[en] Background: PET with "1"8F-FDG has been considered of limited value for the detection of bladder cancer because of the urinary excretion of the tracer. Purpose: To investigate the clinical value of dual phase "1"8F-FDG PET/CT with oral diuretic in the diagnosis of bladder cancer. Methods: 107 patients with suspected bladder cancer were enrolled in the present study from May, 2003 to May, 2012. Each patient underwent the whole body "1"8F-FDG PET/CT scans routinely. After that, all patients received the forced diuresis by orally administration of furosemide (40 mg) and drinking a lot of water. Two hours later, after several times of urination, the patients underwent an additional delayed pelvic PET/CT scans. The intravesical radioactivity was compared between the routine and delayed the scans and the visualization of the tumor was evaluated. The diagnostic efficacy was determined based on the pathological examinations and the clinical following-up. Results: With the forced diuresis, intravesical "1"8F-FDG activity decreased significantly in 96.3% of the patients. The lesions on the wall of urinary bladder were visualized clearly in the delayed PET images, which weren't seen in the rout/ne PET images. "1"8F-FDG PET/CT was positive in 75 patients who all then received the operation. 69 patients were diagnosed pathologically to have the bladder cancer and 6 patients to have benign diseases. "1"8F-FDG PET/CT was negative in another 32 patients. Four patients of them were then diagnosed to be bladder cancer. Another 28 patients were clinically followed up more than 6 months and none of them was found to have bladder cancer. The sensitivity, specificity and accuracy of the dual phase PET/CT imaging for diagnosing the bladder cancer were 94.5%(69/73), 82.4%(28/34) and 90.7%(97/107), respectively. Conclusion: The forced diuresis using oral furosemide can significantly reduce the intravesical radioactivity and improve the detectability of "1"8F-FDG PET/CT for the bladder cancer. (authors)

[en] Objective To evaluate the complementary value of ¹¹C-choline (CHO) PET/CT to ¹⁸F-FDG PET/CT in the staging of locally advanced nasopharyngeal carcinoma (NPC) and diagnosis of HCC. Methods: From December 2007 to January 2010, 15 patients with locally advanced NPC and 76 patients with HCC were prospectively enrolled into this study. The research was approved by the ethics committee, and all patients signed informed consents. Whole body ¹⁸F-FDG PET/CT scans were performed on all patients and regional ¹¹C-CHO PET/CT was conducted in 43 patients (15 with NPC, 28 with HCC). A lesion with increased uptake of either ¹¹C-CHO or ¹⁸F-FDG was considered positive. SUV_max, tumor/brain (T/B) ratio and tumor/liver (T/L) ratio were calculated for semi-quantitative analysis. Two-sample t test, χ² test, Fisher exact test and linear correlation analysis were used for statistical analysis. Results: (1) The lesion SUV_max of ¹⁸F-FDG was higher compared to ¹¹C-CHO (12.81 ± 5.00 vs 6.84 ± 2.76; t=6.416, P<0.01) in NPC patients. However, ¹¹C-CHO PET/CT had a much higher T/B ratio than ¹⁸F-FDG (18.62 ±7.95 vs 1.38 ±0.59; t=8.801, P< 0.01). Significant correlation was found between the 2 tracers with regard to NPC lesion uptake (r=0.712, P<0.01). Compared with ¹⁸F-FDG PET/CT, ¹¹C-CHO PET/CT had better delineation of intracranial invasion in 50.0% of patients (12/12 vs 6/12; χ'2=8.000, P<0.05), skull base invasion in 4/14 patients and orbital invasion in 3/3 patients. (2) ¹⁸F-FDG PET/CT showed positive findings in 63.1% (48/76) of HCC patients. In 28 HCC patients with negative findings on ¹⁸F-FDG PET/CT, ¹¹C-CHO PET/CT was positive in 71.4% (20/28) of patients. The dual-tracer PET/CT improved the diagnostic sensitivity (89.5%, 68/76) of HCC compared with ¹⁸F-FDG PET/CT (63.1%,48/76) alone (χ²=14.559, P<0.01). ¹¹C-CHO PET/CT was more sensitive than ¹⁸F-FDG PET/CT for the detection of well differentiated HCC (6/9 vs 35.7% (5/14); P=0.214). For the detection of moderately differentiated HCC, the sensitivity of ¹¹C-CHO and ¹⁸F-FDG PET/CT was similar to each other (6/7 vs 72.0% (18/25), P=0.648). ¹¹C-CHO PET/CT was more sensitive than ¹⁸F-FDG for the detection of HCC lesions <5.0 cm (72.7% (16/22) vs 42.1% (16/38); χ²=5.249, P<0.05), especially for lesions < 2.0 cm (5/7 vs 0/7; P=0.021). Conclusions: ¹¹C-CHO PET/CT could improve the accuracy in T staging of NPC. It might also play a complementary role for ¹⁸F-FDG PET/CT in the detection of HCC. (authors)

