Application of Imaging Indicators Based on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Colorectal Peritoneal Carcinomatosis.

Objective: The imaging features of peritoneal carcinomatosis (PC) with different locations and pathological types of colorectal cancer (CRC) on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) were analyzed and discussed. Methods: The PET/CT data of 132 patients with colorectal peritoneal carcinomatosis (CRPC) who met the inclusion and exclusion criteria between May 30, 2016, and December 31, 2019, were collected and analyzed. Observations included the location and pathological type of CRC, the peritoneal cancer index (PCI), standardized uptake maximum value (SUVmax), and retention index (RI) of the CRPC. Statistical analysis was performed using SPSS 20.0 software, and P < 0.05 was considered statistically significant. Results: (1) The range of the PCI in the 132 patients studied was 2-30, with a mean value of 7.40 ± 8.14. The maximum long diameter of the CRPC lesions ranged from 0.6 to 12.1 cm, with an average of 3.23 ± 1.94 cm. The SUVmax ranged from 1.2 to 31.0, with a mean value of 9.65 ± 6.01. The SUVmax and size correlation coefficient for maximal CRPC lesions was r = 0.47 (P < 0.001). The RI range of the 72 patients who underwent time-lapse scanning was -10.0-112.2%, with RI quartiles of 13.5-48.9%; RI was ≥5% in 65 cases and <5% in seven cases. (2) The patients were grouped by the location of their CRC: the right-sided colon cancer (RCC, n = 37), left-sided colon cancer (LCC, n = 44), and rectal cancer groups (RC, n = 51). There were significant differences in the CRC pathological types (P = 0.009) and PCI scores (P = 0.02) between the RCC and RC groups and the RI between the RCC group and the other two groups (P < 0.001). (3) There were 88 patients organized into three groups by the pathology of their CRC: the moderately well-differentiated adenocarcinoma (group A, n = 57), poorly differentiated adenocarcinoma (group B, n = 16), and mucinous adenocarcinoma groups (group C, n = 15 cases, including one case of signet-ring cell carcinoma). There were significant differences in the CRC position (P = 0.003) and SUVmax (P = 0.03) between groups A and C. Conclusion: The PCI, SUVmax, and RI of peritoneal metastatic carcinoma caused by CRC in different locations and pathological types vary. Mucinous adenocarcinoma and poorly differentiated adenocarcinoma are relatively common in the right colon, and the PCI of peritoneal metastatic carcinoma is fairly high, but the SUVmax and RI are somewhat low.

Distribution Characteristics of Colorectal Peritoneal Carcinomatosis Based on the Positron Emission Tomography/Peritoneal Cancer Index.

Background: Colorectal peritoneal carcinomatosis (CRPC) is a primary cause of death in colorectal cancer (CRC) patients. In the past, computed tomography (CT) has been the primary method used to evaluate the distribution of CRPC. This study uses 18F-FDG positron emission tomography/computed tomography (PET/CT) to investigate the distribution characteristics of CRPC. Materials and Methods: The distribution characteristics of 46 patients with CRC who were treated in the authors' hospital were retrospectively analyzed using the peritoneal cancer index (PCI). Results: The 46 patients in the study showed CRPC involvement in 203 of the 598 abdominal and pelvic regions studied (33.9%, 203/598). The regional proportions of CRPC involvement, from high to low, were as follows: region 6 (13.8%), region 0 (10.3%), region 1 (9.9%), region 5 (8.9%), region 7 (8.4%), region 3 (8.4%), region 2 (7.4%), region 4 (7.4%), region 11 (6.9%), region 8 (6.4%), region 12 (5.4%), region 9 (3.4%), and region 10 (3.4%). Thirty-three patients had a PCI of <20, and 13 patients had a PCI of ≥20. Those 13 were among the 17 (37% 17/46) who had CRPC involvement in all three regions. According to the location of the primary CRC focus, the 46 patients were divided into three groups: right hemicolon, left hemicolon, and rectum. The frequency of CRPC was greater in the rectum group than in the left hemicolon group, and the SUVmax of CRPC was greater in the right hemicolon group than in the left hemicolon group; these differences were statistically significant (p < 0.05). Conclusions: The distribution of CRPC has certain characteristics in the abdominal and pelvic cavities. The PET-PCI scores can provide a basis for the diagnosis and clinical treatment strategies in patients with CRC.

[Experimental study for thrombocytopenic purpura therapy by targeting macrophages in liver and spleen].

The study purpose was to explore whether dichloromethylene diphosphonate (Cl(2)MDP)-loaded gelatin particles can induce the depletion of macrophage in reticuloendothelial system of liver and spleen or can depress the immunity of macrophage in SD rat models of immune thrombocytopenic purpura (ITP) to treat the ITP rats. New Zealand rabbits were immunized with platelets of SD rats to prepare rabbit anti-rat platelet serum, and the serum was intravenously injected into SD rats to produce the ITP model. In experimental ITP models, 150 microl of anti-platelet serum was intravenously injected into SD rats per 24 hours. The platelet counts maintained pathological level and were persistently less than 50 x 10(9)/L in the models during experiment process. The MTT test of macrophage RAW264.7 was carried out by means of Cl(2)MDP-loaded gelatin particles in vitro. After intravenous injection of a group dose of Cl(2)MDP-gelatin particles, the platelet counts of the rats were measured at the time of 4 hours, 24 hours, 48 hours, 72 hours and 96 hours, respectively, and bleeding times were detected in 24 hours. The results showed that Cl(2)MDP-loaded gelatin particles increased the platelet counts of ITP models to mean of 180 x 10(9)/L, a physiological level in 24 hours after injection, and kept this platelet level through whole process of 120 hours. Furthermore, rats pre-treated with Cl(2)MDP-loaded gelatin particles avoided the decrease of platelet counts significantly when they were injected anti-platelet serum. It is concluded that Cl(2)MDP-loaded gelatin particles restrain multiplication of macrophage RAW264.7, and promptly, effectively restore platelet counts of ITP models to physiological level in a dose dependent manner. So, the targeting therapy of drug-loaded gelatin particles offers a new idea and approach to treat ITP, and this strategy is worthy of further studies.