NGHIÊN CỨU ĐẶC ĐIỂM HÌNH ẢNH 18FDG-PET/CT HẠCH CỔ Ở BỆNH NHÂN UNG THƯ VÒM MŨI HỌNG

SUMMARY

Purpose: Describe imaging characteristics and evaluate the role of 18FDG-PET/CT in the diagnosis of cervical lymph nodes in nasopharyngeal cancer patients.

Subjects and methods: Prospective description of 60 patients with nasopharyngeal carcinoma identified by biopsy and histopathology and untreated (in which 55 patients with undifferentiated carcinoma and 5 patients with squamous cell carcinoma), were taken with 18FDG PET/CT and compared with ultrasound and done FNA lymph nodes respectively, from June 2018 to July 2019 to K Central Hospital, Tan Trieu campus. All 18FDG-PET/CT films were read and compared with their respective locations on ultrasound and lymph node FNA before treatment.

Results: In total 60 patients common age is 52.3±11.1, male/female ≈ 5/1; A total of 379 bilateral cervical lymph nodes on PET/CT, 195 lymph nodes in the left neck are common (51.5%), the most common lymph node location in group II (96.7% of patients and 61% of total lymph nodes). There are 322/379 (85%) lymph nodes with structural loss on ultrasound, there is a correlation between lymph node size and lymph node absorption on 18FDG-PET/CT with r=0.6, cervical lymph node groups 322/379 Structural abnormal lymph nodes with SUVmax = 9.5 ± 4.6 (nearly 4 times higher than 57/379 normal lymph nodes with SUVmax = 2.6 ± 2.5). In a total of 379 lymph nodes over 60 patients, there was a close agreement between the lymph nodes with loss of umbilical fat structure on ultrasound with SUVmax>2.5 threshold of 92.9% (kappa=0.67) and better at the threshold. SUVmax>3.5 was 92.9% (Cohen's kappa=0.75) on PET/CT. In addition, cytology was positive in 60/89 lymph nodes undergoing FNA, which was in close concordance with ultrasonography of loss of hilar fat structure and cytological diagnosis of 83.4% (Cohen's kappa = 0.62). ). The cytological diagnosis was mild with increased uptake with SUVmax>2.5 threshold of 75.3% (Cohen's kappa = 0.3), but there was a strong correlation when the lymph node imaging was increased. Absorption with SUVmax >2.5 on PET/CT and loss of umbilical cord fat on ultrasound with cytological diagnosis was 87.6% (Cohen's kappa = 0.69). In particular, out of a total of 340/379 lymph nodes with threshold SUVmax>2.5 on PET/CT are considered as metastatic nodes, changing the stage of 25/60 patients (41.67%); in which 17 patients increased and 8 patients decreased stage N compared with staging by other imaging methods before having PET/CT.

Conclusion: 18FDG-PET/CT scan is an imaging method with accurate diagnostic value in diagnosing cervical lymph nodes in patients with cervical cancer, useful for treatment planning.

Key words: lymph nodes, nasopharyngeal cancer, 18FDG-PET/CT lymph nodes on nasopharngeal cancer.