[en] Objective: This study aims to investigate the clinical value of ¹⁸F-FDG PET/CT in diagnosing solitary hypermetabolic lesion of the bone. Methods: Twenty-two patients with solitary FDG uptake in the bone were enrolled. Patient diagnosis was confirmed by biopsy or surgery. PET/CT images were analyzed. Results: Of the 22 patients, 5 had primary bone lymphoma and bone eosinophilic granuloma, 4 had plasma cell myeloma and osteosarcoma, and 2 had Ewing's sarcoma and giant cell tumoroi the bone. The mean SUV_max of bone lesions is 11.08 ± 8.06(2.1-32.6). Nineteen lesions had welldistributed FDG uptake. The other three lesions were unevenly distributed. No significant difference in FDG uptake was found between malignant and benign lesions (SUV_max: 8.86 ± 2.40 vs. 12.12 ± 9.58, respectively; t = -1.241, P = 0.231), and among different kinds of bone lesions (F = 0.296, df = 5, P = 0.908). Syn-modality CT images showed that 17 patients have osteolytic changes,5 of which with sclerosis edge.Some bone lesions presented as 'bow tie sign', 'soap bubble sign', and 'lace sign'. The other 5 patients, 3 with primary bone lymphoma and 2 with osteosarcoma, presented with ossification changes. Otherwise, soft tissue mass was formulated in 17 patients, and periosteal proliferation developed in 4 patients. Conclusion: Syn-modality CT images should be included in the differential diagnosis of solitary hypermetabolic lesion of the bone. (authors)

[en] Objective: To establish a diagnostic model based on ¹⁸F-FDG PET/CT and clinical data and assess its diagnostic potency for characterizing SPN. Methods: From November 2004 to May 2014, 164 patients with SPN who underwent ¹⁸F-FDG PET/CT scan were retrospectively analyzed. The patients' clinical factors (age, gender, history of smoking and history of malignancy), information on CT (diameter, location and spiculated edge of the lesion) and metabolic information on PET imaging were collected to establish a diagnostic model by using the binary logistic regression. Then, the optimal operating point (OOP) of the established model was set. The diagnostic potencies of the established model and PET were assessed by ROC curve. Results: Malignancy was diagnosed in 104 of 164 SPN patients. The rest 60 patients had benign diseases. The factors of age, spiculation(0: no spiculation, 1: obvious spiculation) and metabolic information(0: ≤ mediastinal blood pool, 1: > mediastinal blood pool) were demonstrated to be useful for the establishment of the model (χ² = 5.486, 16.240, 33.855, all P < 0.05). However, the factors of gender, history of smoking, the diameter and location of lesions showed no influence for the model (χ² = 2.452, 0.453, 0.127, 0.390, all P > 0.05) and rejected from the model established. The history of malignancy was excluded from statistical analysis because there were only 2 patients with history of malignancy. The established model was as follows; P=1/(1 + e^-z), z = -5.512 + 0.061 × age + 2.208 × spiculation + 3.767 × metabolic increase. The ROC AUC of the established model and PET using two-point scoring scale (TPSS) for charactering SPN were 0.92(95% CI: 0.87-0.96) and 0.80(95% CI: 0.73-0.86). The model had higher diagnostic efficacy compared with TPSS (z = 4.369, P < 0.05). When P = 0.7967 was set as an OOP, the diagnostic sensitivities of the model and PET for charactering SPN were 91.3% (95/104) and 94.2% (98/104) respectively, and no significant difference was found between them (χ² = 0.800, P > 0.05). However, significant difference was found between the diagnostic specificities of them (80.0%(48/60) vs 65.0%(39/60); χ² = 7.111, P < 0.05). Conclusions: A new diagnostic model for characterizing SPN based on the information from ¹⁸F-FDG PET, thin-section CT and clinical data is successfully established. Its sensitivity for diagnosis of lung cancer is high, and its specificity is superior to PET using with TPSS. This model has a potential value for clinical application. (authors)

