Background: The objective of this study is to evaluate the diagnostic accuracy of ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in detecting recurrence in patients with differentiated thyroid cancer (DTC) who have negative whole-body scans (WBSs) but elevated serum thyroglobulin (Tg) or thyroglobulin antibody (TgAb) levels. Methods: This systematic review/meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Diagnostic Test Accuracy criteria (International Prospective Register of Systematic Reviews registration number: CRD42022340924). A comprehensive search of the MEDLINE, EMBASE, and Cochrane databases identified articles reporting the diagnostic accuracy of FDG PET/CT for the detection of recurrence in patients with DTC with negative WBS and elevated serum Tg or TgAb levels published between January 2012 and June 2023. Meta-analyses were performed to determine the diagnostic accuracy of FDG PET/CT on the total target population as well as on subgroups stratified by serum Tg or TgAb, and thyrotropin (TSH) stimulation status at the time of FDG PET/CT. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework was applied to evaluate the quality of evidence and the strength of recommendations to facilitate translation of the meta-analysis results into practical recommendations for clinical guidelines. Results: A total of 24 studies involving 1988 patients were included for analysis. The overall pooled sensitivity and specificity values were 0.87 (95% confidence interval [CI] = 0.83–0.92; I ² = 75%) and 0.84 (CI = 0.80–0.89; I ² = 44%), respectively. Subgroup analyses revealed no significant differences in the diagnostic accuracy of FDG PET/CT in patients stratified by serum Tg or TgAb levels, and TSH stimulation status at the time of PET/CT. Treatment plans were changed following FDG PET/CT imaging in 40% (CI = 34–47%; I ² = 39%) of cases. The quality level of evidence for using FDG PET/CT was moderate in both sensitivity and specificity according to the GRADE system. Conclusion: There is moderate quality evidence demonstrating the high diagnostic accuracy of FDG PET/CT in detecting recurrence in patients with DTC with negative WBS and elevated serum Tg or TgAb levels. This evidence corroborates the current guidelines' endorsement of FDG PET/CT as a diagnostic tool in such patients.

Young Joo Park, Eun Kyung Lee, Young Shin Song, Bon Seok Koo, Hyungju Kwon, Keunyoung Kim, Mijin Kim, Bo Hyun Kim, Won Gu Kim, Won Bae Kim, Won Woong Kim, Jung-Han Kim, Hee Kyung Kim, Hee Young Na, Shin Je Moon, Jung-Eun Moon, Sohyun Park, Jun-Ook Park, Ji-In Bang, Kyorim Back, Youngduk Seo, Dong Yeob Shin, Su-Jin Shin, Hwa Young Ahn, So Won Oh, Seung Hoon Woo, Ho-Ryun Won, Chang Hwan Ryu, Jee Hee Yoon, Ka Hee Yi, Min Kyoung Lee, Sang-Woo Lee, Seung Eun Lee, Sihoon Lee, Young Ah Lee, Joon-Hyop Lee, Ji Ye Lee, Jieun Lee, Cho Rok Lee, Dong-Jun Lim, Jae-Yol Lim, Yun Kyung Jeon, Kyong Yeun Jung, Ari Chong, Yun Jae Chung, Chan Kwon Jung, Kwanhoon Jo, Yoon Young Cho, A Ram Hong, Chae Moon Hong, Ho-Cheol Kang, Sun Wook Kim, Woong Youn Chung, Do Joon Park, Dong Gyu Na, Korean Thyroid Association Guideline Committee on the Managements of Thyroid Nodule and Cancer. Int J Thyroidol 2024;17:1-20. https://doi.org/10.11106/ijt.2024.17.1.1

Mitochondrial oxidative phosphorylation (OXPHOS) system dysfunction in cancer cells has been exploited as a target for anti-cancer therapeutic intervention. The downregulation of CR6-interacting factor 1 (CRIF1), an essential mito-ribosomal factor, can impair mitochondrial function in various cell types. In this study, we investigated whether CRIF1 deficiency induced by siRNA and siRNA nanoparticles could suppress MCF-7 breast cancer growth and tumor development, respectively. Our results showed that CRIF1 silencing decreased the assembly of mitochondrial OXPHOS complexes I and II, which induced mitochondrial dysfunction, mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential depolarization, and excessive mitochondrial fission. CRIF1 inhibition reduced p53-induced glycolysis and apoptosis regulator (TIGAR) expression, as well as NADPH synthesis, leading to additional increases in ROS production. The downregulation of CRIF1 suppressed cell proliferation and inhibited cell migration through the induction of G0/G1 phase cell cycle arrest in MCF-7 breast cancer cells. Similarly, the intratumoral injection of CRIF1 siRNA-encapsulated PLGA nanoparticles inhibited tumor growth, downregulated the assembly of mitochondrial OXPHOS complexes I and II, and induced the expression of cell cycle protein markers (p53, p21, and p16) in MCF-7 xenograft mice. Thus, the inhibition of mitochondrial OXPHOS protein synthesis through CRIF1 deletion destroyed mitochondrial function, leading to elevated ROS levels and inducing antitumor effects in MCF-7 cells.

Mijin Kim, Ji-In Bang, Ho-Cheol Kang, Sun Wook Kim, Dong Gyu Na, Young Joo Park, Youngduk Seo, Young Shin Song, So Won Oh, Sang-Woo Lee, Eun Kyung Lee, Ji Ye Lee, Dong-Jun Lim, Ari Chong, Yun Jae Chung, Chae Moon Hong, Min Kyoung Lee, Bo Hyun Kim, Korean Thyroid Association Guideline Committee on the Managements of Thyroid Nodule and Cancer. Int J Thyroidol 2024;17:115-46. https://doi.org/10.11106/ijt.2024.17.1.115

Mutations in the F-box only protein 7 (FBXO7) gene are the cause of autosomal recessive parkinsonian-pyramidal syndrome. Herein, we report a patient with a novel FBXO7 mutation with a unique clinical presentation. A 43-year-old male visited our hospital with complaints of progressing gait disturbance since a generalized tonic clonic seizure. There were no past neurological symptoms or familial disorders. Neurological examination revealed bradykinesia, masked face, stooped posture, parkinsonian gait, and postural instability. The bilateral uptake by dopamine transporters was nearly abolished, as determined by N-(3-[18F]fluoropropyl)- 2β-carbon ethoxy-3β-(4-iodophenyl) nortropane positron emission tomography (18F-FP-CIT PET). Next-generation sequencing revealed a heterozygous c.1066_1069delTCTG (p.Ser356ArgfsTer56) frameshift variant and a heterozygous c.80G>A (p.Arg27His) missense variant of the FBXO7 gene. The patient’s specific clinical features, medication-refractory parkinsonism and seizures further broaden the spectrum of FBXO7 mutations. The nearly abolished dopamine transporter uptake identified by 18F-FP-CIT PET is frequently found in patients with FBXO7 mutations, which is different from the usual rostrocaudal gradient that is observed in patients with Parkinson’s disease.