Comparison of post-COVID-19 vaccination hypermetabolic lymphadenopathy on 18F-fluorodeoxyglucose PET/CT between virus-vector vaccine and mRNA vaccine.

PURPOSE: We compared hypermetabolic lymphadenopathy (HLN) on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) after virus-vector and mRNA vaccines for coronavirus disease 2019 (COVID-19). METHODS: This retrospective study included 573 participants who underwent FDG PET/CT after receiving a virus-vector vaccine (ChAdOx1, AstraZeneca [AZ] group) or an mRNA vaccine (mRNA-1273, Moderna [M] group) from July 2021 to October 2021. The incidence and avidity of HLN were evaluated and correlated with clinical features and vaccine type. The final analysis was conducted with 263 participants in the AZ group and 310 participants in the M group. RESULTS: The HLN incidence was significantly lower in the AZ group than in the M group (38/263 [14%] vs. 74/310 [24%], p = 0.006). The FDG avidity of HLN was comparable between the two groups. The HLN incidence in both groups was significantly higher within 4 weeks after the vaccination compared with more than 4 weeks. The HLN incidence within 4 weeks of the vaccination was significantly higher in the M group than in the AZ group (p = 0.008), whereas a difference in HLN incidence between the two groups was not observed after the same duration (p = 0.11). CONCLUSIONS: The mRNA mRNA-1273 COVID-19 vaccine was found to be associated with higher glucose hypermetabolism in regional lymph nodes within the first 4 weeks compared with the virus-vector vaccine, as indicated by the presence of HLN on FDG PET/CT. The degree of glucose hypermetabolism was comparable between the two vaccines.

NP-59 Adrenal Scintigraphy as an Imaging Biomarker to Predict KCNJ5 Mutation in Primary Aldosteronism Patients.

Purpose: Somatic KCNJ5 mutation occurs in half of unilateral primary aldosteronism (PA) and is associated with more severe phenotype. Mutation status can only be identified by tissue sample from adrenalectomy. NP-59 adrenal scintigraphy is a noninvasive functional study for disease activity assessment. This study aimed to evaluate the predictive value of NP-59 adrenal scintigraphy in somatic KCNJ5 mutation among PA patients who received adrenalectomy. Methods: Sixty-two PA patients who had NP-59 adrenal scintigraphy before adrenalectomy with available KCNJ5 mutation status were included. Two semiquantitative parameters, adrenal to liver ratio (ALR) and lesion to contralateral ratio of bilateral adrenal glands (CON) derived from NP-59 adrenal scintigraphy, of mutated and wild-type patients were compared. Cutoff values calculated by receiver-operating characteristic (ROC) analysis were used as a predictor of KCNJ5 mutation. Results: Twenty patients had KCNJ5 mutation and 42 patients were wild type. Patients harboring KCNJ5 mutation had both higher ALR and CON (p = 0.0031 and 0.0833, respectively) than wild-type patients. With ALR and CON cutoff of 2.10 and 1.95, the sensitivity and specificity to predict KCNJ5 mutation were 85%, 57% and 45%, 93%, respectively. Among 20 patients with KCNJ5 mutation, 16 showed G151R point mutation (KCNJ5- G151R) and 4 showed L168R point mutation (KCNJ5-L168R), which former one had significantly lower ALR (p=0.0471). Conclusion: PA patients harboring somatic KCNJ5 mutation had significantly higher NP-59 uptake regarding to ALR and CON than those without mutation. APAs with KCNJ5-L168R point mutation showed significantly higher ALR than those with KCNJ5-G151R point mutation.

Predicting tumor responses and patient survival in chemoradiotherapy-treated patients with non-small-cell lung cancer using dynamic contrast-enhanced integrated magnetic resonance-positron-emission tomography.

PURPOSE: We investigated whether radiologic parameters by dynamic contrast-enhanced (DCE) integrated magnetic resonance-positron-emission tomography (MR-PET) predicts tumor response to treatment and survival in non-metastatic non-small-cell lung cancer (NSCLC) patients receiving chemoradiotherapy (CRT). METHODS: Patients underwent DCE integrated MR-PET imaging 1 week before CRT. The following parameters were analyzed: primary tumor size, gross tumor volume, maximal standardized uptake value (SUVmax), total lesion glycolysis (TLG), apparent diffusion coefficient (ADC), volume transfer constant (Ktrans), reverse reflux rate constant (kep), extracellular extravascular volume fraction (ve), blood plasma volume fraction (vp), and initial area under the time-concentration curve defined over the first 60 s post-enhancement (iAUC60). CRT responses were defined using the revised Response Evaluation Criteria in Solid Tumors (RECIST) guideline (version 1.1). RESULTS: Thirty patients were included. Non-responders demonstrated higher baseline TLG (p = 0.012), and lower baseline Ktrans (p = 0.020) and iAUC60 (p = 0.016) compared to responders, indicating the usefulness of DCE integrated MR-PET to predict treatment responses. Receiver operating characteristic curve indicated that TLG has the best differentiation capability to predict responders. By setting the threshold of TLG to 277, the sensitivity, specificity, and accuracy were 66.7%, 83.3%, and 75.0%, respectively, with an area under the curve of 0.776. The median follow-up time was 19.6 (range 7.8-32.0) months. In univariate analyses, baseline TLG >277 (p = 0.005) and baseline Ktrans <254 (10-3 min-1; p = 0.015) correlated with poor survival after CRT. In multivariate analysis, baseline TLG >277 remained the significant factor in predicting progression (p = 0.012) and death (p = 0.031). CONCLUSIONS: The radiologic parameters derived from DCE integrated MR-PET scans are useful for predicting treatment response in NSCLC patients treated with CRT; furthermore, these parameters are correlated with clinical and survival outcomes including tumor progression and death.

Response assessment of stereotactic body radiation therapy using dynamic contrast-enhanced integrated MR-PET in non-small cell lung cancer patients.

PURPOSE: To evaluate the response in patients undergoing SBRT using dynamic contrast-enhanced (DCE) integrated magnetic resonance positron emission tomography (MR-PET). Stereotactic body radiation therapy (SBRT) is efficacious as a front-line local treatment for non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: We prospectively enrolled 19 lung tumors in 17 nonmetastatic NSCLC patients who were receiving SBRT as a primary treatment. They underwent DCE-integrated 3T MR-PET before and 6 weeks after SBRT. The following image parameters were analyzed: tumor size, standardized uptake value (SUV), apparent diffusion coefficient, Ktrans , kep , ve , vp , and iAUC60 . Chest computed tomography (CT) was performed at 3 months after SBRT. RESULTS: SBRT treatment led to tumor changes including significant decreases in the SUVmax (-61%, P < 0.001), Ktrans mean (-72%, P = 0.005), Ktrans standard deviation (SD; -85%, P = 0.046), kep mean (-53%, P = 0.014), kep SD (-63%, P = 0.001), and vp SD (-58%, P = 0.002). The PET SUVmax was correlated with the MR kep mean (P = 0.002) and kep SD (P < 0.001). The percentage reduction in Ktrans mean (P < 0.001) and kep mean (P = 0.034) at 6 weeks post-SBRT were significantly correlated with the percentage reduction in tumor size, as measured using CT at 3 months after SBRT. Univariate analyses revealed a trend toward disease progression when the initial SUVmax > 10 (P = 0.083). CONCLUSION: In patients with NSCLC who are receiving SBRT, DCE-integrated MR-PET can be used to evaluate the response after SBRT and to predict the local treatment outcome. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:191-199.