Objective To investigate the value of 18F-FDG PET/CT in the phasing and grading of renal cell carcinoma (RCC) complicated with vena cava tumor thrombus (VCTT).Methods From December 2011 to September 2015,a total of 72 patients (52 males,20 females,age:36-74 years) were enrolled in this retrospectively study.All patients underwent 18F-FDG PET/CT and contrast-enhanced CT studies,and were diagnosed as RCC.The RCC patients combined with VCTT were classified by Mayo-level.Wilcoxon rank sum test was used to compare the grading of VCTT by PET/CT and contrast-enhanced CT.NM staging on abdominal area level was performed and the results were compared with x2 test.Results VCTT was identified in 18 RCC patients and the grading results by PET/CT were as follows:9 cases in Level 0,4 cases in Level Ⅰ,2 cases in Level Ⅱ,1 case in Level Ⅲ,and 2 cases in Level Ⅳ.When evaluated by PET/CT,20 cases were in N0M0,21 were in N1M0,9 were in N0M1,and 22 were in N1M1.NM staging results by contrast-enhanced CT were as follows:50 cases in N0M0,10 in N1M0,10 in N0M1,and 2 in N1M1.In addition,2 N1 and 2 M1 were found by the whole body PET/CT.The classification results of VCTT and staging of abdominal level by PET/CT were significantly better than those by contrast-enhanced CT (z=-2.462,P＜0.05;x2=32.806,P＜0.01).Conclusion 18F-FDG PET/CT is not only valuable for detecting primary RCC and local metastasis,but also useful for finding where the VCTT extends,which is conducive to therapeutic planning and further clinical treatment.

Objective:To investigate the therapeutic efficacy and potential mechanisms of integrin α vβ 3-targeted radionuclide therapy (TRT) in combination with anti-programmed cell death protein ligand 1 (PD-L1) immunotherapy. Methods:Integrin α vβ 3-targeted molecule Arg-Gly-Asp (RGD) was conjugated with Evans blue (EB) and then labeled with 177Lu to obtain 177Lu-EB-RGD. The radioactivity and radiochemical purity were determined. MicroSPECT imaging, biodistribution, and in vivo therapeutic efficacy were subsequently performed in MC38 murine colon cancer models. Volume of tumor and body mass of mice were observed to assess the therapeutic efficacy and safety ( n=9 in each group). Flow cytometry was used to evaluate therapy response of saline-treated (control, group A), 18.5 MBq 177Lu-EB-RGD-treated (group B), 10 mg/kg PD-L1 antibody-treated (group C), TRT combined with immunotherapy-treated (group D, 18.5 MBq 177Lu-EB-RGD and 10 mg/kg PD-L1 antibody) mice and alterations in tumor microenvironment (PD-L1 + immune cells, CD8 + T cells and regulatory T cells). Independent-sample t test and repeated measures analysis of variance were used for data analysis. Results:The radioactivity of 177Lu-EB-RGD was (55.85±14.00) GBq/μmol. SPECT imaging clearly visualized the MC38 tumors in mice models with high uptake and long retention time, the tumor/muscle ratio reached 14.87±0.88 at 24 h postinjection, while less uptake and retention in normal tissues. Tumor uptake of 177Lu-EB-RGD was significantly higher than that of 177Lu-RGD 4 h post-injection ((12.00±1.60) vs (3.69±0.37) %ID/g; t=8.63, P<0.01). The efficacy results between each treatment group was significantly different ( F=7.32, P=0.03) at day 6 post-treatment. The combination therapy showed the most outstanding anti-tumor efficacy with 7/9 mice showed complete response. Flow cytometry results showed that TRT up-regulated the PD-L1 expression significantly, namely, PD-L1 + immune cells in group B and group A were significantly different (CD45 + /PD-L1: 2.34% vs 0.95%, CD11b + /PD-L1: 2.41% vs 0.66%; t values: 11.17 and 8.70, both P<0.01); immunotherapy and combination therapy dramatically stimulated the infiltration of CD8 + T cells (2.07% vs 0.26%, 2.71% vs 0.26%; t values: 4.10 and 6.03, both P<0.05). Conclusion:TRT in combination with immunotherapy synergistically enhance anti-tumor efficacy, which is expected to play a role in the treatment of patients with advanced tumor where TRT can be applied.

