[Prognostic Value of 18F-FDG PET/CT Metabolic Parameters in Patients with Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To investigate the prognostic value of metabolic parameters of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in diffuse large B-cell lymphoma (DLBCL). METHODS: The clinical data of 58 patients with DLBCL who were examined by 18F-FDG PET/CT before treatment and confirmed by pathology were analyzed retrospectively. The relationships between maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and clinical factors were analyzed. Kaplan Meier method, Log-rank test and multivariate Cox regression were used to analyze the relationships between metabolic SUVmax, MTV, TLG and times of total overall survival (OS) and progression-free survival (PFS). RESULTS: The SUVmax, MTV and TLG of 58 DLBCL patients were 21.45 (10.26-42.38), 27.30 (14.20-133.25) cm3 and 322.85 (47.35-1438.20), respectively. Univariate analysis showed that large mass, Ann Arbor stage, international prognostic index, MTV and TLG were the factors influencing OS and PFS in DLBCL patients (P<0.05), while lactate dehydrogenase and SUVmax were the factors influencing PFS only (P<0.05). Multivariate analysis showed that MTV (HR=2.974, 95%CI: 1.803-7.225)/(HR=3.925, 95%CI: 1.973-8.246) and TLG (HR=2.583, 95%CI: 1.192-5.316)/(HR=2.874, 95%CI: 1.538-6.483) were independent risk factors for OS and PFS in DLBCL patients (P<0.05), and international prognostic index (HR=2.490, 95%CI: 1.150-4.962) was independent risk factor for OS in DLBCL patients (P<0.05). CONCLUSION: MTV and TLG are independent risk factors for OS and PFS in patients with DLBCL, which may be valuable for prognosis of patients with DLBCL.

[Differential Diagnostic Value of 18F-FDG PET/CT Imaging in Multiple Myeloma and Bone Metastases].

OBJECTIVE: To investigate the imaging characteristics of 18F-FDG positron emission computed tomography (18F-FDG PET/CT) in multiple myeloma (MM) patients and to analyze its application value in MM and bone metastases. METHODS: A retrospective analysis was made on MM patients (n=72) and bone metastases patients (n=50) admitted to Hainan Western Central Hospital from January 2017 to March 2019. All patients underwent 18F-FDG PET/CT examination. The distribution of lesions, bone destruction, maximum standardized uptake (SUVmax) and metabolic homogeneity were analyzed in both groups. RESULTS: More than 80% of MM and bone metastases involved thoracic bone, spine and pelvis, followed by limbs. MM was more common in the lesions of thoracic bone and skull than those in bone metastases, the difference was statistically significant (P＜0.05). The majority of MM patients presented osteolytic bone destruction (97.2%), mostly showing "insect-like phagocytic pattern", so the bone showed dilated changes, and osteogenic changes were rarely seen (2.8%). Osteolytic bone destruction accounted for 74.0% in patients with bone metastatic tumor, presenting "focal" appearance more often, and osteogenic changes accounted for 26.0%. Osteolytic bone destruction in patients with MM was significantly higher than that in patients with bone metastases（χ2=14.757，P＜0.05）. The SUVmax of MM (4.25±2.16)was significantly lower than that of bone metastases (7.84±3.25) (t=6.830, P＜0.05). Diffuse mild uptake of 18F-FDG was more common in patients with MM, and heterogeneous high uptake of 18F-FDG was more common in patients with bone metastasis, the difference was statistically significant (P＜0.05). CONCLUSION: 18F-FDG PET/CT examination is helpful to acquire the imaging features of bone structure and metabolic changes, and shows an important clinical value in the differential diagnosis of MM and bone metastases.