. 3.1 ± 0.4, P < 0.001), diagnostic accuracy (97.4% vs. 82.2%, P = 0.033), and bleeding complication (25.6% vs. 42.2%, P = 0.034) of group 2 and group 1 were statistically different.

CONCLUSION

A biopsy guided by CT plus pre-procedure 18F-FDG PET/CT (PETCTLB) is a safe procedure that can provide a precise diagnosis in the majority of lung nodules/masses. It has better diagnostic performance than CTLB.

The sensitivity and specificity of 18F-FDG PET/CT in spinal leptomeningeal metastases: the synergistic effect of the 18F-FDG PET-CT to gadolinium-enhanced MRI

Background

Magnetic resonance imaging (MRI) plays an important role in the diagnosis of leptomeningeal metastases (LM); however, some sub-centimeter lesions may be missed. Positron emission tomography/computed tomography (PET/CT) has a high sensitivity and may play a synergistic role with MRI in diagnosing spinal LM (SLM). We aimed to retrospectively evaluate the detection of SLM with 18F-fluorodeoxyglucose PET/CT (18F-FDG PET/CT) compared to that of whole spinal cord MRI in a single center.

Methods

Patients with SLM who had undergone 18F-FDG PET/CT and MRI were enrolled. 18F-FDG PET/CT imaging findings were independently reviewed by 2 nuclear medicine physicians. 18F-FDG PET/CT findings of SLMs were described. A consistency test was conducted to assess the patient-based diagnostic results obtained by the 2 physicians. Patient-based sensitivity, accuracy, and specificity in diagnosing SLM between 18F-FDG PET/CT and MRI of the whole spinal cord were compared using the chi-square or Fisher's exact test. A P value of <0.05 was considered statistically significant. The receiver operating characteristic (ROC) curve was obtained to assess the diagnostic performance of maximum standardized uptake value (SUVmax) to diagnose SLM.

Results

A total of 16 patients with SLM were included in this study from October 2010 to April 2022. The primary tumor involved the lungs, liver, ovaries, prostate, esophagus, and unknown primary site. The mean age of patients, including 13 males and 3 females, was 57.8±11.2 (range, 34-73) years. Of 16 patients with SLM, 10 had nodular diseases, 2 had linear diseases, and 4 had mixed diseases. The kappa value of the consistency test of the 2 radiologists' diagnostic results was 0.765. The patient-based sensitivity, specificity, and accuracy of 18F-FDG PET/CT in diagnosing SLM were 87.5%, 89.2%, and 88.7%, respectively and those of whole spinal cord MRI were 75.0%, 100.0%, and 92.5%, respectively. There were no significant differences in sensitivity, specificity, and accuracy between the 2 methods, with P values of 0.654, 0.115, and 0.506, respectively. However, more nodular diseases were observed on PET/CT. The area under the ROC curve (AUC) for the prediction of SLM by SUVmax was 0.907 [95% confidence interval (CI): 0.831-0.983]. When SUVmax ≥2.45, the Youden index was the largest, and the sensitivity and specificity were 89.3% and 75.7%, respectively.

Conclusions

18F-FDG PET/CT is a good choice of imaging modality for assessing SLM. In the diagnosis of SLMs, PET/CT and enhanced MRI can play a better synergistic role.

Estrogen receptor alpha gene PvuII polymorphism and risk of fracture in postmenopausal women: a meta-analysis

Numerous studies have evaluated the association between estrogen receptor alpha (ESR1) gene PvuII polymorphism and fracture risk in postmenopausal women. However, the results have been inconsistent. We performed a meta-analysis to examine the association between the ESR1 gene PvuII polymorphism and fracture risk in postmenopausal women. Studies published from PubMed, Google Scholar, and China National Knowledge Infrastructure data were retrieved. Pooled odds ratios with 95% confidence intervals were calculated using fixed- or random-effects models. A total of 6 case-control studies containing 592 patients and 705 controls were included in this meta-analysis. We found no association between the PvuII polymorphism in the ESR1 gene and fracture in postmenopausal women. Taking into account the effect of ethnicity, further stratified analyses were performed. In the subgroup analysis, no significant association was found in Caucasians and in Asians. No publication bias was found in the present study (all P > 0.05). In conclusion, the ESR1 gene PvuII polymorphism may not be associated with fracture risk in postmenopausal women. Additional larger studies are needed to confirm this conclusion.

Functional MR imaging of the cervical spinal cord by use of electrical stimulation at LI4 (Hegu)

The purpose is to investigate the cervical spinal cord mapping on electrical stimulation at LI4 (Hegu) by using 'signal enhancement by extravascular water protons' (SEEP)-fMRI, and to establish the response of acupoint-stimulation in spinal cord. Three healthy volunteers were underwent low-frequency electrical stimulation at LI4. Meanwhile, a single-shot fast spin-echo (SSFSE) sequence was used to perform functional MR imaging on a 1.5 T GE Signa MR system. Cord activation was measured both in the sagittal and transverse imaging planes and then analyzed by AFNI (analysis of functional neuroimages) system. In the sagittal view, two subjects had an fMRI response in the cervical spinal cord upon electrical stimulation at LI4. The localizations of the segmental fMRI activation are both at C6 through T1 and C2/3 cervical spinal cord level. In the transverse imaging plane, significant fMRI responses could be measured in the last subjects locating at C6/7 segment, the cross-sectional localization of the activity measured in the spinal cord was most in terms of the ipsilateral posterior direction. It is concluded that the fMRI technique can be used for detecting with activity in the human cervical spinal cord by a single-shot fast spin-echo sequence on a 1.5 T GE clinical system. Investigating the acupoint-stimulation response in the spinal cord using the spinal fMRI will be helpful for the further discussion on the mechanisms of acupuncture to spinal cord diseases.