Objective:To investigate the clinical utility of 68Ga-labeled fibroblast activation protein inhibitor (FAPI) PET/CT in the detection of primary and metastatic gastric signet-ring cell carcinoma (GSRCC) and compared the results with those of 18F-FDG PET/CT. Methods:A total of 21 patients (10 males, 11 females, average age 52 years) with primary and metastatic GSRCC who underwent 68Ga-FAPI and 18F-FDG PET/CT at the First Affiliated Hospital of Xiamen University from June 2020 to May 2022 were retrospectively analyzed. Pathological results of surgery and (or) biopsy were used as the " gold standard" for final diagnosis. In cases whose surgery or tissue biopsies were not available, clinical and radiographic follow-up results were used as the reference standards. Wilcoxon signed-rank test was used to compare the SUV max of 18F-FDG and 68Ga-FAPI. McNemar χ2 test was used to compare the detection rate between 18F-FDG and 68Ga-FAPI PET/CT. Results:68Ga-FAPI PET/CT showed higher SUV max than 18F-FDG in primary tumors (5.3(2.4, 15.7) vs 2.4(1.8, 2.5); z=2.31, P=0.021), local recurrences (7.8(6.0, 8.9) vs 2.4(1.9, 3.4); z=2.20, P=0.028), lymph nodes metastases (7.7(4.5, 12.2) vs 2.4(1.9, 3.6); z=6.01, P<0.001) and bone/visceral metastases (6.7(5.3, 11.1) vs 2.4(2.0, 3.4); z=11.36, P<0.001). Regarding diagnostic accuracy, 68Ga-FAPI PET/CT showed higher sensitivities than 18F-FDG for primary tumors (7/9 vs 2/9; χ2=3.20, P=0.063) and local recurrences (7/7 vs 2/7; χ2=3.20, P=0.063). It also demonstrated higher lesion detection rates than 18F-FDG for suspicious lymph node metastases (86%(65/76) vs 32%(24/76); χ2=31.37, P<0.001) and bone/visceral metastases (99%(184/185) vs 39%(73/185); χ2=107.08, P<0.001). Conclusions:68Ga-FAPI PET/CT showed higher tumor uptake and lesion detection rate than 18F-FDG in the primary and metastatic GSRCC. 68Ga-FAPI PET/CT demonstrates good diagnostic performance for tumor detection, staging, and restaging of GSRCC, which is helpful to further guide clinical treatment strategy.

Objective:To develop a tetramer probe targeting fibroblast activation protein (FAP), named 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-4P(FAP inhibitor (FAPI)) 4, evaluate its biodistribution and PET image in FAP-positive-tumor bearing nude mice, and explore its feasibility as a novel radio-regent for treatment of FAP-positive tumor. Methods:FAP tetramer probe was constructed on the FAPI-46 motif with four mini-polyethylene glycol (PEG)(PEG 3) spacers between the four FAPI motifs, denoted as 4P(FAPI) 4. DOTA was used as the chelator for radiolabeling with 68Ga and 177Lu. The FAP binding characteristics were test by in vitro cell competitive binding experiment. Small-animal PET, in vivo biodistribution, and radionuclide targeting therapy were performed in HT-1080-FAP tumor bearing nude mice ( n=39). Independent-sample t test was performed to analyze tumor uptake data, and two-factor repeated measures analysis of variance was utilized to compare tumor volume data in radioactive isotope therapy. Results:Cell experiment showed that FAPI-tetramer and FAPI-monomer had similar half maximal inhibitory concentration values (3.29 and 2.15 nmol/L). 68Ga/ 177Lu radiolabeled FAPI-tetramer had better tumor uptake and retention than FAPI-monomer in small-animal PET and in vivo biodistribution experiment, with the tumor uptake for 177Lu-DOTA-4P(FAPI) 4 and 177Lu-FAPI-46 at 48 h of (18.72±1.32) vs (2.72±1.20) percentage activity of injection dose per gram of tissue (%ID/g) ( t=15.55, P<0.001). 177Lu-DOTA-4P(FAPI) 4 group showed best anti-tumor efficacy compared with 177Lu-FAPI-46 and control group in radionuclide targeting therapy. On the 2nd day after the start of treatment, the tumor volume in the tetramer treatment group was significantly smaller than that in the control group (mean difference 67.19 mm 3, P=0.049); on the 14th day after the start of treatment, the tumor volume in the tetramer treatment group was significantly smaller than that in the monomer treatment group (mean difference 414.33 mm 3, P=0.005). Conclusion:FAPI-tetramer can improve tumor uptake and retention ability compared with FAPI-46, and 177Lu-DOTA-4P(FAPI) 4 can be a promising radio-agent for FAP-positive tumor therapy.

