Systematic review of PET imaging features and clinical applications in pulmonary NUT carcinoma

Purpose Primary pulmonary nuclear protein in testis (NUT) carcinoma is a rare, aggressive malignancy driven by NUTM1 rearrangement. Although 18 F-FDG PET/CT is used in clinical management, its imaging features and value have not been systematically evaluated. Methods This PRISMA 2020 systematic review was registered with PROSPERO (CRD420261292692). PubMed, Embase, Web of Science, Cochrane Library, and grey literature were searched from inception to March 2026. Studies reporting 18 F-FDG PET/CT findings in pathologically confirmed primary pulmonary NUT carcinoma were included. A structured qualitative synthesis was performed. Results Twenty-three studies (86 patients) were included. Tumours consistently showed marked hypermetabolism (SUVmax 5–40; mean, 12–14) with frequent central necrosis. A proposed imaging triad was identified: (1) bulky central mass with necrosis; (2) ipsilateral coalescent mediastinal/hilar lymphadenopathy; and (3) extensive ipsilateral pleural involvement. The contralateral lung remained relatively spared and brain metastases were rare at initial diagnosis. PET/CT led to M-stage reclassification in 55% of patients through occult metastasis detection, was superior to bone scintigraphy for osteolytic lesions, and revealed initial treatment response followed by rapid progression on serial monitoring. Conclusions Primary pulmonary NUT carcinoma demonstrates a characteristic hypermetabolic phenotype with a proposed imaging triad on 18 F-FDG PET/CT. PET/CT is crucial for staging modification, metastasis detection, and treatment response monitoring. Recognition of this profile may facilitate earlier diagnosis and clinical management. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261292692 , identifier CRD420261292692.