[en] The radiolabeling method of polypeptide (cNGQGEQc) for specific targeting lung cancer with ¹³¹I was established, and the biodistribution of ¹³¹I-cNGQGEQc in normal mice was carried out. Radiolabeling of polypeptide with ¹³¹I was performed by chloramine-T method by tyrosine linked its N-terminal. The labeling ratio and radiochemical purity were determined using paper chromatography. The octanol-water partition coefficient and stability in vitro in saline and normal human serum of labeling polypeptide were also determined. The biodistribution of ¹³¹I-cNGQGEQc in normal mice were measured through caudal vein injection of the labeled peptide. The results showed that the labeling yield of ¹³¹I-cNGQGEQc was more than 90% with specific activity of 0.4 TBq/g. The ¹³¹I-cNGQGEQc had good stability in saline and normal human serum. The octanol-water partition coefficient lgP = -1.68, which indicate that radiolabeled polypeptide was water soluble. The biodistribution in mice demonstrated that the radioactivity in kidney was obviously higher than that of other organs, and it was metabolized mainly in kidney, as indicated by their uptake of (10.59 ± 4.66)%ID/g at 1 h and (1.79 ± 0.89)%ID/g at 12 h, respectively. In conclusion, ¹³¹I-cNGQGEQc can be easily labeled with a high labeling ratio and was stable in vitro. It has good distribution characteristics, and can be used in further study on targeting diagnosis and treatment. (authors)

[en] Objective: To investigate the value of ¹⁸F-FDG PET/CT in the evaluation of treatment response and prognosis for patients with recurrent uterine cervical cancer. Methods: Forty-five patients with recurrent uterine cervical cancer underwent ¹⁸F-FDG PET/CT before and after treatment from October 2004 to December 2014, and their PET/CT results were retrospectively analyzed. Treatment response was categorized as complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD) and progressive metabolic disease (PMD) according to PET response criteria in solid tumors (PERCIST). Kaplan-Meier survival analysis was used. The difference of progression-free survival (PFS) between patients with and without PMD was compared by χ² test. The PFS difference among patients with different SUV_max on pretreatment PET/CT was also compared by χ² test. Results: After treatment, 22.2%(10/45) of patients were categorized as CMR, 22.2%(10/45) as PMR, 4.4%(2/45) as SMD and 51.1%(23/45) as PMD by post-treatment ¹⁸F-FDG PET/CT. Thirty-two patients had long-term (6-64 months) clinical follow-up. The PFS was 1-64 months and the median PFS was 5 months. The patients without PMD had a significantly better PFS than those with PMD(12.2 vs 4.2 months, χ² = 7.223, P < 0.01). Patients with lesion SUV_max < 7.5 on pretreatment PET/CT had a better PFS than those with SUV_max ≥ 7.5 (16.3 vs 5.9 months, χ² = 5.415, P < 0.05). Conclusion: ¹⁸F-FDG PET/CT is useful for the evaluation of treatment response and prognosis in patients with recurrent cancer of the uterine cervix. (authors)

[en] Background: Integrin signal transduction pathways provide an important basis for molecular targeting therapy of cancer in tumor growth, infiltration and transfer. Existing research data have shown that small molecular peptide labeled with radionuclide has good clinical application prospects, but the successful researches on lung cancer have not been reported so far. It is considered that the main reason is the lack of small molecule peptide for specific targeting lung cancer. Purpose: Based on the small molecular peptide cNGQGEQc for specifically identifying integrin α3 and β1 found previously, polypeptide cNGQGEQc is selected and radiolabelled with "1"3"1I. And the inhibitory effect of "1"3"1I-cNGQGEQc in nude mice bearing lung adenocarcinoma is observed. Methods: The coupling of cNGQGEQc and tyrosine was done in the processing of solid phase synthesis of small molecular peptide. Chloramine-T method was used for radiolabelling of cNGQGEQc with "1"3"1I. Twenty nude mice bearing NCI-H1975 were built and randomly divided into four groups with five mice in each group, including the group of "1"3"1I-cNGQGEQc, the group of "1"3"1I-cNAQAEQc, the group of "1"3"1I and the saline control group. The general condition was observed in nude mice bearing tumor after tail vein injection of corresponding drugs. And the tumor sizes after grafting were measured per 3 days in 30 days. The inhibitory rate of tumor in each group was calculated. Results: The labeling efficiencies of "1"3"1I-cNGQGEQc and "1"3"1I-cNAQAEQc were greater than 90% with the radiochemical purity of more than 95%, and "1"3"1I-cNGQGEQc had obvious inhibitory effect for transplantation tumor in nude mice bearing NCI-H1975 adenocarcinoma of lung. After a treatment for 30 days the tumor inhibitory rates were 60.93% for the group of "1"3"1I-cNGQGEQc, 11.63% for the group of "1"3"1I-cNAQAEQ and 10.70% for the group of "1"3"1I. Conclusion: "1"3"1I-cNGQGEQC has a good affinity and effective inhibit effect for the NCI-H1975 lung adenocarcinoma. Integrin is a promising targeting therapy agent for non-small cell lung cancer. (authors)