Objective:To summarize clinical characteristics of and treatment experience with patients with critical illnesses in a dermatological ward.Methods:All patients with serious or life-threatening conditions, who were hospitalized at the dermatological ward of the Second Xiangya Hospital of Central South University from July 9, 2011 to December 31, 2020, were collected, and their clinical data were retrospectively analyzed. Demographic characteristics, disease types and proportions, main complications, causes of serious or life-threatening conditions, important treatment measures and outcomes were summarized, and causes of death were also analyzed and discussed.Results:A total of 1 057 patients with critical illnesses were collected, with a male-to-female ratio of 1∶1.11, and 64.81% of them aged 18 to 65 years. The types of diseases mainly included drug eruptions (332 cases) , connective tissue diseases (226 cases) , bullous skin diseases (104 cases) , psoriasis (57 cases) , erythroderma (45 cases) , infectious skin diseases (67 cases) , etc. Among them, psoriasis (39 cases) and erythroderma (32 cases) mostly occurred in males, and connective tissue diseases (168 cases) mostly occurred in females. Common complications mainly involved infections, important organ damage or dysfunction, hypoalbuminemia, and fluid, electrolyte and acid-base imbalances. A total of 94 patients were diagnosed with life-threatening conditions, which were found to be mainly caused by primary skin diseases, hematologic abnormalities, respiratory failure, nervous system abnormalities, renal failure, sepsis, fluid, electrolyte and acid-base imbalances, etc. During the management of critical illnesses, 43 patients were treated with high-dose glucocorticoid pulse therapy, 264 were treated with gamma-globulin pulse therapy, 355 were transfused with other blood products, and 34 received special therapies such as hemoperfusion/immunoadsorption therapy, plasma exchange, dialysis, artificial liver support therapy; 42 patients were transferred to the intensive care unit (ICU) , 12 were transferred to the department of surgery for operations, and 12 were transferred to the department of obstetrics and gynecology for delivery or induction of labor. After treatment, 989 patients (93.57%) achieved improvement and were discharged. A total of 14 patients (1.32%) died, of whom 7 died of secondary sepsis, 2 died of severe pulmonary infections, 2 died of asphyxia caused by respiratory mucosa shedding-induced airway obstruction, the other 3 died of gastrointestinal hemorrhage, cerebral hemorrhage and neuropsychiatric systemic lupus erythematosus, respectively.Conclusions:Critical cases in the dermatological ward mainly suffered from serious skin diseases such as severe drug eruptions, connective tissue diseases and bullous skin diseases, as well as complications such as severe underlying diseases, severe organ dysfunction, sepsis or severe fluid, electrolyte and acid-base imbalances. In terms of treatment, it is of critical significance to make a clear diagnosis and assess the severity of disease as early as possible, monitor and prevent possible complications, and to consult with specialists in relevant disciplines in time.