[en] Objective: To establish a radiolabeling method of specific polypeptide for lung cancer targeting with ¹³¹I and report the acute toxicity in normal mice of injections of iodine labeled and unlabelled polypeptide. Methods: Amino acid sequence of polypeptide was cNGQGEQc. The tyrosine was directly conjugated with peptide cNGQGEQc during its synthesis. Radiolabeling of polypeptide with ¹³¹I was performed by chloramine-T method. 72 normal mice were randomly divided into three groups, each group had 24 mice. The first and second groups received, intraperitoneal injection of unlabelled polypeptide with 50 μg/0.7 ml and ¹³¹I labeled-polypeptide with 18.5 MBq/0.7 ml respectively, and the third group was intraperitoneally injected with 0.7 ml normal saline. The acute toxicity reaction was observed in mice of each group after injection. Results: Compared to control group of normal saline, there were no obvious acute toxicity in the group with unlabelled polypeptide and the group with ¹³¹I-cNGQGEQc in which all the mice were alive with normal physical conditions and body weight increasing. Conclusion: No apparent acute toxic reaction was observed in mice received with unlabelled polypeptide and ¹³¹I-cNGQGEQc polypeptide. (authors)

[en] Epithelial growth factor receptor(EGFR) plays an important role in numerous cancers and many types of targeting EGFR drugs have been approved by the Food and Drug Administration. However, the individual sensitivity and efficiency rates of these targeting EGFR medicines are low. Many studies have shown that patients with high EGFR expression or mutation are responsive to targeting drugs. Therefore, clearing the EGFR expression and mutation status is significant for clinical medication. PET is a noninvasive in vivo imaging technique that enables the visualization and quantification of the distribution of molecules labeled with positron-emitting isotopes at a picomolar level. PET can guide the precision medicine for these targeting EGFR drugs. This review summarizes the small-molecule PET probes for targeting EGFR. (authors)

[en] [${}^{18}$F]FAPI-42 is a new fibroblast activation protein (FAP)-specific tracer used for cancer imaging. Here, we describe the optimal acquisition time and in vivo evaluation of [${}^{18}$F]FAPI-42 and compared intra-individual biodistribution, tumor uptake, and detection ability to [${}^{68}$Ga]Ga-FAPI-04. A total of 22 patients with various types of cancer received [${}^{18}$F]FAPI-42 whole-body positron emission tomography/computed tomography (PET/CT). Among them, 4 patients underwent PET/CT scans, including an early dynamic 20-min, static 1-h, and static 2-h scans. The in vivo biodistribution in normal organs and tumor uptake were semiquantitatively evaluated using the standardized uptake value (SUV) and tumor-to-background ratio (TBR). Furthermore, both [${}^{18}$F]FAPI-42 and [${}^{68}$Ga]Ga-FAPI-04 PET/CT were performed in 12 patients to compare biodistribution, tumor uptake, and tumor detection ability. [${}^{18}$F]FAPI-42 uptake in the tumors was rapid and reached a high level with an average SUVmax of 15.8 at 18 min, which stayed at a similarly high level to 2 h. The optimal image acquisition time for [${}^{18}$F]FAPI-42 was determined to be 1 h postinjection. For tumor detection, [${}^{18}$F]FAPI-42 had a high uptake and could be clearly visualized in the lesions. Compared to [${}^{68}$Ga]Ga-FAPI-04, [${}^{18}$F]FAPI-42 had the same detectability for 144 positive lesions. In addition, [${}^{18}$F]FAPI-42 showed a higher SUVmax in liver and bone lesions (P < 0.05) and higher TBRs in liver, bone, lymph node, pleura, and peritoneal lesions (all P < 0.05). The present study demonstrates that the optimal image acquisition time of [${}^{18}$F]FAPI-42 is 1 h postinjection and that [${}^{18}$F]FAPI-42 exhibits comparable lesion detectability to [${}^{68}$Ga]Ga-FAPI-04.